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firebird-mirror/src/jrd/btr.cpp

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/*
* PROGRAM: JRD Access Method
* MODULE: btr.cpp
* DESCRIPTION: B-tree management code
*
* The contents of this file are subject to the Interbase Public
* License Version 1.0 (the "License"); you may not use this file
* except in compliance with the License. You may obtain a copy
* of the License at http://www.Inprise.com/IPL.html
*
* Software distributed under the License is distributed on an
* "AS IS" basis, WITHOUT WARRANTY OF ANY KIND, either express
* or implied. See the License for the specific language governing
* rights and limitations under the License.
*
* The Original Code was created by Inprise Corporation
* and its predecessors. Portions created by Inprise Corporation are
* Copyright (C) Inprise Corporation.
*
* All Rights Reserved.
* Contributor(s): ______________________________________.
*
* 2002.10.30 Sean Leyne - Removed support for obsolete "PC_PLATFORM" define
*
*/
#include "firebird.h"
#include <string.h>
#include <stdlib.h>
#include <math.h>
#include "memory_routines.h"
#include "../common/classes/vector.h"
#include "../common/classes/VaryStr.h"
#include <stdio.h>
#include "../jrd/jrd.h"
#include "../jrd/ods.h"
#include "../jrd/val.h"
#include "../jrd/btr.h"
#include "../jrd/btn.h"
#include "../jrd/req.h"
#include "../jrd/tra.h"
#include "../jrd/intl.h"
#include "gen/iberror.h"
#include "../jrd/lck.h"
#include "../jrd/cch.h"
#include "../jrd/sort.h"
#include "../common/gdsassert.h"
#include "../jrd/btr_proto.h"
#include "../jrd/cch_proto.h"
#include "../jrd/dpm_proto.h"
#include "../jrd/err_proto.h"
#include "../jrd/evl_proto.h"
#include "../jrd/exe_proto.h"
#include "../yvalve/gds_proto.h"
#include "../jrd/intl_proto.h"
#include "../jrd/jrd_proto.h"
#include "../jrd/lck_proto.h"
#include "../jrd/met_proto.h"
#include "../jrd/mov_proto.h"
#include "../jrd/pag_proto.h"
#include "../jrd/tra_proto.h"
using namespace Jrd;
using namespace Ods;
using namespace Firebird;
//#define DEBUG_BTR_SPLIT
//Debug page numbers into log file
//#define DEBUG_BTR_PAGES
namespace
{
const unsigned MAX_LEVELS = 16;
const size_t OVERSIZE = (MAX_PAGE_SIZE + BTN_PAGE_SIZE + MAX_KEY + sizeof(SLONG) - 1) / sizeof(SLONG);
// END_LEVEL (~0) is choosen here as a unknown/none value, because it's
// already reserved as END_LEVEL marker for page number and record number.
//
// NO_VALUE_PAGE and NO_VALUE are the same constant, but with different size
// Sign-extension mechanizm guaranties that they may be compared to each other safely
const ULONG NO_VALUE_PAGE = END_LEVEL;
const RecordNumber NO_VALUE(END_LEVEL);
// A split page will never have the number 0, because that's the value
// of the main page.
const ULONG NO_SPLIT = 0;
// Thresholds for determing of a page should be garbage collected
// Garbage collect if page size is below GARBAGE_COLLECTION_THRESHOLD
#define GARBAGE_COLLECTION_BELOW_THRESHOLD (dbb->dbb_page_size / 4)
// Garbage collect only if new merged page will
// be lower as GARBAGE_COLLECTION_NEW_PAGE_MAX_THRESHOLD
// 256 is the old maximum possible key_length.
#define GARBAGE_COLLECTION_NEW_PAGE_MAX_THRESHOLD ((dbb->dbb_page_size - 256))
struct INT64_KEY
{
double d_part;
SSHORT s_part;
};
// I assume this wasn't done sizeof(INT64_KEY) on purpose, since alignment might affect it.
const size_t INT64_KEY_LENGTH = sizeof (double) + sizeof (SSHORT);
const double pow10_table[] =
{
1.e00, 1.e01, 1.e02, 1.e03, 1.e04, 1.e05, 1.e06, 1.e07, 1.e08, 1.e09,
1.e10, 1.e11, 1.e12, 1.e13, 1.e14, 1.e15, 1.e16, 1.e17, 1.e18, 1.e19,
1.e20, 1.e21, 1.e22, 1.e23, 1.e24, 1.e25, 1.e26, 1.e27, 1.e28, 1.e29,
1.e30, 1.e31, 1.e32, 1.e33, 1.e34, 1.e35, 1.e36
};
inline double powerof10(int index)
{
return (index <= 0) ? pow10_table[-index] : 1.0 / pow10_table[index];
}
const struct // Used in make_int64_key()
{
FB_UINT64 limit;
SINT64 factor;
SSHORT scale_change;
} int64_scale_control[] =
{
{ QUADCONST(922337203685470000), QUADCONST(1), 0 },
{ QUADCONST(92233720368547000), QUADCONST(10), 1 },
{ QUADCONST(9223372036854700), QUADCONST(100), 2 },
{ QUADCONST(922337203685470), QUADCONST(1000), 3 },
{ QUADCONST(92233720368548), QUADCONST(10000), 4 },
{ QUADCONST(9223372036855), QUADCONST(100000), 5 },
{ QUADCONST(922337203686), QUADCONST(1000000), 6 },
{ QUADCONST(92233720369), QUADCONST(10000000), 7 },
{ QUADCONST(9223372035), QUADCONST(100000000), 8 },
{ QUADCONST(922337204), QUADCONST(1000000000), 9 },
{ QUADCONST(92233721), QUADCONST(10000000000), 10 },
{ QUADCONST(9223373), QUADCONST(100000000000), 11 },
{ QUADCONST(922338), QUADCONST(1000000000000), 12 },
{ QUADCONST(92234), QUADCONST(10000000000000), 13 },
{ QUADCONST(9224), QUADCONST(100000000000000), 14 },
{ QUADCONST(923), QUADCONST(1000000000000000), 15 },
{ QUADCONST(93), QUADCONST(10000000000000000), 16 },
{ QUADCONST(10), QUADCONST(100000000000000000), 17 },
{ QUADCONST(1), QUADCONST(1000000000000000000), 18 },
{ QUADCONST(0), QUADCONST(0), 0 }
};
/* The first four entries in the array int64_scale_control[] ends with the
* limit having 0's in the end. This is to inhibit any rounding off that
* DOUBLE precision can introduce. DOUBLE can easily store upto 92233720368547
* uniquely. Values after this tend to round off to the upper limit during
* division. Hence the ending with 0's so that values will be bunched together
* in the same limit range and scale control for INT64 index temporary_key calculation.
*
* This part was changed as a fix for bug 10267. - bsriram 04-Mar-1999
*/
// enumerate the possible outcomes of deleting a node
enum contents {
contents_empty = 0,
contents_single,
contents_below_threshold,
contents_above_threshold
};
typedef HalfStaticArray<IndexJumpNode, 32> JumpNodeList;
struct FastLoadLevel
{
temporary_key key;
btree_page* bucket;
win_for_array window;
ULONG splitPage;
RecordNumber splitRecordNumber;
UCHAR* pointer;
UCHAR* newAreaPointer;
USHORT totalJumpSize;
IndexNode levelNode;
JumpNodeList* jumpNodes;
temporary_key jumpKey;
};
} // namespace
static ULONG add_node(thread_db*, WIN*, index_insertion*, temporary_key*, RecordNumber*,
ULONG*, ULONG*);
static void compress(thread_db*, const dsc*, temporary_key*, USHORT, bool, bool, USHORT);
static USHORT compress_root(thread_db*, index_root_page*);
static void copy_key(const temporary_key*, temporary_key*);
static contents delete_node(thread_db*, WIN*, UCHAR*);
static void delete_tree(thread_db*, USHORT, USHORT, PageNumber, PageNumber);
static DSC* eval(thread_db*, const ValueExprNode*, DSC*, bool*);
static ULONG fast_load(thread_db*, IndexCreation&, SelectivityList&);
static index_root_page* fetch_root(thread_db*, WIN*, const jrd_rel*, const RelationPages*);
static UCHAR* find_node_start_point(btree_page*, temporary_key*, UCHAR*, USHORT*,
bool, bool, bool = false, RecordNumber = NO_VALUE);
static UCHAR* find_area_start_point(btree_page*, const temporary_key*, UCHAR*,
USHORT*, bool, bool, RecordNumber = NO_VALUE);
static ULONG find_page(btree_page*, const temporary_key*, const index_desc*, RecordNumber = NO_VALUE,
bool = false);
static contents garbage_collect(thread_db*, WIN*, ULONG);
static void generate_jump_nodes(thread_db*, btree_page*, JumpNodeList*, USHORT,
USHORT*, USHORT*, USHORT*, USHORT);
static ULONG insert_node(thread_db*, WIN*, index_insertion*, temporary_key*,
RecordNumber*, ULONG*, ULONG*);
static INT64_KEY make_int64_key(SINT64, SSHORT);
#ifdef DEBUG_INDEXKEY
static void print_int64_key(SINT64, SSHORT, INT64_KEY);
#endif
static string print_key(thread_db*, jrd_rel*, index_desc*, Record*);
static contents remove_node(thread_db*, index_insertion*, WIN*);
static contents remove_leaf_node(thread_db*, index_insertion*, WIN*);
static bool scan(thread_db*, UCHAR*, RecordBitmap**, RecordBitmap*, index_desc*,
const IndexRetrieval*, USHORT, temporary_key*,
bool&, const temporary_key&);
static void update_selectivity(index_root_page*, USHORT, const SelectivityList&);
static void checkForLowerKeySkip(bool&, const bool, const IndexNode&, const temporary_key&,
const index_desc&, const IndexRetrieval*);
// BtrPageLock class
BtrPageGCLock::BtrPageGCLock(thread_db* tdbb)
: Lock(tdbb, PageNumber::getLockLen(), LCK_btr_dont_gc)
{
}
BtrPageGCLock::~BtrPageGCLock()
{
// assert in debug build
fb_assert(!lck_id);
// lck_id might be set only if exception occurs
if (lck_id)
LCK_release(JRD_get_thread_data(), this);
}
void BtrPageGCLock::disablePageGC(thread_db* tdbb, const PageNumber& page)
{
page.getLockStr(getKeyPtr());
LCK_lock(tdbb, this, LCK_read, LCK_WAIT);
}
void BtrPageGCLock::enablePageGC(thread_db* tdbb)
{
LCK_release(tdbb, this);
}
bool BtrPageGCLock::isPageGCAllowed(thread_db* tdbb, const PageNumber& page)
{
BtrPageGCLock lock(tdbb);
page.getLockStr(lock.getKeyPtr());
ThreadStatusGuard temp_status(tdbb);
if (!LCK_lock(tdbb, &lock, LCK_write, LCK_NO_WAIT))
return false;
LCK_release(tdbb, &lock);
return true;
}
// IndexErrorContext class
void IndexErrorContext::raise(thread_db* tdbb, idx_e result, Record* record)
{
fb_assert(result != idx_e_ok);
if (result == idx_e_conversion || result == idx_e_interrupt)
ERR_punt();
const MetaName& relationName = isLocationDefined ? m_location.relation->rel_name : m_relation->rel_name;
const USHORT indexId = isLocationDefined ? m_location.indexId : m_index->idx_id;
MetaName indexName(m_indexName), constraintName;
if (indexName.isEmpty())
MET_lookup_index(tdbb, indexName, relationName, indexId + 1);
if (indexName.hasData())
MET_lookup_cnstrt_for_index(tdbb, constraintName, indexName);
else
indexName = "***unknown***";
const bool haveConstraint = constraintName.hasData();
if (!haveConstraint)
constraintName = "***unknown***";
switch (result)
{
case idx_e_keytoobig:
ERR_post_nothrow(Arg::Gds(isc_imp_exc) <<
Arg::Gds(isc_keytoobig) << Arg::Str(indexName));
break;
case idx_e_foreign_target_doesnt_exist:
ERR_post_nothrow(Arg::Gds(isc_foreign_key) <<
Arg::Str(constraintName) << Arg::Str(relationName) <<
Arg::Gds(isc_foreign_key_target_doesnt_exist));
break;
case idx_e_foreign_references_present:
ERR_post_nothrow(Arg::Gds(isc_foreign_key) <<
Arg::Str(constraintName) << Arg::Str(relationName) <<
Arg::Gds(isc_foreign_key_references_present));
break;
case idx_e_duplicate:
if (haveConstraint)
{
ERR_post_nothrow(Arg::Gds(isc_unique_key_violation) <<
Arg::Str(constraintName) << Arg::Str(relationName));
}
else
ERR_post_nothrow(Arg::Gds(isc_no_dup) << Arg::Str(indexName));
break;
default:
fb_assert(false);
}
if (record)
{
const string keyString = print_key(tdbb, m_relation, m_index, record);
if (keyString.hasData())
ERR_post_nothrow(Arg::Gds(isc_idx_key_value) << Arg::Str(keyString));
}
ERR_punt();
}
USHORT BTR_all(thread_db* tdbb, jrd_rel* relation, IndexDescAlloc** csb_idx, RelationPages* relPages)
{
/**************************************
*
* B T R _ a l l
*
**************************************
*
* Functional description
* Return descriptions of all indices for relation. If there isn't
* a known index root, assume we were called during optimization
* and return no indices.
*
**************************************/
SET_TDBB(tdbb);
const Database* dbb = tdbb->getDatabase();
CHECK_DBB(dbb);
WIN window(relPages->rel_pg_space_id, -1);
index_root_page* const root = fetch_root(tdbb, &window, relation, relPages);
if (!root)
return 0;
delete *csb_idx;
*csb_idx = FB_NEW_RPT(*tdbb->getDefaultPool(), root->irt_count) IndexDescAlloc();
index_desc* buffer = (*csb_idx)->items;
USHORT count = 0;
for (USHORT i = 0; i < root->irt_count; i++)
{
if (BTR_description(tdbb, relation, root, &buffer[count], i))
count++;
}
CCH_RELEASE(tdbb, &window);
return count;
}
void BTR_complement_key(temporary_key* key)
{
/**************************************
*
* B T R _ c o m p l e m e n t _ k e y
*
**************************************
*
* Functional description
* Negate a key for descending index.
*
**************************************/
UCHAR* p = key->key_data;
for (const UCHAR* const end = p + key->key_length; p < end; p++)
*p ^= -1;
}
void BTR_create(thread_db* tdbb,
IndexCreation& creation,
SelectivityList& selectivity)
{
/**************************************
*
* B T R _ c r e a t e
*
**************************************
*
* Functional description
* Create a new index.
*
**************************************/
SET_TDBB(tdbb);
const Database* const dbb = tdbb->getDatabase();
CHECK_DBB(dbb);
jrd_rel* const relation = creation.relation;
index_desc* const idx = creation.index;
// Now that the index id has been checked out, create the index.
idx->idx_root = fast_load(tdbb, creation, selectivity);
// Index is created. Go back to the index root page and update it to
// point to the index.
RelationPages* const relPages = relation->getPages(tdbb);
WIN window(relPages->rel_pg_space_id, relPages->rel_index_root);
index_root_page* const root = (index_root_page*) CCH_FETCH(tdbb, &window, LCK_write, pag_root);
CCH_MARK(tdbb, &window);
root->irt_rpt[idx->idx_id].setRoot(idx->idx_root);
update_selectivity(root, idx->idx_id, selectivity);
CCH_RELEASE(tdbb, &window);
}
bool BTR_delete_index(thread_db* tdbb, WIN* window, USHORT id)
{
/**************************************
*
* B T R _ d e l e t e _ i n d e x
*
**************************************
*
* Functional description
* Delete an index if it exists.
* Return true if index tree was there.
*
**************************************/
SET_TDBB(tdbb);
const Database* dbb = tdbb->getDatabase();
CHECK_DBB(dbb);
// Get index descriptor. If index doesn't exist, just leave.
index_root_page* const root = (index_root_page*) window->win_buffer;
bool tree_exists = false;
if (id >= root->irt_count)
CCH_RELEASE(tdbb, window);
else
{
index_root_page::irt_repeat* irt_desc = root->irt_rpt + id;
CCH_MARK(tdbb, window);
const PageNumber next(window->win_page.getPageSpaceID(), irt_desc->getRoot());
tree_exists = (irt_desc->getRoot() != 0);
// remove the pointer to the top-level index page before we delete it
irt_desc->setRoot(0);
irt_desc->irt_flags = 0;
const PageNumber prior = window->win_page;
const USHORT relation_id = root->irt_relation;
CCH_RELEASE(tdbb, window);
delete_tree(tdbb, relation_id, id, next, prior);
}
return tree_exists;
}
bool BTR_description(thread_db* tdbb, jrd_rel* relation, index_root_page* root, index_desc* idx,
USHORT id)
{
/**************************************
*
* B T R _ d e s c r i p t i o n
*
**************************************
*
* Functional description
* See if index exists, and if so, pick up its description.
* Index id's must fit in a short - formerly a UCHAR.
*
**************************************/
SET_TDBB(tdbb);
if (id >= root->irt_count)
return false;
const index_root_page::irt_repeat* irt_desc = &root->irt_rpt[id];
if (irt_desc->getRoot() == 0)
return false;
idx->idx_id = id;
idx->idx_root = irt_desc->getRoot();
idx->idx_count = irt_desc->irt_keys;
idx->idx_flags = irt_desc->irt_flags;
idx->idx_runtime_flags = 0;
idx->idx_foreign_primaries = NULL;
idx->idx_foreign_relations = NULL;
idx->idx_foreign_indexes = NULL;
idx->idx_primary_relation = 0;
idx->idx_primary_index = 0;
idx->idx_expression = NULL;
idx->idx_expression_statement = NULL;
// pick up field ids and type descriptions for each of the fields
const UCHAR* ptr = (UCHAR*) root + irt_desc->irt_desc;
index_desc::idx_repeat* idx_desc = idx->idx_rpt;
for (int i = 0; i < idx->idx_count; i++, idx_desc++)
{
const irtd* key_descriptor = (irtd*) ptr;
idx_desc->idx_field = key_descriptor->irtd_field;
idx_desc->idx_itype = key_descriptor->irtd_itype;
idx_desc->idx_selectivity = key_descriptor->irtd_selectivity;
ptr += sizeof(irtd);
}
idx->idx_selectivity = idx_desc->idx_selectivity;
if (idx->idx_flags & idx_expressn)
{
MET_lookup_index_expression(tdbb, relation, idx);
fb_assert(idx->idx_expression != NULL);
}
return true;
}
DSC* BTR_eval_expression(thread_db* tdbb, index_desc* idx, Record* record, bool& notNull)
{
SET_TDBB(tdbb);
fb_assert(idx->idx_expression != NULL);
jrd_req* const org_request = tdbb->getRequest();
jrd_req* const expr_request = idx->idx_expression_statement->findRequest(tdbb);
fb_assert(expr_request != org_request);
fb_assert(expr_request->req_caller == NULL);
expr_request->req_caller = org_request;
expr_request->req_flags &= req_in_use;
expr_request->req_flags |= req_active;
TRA_attach_request(tdbb->getTransaction(), expr_request);
tdbb->setRequest(expr_request);
fb_assert(expr_request->req_transaction);
expr_request->req_rpb[0].rpb_record = record;
expr_request->req_rpb[0].rpb_number.setValue(BOF_NUMBER);
expr_request->req_rpb[0].rpb_number.setValid(true);
expr_request->req_flags &= ~req_null;
DSC* result = NULL;
try
{
Jrd::ContextPoolHolder context(tdbb, expr_request->req_pool);
expr_request->req_timestamp = org_request ?
org_request->req_timestamp : TimeStamp::getCurrentTimeStamp();
if (!(result = EVL_expr(tdbb, expr_request, idx->idx_expression)))
result = &idx->idx_expression_desc;
notNull = !(expr_request->req_flags & req_null);
}
catch (const Exception&)
{
EXE_unwind(tdbb, expr_request);
tdbb->setRequest(org_request);
expr_request->req_caller = NULL;
expr_request->req_flags &= ~req_in_use;
expr_request->req_timestamp.invalidate();
throw;
}
EXE_unwind(tdbb, expr_request);
tdbb->setRequest(org_request);
expr_request->req_caller = NULL;
expr_request->req_flags &= ~req_in_use;
expr_request->req_timestamp.invalidate();
return result;
}
static void checkForLowerKeySkip(bool& skipLowerKey,
const bool partLower,
const IndexNode& node,
const temporary_key& lower,
const index_desc& idx,
const IndexRetrieval* retrieval)
{
if (node.prefix == 0)
{
// If the prefix is 0 we have a full key.
// (first node on every new page for example has prefix zero)
if (partLower)
{
// With multi-segment compare first part of data with lowerKey
skipLowerKey = ((lower.key_length <= node.length) &&
(memcmp(node.data, lower.key_data, lower.key_length) == 0));
if (skipLowerKey && (node.length > lower.key_length))
{
// We've bigger data in the node than in the lowerKey,
// now check the segment-number
const UCHAR* segp = node.data + lower.key_length;
const USHORT segnum =
idx.idx_count - (UCHAR)((idx.idx_flags & idx_descending) ? ((*segp) ^ -1) : *segp);
if (segnum < retrieval->irb_lower_count)
skipLowerKey = false;
}
}
else
{
// Compare full data with lowerKey
skipLowerKey = ((lower.key_length == node.length) &&
(memcmp(node.data, lower.key_data, lower.key_length) == 0));
}
}
else
{
// Check if we have a duplicate node (for the same page)
if (node.prefix < lower.key_length)
{
if (node.prefix + node.length == lower.key_length)
skipLowerKey = (memcmp(node.data, lower.key_data + node.prefix, node.length) == 0);
else
skipLowerKey = false;
}
else if ((node.prefix == lower.key_length) && node.length)
{
// In case of multi-segment check segment-number else
// it's a different key
if (partLower)
{
const USHORT segnum = idx.idx_count - (UCHAR)((idx.idx_flags & idx_descending) ?
(*node.data) ^ -1 : *node.data);
if (segnum < retrieval->irb_lower_count)
skipLowerKey = false;
}
else
skipLowerKey = false;
}
}
}
void BTR_evaluate(thread_db* tdbb, const IndexRetrieval* retrieval, RecordBitmap** bitmap,
RecordBitmap* bitmap_and)
{
/**************************************
*
* B T R _ e v a l u a t e
*
**************************************
*
* Functional description
* Do an index scan and return a bitmap
* of all candidate record numbers.
*
**************************************/
SET_TDBB(tdbb);
// Remove ignore_nulls flag for older ODS
//const Database* dbb = tdbb->getDatabase();
index_desc idx;
RelationPages* relPages = retrieval->irb_relation->getPages(tdbb);
WIN window(relPages->rel_pg_space_id, -1);
temporary_key lower, upper;
lower.key_flags = 0;
lower.key_length = 0;
upper.key_flags = 0;
upper.key_length = 0;
btree_page* page = BTR_find_page(tdbb, retrieval, &window, &idx, &lower, &upper);
const bool descending = (idx.idx_flags & idx_descending);
bool skipLowerKey = (retrieval->irb_generic & irb_exclude_lower);
const bool partLower = (retrieval->irb_lower_count < idx.idx_count);
// If there is a starting descriptor, search down index to starting position.
// This may involve sibling buckets if splits are in progress. If there
// isn't a starting descriptor, walk down the left side of the index.
USHORT prefix;
UCHAR* pointer;
if (retrieval->irb_lower_count)
{
while (!(pointer = find_node_start_point(page, &lower, 0, &prefix,
idx.idx_flags & idx_descending, (retrieval->irb_generic & (irb_starting | irb_partial)))))
{
page = (btree_page*) CCH_HANDOFF(tdbb, &window, page->btr_sibling, LCK_read, pag_index);
}
// Compute the number of matching characters in lower and upper bounds
if (retrieval->irb_upper_count)
{
prefix = IndexNode::computePrefix(upper.key_data, upper.key_length,
lower.key_data, lower.key_length);
}
if (skipLowerKey)
{
IndexNode node;
node.readNode(pointer, true);
if ((lower.key_length == node.prefix + node.length) ||
(lower.key_length <= node.prefix + node.length) && partLower)
{
const UCHAR* p = node.data, *q = lower.key_data + node.prefix;
const UCHAR* const end = lower.key_data + lower.key_length;
while (q < end)
{
if (*p++ != *q++)
{
skipLowerKey = false;
break;
}
}
if ((q >= end) && (p < node.data + node.length) && skipLowerKey && partLower)
{
// since key length always is multiplier of (STUFF_COUNT + 1) (for partial
// compound keys) and we passed lower key completely then p pointed
// us to the next segment number and we can use this fact to calculate
// how many segments is equal to lower key
const USHORT segnum = idx.idx_count - (UCHAR) (descending ? ((*p) ^ -1) : *p);
if (segnum < retrieval->irb_lower_count)
skipLowerKey = false;
}
}
else
skipLowerKey = false;
}
}
else
{
pointer = page->btr_nodes + page->btr_jump_size;
prefix = 0;
skipLowerKey = false;
}
// if there is an upper bound, scan the index pages looking for it
if (retrieval->irb_upper_count)
{
while (scan(tdbb, pointer, bitmap, bitmap_and, &idx, retrieval, prefix, &upper,
skipLowerKey, lower))
{
page = (btree_page*) CCH_HANDOFF(tdbb, &window, page->btr_sibling, LCK_read, pag_index);
pointer = page->btr_nodes + page->btr_jump_size;
prefix = 0;
}
}
else
{
// if there isn't an upper bound, just walk the index to the end of the level
const UCHAR* endPointer = (UCHAR*) page + page->btr_length;
const bool ignoreNulls =
(retrieval->irb_generic & irb_ignore_null_value_key) && (idx.idx_count == 1);
IndexNode node;
pointer = node.readNode(pointer, true);
// Check if pointer is still valid
if (pointer > endPointer)
BUGCHECK(204); // msg 204 index inconsistent
while (true)
{
if (node.isEndLevel)
break;
if (!node.isEndBucket)
{
// If we're walking in a descending index and we need to ignore NULLs
// then stop at the first NULL we see (only for single segment!)
if (descending && ignoreNulls && node.prefix == 0 &&
node.length >= 1 && node.data[0] == 255)
{
break;
}
if (skipLowerKey)
checkForLowerKeySkip(skipLowerKey, partLower, node, lower, idx, retrieval);
if (!skipLowerKey)
{
if (!bitmap_and || bitmap_and->test(node.recordNumber.getValue()))
RBM_SET(tdbb->getDefaultPool(), bitmap, node.recordNumber.getValue());
}
pointer = node.readNode(pointer, true);
// Check if pointer is still valid
if (pointer > endPointer)
BUGCHECK(204); // msg 204 index inconsistent
continue;
}
page = (btree_page*) CCH_HANDOFF(tdbb, &window, page->btr_sibling, LCK_read, pag_index);
endPointer = (UCHAR*) page + page->btr_length;
pointer = page->btr_nodes + page->btr_jump_size;
pointer = node.readNode(pointer, true);
// Check if pointer is still valid
if (pointer > endPointer)
BUGCHECK(204); // msg 204 index inconsistent
}
}
CCH_RELEASE(tdbb, &window);
}
UCHAR* BTR_find_leaf(btree_page* bucket, temporary_key* key, UCHAR* value,
USHORT* return_value, bool descending, bool retrieval)
{
/**************************************
*
* B T R _ f i n d _ l e a f
*
**************************************
*
* Functional description
* Locate and return a pointer to the insertion point.
* If the key doesn't belong in this bucket, return NULL.
* A flag indicates the index is descending.
*
**************************************/
return find_node_start_point(bucket, key, value, return_value, descending, retrieval);
}
btree_page* BTR_find_page(thread_db* tdbb,
const IndexRetrieval* retrieval,
WIN* window,
index_desc* idx,
temporary_key* lower,
temporary_key* upper)
{
/**************************************
*
* B T R _ f i n d _ p a g e
*
**************************************
*
* Functional description
* Initialize for an index retrieval.
*
**************************************/
SET_TDBB(tdbb);
// Generate keys before we get any pages locked to avoid unwind
// problems -- if we already have a key, assume that we
// are looking for an equality
if (retrieval->irb_key)
{
copy_key(retrieval->irb_key, lower);
copy_key(retrieval->irb_key, upper);
}
else
{
idx_e errorCode = idx_e_ok;
if (retrieval->irb_upper_count)
{
errorCode = BTR_make_key(tdbb, retrieval->irb_upper_count,
retrieval->irb_value + retrieval->irb_desc.idx_count,
&retrieval->irb_desc, upper,
(retrieval->irb_generic & irb_starting) != 0);
}
if (errorCode == idx_e_ok)
{
if (retrieval->irb_lower_count)
{
errorCode = BTR_make_key(tdbb, retrieval->irb_lower_count,
retrieval->irb_value, &retrieval->irb_desc, lower,
(retrieval->irb_generic & irb_starting) != 0);
}
}
if (errorCode != idx_e_ok)
{
index_desc temp_idx = retrieval->irb_desc; // to avoid constness issues
IndexErrorContext context(retrieval->irb_relation, &temp_idx);
context.raise(tdbb, errorCode, NULL);
}
}
RelationPages* relPages = retrieval->irb_relation->getPages(tdbb);
fb_assert(window->win_page.getPageSpaceID() == relPages->rel_pg_space_id);
window->win_page = relPages->rel_index_root;
index_root_page* rpage = (index_root_page*) CCH_FETCH(tdbb, window, LCK_read, pag_root);
if (!BTR_description(tdbb, retrieval->irb_relation, rpage, idx, retrieval->irb_index))
{
CCH_RELEASE(tdbb, window);
IBERROR(260); // msg 260 index unexpectedly deleted
}
btree_page* page = (btree_page*) CCH_HANDOFF(tdbb, window, idx->idx_root, LCK_read, pag_index);
// If there is a starting descriptor, search down index to starting position.
// This may involve sibling buckets if splits are in progress. If there
// isn't a starting descriptor, walk down the left side of the index (right
// side if we are going backwards).
// Ignore NULLs if flag is set and this is a 1 segment index,
// ASC index and no lower bound value is given.
const bool ignoreNulls = ((idx->idx_count == 1) && !(idx->idx_flags & idx_descending) &&
(retrieval->irb_generic & irb_ignore_null_value_key) && !(retrieval->irb_lower_count));
const bool firstData = (retrieval->irb_lower_count || ignoreNulls);
if (firstData)
{
// Make a temporary key with length 1 and zero byte, this will return
// the first data value after the NULLs for an ASC index.
temporary_key firstNotNullKey;
firstNotNullKey.key_flags = 0;
firstNotNullKey.key_data[0] = 0;
firstNotNullKey.key_length = 1;
while (page->btr_level > 0)
{
while (true)
{
const temporary_key* tkey = ignoreNulls ? &firstNotNullKey : lower;
const ULONG number = find_page(page, tkey, idx,
NO_VALUE, (retrieval->irb_generic & (irb_starting | irb_partial)));
if (number != END_BUCKET)
{
page = (btree_page*) CCH_HANDOFF(tdbb, window, number, LCK_read, pag_index);
break;
}
page = (btree_page*) CCH_HANDOFF(tdbb, window, page->btr_sibling, LCK_read, pag_index);
}
}
}
else
{
IndexNode node;
while (page->btr_level > 0)
{
UCHAR* pointer;
const UCHAR* const endPointer = (UCHAR*) page + page->btr_length;
pointer = page->btr_nodes + page->btr_jump_size;
pointer = node.readNode(pointer, false);
// Check if pointer is still valid
if (pointer > endPointer)
BUGCHECK(204); // msg 204 index inconsistent
page = (btree_page*) CCH_HANDOFF(tdbb, window, node.pageNumber, LCK_read, pag_index);
}
}
return page;
}
void BTR_insert(thread_db* tdbb, WIN* root_window, index_insertion* insertion)
{
/**************************************
*
* B T R _ i n s e r t
*
**************************************
*
* Functional description
* Insert a node into an index.
*
**************************************/
SET_TDBB(tdbb);
index_desc* idx = insertion->iib_descriptor;
RelationPages* relPages = insertion->iib_relation->getPages(tdbb);
WIN window(relPages->rel_pg_space_id, idx->idx_root);
btree_page* bucket = (btree_page*) CCH_FETCH(tdbb, &window, LCK_read, pag_index);
UCHAR root_level = bucket->btr_level;
if (bucket->btr_level == 0)
{
CCH_RELEASE(tdbb, &window);
CCH_FETCH(tdbb, &window, LCK_write, pag_index);
}
CCH_RELEASE(tdbb, root_window);
temporary_key key;
key.key_flags = 0;
key.key_length = 0;
RecordNumber recordNumber(0);
BtrPageGCLock lock(tdbb);
insertion->iib_dont_gc_lock = &lock;
ULONG split_page = add_node(tdbb, &window, insertion, &key, &recordNumber, NULL, NULL);
if (split_page == NO_SPLIT)
return;
// The top of the index has split. We need to make a new level and
// update the index root page. Oh boy.
index_root_page* root = (index_root_page*) CCH_FETCH(tdbb, root_window, LCK_write, pag_root);
window.win_page = root->irt_rpt[idx->idx_id].getRoot();
bucket = (btree_page*) CCH_FETCH(tdbb, &window, LCK_write, pag_index);
if (window.win_page.getPageNum() != idx->idx_root)
{
// AB: It could be possible that the "top" page meanwhile was changed by
// another insert. In that case we are going to insert our split_page
// in the existing "top" page instead of making a new "top" page.
// hvlad: yes, old "top" page could be changed, and more - it could have
// a split too. In this case we should insert our split page not at the
// current "top" page but at the page at correct level.
// Note, while we propagate our split page at lower level, "top" page
// could be splitted again. Thus, to avoid endless loop we won't release
// root page while propagate our split page.
lock.enablePageGC(tdbb);
if (bucket->btr_level < root_level + 1)
{
CCH_RELEASE(tdbb, &window);
CCH_RELEASE(tdbb, root_window);
BUGCHECK(204); // msg 204 index inconsistent
}
index_insertion propagate = *insertion;
propagate.iib_number.setValue(split_page);
propagate.iib_descriptor->idx_root = window.win_page.getPageNum();
propagate.iib_key = &key;
propagate.iib_btr_level = root_level + 1;
temporary_key ret_key;
ret_key.key_flags = 0;
ret_key.key_length = 0;
split_page = add_node(tdbb, &window, &propagate, &ret_key, &recordNumber, NULL, NULL);
if (split_page == NO_SPLIT)
{
CCH_RELEASE(tdbb, root_window);
return;
}
if (split_page == NO_VALUE_PAGE)
{
CCH_RELEASE(tdbb, &window);
CCH_RELEASE(tdbb, root_window);
BUGCHECK(204); // msg 204 index inconsistent
}
window.win_page = root->irt_rpt[idx->idx_id].getRoot();
bucket = (btree_page*) CCH_FETCH(tdbb, &window, LCK_write, pag_index);
key = ret_key;
}
// the original page was marked as not garbage-collectable, but
// since it is the root page it won't be garbage-collected anyway,
// so go ahead and mark it as garbage-collectable now.
lock.enablePageGC(tdbb);
WIN new_window(relPages->rel_pg_space_id, split_page);
btree_page* new_bucket = (btree_page*) CCH_FETCH(tdbb, &new_window, LCK_read, pag_index);
if (bucket->btr_level != new_bucket->btr_level)
{
CCH_RELEASE(tdbb, root_window);
CCH_RELEASE(tdbb, &new_window);
CCH_RELEASE(tdbb, &window);
BUGCHECK(204); // msg 204 index inconsistent
}
// hvlad: save some info from bucket for latter use before releasing a page
const USHORT btr_relation = bucket->btr_relation;
const UCHAR btr_level = bucket->btr_level + 1;
const UCHAR btr_id = bucket->btr_id;
const USHORT btr_jump_interval = bucket->btr_jump_interval;
// hvlad: don't even try to use page buffer after page was released
bucket = NULL;
CCH_RELEASE(tdbb, &new_window);
CCH_RELEASE(tdbb, &window);
if (btr_level >= MAX_LEVELS)
{
CCH_RELEASE(tdbb, root_window);
// Maximum level depth reached
status_exception::raise(Arg::Gds(isc_imp_exc) <<
Arg::Gds(isc_max_idx_depth) << Arg::Num(MAX_LEVELS));
}
// Allocate and format new bucket, this will always be a non-leaf page
new_bucket = (btree_page*) DPM_allocate(tdbb, &new_window);
CCH_precedence(tdbb, &new_window, window.win_page);
new_bucket->btr_header.pag_type = pag_index;
new_bucket->btr_relation = btr_relation;
new_bucket->btr_level = btr_level;
new_bucket->btr_id = btr_id;
// Write jumpinfo
new_bucket->btr_jump_interval = btr_jump_interval;
new_bucket->btr_jump_size = 0;
new_bucket->btr_jump_count = 0;
UCHAR* pointer = new_bucket->btr_nodes;
// Set up first node as degenerate, but pointing to first bucket on
// next level.
IndexNode node;
node.setNode(0, 0, RecordNumber(0), window.win_page.getPageNum());
pointer = node.writeNode(pointer, false);
// Move in the split node
node.setNode(0, key.key_length, recordNumber, split_page);
node.data = key.key_data;
pointer = node.writeNode(pointer, false);
// mark end of level
node.setEndLevel();
pointer = node.writeNode(pointer, false);
// Calculate length of bucket
new_bucket->btr_length = pointer - (UCHAR*) new_bucket;
// update the root page to point to the new top-level page,
// and make sure the new page has higher precedence so that
// it will be written out first--this will make sure that the
// root page doesn't point into space
CCH_RELEASE(tdbb, &new_window);
CCH_precedence(tdbb, root_window, new_window.win_page);
CCH_MARK(tdbb, root_window);
root->irt_rpt[idx->idx_id].setRoot(new_window.win_page.getPageNum());
CCH_RELEASE(tdbb, root_window);
}
idx_e BTR_key(thread_db* tdbb, jrd_rel* relation, Record* record, index_desc* idx,
temporary_key* key, const bool fuzzy, USHORT count)
{
/**************************************
*
* B T R _ k e y
*
**************************************
*
* Functional description
* Compute a key from a record and an index descriptor.
* Note that compound keys are expanded by 25%. If this
* changes, both BTR_key_length and GDEF exe.e have to
* change.
*
**************************************/
temporary_key temp;
temp.key_flags = 0;
temp.key_length = 0;
DSC desc;
DSC* desc_ptr;
SET_TDBB(tdbb);
const Database* dbb = tdbb->getDatabase();
CHECK_DBB(dbb);
index_desc::idx_repeat* tail = idx->idx_rpt;
key->key_flags = 0;
key->key_nulls = 0;
const bool descending = (idx->idx_flags & idx_descending);
if (!count)
count = idx->idx_count;
const USHORT maxKeyLength = dbb->getMaxIndexKeyLength();
try {
const USHORT keyType = fuzzy ?
INTL_KEY_PARTIAL :
((idx->idx_flags & idx_unique) ? INTL_KEY_UNIQUE : INTL_KEY_SORT);
// Special case single segment indices
if (idx->idx_count == 1)
{
bool isNull;
// for expression indices, compute the value of the expression
if (idx->idx_flags & idx_expressn)
{
bool notNull;
desc_ptr = BTR_eval_expression(tdbb, idx, record, notNull);
// Multi-byte text descriptor is returned already adjusted.
isNull = !notNull;
}
else
{
desc_ptr = &desc;
// In order to "map a null to a default" value (in EVL_field()),
// the relation block is referenced.
// Reference: Bug 10116, 10424
//
isNull = !EVL_field(relation, record, tail->idx_field, desc_ptr);
if (!isNull && desc_ptr->dsc_dtype == dtype_text)
{
// That's necessary for NO-PAD collations.
INTL_adjust_text_descriptor(tdbb, desc_ptr);
}
}
if (isNull)
key->key_nulls = 1;
key->key_flags |= key_empty;
compress(tdbb, desc_ptr, key, tail->idx_itype, isNull, descending, keyType);
}
else
{
UCHAR* p = key->key_data;
SSHORT stuff_count = 0;
temp.key_flags |= key_empty;
for (USHORT n = 0; n < count; n++, tail++)
{
for (; stuff_count; --stuff_count)
{
*p++ = 0;
if (p - key->key_data >= maxKeyLength)
return idx_e_keytoobig;
}
desc_ptr = &desc;
// In order to "map a null to a default" value (in EVL_field()),
// the relation block is referenced.
// Reference: Bug 10116, 10424
const bool isNull = !EVL_field(relation, record, tail->idx_field, desc_ptr);
if (isNull)
key->key_nulls |= 1 << n;
else
{
if (desc_ptr->dsc_dtype == dtype_text)
{
// That's necessary for NO-PAD collations.
INTL_adjust_text_descriptor(tdbb, desc_ptr);
}
}
compress(tdbb, desc_ptr, &temp, tail->idx_itype, isNull, descending, keyType);
const UCHAR* q = temp.key_data;
for (USHORT l = temp.key_length; l; --l, --stuff_count)
{
if (stuff_count == 0)
{
*p++ = idx->idx_count - n;
stuff_count = STUFF_COUNT;
if (p - key->key_data >= maxKeyLength)
return idx_e_keytoobig;
}
*p++ = *q++;
if (p - key->key_data >= maxKeyLength)
return idx_e_keytoobig;
}
}
key->key_length = (p - key->key_data);
if (temp.key_flags & key_empty)
key->key_flags |= key_empty;
}
if (key->key_length >= maxKeyLength)
return idx_e_keytoobig;
if (descending)
BTR_complement_key(key);
} // try
catch (const Exception& ex)
{
ex.stuffException(tdbb->tdbb_status_vector);
key->key_length = 0;
return (tdbb->tdbb_flags & TDBB_sys_error) ? idx_e_interrupt : idx_e_conversion;
}
return idx_e_ok;
}
USHORT BTR_key_length(thread_db* tdbb, jrd_rel* relation, index_desc* idx)
{
/**************************************
*
* B T R _ k e y _ l e n g t h
*
**************************************
*
* Functional description
* Compute the maximum key length for an index.
*
**************************************/
SET_TDBB(tdbb);
// hvlad: in ODS11 key of descending index can be prefixed with
// one byte value. See comments in compress
const SLONG prefix = (idx->idx_flags & idx_descending) ? 1 : 0;
const Format* format = MET_current(tdbb, relation);
index_desc::idx_repeat* tail = idx->idx_rpt;
SLONG length;
// If there is only a single key, the computation is straightforward.
if (idx->idx_count == 1)
{
switch (tail->idx_itype)
{
case idx_numeric:
length = sizeof(double);
break;
case idx_sql_time:
length = sizeof(ULONG);
break;
case idx_sql_date:
length = sizeof(SLONG);
break;
case idx_timestamp:
length = sizeof(SINT64);
break;
case idx_numeric2:
length = INT64_KEY_LENGTH;
break;
case idx_boolean:
length = sizeof(UCHAR);
break;
default:
if (idx->idx_flags & idx_expressn)
{
fb_assert(idx->idx_expression != NULL);
length = idx->idx_expression_desc.dsc_length;
if (idx->idx_expression_desc.dsc_dtype == dtype_varying)
{
length = length - sizeof(SSHORT);
}
}
else
{
length = format->fmt_desc[tail->idx_field].dsc_length;
if (format->fmt_desc[tail->idx_field].dsc_dtype == dtype_varying) {
length = length - sizeof(SSHORT);
}
}
if (tail->idx_itype >= idx_first_intl_string) {
length = INTL_key_length(tdbb, tail->idx_itype, length);
}
break;
}
return length + prefix;
}
// Compute length of key for segmented indices.
SLONG key_length = 0;
for (USHORT n = 0; n < idx->idx_count; n++, tail++)
{
switch (tail->idx_itype)
{
case idx_numeric:
length = sizeof(double);
break;
case idx_sql_time:
length = sizeof(ULONG);
break;
case idx_sql_date:
length = sizeof(ULONG);
break;
case idx_timestamp:
length = sizeof(SINT64);
break;
case idx_numeric2:
length = INT64_KEY_LENGTH;
break;
case idx_boolean:
length = sizeof(UCHAR);
break;
default:
length = format->fmt_desc[tail->idx_field].dsc_length;
if (format->fmt_desc[tail->idx_field].dsc_dtype == dtype_varying)
length -= sizeof(SSHORT);
if (tail->idx_itype >= idx_first_intl_string)
length = INTL_key_length(tdbb, tail->idx_itype, length);
break;
}
key_length += ((length + prefix + STUFF_COUNT - 1) / STUFF_COUNT) * (STUFF_COUNT + 1);
}
return key_length;
}
bool BTR_lookup(thread_db* tdbb, jrd_rel* relation, USHORT id, index_desc* buffer,
RelationPages* relPages)
{
/**************************************
*
* B T R _ l o o k u p
*
**************************************
*
* Functional description
* Return a description of the specified index.
*
**************************************/
SET_TDBB(tdbb);
WIN window(relPages->rel_pg_space_id, -1);
index_root_page* const root = fetch_root(tdbb, &window, relation, relPages);
if (!root)
return false;
const bool result = (id < root->irt_count && BTR_description(tdbb, relation, root, buffer, id));
CCH_RELEASE(tdbb, &window);
return result;
}
idx_e BTR_make_key(thread_db* tdbb,
USHORT count,
const ValueExprNode* const* exprs,
const index_desc* idx,
temporary_key* key,
bool fuzzy)
{
/**************************************
*
* B T R _ m a k e _ k e y
*
**************************************
*
* Functional description
* Construct a (possibly) compound search key given a key count,
* a vector of value expressions, and a place to put the key.
*
**************************************/
DSC temp_desc;
temporary_key temp;
temp.key_flags = 0;
temp.key_length = 0;
SET_TDBB(tdbb);
const Database* dbb = tdbb->getDatabase();
fb_assert(count > 0);
fb_assert(idx != NULL);
fb_assert(exprs != NULL);
fb_assert(key != NULL);
key->key_flags = 0;
key->key_nulls = 0;
const bool descending = (idx->idx_flags & idx_descending);
const index_desc::idx_repeat* tail = idx->idx_rpt;
const USHORT keyType = fuzzy ?
INTL_KEY_PARTIAL : ((idx->idx_flags & idx_unique) ? INTL_KEY_UNIQUE : INTL_KEY_SORT);
const USHORT maxKeyLength = dbb->getMaxIndexKeyLength();
// If the index is a single segment index, don't sweat the compound stuff
if (idx->idx_count == 1)
{
bool isNull;
const dsc* desc = eval(tdbb, *exprs, &temp_desc, &isNull);
key->key_flags |= key_empty;
if (isNull)
key->key_nulls = 1;
compress(tdbb, desc, key, tail->idx_itype, isNull, descending, keyType);
if (fuzzy && (key->key_flags & key_empty))
key->key_length = 0;
}
else
{
// Make a compound key
UCHAR* p = key->key_data;
SSHORT stuff_count = 0;
bool is_key_empty = true;
USHORT prior_length = 0;
USHORT n = 0;
for (; n < count; n++, tail++)
{
for (; stuff_count; --stuff_count)
{
*p++ = 0;
if (p - key->key_data >= maxKeyLength)
return idx_e_keytoobig;
}
bool isNull;
const dsc* desc = eval(tdbb, *exprs++, &temp_desc, &isNull);
if (isNull)
key->key_nulls |= 1 << n;
temp.key_flags |= key_empty;
compress(tdbb, desc, &temp, tail->idx_itype, isNull, descending,
(n == count - 1 ?
keyType : ((idx->idx_flags & idx_unique) ? INTL_KEY_UNIQUE : INTL_KEY_SORT)));
if (!(temp.key_flags & key_empty))
is_key_empty = false;
prior_length = (p - key->key_data);
const UCHAR* q = temp.key_data;
for (USHORT l = temp.key_length; l; --l, --stuff_count)
{
if (stuff_count == 0)
{
*p++ = idx->idx_count - n;
stuff_count = STUFF_COUNT;
if (p - key->key_data >= maxKeyLength)
return idx_e_keytoobig;
}
*p++ = *q++;
if (p - key->key_data >= maxKeyLength)
return idx_e_keytoobig;
}
}
// AB: Fix bug SF #1242982
// Equality search on first segment (integer) in compound indexes resulted
// in more scans on specific values (2^n, f.e. 131072) than needed.
if (!fuzzy && (n != idx->idx_count))
{
for (; stuff_count; --stuff_count)
{
*p++ = 0;
if (p - key->key_data >= maxKeyLength)
return idx_e_keytoobig;
}
}
// dimitr: If the search is fuzzy and the last segment is empty,
// then skip it for the lookup purposes. It enforces
// the rule that every string starts with an empty string.
if (fuzzy && (temp.key_flags & key_empty))
key->key_length = prior_length;
else
key->key_length = (p - key->key_data);
if (is_key_empty)
{
key->key_flags |= key_empty;
if (fuzzy)
key->key_length = 0;
}
}
if (key->key_length >= maxKeyLength)
return idx_e_keytoobig;
if (descending)
BTR_complement_key(key);
return idx_e_ok;
}
void BTR_make_null_key(thread_db* tdbb, const index_desc* idx, temporary_key* key)
{
/**************************************
*
* B T R _ m a k e _ n u l l _ k e y
*
**************************************
*
* Functional description
* Construct a (possibly) compound search key consist from
* all null values. This is worked only for ODS11 and later
*
**************************************/
dsc null_desc;
null_desc.dsc_dtype = dtype_text;
null_desc.dsc_flags = 0;
null_desc.dsc_sub_type = 0;
null_desc.dsc_scale = 0;
null_desc.dsc_length = 1;
null_desc.dsc_ttype() = ttype_ascii;
null_desc.dsc_address = (UCHAR*) " ";
temporary_key temp;
temp.key_flags = 0;
temp.key_length = 0;
SET_TDBB(tdbb);
fb_assert(idx != NULL);
fb_assert(key != NULL);
key->key_flags = 0;
key->key_nulls = (1 << idx->idx_count) - 1;
const bool descending = (idx->idx_flags & idx_descending);
const index_desc::idx_repeat* tail = idx->idx_rpt;
// If the index is a single segment index, don't sweat the compound stuff
if ((idx->idx_count == 1) || (idx->idx_flags & idx_expressn))
{
compress(tdbb, &null_desc, key, tail->idx_itype, true, descending, false);
}
else
{
// Make a compound key
UCHAR* p = key->key_data;
SSHORT stuff_count = 0;
temp.key_flags |= key_empty;
for (USHORT n = 0; n < idx->idx_count; n++, tail++)
{
for (; stuff_count; --stuff_count)
*p++ = 0;
compress(tdbb, &null_desc, &temp, tail->idx_itype, true, descending, false);
const UCHAR* q = temp.key_data;
for (USHORT l = temp.key_length; l; --l, --stuff_count)
{
if (stuff_count == 0)
{
*p++ = idx->idx_count - n;
stuff_count = STUFF_COUNT;
}
*p++ = *q++;
}
}
key->key_length = (p - key->key_data);
if (temp.key_flags & key_empty)
key->key_flags |= key_empty;
}
if (descending)
BTR_complement_key(key);
}
bool BTR_next_index(thread_db* tdbb, jrd_rel* relation, jrd_tra* transaction, index_desc* idx, WIN* window)
{
/**************************************
*
* B T R _ n e x t _ i n d e x
*
**************************************
*
* Functional description
* Get next index for relation. Index ids
* recently changed from UCHAR to SHORT
*
**************************************/
SET_TDBB(tdbb);
USHORT id;
if (idx->idx_id == idx_invalid)
{
id = 0;
window->win_bdb = NULL;
}
else
id = idx->idx_id + 1;
index_root_page* root;
if (window->win_bdb)
root = (index_root_page*) window->win_buffer;
else
{
RelationPages* const relPages = transaction ?
relation->getPages(tdbb, transaction->tra_number) : relation->getPages(tdbb);
if (!(root = fetch_root(tdbb, window, relation, relPages)))
return false;
}
for (; id < root->irt_count; ++id)
{
const index_root_page::irt_repeat* irt_desc = root->irt_rpt + id;
if (irt_desc->getTransaction() && transaction)
{
const TraNumber trans = irt_desc->getTransaction();
CCH_RELEASE(tdbb, window);
const int trans_state = TRA_wait(tdbb, transaction, trans, jrd_tra::tra_wait);
if ((trans_state == tra_dead) || (trans_state == tra_committed))
{
// clean up this left-over index
root = (index_root_page*) CCH_FETCH(tdbb, window, LCK_write, pag_root);
irt_desc = root->irt_rpt + id;
if (irt_desc->getTransaction() == trans)
BTR_delete_index(tdbb, window, id);
else
CCH_RELEASE(tdbb, window);
root = (index_root_page*) CCH_FETCH(tdbb, window, LCK_read, pag_root);
continue;
}
root = (index_root_page*) CCH_FETCH(tdbb, window, LCK_read, pag_root);
}
if (BTR_description(tdbb, relation, root, idx, id))
return true;
}
CCH_RELEASE(tdbb, window);
return false;
}
void BTR_remove(thread_db* tdbb, WIN* root_window, index_insertion* insertion)
{
/**************************************
*
* B T R _ r e m o v e
*
**************************************
*
* Functional description
* Remove an index node from a b-tree.
* If the node doesn't exist, don't get overly excited.
*
**************************************/
//const Database* dbb = tdbb->getDatabase();
index_desc* idx = insertion->iib_descriptor;
RelationPages* relPages = insertion->iib_relation->getPages(tdbb);
WIN window(relPages->rel_pg_space_id, idx->idx_root);
btree_page* page = (btree_page*) CCH_FETCH(tdbb, &window, LCK_read, pag_index);
// If the page is level 0, re-fetch it for write
const UCHAR level = page->btr_level;
if (level == 0)
{
CCH_RELEASE(tdbb, &window);
CCH_FETCH(tdbb, &window, LCK_write, pag_index);
}
// remove the node from the index tree via recursive descent
contents result = remove_node(tdbb, insertion, &window);
// if the root page points at only one lower page, remove this
// level to prevent the tree from being deeper than necessary--
// do this only if the level is greater than 1 to prevent
// excessive thrashing in the case where a small table is
// constantly being loaded and deleted.
if ((result == contents_single) && (level > 1))
{
// we must first release the windows to obtain the root for write
// without getting deadlocked
CCH_RELEASE(tdbb, &window);
CCH_RELEASE(tdbb, root_window);
index_root_page* root = (index_root_page*) CCH_FETCH(tdbb, root_window, LCK_write, pag_root);
page = (btree_page*) CCH_FETCH(tdbb, &window, LCK_write, pag_index);
// get the page number of the child, and check to make sure
// the page still has only one node on it
UCHAR* pointer = page->btr_nodes + page->btr_jump_size;
IndexNode pageNode;
pointer = pageNode.readNode(pointer, false);
const ULONG number = pageNode.pageNumber;
pointer = pageNode.readNode(pointer, false);
if (!(pageNode.isEndBucket || pageNode.isEndLevel))
{
CCH_RELEASE(tdbb, &window);
CCH_RELEASE(tdbb, root_window);
return;
}
CCH_MARK(tdbb, root_window);
root->irt_rpt[idx->idx_id].setRoot(number);
// release the pages, and place the page formerly at the top level
// on the free list, making sure the root page is written out first
// so that we're not pointing to a released page
CCH_RELEASE(tdbb, root_window);
CCH_MARK(tdbb, &window);
page->btr_header.pag_flags |= btr_released;
CCH_RELEASE(tdbb, &window);
PAG_release_page(tdbb, window.win_page, root_window->win_page);
}
if (window.win_bdb)
CCH_RELEASE(tdbb, &window);
if (root_window->win_bdb)
CCH_RELEASE(tdbb, root_window);
}
void BTR_reserve_slot(thread_db* tdbb, IndexCreation& creation)
{
/**************************************
*
* B T R _ r e s e r v e _ s l o t
*
**************************************
*
* Functional description
* Reserve a slot on an index root page
* in preparation to index creation.
*
**************************************/
SET_TDBB(tdbb);
const Database* const dbb = tdbb->getDatabase();
CHECK_DBB(dbb);
jrd_rel* const relation = creation.relation;
index_desc* const idx = creation.index;
jrd_tra* const transaction = creation.transaction;
fb_assert(relation);
RelationPages* const relPages = relation->getPages(tdbb);
fb_assert(relPages && relPages->rel_index_root);
fb_assert(transaction);
// Get root page, assign an index id, and store the index descriptor.
// Leave the root pointer null for the time being.
// Index id for temporary index instance of global temporary table is
// already assigned, use it.
const bool use_idx_id = (relPages->rel_instance_id != 0);
if (use_idx_id)
fb_assert(idx->idx_id <= dbb->dbb_max_idx);
WIN window(relPages->rel_pg_space_id, relPages->rel_index_root);
index_root_page* root = (index_root_page*) CCH_FETCH(tdbb, &window, LCK_write, pag_root);
CCH_MARK(tdbb, &window);
// check that we create no more indexes than will fit on a single root page
if (root->irt_count > dbb->dbb_max_idx)
{
CCH_RELEASE(tdbb, &window);
ERR_post(Arg::Gds(isc_no_meta_update) <<
Arg::Gds(isc_max_idx) << Arg::Num(dbb->dbb_max_idx));
}
// Scan the index page looking for the high water mark of the descriptions and,
// perhaps, an empty index slot
if (use_idx_id && (idx->idx_id >= root->irt_count))
{
memset(root->irt_rpt + root->irt_count, 0,
sizeof(index_root_page::irt_repeat) * (idx->idx_id - root->irt_count + 1));
root->irt_count = idx->idx_id + 1;
}
UCHAR* desc = 0;
USHORT len, space;
index_root_page::irt_repeat* slot = NULL;
index_root_page::irt_repeat* end = NULL;
for (int retry = 0; retry < 2; ++retry)
{
len = idx->idx_count * sizeof(irtd);
space = dbb->dbb_page_size;
slot = NULL;
end = root->irt_rpt + root->irt_count;
for (index_root_page::irt_repeat* root_idx = root->irt_rpt; root_idx < end; root_idx++)
{
if (root_idx->isUsed())
space = MIN(space, root_idx->irt_desc);
if (!root_idx->isUsed() && !slot)
{
if (!use_idx_id || (root_idx - root->irt_rpt) == idx->idx_id)
slot = root_idx;
}
}
space -= len;
desc = (UCHAR*) root + space;
// Verify that there is enough room on the Index root page.
if (desc < (UCHAR*) (end + 1))
{
// Not enough room: Attempt to compress the index root page and try again.
// If this is the second try already, then there really is no more room.
if (retry)
{
CCH_RELEASE(tdbb, &window);
ERR_post(Arg::Gds(isc_no_meta_update) <<
Arg::Gds(isc_index_root_page_full));
}
compress_root(tdbb, root);
}
else
break;
}
// If we didn't pick up an empty slot, allocate a new one
fb_assert(!use_idx_id || (use_idx_id && slot));
if (!slot)
{
slot = end;
root->irt_count++;
}
idx->idx_id = slot - root->irt_rpt;
slot->irt_desc = space;
fb_assert(idx->idx_count <= MAX_UCHAR);
slot->irt_keys = (UCHAR) idx->idx_count;
slot->irt_flags = idx->idx_flags;
slot->setTransaction(transaction->tra_number);
// Exploit the fact idx_repeat structure matches ODS IRTD one
memcpy(desc, idx->idx_rpt, len);
CCH_RELEASE(tdbb, &window);
}
void BTR_selectivity(thread_db* tdbb, jrd_rel* relation, USHORT id, SelectivityList& selectivity)
{
/**************************************
*
* B T R _ s e l e c t i v i t y
*
**************************************
*
* Functional description
* Update index selectivity on the fly.
* Note that index leaf pages are walked
* without visiting data pages. Thus the
* effects of uncommitted transactions
* will be included in the calculation.
*
**************************************/
SET_TDBB(tdbb);
RelationPages* relPages = relation->getPages(tdbb);
WIN window(relPages->rel_pg_space_id, -1);
index_root_page* root = fetch_root(tdbb, &window, relation, relPages);
if (!root)
return;
ULONG page;
if (id >= root->irt_count || !(page = root->irt_rpt[id].getRoot()))
{
CCH_RELEASE(tdbb, &window);
return;
}
window.win_flags = WIN_large_scan;
window.win_scans = 1;
btree_page* bucket = (btree_page*) CCH_HANDOFF(tdbb, &window, page, LCK_read, pag_index);
// go down the left side of the index to leaf level
UCHAR* pointer = bucket->btr_nodes + bucket->btr_jump_size;
while (bucket->btr_level)
{
IndexNode pageNode;
pageNode.readNode(pointer, false);
bucket = (btree_page*) CCH_HANDOFF(tdbb, &window, pageNode.pageNumber, LCK_read, pag_index);
pointer = bucket->btr_nodes + bucket->btr_jump_size;
page = pageNode.pageNumber;
}
FB_UINT64 nodes = 0;
FB_UINT64 duplicates = 0;
temporary_key key;
key.key_flags = 0;
key.key_length = 0;
SSHORT l;
bool firstNode = true;
const bool descending = (root->irt_rpt[id].irt_flags & irt_descending);
const ULONG segments = root->irt_rpt[id].irt_keys;
// SSHORT count, stuff_count, pos, i;
HalfStaticArray<FB_UINT64, 4> duplicatesList;
duplicatesList.grow(segments);
memset(duplicatesList.begin(), 0, segments * sizeof(FB_UINT64));
//const Database* dbb = tdbb->getDatabase();
// go through all the leaf nodes and count them;
// also count how many of them are duplicates
IndexNode node;
while (page)
{
pointer = node.readNode(pointer, true);
while (true)
{
if (node.isEndBucket || (nodes % 100 == 0))
{
if (--tdbb->tdbb_quantum < 0)
JRD_reschedule(tdbb, 0, true);
}
if (node.isEndBucket || node.isEndLevel)
break;
++nodes;
l = node.length + node.prefix;
if (segments > 1 && !firstNode)
{
// Initialize variables for segment duplicate check.
// count holds the current checking segment (starting by
// the maximum segment number to 1).
const UCHAR* p1 = key.key_data;
const UCHAR* const p1_end = p1 + key.key_length;
const UCHAR* p2 = node.data;
const UCHAR* const p2_end = p2 + node.length;
SSHORT count, stuff_count;
if (node.prefix == 0)
{
count = *p2;
//pos = 0;
stuff_count = 0;
}
else
{
const SSHORT pos = node.prefix;
// find the segment number were we're starting.
const SSHORT i = (pos / (STUFF_COUNT + 1)) * (STUFF_COUNT + 1);
if (i == pos)
{
// We _should_ pick number from data if available
count = *p2;
}
else
count = *(p1 + i);
// update stuff_count to the current position.
stuff_count = STUFF_COUNT + 1 - (pos - i);
p1 += pos;
}
//Look for duplicates in the segments
while ((p1 < p1_end) && (p2 < p2_end))
{
if (stuff_count == 0)
{
if (*p1 != *p2)
{
// We're done
break;
}
count = *p2;
p1++;
p2++;
stuff_count = STUFF_COUNT;
}
if (*p1 != *p2)
{
//We're done
break;
}
p1++;
p2++;
stuff_count--;
}
// For descending indexes the segment-number is also
// complemented, thus reverse it back.
// Note: values are complemented per UCHAR base.
if (descending)
count = (255 - count);
if ((p1 == p1_end) && (p2 == p2_end))
count = 0; // All segments are duplicates
for (ULONG i = count + 1; i <= segments; i++)
duplicatesList[segments - i]++;
}
// figure out if this is a duplicate
bool dup;
if (node.nodePointer == bucket->btr_nodes + bucket->btr_jump_size)
dup = node.keyEqual(key.key_length, key.key_data);
else
dup = (!node.length && (l == key.key_length));
if (dup && !firstNode)
++duplicates;
if (firstNode)
firstNode = false;
// keep the key value current for comparison with the next key
key.key_length = l;
memcpy(key.key_data + node.prefix, node.data, node.length);
pointer = node.readNode(pointer, true);
}
if (node.isEndLevel || !(page = bucket->btr_sibling))
break;
bucket = (btree_page*) CCH_HANDOFF_TAIL(tdbb, &window, page, LCK_read, pag_index);
pointer = bucket->btr_nodes + bucket->btr_jump_size;
}
CCH_RELEASE_TAIL(tdbb, &window);
// calculate the selectivity
selectivity.grow(segments);
if (segments > 1)
{
for (ULONG i = 0; i < segments; i++)
selectivity[i] = (float) (nodes ? 1.0 / (float) (nodes - duplicatesList[i]) : 0.0);
}
else
selectivity[0] = (float) (nodes ? 1.0 / (float) (nodes - duplicates) : 0.0);
// Store the selectivity on the root page
window.win_page = relPages->rel_index_root;
window.win_flags = 0;
root = (index_root_page*) CCH_FETCH(tdbb, &window, LCK_write, pag_root);
CCH_MARK(tdbb, &window);
update_selectivity(root, id, selectivity);
CCH_RELEASE(tdbb, &window);
}
bool BTR_types_comparable(const dsc& target, const dsc& source)
{
/**************************************
*
* B T R _ t y p e s _ c o m p a r a b l e
*
**************************************
*
* Functional description
* Return whether two datatypes are comparable in terms of the CVT rules.
* The purpose is to ensure that compress() converts datatypes in the same
* direction as CVT2_compare(), thus causing index scans to always deliver
* the same results as the generic boolean evaluation.
*
**************************************/
if (source.isNull() || DSC_EQUIV(&source, &target, true))
return true;
if (DTYPE_IS_TEXT(target.dsc_dtype))
{
// should we also check for the INTL stuff here?
return (DTYPE_IS_TEXT(source.dsc_dtype) || source.dsc_dtype == dtype_dbkey);
}
if (target.dsc_dtype == dtype_int64)
return (source.dsc_dtype <= dtype_long || source.dsc_dtype == dtype_int64);
if (DTYPE_IS_NUMERIC(target.dsc_dtype))
return (source.dsc_dtype <= dtype_double || source.dsc_dtype == dtype_int64);
if (target.dsc_dtype == dtype_sql_date)
return (source.dsc_dtype <= dtype_sql_date || source.dsc_dtype == dtype_timestamp);
if (DTYPE_IS_DATE(target.dsc_dtype))
return (source.dsc_dtype <= dtype_timestamp);
if (target.dsc_dtype == dtype_boolean)
return DTYPE_IS_TEXT(source.dsc_dtype) || source.dsc_dtype == dtype_boolean;
return false;
}
static ULONG add_node(thread_db* tdbb,
WIN* window,
index_insertion* insertion,
temporary_key* new_key,
RecordNumber* new_record_number,
ULONG* original_page,
ULONG* sibling_page)
{
/**************************************
*
* a d d _ n o d e
*
**************************************
*
* Functional description
* Insert a node in an index. This recurses to the leaf level.
* If a split occurs, return the new index page number and its
* leading string.
*
**************************************/
SET_TDBB(tdbb);
btree_page* bucket = (btree_page*) window->win_buffer;
// For leaf level guys, loop thru the leaf buckets until insertion
// point is found (should be instant)
if (bucket->btr_level == insertion->iib_btr_level)
{
while (true)
{
const ULONG split = insert_node(tdbb, window, insertion, new_key,
new_record_number, original_page, sibling_page);
if (split != NO_VALUE_PAGE)
return split;
bucket = (btree_page*) CCH_HANDOFF(tdbb, window, bucket->btr_sibling, LCK_write, pag_index);
}
}
// If we're above the leaf level, find the appropriate node in the chain of sibling pages.
// Hold on to this position while we recurse down to the next level, in case there's a
// split at the lower level, in which case we need to insert the new page at this level.
ULONG page;
while (true)
{
page = find_page(bucket, insertion->iib_key, insertion->iib_descriptor,
insertion->iib_number);
if (page != END_BUCKET)
break;
bucket = (btree_page*) CCH_HANDOFF(tdbb, window, bucket->btr_sibling, LCK_read, pag_index);
}
BtrPageGCLock lockCurrent(tdbb);
lockCurrent.disablePageGC(tdbb, window->win_page);
// Fetch the page at the next level down. If the next level is leaf level,
// fetch for write since we know we are going to write to the page (most likely).
const PageNumber index = window->win_page;
CCH_HANDOFF(tdbb, window, page,
(SSHORT) ((bucket->btr_level == 1 + insertion->iib_btr_level) ? LCK_write : LCK_read),
pag_index);
// now recursively try to insert the node at the next level down
index_insertion propagate;
BtrPageGCLock lockLower(tdbb);
propagate.iib_dont_gc_lock = insertion->iib_dont_gc_lock;
propagate.iib_btr_level = insertion->iib_btr_level;
insertion->iib_dont_gc_lock = &lockLower;
ULONG split = add_node(tdbb, window, insertion, new_key, new_record_number, &page,
&propagate.iib_sibling);
if (split == NO_SPLIT)
{
lockCurrent.enablePageGC(tdbb);
insertion->iib_dont_gc_lock = propagate.iib_dont_gc_lock;
return NO_SPLIT;
}
#ifdef DEBUG_BTR_SPLIT
string s;
s.printf("page %ld splitted. split %ld, right %ld, parent %ld",
page, split, propagate.iib_sibling, index);
gds__trace(s.c_str());
#endif
// The page at the lower level split, so we need to insert a pointer
// to the new page to the page at this level.
window->win_page = index;
bucket = (btree_page*) CCH_FETCH(tdbb, window, LCK_write, pag_index);
propagate.iib_number = RecordNumber(split);
propagate.iib_descriptor = insertion->iib_descriptor;
propagate.iib_relation = insertion->iib_relation;
propagate.iib_duplicates = NULL;
propagate.iib_key = new_key;
// now loop through the sibling pages trying to find the appropriate
// place to put the pointer to the lower level page--remember that the
// page we were on could have split while we weren't looking
ULONG original_page2;
ULONG sibling_page2;
while (true)
{
split = insert_node(tdbb, window, &propagate, new_key, new_record_number, &original_page2,
&sibling_page2);
if (split != NO_VALUE_PAGE)
break;
bucket = (btree_page*) CCH_HANDOFF(tdbb, window, bucket->btr_sibling, LCK_write, pag_index);
}
// the split page on the lower level has been propagated, so we can go back to
// the page it was split from, and mark it as garbage-collectable now
lockLower.enablePageGC(tdbb);
insertion->iib_dont_gc_lock = propagate.iib_dont_gc_lock;
lockCurrent.enablePageGC(tdbb);
if (original_page)
*original_page = original_page2;
if (sibling_page)
*sibling_page = sibling_page2;
return split;
}
static void compress(thread_db* tdbb,
const dsc* desc,
temporary_key* key,
USHORT itype,
bool isNull, bool descending, USHORT key_type)
{
/**************************************
*
* c o m p r e s s
*
**************************************
*
* Functional description
* Compress a data value into an index key.
*
**************************************/
union {
INT64_KEY temp_int64_key;
double temp_double;
ULONG temp_ulong;
SLONG temp_slong;
SINT64 temp_sint64;
UCHAR temp_char[sizeof(INT64_KEY)];
} temp;
bool temp_is_negative = false;
bool int64_key_op = false;
// For descending index and new index structure we insert 0xFE at the beginning.
// This is only done for values which begin with 0xFE (254) or 0xFF (255) and
// is needed to make a difference between a NULL state and a VALUE.
// Note! By descending index key is complemented after this compression routine.
// Further a NULL state is always returned as 1 byte 0xFF (descending index).
const UCHAR desc_end_value_prefix = 0x01; // ~0xFE
const UCHAR desc_end_value_check = 0x00; // ~0xFF;
const Database* dbb = tdbb->getDatabase();
UCHAR* p = key->key_data;
if (isNull)
{
const UCHAR pad = 0;
key->key_flags &= ~key_empty;
// AB: NULL should be threated as lowest value possible.
// Therefore don't complement pad when we have an ascending index.
if (descending)
{
// DESC NULLs are stored as 1 byte
*p++ = pad;
key->key_length = (p - key->key_data);
}
else
key->key_length = 0; // ASC NULLs are stored with no data
return;
}
if (itype == idx_string || itype == idx_byte_array || itype == idx_metadata ||
itype >= idx_first_intl_string)
{
VaryStr<MAX_KEY> buffer;
const UCHAR pad = (itype == idx_string) ? ' ' : 0;
UCHAR* ptr;
size_t length;
if (itype >= idx_first_intl_string || itype == idx_metadata)
{
DSC to;
// convert to an international byte array
to.dsc_dtype = dtype_text;
to.dsc_flags = 0;
to.dsc_sub_type = 0;
to.dsc_scale = 0;
to.dsc_ttype() = ttype_sort_key;
to.dsc_length = MIN(MAX_KEY, sizeof(buffer));
ptr = to.dsc_address = reinterpret_cast<UCHAR*>(buffer.vary_string);
length = INTL_string_to_key(tdbb, itype, desc, &to, key_type);
}
else
length = MOV_get_string(desc, &ptr, &buffer, MAX_KEY);
if (length)
{
// clear key_empty flag, because length is >= 1
key->key_flags &= ~key_empty;
if (length > sizeof(key->key_data))
length = sizeof(key->key_data);
if (descending && ((*ptr == desc_end_value_prefix) || (*ptr == desc_end_value_check)))
{
*p++ = desc_end_value_prefix;
if ((length + 1) > sizeof(key->key_data))
length = sizeof(key->key_data) - 1;
}
memcpy(p, ptr, length);
p += length;
}
else
{
// Leave key_empty flag, because the string is an empty string
if (descending && ((pad == desc_end_value_prefix) || (pad == desc_end_value_check)))
*p++ = desc_end_value_prefix;
*p++ = pad;
}
while (p > key->key_data)
{
if (*--p != pad)
break;
}
key->key_length = p + 1 - key->key_data;
return;
}
// The index is numeric.
// For idx_numeric...
// Convert the value to a double precision number,
// then zap it to compare in a byte-wise order.
// For idx_numeric2...
// Convert the value to a INT64_KEY struct,
// then zap it to compare in a byte-wise order.
// clear key_empty flag for all other types
key->key_flags &= ~key_empty;
size_t temp_copy_length = sizeof(double);
if (itype == idx_numeric)
{
temp.temp_double = MOV_get_double(desc);
temp_is_negative = (temp.temp_double < 0);
#ifdef DEBUG_INDEXKEY
fprintf(stderr, "NUMERIC %lg ", temp.temp_double);
#endif
}
else if (itype == idx_numeric2)
{
int64_key_op = true;
temp.temp_int64_key = make_int64_key(MOV_get_int64(desc, desc->dsc_scale), desc->dsc_scale);
temp_copy_length = sizeof(temp.temp_int64_key.d_part);
temp_is_negative = (temp.temp_int64_key.d_part < 0);
#ifdef DEBUG_INDEXKEY
print_int64_key(*(const SINT64*) desc->dsc_address,
desc->dsc_scale, temp.temp_int64_key);
#endif
}
else if (itype == idx_timestamp)
{
GDS_TIMESTAMP timestamp;
timestamp = MOV_get_timestamp(desc);
const ULONG SECONDS_PER_DAY = 24 * 60 * 60;
temp.temp_sint64 = ((SINT64) (timestamp.timestamp_date) *
(SINT64) (SECONDS_PER_DAY * ISC_TIME_SECONDS_PRECISION)) +
(SINT64) (timestamp.timestamp_time);
temp_copy_length = sizeof(SINT64);
#ifdef DEBUG_INDEXKEY
fprintf(stderr, "TIMESTAMP2: %d:%u ",
((const SLONG*) desc->dsc_address)[0],
((const ULONG*) desc->dsc_address)[1]);
fprintf(stderr, "TIMESTAMP2: %20" QUADFORMAT "d ", temp.temp_sint64);
#endif
}
else if (itype == idx_sql_date)
{
temp.temp_slong = MOV_get_sql_date(desc);
temp_copy_length = sizeof(SLONG);
#ifdef DEBUG_INDEXKEY
fprintf(stderr, "DATE %d ", temp.temp_slong);
#endif
}
else if (itype == idx_sql_time)
{
temp.temp_ulong = MOV_get_sql_time(desc);
temp_copy_length = sizeof(ULONG);
temp_is_negative = false;
#ifdef DEBUG_INDEXKEY
fprintf(stderr, "TIME %u ", temp.temp_ulong);
#endif
}
else if (desc->dsc_dtype == dtype_timestamp)
{
// This is the same as the pre v6 behavior. Basically, the
// customer has created a NUMERIC index, and is probing into that
// index using a TIMESTAMP value.
// eg: WHERE anInteger = TIMESTAMP '1998-9-16'
temp.temp_double = MOV_date_to_double(desc);
temp_is_negative = (temp.temp_double < 0);
#ifdef DEBUG_INDEXKEY
fprintf(stderr, "TIMESTAMP1 special %lg ", temp.temp_double);
#endif
}
else if (itype == idx_boolean)
{
temp.temp_char[0] = UCHAR(MOV_get_boolean(desc) ? 1 : 0);
temp_copy_length = sizeof(UCHAR);
#ifdef DEBUG_INDEXKEY
fprintf(stderr, "BOOLEAN %d ", temp.temp_char[0]);
#endif
}
else
{
temp.temp_double = MOV_get_double(desc);
temp_is_negative = (temp.temp_double < 0);
#ifdef DEBUG_INDEXKEY
fprintf(stderr, "NUMERIC %lg ", temp.temp_double);
#endif
}
// This trick replaces possibly negative zero with positive zero, so that both
// would be compressed to the same index key and thus properly compared (see CORE-3547).
if (temp.temp_double == 0)
{
temp.temp_double = 0;
}
#ifdef IEEE
const UCHAR* q;
#ifndef WORDS_BIGENDIAN
// For little-endian machines, reverse the order of bytes for the key
// Copy the first set of bytes into key_data
size_t length = temp_copy_length;
/*
AB: Speed things a little up, remember that this is function is called a lot.
for (q = temp.temp_char + temp_copy_length; length; --length)
{
*p++ = *--q;
}
*/
q = temp.temp_char + temp_copy_length;
while (length)
{
if (length >= 8)
{
q -= 8;
p[0] = q[7];
p[1] = q[6];
p[2] = q[5];
p[3] = q[4];
p[4] = q[3];
p[5] = q[2];
p[6] = q[1];
p[7] = q[0];
p += 8;
length -= 8;
}
else if (length >= 4)
{
q -= 4;
p[0] = q[3];
p[1] = q[2];
p[2] = q[1];
p[3] = q[0];
p += 4;
length -= 4;
}
else
{
*p++ = *--q;
length--;
}
}
// Copy the next 2 bytes into key_data, if key is of an int64 type
if (int64_key_op)
{
for (q = temp.temp_char + sizeof(double) + sizeof(SSHORT), length = sizeof(SSHORT);
length; --length)
{
*p++ = *--q;
}
}
#else
// For big-endian machines, copy the bytes as laid down
// Copy the first set of bytes into key_data
size_t length = temp_copy_length;
for (q = temp.temp_char; length; --length)
*p++ = *q++;
// Copy the next 2 bytes into key_data, if key is of an int64 type
if (int64_key_op)
{
for (q = temp.temp_char + sizeof(double), length = sizeof(SSHORT); length; --length)
{
*p++ = *q++;
}
}
#endif // !WORDS_BIGENDIAN
#else // IEEE
// The conversion from G_FLOAT to D_FLOAT made below was removed because
// it prevented users from entering otherwise valid numbers into a field
// which was in an index. A D_FLOAT has the sign and 7 of 8 exponent
// bits in the first byte and the remaining exponent bit plus the first
// 7 bits of the mantissa in the second byte. For G_FLOATS, the sign
// and 7 of 11 exponent bits go into the first byte, with the remaining
// 4 exponent bits going into the second byte, with the first 4 bits of
// the mantissa. Why this conversion was done is unknown, but it is
// of limited utility, being useful for reducing the compressed field
// length only for those values which have 0 for the last 6 bytes and
// a nonzero value for the 5-7 bits of the mantissa.
*p++ = temp.temp_char[1];
*p++ = temp.temp_char[0];
*p++ = temp.temp_char[3];
*p++ = temp.temp_char[2];
*p++ = temp.temp_char[5];
*p++ = temp.temp_char[4];
*p++ = temp.temp_char[7];
*p++ = temp.temp_char[6];
#error compile_time_failure:
#error Code needs to be written in the non - IEEE floating point case
#error to handle the following:
#error a) idx_sql_date, idx_sql_time, idx_timestamp b) idx_numeric2
#endif // IEEE
// Test the sign of the double precision number. Just to be sure, don't
// rely on the byte comparison being signed. If the number is negative,
// complement the whole thing. Otherwise just zap the sign bit.
if (temp_is_negative)
{
((SSHORT *) key->key_data)[0] = -((SSHORT *) key->key_data)[0] - 1;
((SSHORT *) key->key_data)[1] = -((SSHORT *) key->key_data)[1] - 1;
((SSHORT *) key->key_data)[2] = -((SSHORT *) key->key_data)[2] - 1;
((SSHORT *) key->key_data)[3] = -((SSHORT *) key->key_data)[3] - 1;
}
else
key->key_data[0] ^= 1 << 7;
if (int64_key_op)
{
// Complement the s_part for an int64 key.
// If we just flip the sign bit, which is equivalent to adding 32768, the
// short part will unsigned-compare correctly.
key->key_data[8] ^= 1 << 7;
//p = &key->key_data[(!int64_key_op) ? temp_copy_length - 1 : INT64_KEY_LENGTH - 1];
p = &key->key_data[INT64_KEY_LENGTH - 1];
}
else
p = &key->key_data[temp_copy_length - 1];
// Finally, chop off trailing binary zeros
while (!(*p) && (p > key->key_data))
--p;
key->key_length = (p - key->key_data) + 1;
// By descending index, check first byte
q = key->key_data;
if (descending && (key->key_length >= 1) &&
((*q == desc_end_value_prefix) || (*q == desc_end_value_check)))
{
p = key->key_data;
p++;
memmove(p, q, key->key_length);
key->key_data[0] = desc_end_value_prefix;
key->key_length++;
}
#ifdef DEBUG_INDEXKEY
{
fprintf(stderr, "temporary_key: length: %d Bytes: ", key->key_length);
for (int i = 0; i < key->key_length; i++)
fprintf(stderr, "%02x ", key->key_data[i]);
fprintf(stderr, "\n");
}
#endif
}
static USHORT compress_root(thread_db* tdbb, index_root_page* page)
{
/**************************************
*
* c o m p r e s s _ r o o t
*
**************************************
*
* Functional description
* Compress an index root page.
*
**************************************/
SET_TDBB(tdbb);
const Database* dbb = tdbb->getDatabase();
CHECK_DBB(dbb);
UCharBuffer temp_buffer;
UCHAR* const temp = temp_buffer.getBuffer(dbb->dbb_page_size);
memcpy(temp, page, dbb->dbb_page_size);
UCHAR* p = (UCHAR*) page + dbb->dbb_page_size;
index_root_page::irt_repeat* root_idx = page->irt_rpt;
for (const index_root_page::irt_repeat* const end = root_idx + page->irt_count;
root_idx < end; root_idx++)
{
if (root_idx->getRoot())
{
const USHORT len = root_idx->irt_keys * sizeof(irtd);
p -= len;
memcpy(p, temp + root_idx->irt_desc, len);
root_idx->irt_desc = p - (UCHAR*) page;
}
}
return p - (UCHAR*) page;
}
static void copy_key(const temporary_key* in, temporary_key* out)
{
/**************************************
*
* c o p y _ k e y
*
**************************************
*
* Functional description
* Copy a key.
*
**************************************/
out->key_length = in->key_length;
out->key_flags = in->key_flags;
memcpy(out->key_data, in->key_data, in->key_length);
}
static contents delete_node(thread_db* tdbb, WIN* window, UCHAR* pointer)
{
/**************************************
*
* d e l e t e _ n o d e
*
**************************************
*
* Functional description
* Delete a node from a page and return whether it
* empty, if there is a single node on it, or if it
* is above or below the threshold for garbage collection.
*
**************************************/
SET_TDBB(tdbb);
const Database* dbb = tdbb->getDatabase();
CHECK_DBB(dbb);
btree_page* page = (btree_page*) window->win_buffer;
CCH_MARK(tdbb, window);
const bool leafPage = (page->btr_level == 0);
// Read node that need to be removed
IndexNode removingNode;
UCHAR* localPointer = removingNode.readNode(pointer, leafPage);
const USHORT offsetDeletePoint = (pointer - (UCHAR*) page);
// Read the next node after the removing node
IndexNode nextNode;
const USHORT offsetNextPoint = (localPointer - (UCHAR*) page);
localPointer = nextNode.readNode(localPointer, leafPage);
// Save data in tempKey so we can rebuild from it
USHORT newNextPrefix = nextNode.prefix;
USHORT newNextLength = 0;
USHORT length = MAX(removingNode.length + removingNode.prefix, nextNode.length + nextNode.prefix);
HalfStaticArray<UCHAR, MAX_KEY> tempBuf;
UCHAR* tempData = tempBuf.getBuffer(length);
length = 0;
if (nextNode.prefix > removingNode.prefix)
{
// The next node uses data from the node that is going to
// be removed so save it.
length = nextNode.prefix - removingNode.prefix;
newNextPrefix -= length;
newNextLength += length;
memcpy(tempData, removingNode.data, length);
}
memcpy(tempData + length, nextNode.data, nextNode.length);
newNextLength += nextNode.length;
// Update the page prefix total.
page->btr_prefix_total -= (removingNode.prefix + (nextNode.prefix - newNextPrefix));
// Update the next node so we are ready to save it.
nextNode.prefix = newNextPrefix;
nextNode.length = newNextLength;
nextNode.data = tempData;
pointer = nextNode.writeNode(pointer, leafPage);
// below this point tempData contents is not used anymore and buffer may be reused
// Compute length of rest of bucket and move it down.
length = page->btr_length - (localPointer - (UCHAR*) page);
if (length)
{
// Could be overlapping buffers.
// memmove() is guaranteed to work non-destructivly on overlapping buffers.
memmove(pointer, localPointer, length);
pointer += length;
localPointer += length;
}
// Set page size and get delta
USHORT delta = page->btr_length;
page->btr_length = pointer - (UCHAR*) page;
delta -= page->btr_length;
// We use a fast approach here.
// Only update offsets pointing after the deleted node and
// remove jump nodes pointing to the deleted node or node
// next to the deleted one.
JumpNodeList tmpJumpNodes;
JumpNodeList* jumpNodes = &tmpJumpNodes;
pointer = page->btr_nodes;
// We are going to rebuild jump nodes. In the end of this process we will either have
// the same jump nodes as before or one jump node less. The jump table size
// by its definition is a good upper estimate for summary size of all existing
// jump nodes data length's.
// After rebuild jump node next after removed one may have new length longer than
// before rebuild but no longer than length of removed node. All other nodes didn't
// change its lengths. Therefore the jump table size is valid upper estimate
// for summary size of all new jump nodes data length's too.
tempData = tempBuf.getBuffer(page->btr_jump_size);
UCHAR* const tempEnd = tempBuf.end();
bool rebuild = false;
UCHAR n = page->btr_jump_count;
IndexJumpNode jumpNode, delJumpNode;
IndexJumpNode* jumpPrev = NULL;
temporary_key jumpKey;
jumpKey.key_length = 0;
USHORT jumpersNewSize = 0;
while (n)
{
pointer = jumpNode.readJumpNode(pointer);
// Jump nodes pointing to the deleted node are removed.
if ((jumpNode.offset < offsetDeletePoint) || (jumpNode.offset >= offsetNextPoint))
{
IndexJumpNode newJumpNode;
if (rebuild && jumpNode.prefix > delJumpNode.prefix)
{
// This node has prefix against a removing jump node
const USHORT addLength = jumpNode.prefix - delJumpNode.prefix;
newJumpNode.prefix = jumpNode.prefix - addLength;
newJumpNode.length = jumpNode.length + addLength;
newJumpNode.offset = jumpNode.offset;
if (jumpNode.offset == offsetNextPoint)
newJumpNode.offset = offsetDeletePoint;
else if (jumpNode.offset > offsetDeletePoint)
newJumpNode.offset -= delta;
newJumpNode.data = tempData;
tempData += newJumpNode.length;
fb_assert(tempData < tempEnd);
memcpy(newJumpNode.data, delJumpNode.data, addLength);
memcpy(newJumpNode.data + addLength, jumpNode.data, jumpNode.length);
// update jump key data
memcpy(jumpKey.key_data + newJumpNode.prefix, newJumpNode.data, newJumpNode.length);
}
else
{
newJumpNode.prefix = jumpNode.prefix;
newJumpNode.length = jumpNode.length;
newJumpNode.offset = jumpNode.offset;
if (jumpNode.offset == offsetNextPoint)
newJumpNode.offset = offsetDeletePoint;
else if (jumpNode.offset > offsetDeletePoint)
newJumpNode.offset -= delta;
newJumpNode.data = tempData;
tempData += newJumpNode.length;
fb_assert(tempData < tempEnd);
memcpy(newJumpNode.data, jumpNode.data, newJumpNode.length);
}
// There is no sense in jump node pointing to the first index node on page.
if ((UCHAR*) page + newJumpNode.offset == page->btr_nodes + page->btr_jump_size)
{
fb_assert(!jumpPrev);
delJumpNode = jumpNode;
rebuild = true;
memcpy(jumpKey.key_data + jumpNode.prefix, jumpNode.data, jumpNode.length);
jumpKey.key_length = jumpNode.prefix + jumpNode.length;
n--;
tempData = newJumpNode.data;
continue;
}
IndexNode newNode;
newNode.readNode(newJumpNode.offset + (UCHAR*) page, leafPage);
const USHORT newPrefix = newNode.prefix;
// We must enforce two conditions below:
// newJumpNode.prefix + newJumpNode.length == newPrefix, and
// jumpPrev != NULL : newJumpNode.prefix <= jumpPrev->prefix + jumpPrev->length, or
// jumpPrev == NULL : newJumpNode.prefix = 0 && newJumpNode.length == newPrefix.
// Also, if we know not all bytes in newPrefix, i.e. if
// newPrefix > newJumpNode.prefix + newJumpNode.length
// then we shoud walk index nodes from previous jump point to the new one and
// fill absent bytes in jumpKey
if (newJumpNode.prefix + newJumpNode.length > newPrefix)
{
if (newJumpNode.prefix > newPrefix)
{
newJumpNode.prefix = newPrefix;
newJumpNode.length = 0;
}
else // newJumpNode.prefix <= newPrefix
newJumpNode.length = newPrefix - newJumpNode.prefix;
}
if (newJumpNode.prefix + newJumpNode.length < newPrefix &&
jumpPrev &&
newPrefix <= jumpPrev->prefix + jumpPrev->length)
{
newJumpNode.prefix = newPrefix;
newJumpNode.length = 0;
}
if (newJumpNode.prefix + newJumpNode.length != newPrefix ||
jumpPrev && (newJumpNode.prefix > jumpPrev->prefix + jumpPrev->length))
{
UCHAR* prevPtr = page->btr_jump_size + page->btr_nodes;
if (jumpPrev)
{
fb_assert(jumpKey.key_length >= jumpPrev->prefix + jumpPrev->length);
newJumpNode.prefix = jumpPrev->prefix + jumpPrev->length;
newJumpNode.length = newPrefix - newJumpNode.prefix;
prevPtr = jumpPrev->offset + (UCHAR*) page;
}
else
{
newJumpNode.prefix = 0;
newJumpNode.length = newPrefix;
}
const UCHAR* endPtr = newJumpNode.offset + (UCHAR*) page;
IndexNode prevNode;
while (prevPtr < endPtr)
{
prevPtr = prevNode.readNode(prevPtr, leafPage);
if (prevNode.prefix < newPrefix && prevNode.length)
{
const USHORT len = MIN(newPrefix - prevNode.prefix, prevNode.length);
memcpy(jumpKey.key_data + prevNode.prefix, prevNode.data, len);
jumpKey.key_length = prevNode.prefix + len;
}
}
fb_assert(jumpKey.key_length >= newPrefix);
fb_assert(newJumpNode.data + newJumpNode.length < tempEnd);
memcpy(newJumpNode.data, jumpKey.key_data + newJumpNode.prefix, newJumpNode.length);
}
memcpy(jumpKey.key_data + newJumpNode.prefix, newJumpNode.data, newJumpNode.length);
jumpKey.key_length = newJumpNode.prefix + newJumpNode.length;
jumpersNewSize += newJumpNode.getJumpNodeSize();
if (jumpersNewSize > page->btr_jump_size)
break;
jumpNodes->add(newJumpNode);
jumpPrev = &jumpNodes->back();
rebuild = false;
tempData = newJumpNode.data + newJumpNode.length;
fb_assert(tempData < tempEnd);
}
else
{
delJumpNode = jumpNode;
rebuild = true;
}
n--;
}
// Update jump information
page->btr_jump_count = (UCHAR) jumpNodes->getCount();
// Write jump nodes
pointer = page->btr_nodes;
IndexJumpNode* walkJumpNode = jumpNodes->begin();
for (size_t i = 0; i < jumpNodes->getCount(); i++)
pointer = walkJumpNode[i].writeJumpNode(pointer);
jumpNodes->clear();
// check to see if the page is now empty
pointer = page->btr_nodes + page->btr_jump_size;
IndexNode node;
pointer = node.readNode(pointer, leafPage);
if (node.isEndBucket || node.isEndLevel)
return contents_empty;
// check to see if there is just one node
pointer = node.readNode(pointer, leafPage);
if (node.isEndBucket || node.isEndLevel)
return contents_single;
// check to see if the size of the page is below the garbage collection threshold,
// meaning below the size at which it should be merged with its left sibling if possible.
if (page->btr_length < GARBAGE_COLLECTION_BELOW_THRESHOLD)
return contents_below_threshold;
return contents_above_threshold;
}
static void delete_tree(thread_db* tdbb,
USHORT rel_id, USHORT idx_id, PageNumber next, PageNumber prior)
{
/**************************************
*
* d e l e t e _ t r e e
*
**************************************
*
* Functional description
* Release index pages back to free list.
*
**************************************/
SET_TDBB(tdbb);
WIN window(next.getPageSpaceID(), -1);
window.win_flags = WIN_large_scan;
window.win_scans = 1;
ULONG down = next.getPageNum();
// Delete the index tree from the top down.
while (next.getPageNum())
{
window.win_page = next;
btree_page* page = (btree_page*) CCH_FETCH(tdbb, &window, LCK_write, 0);
// do a little defensive programming--if any of these conditions
// are true we have a damaged pointer, so just stop deleting. At
// the same time, allow updates of indexes with id > 255 even though
// the page header uses a byte for its index id. This requires relaxing
// the check slightly introducing a risk that we'll pick up a page belonging
// to some other index that is ours +/- (256*n). On the whole, unlikely.
if (page->btr_header.pag_type != pag_index ||
page->btr_id != (UCHAR)(idx_id % 256) || page->btr_relation != rel_id)
{
CCH_RELEASE(tdbb, &window);
return;
}
// if we are at the beginning of a non-leaf level, position
// "down" to the beginning of the next level down
if (next.getPageNum() == down)
{
if (page->btr_level)
{
UCHAR* pointer = page->btr_nodes + page->btr_jump_size;
IndexNode pageNode;
pageNode.readNode(pointer, false);
down = pageNode.pageNumber;
}
else
down = 0;
}
// go through all the sibling pages on this level and release them
next = page->btr_sibling;
CCH_RELEASE_TAIL(tdbb, &window);
PAG_release_page(tdbb, window.win_page, prior);
prior = window.win_page;
// if we are at end of level, go down to the next level
if (!next.getPageNum())
next = down;
}
}
static DSC* eval(thread_db* tdbb, const ValueExprNode* node, DSC* temp, bool* isNull)
{
/**************************************
*
* e v a l
*
**************************************
*
* Functional description
* Evaluate an expression returning a descriptor, and
* a flag to indicate a null value.
*
**************************************/
SET_TDBB(tdbb);
jrd_req* request = tdbb->getRequest();
dsc* desc = EVL_expr(tdbb, request, node);
*isNull = false;
if (desc && !(request->req_flags & req_null))
return desc;
*isNull = true;
temp->dsc_dtype = dtype_text;
temp->dsc_flags = 0;
temp->dsc_sub_type = 0;
temp->dsc_scale = 0;
temp->dsc_length = 1;
temp->dsc_ttype() = ttype_ascii;
temp->dsc_address = (UCHAR*) " ";
return temp;
}
static ULONG fast_load(thread_db* tdbb,
IndexCreation& creation,
SelectivityList& selectivity)
{
/**************************************
*
* f a s t _ l o a d
*
**************************************
*
* Functional description
* Do a fast load. The indices have already been passed into sort, and
* are ripe for the plucking. This beast is complicated, but, I hope,
* comprehendable.
*
**************************************/
#ifdef DEBUG_BTR_PAGES
TEXT debugtext[1024];
#endif
SET_TDBB(tdbb);
const Database* const dbb = tdbb->getDatabase();
CHECK_DBB(dbb);
jrd_rel* const relation = creation.relation;
index_desc* const idx = creation.index;
const USHORT key_length = creation.key_length;
Sort* const scb = creation.sort;
const USHORT pageSpaceID = relation->getPages(tdbb)->rel_pg_space_id;
// leaf-page and pointer-page size limits, we always need to
// leave room for the END_LEVEL node.
const USHORT lp_fill_limit = dbb->dbb_page_size - BTN_LEAF_SIZE;
const USHORT pp_fill_limit = dbb->dbb_page_size - BTN_PAGE_SIZE;
// AB: Let's try to determine to size between the jumps to speed up
// index search. Of course the size depends on the key_length. The
// bigger the key, the less jumps we can make. (Although we must
// not forget that mostly the keys are compressed and much smaller
// than the maximum possible key!).
// These values can easily change without effect on previous created
// indices, cause this value is stored on each page.
// Remember, the lower the value how more jumpkeys are generated and
// how faster jumpkeys are recalculated on insert.
const USHORT jumpAreaSize = 512 + ((int) sqrt((float) key_length) * 16);
// key_size | jumpAreaSize
// ----------+-----------------
// 4 | 544
// 8 | 557
// 16 | 576
// 64 | 640
// 128 | 693
// 256 | 768
WIN* window = NULL;
bool error = false;
FB_UINT64 count = 0;
FB_UINT64 duplicates = 0;
const bool descending = (idx->idx_flags & idx_descending);
const ULONG segments = idx->idx_count;
// hvlad: look at IDX_create_index for explanations about NULL indicator below
const int nullIndLen = !descending && (idx->idx_count == 1) ? 1 : 0;
MemoryPool& pool = *tdbb->getDefaultPool();
HalfStaticArray<FB_UINT64, 4> duplicatesList(pool);
HalfStaticArray<FastLoadLevel, 4> levels(pool);
try
{
levels.resize(1);
FastLoadLevel* leafLevel = &levels[0];
// Initialize level
leafLevel->window.win_page.setPageSpaceID(pageSpaceID);
// Allocate and format the first leaf level bucket. Awkwardly,
// the bucket header has room for only a byte of index id and that's
// part of the ODS. So, for now, we'll just record the first byte
// of the id and hope for the best. Index buckets are (almost) always
// located through the index structure (dmp being an exception used
// only for debug) so the id is actually redundant.
btree_page* bucket = (btree_page*) DPM_allocate(tdbb, &leafLevel->window);
bucket->btr_header.pag_type = pag_index;
bucket->btr_relation = relation->rel_id;
bucket->btr_id = (UCHAR)(idx->idx_id % 256);
bucket->btr_level = 0;
bucket->btr_length = BTR_SIZE;
bucket->btr_jump_interval = jumpAreaSize;
bucket->btr_jump_size = 0;
bucket->btr_jump_count = 0;
#ifdef DEBUG_BTR_PAGES
sprintf(debugtext, "\t new page (%d)", windows[0].win_page);
gds__log(debugtext);
#endif
UCHAR* pointer = bucket->btr_nodes;
leafLevel->levelNode.setNode();
leafLevel->jumpNodes = FB_NEW_POOL(pool) JumpNodeList(pool);
leafLevel->newAreaPointer = pointer + jumpAreaSize;
tdbb->tdbb_flags |= TDBB_no_cache_unwind;
leafLevel->bucket = bucket;
duplicatesList.grow(segments);
memset(duplicatesList.begin(), 0, segments * sizeof(FB_UINT64));
// If there's an error during index construction, fall
// thru to release the last index bucket at each level
// of the index. This will prepare for a single attempt
// to deallocate the index pages for reuse.
IndexNode newNode;
IndexNode previousNode;
// pointer holds the "main" pointer for inserting new nodes.
win_for_array split_window;
split_window.win_page.setPageSpaceID(pageSpaceID);
temporary_key split_key, temp_key;
split_key.key_flags = 0;
split_key.key_length = 0;
temp_key.key_flags = 0;
temp_key.key_length = 0;
bool duplicate = false;
IndexNode tempNode;
while (!error)
{
// Get the next record in sorted order.
UCHAR* record;
scb->get(tdbb, reinterpret_cast<ULONG**>(&record));
if (!record)
break;
index_sort_record* isr = (index_sort_record*) (record + key_length);
count++;
record += nullIndLen;
leafLevel = &levels[0]; // reset after possible array reallocation
// restore previous values
bucket = leafLevel->bucket;
leafLevel->splitPage = 0;
temporary_key* const leafKey = &leafLevel->key;
JumpNodeList* const leafJumpNodes = leafLevel->jumpNodes;
temporary_key* const leafJumpKey = &leafLevel->jumpKey;
// Compute the prefix as the length in common with the previous record's key.
USHORT prefix =
IndexNode::computePrefix(leafKey->key_data, leafKey->key_length, record, isr->isr_key_length);
// set node values
newNode.setNode(prefix, isr->isr_key_length - prefix,
RecordNumber(isr->isr_record_number));
newNode.data = record + prefix;
// If the length of the new node will cause us to overflow the bucket,
// form a new bucket.
if (bucket->btr_length + leafLevel->totalJumpSize +
newNode.getNodeSize(true) > lp_fill_limit)
{
// mark the end of the previous page
const RecordNumber lastRecordNumber = previousNode.recordNumber;
previousNode.readNode(previousNode.nodePointer, true);
previousNode.setEndBucket();
pointer = previousNode.writeNode(previousNode.nodePointer, true, false);
bucket->btr_length = pointer - (UCHAR*) bucket;
if (leafLevel->totalJumpSize)
{
// Slide down current nodes;
// CVC: Warning, this may overlap. It seems better to use
// memmove or to ensure manually that leafLevel->totalJumpSize > l
// Also, "sliding down" here is moving contents higher in memory.
const USHORT l = bucket->btr_length - BTR_SIZE;
memmove(bucket->btr_nodes + leafLevel->totalJumpSize, bucket->btr_nodes, l);
// Update JumpInfo
if (leafJumpNodes->getCount() > MAX_UCHAR)
BUGCHECK(205); // msg 205 index bucket overfilled
bucket->btr_jump_interval = jumpAreaSize;
bucket->btr_jump_size = leafLevel->totalJumpSize;
bucket->btr_jump_count = (UCHAR) leafJumpNodes->getCount();
// Write jumpnodes on page.
pointer = bucket->btr_nodes;
IndexJumpNode* walkJumpNode = leafJumpNodes->begin();
for (size_t i = 0; i < leafJumpNodes->getCount(); i++)
{
// Update offset position first.
walkJumpNode[i].offset += leafLevel->totalJumpSize;
pointer = walkJumpNode[i].writeJumpNode(pointer);
}
bucket->btr_length += leafLevel->totalJumpSize;
}
if (bucket->btr_length > dbb->dbb_page_size)
BUGCHECK(205); // msg 205 index bucket overfilled
// Allocate new bucket.
btree_page* split = (btree_page*) DPM_allocate(tdbb, &split_window);
bucket->btr_sibling = split_window.win_page.getPageNum();
split->btr_left_sibling = leafLevel->window.win_page.getPageNum();
split->btr_header.pag_type = pag_index;
split->btr_relation = bucket->btr_relation;
split->btr_level = bucket->btr_level;
split->btr_id = bucket->btr_id;
split->btr_jump_interval = bucket->btr_jump_interval;
split->btr_jump_size = 0;
split->btr_jump_count = 0;
#ifdef DEBUG_BTR_PAGES
sprintf(debugtext, "\t new page (%d), left page (%d)",
split_window.win_page, split->btr_left_sibling);
gds__log(debugtext);
#endif
// Reset position and size for generating jumpnode
pointer = split->btr_nodes;
leafLevel->newAreaPointer = pointer + jumpAreaSize;
leafLevel->totalJumpSize = 0;
leafJumpKey->key_length = 0;
// store the first node on the split page
IndexNode splitNode;
splitNode.setNode(0, leafKey->key_length, lastRecordNumber);
splitNode.data = leafKey->key_data;
pointer = splitNode.writeNode(pointer, true);
previousNode = splitNode;
// save the page number of the previous page and release it
leafLevel->splitPage = leafLevel->window.win_page.getPageNum();
leafLevel->splitRecordNumber = splitNode.recordNumber;
CCH_RELEASE(tdbb, &leafLevel->window);
#ifdef DEBUG_BTR_PAGES
sprintf(debugtext, "\t release page (%d), left page (%d), right page (%d)",
leafLevel->window.win_page,
((btr*) leafLevel->window.win_buffer)->btr_left_sibling,
((btr*) leafLevel->window.win_buffer)->btr_sibling);
gds__log(debugtext);
#endif
// set up the new page as the "current" page
leafLevel->window = split_window;
leafLevel->bucket = bucket = split;
// save the first key on page as the page to be propagated
copy_key(leafKey, &split_key);
// Clear jumplist.
IndexJumpNode* walkJumpNode = leafJumpNodes->begin();
for (size_t i = 0; i < leafJumpNodes->getCount(); i++)
delete[] walkJumpNode[i].data;
leafJumpNodes->clear();
}
// Insert the new node in the current bucket
bucket->btr_prefix_total += prefix;
pointer = newNode.writeNode(pointer, true);
previousNode = newNode;
// if we have a compound-index calculate duplicates per segment.
if (segments > 1 && count > 1)
{
// Initialize variables for segment duplicate check.
// count holds the current checking segment (starting by
// the maximum segment number to 1).
const UCHAR* p1 = leafKey->key_data;
const UCHAR* const p1_end = p1 + leafKey->key_length;
const UCHAR* p2 = newNode.data;
const UCHAR* const p2_end = p2 + newNode.length;
SSHORT segment, stuff_count;
if (newNode.prefix == 0)
{
segment = *p2;
//pos = 0;
stuff_count = 0;
}
else
{
const SSHORT pos = newNode.prefix;
// find the segment number were we're starting.
const SSHORT i = (pos / (STUFF_COUNT + 1)) * (STUFF_COUNT + 1);
if (i == pos)
{
// We _should_ pick number from data if available
segment = *p2;
}
else
segment = *(p1 + i);
// update stuff_count to the current position.
stuff_count = STUFF_COUNT + 1 - (pos - i);
p1 += pos;
}
//Look for duplicates in the segments
while ((p1 < p1_end) && (p2 < p2_end))
{
if (stuff_count == 0)
{
if (*p1 != *p2)
{
// We're done
break;
}
segment = *p2;
p1++;
p2++;
stuff_count = STUFF_COUNT;
}
if (*p1 != *p2)
{
//We're done
break;
}
p1++;
p2++;
stuff_count--;
}
// For descending indexes the segment-number is also
// complemented, thus reverse it back.
// Note: values are complemented per UCHAR base.
if (descending)
segment = (255 - segment);
if ((p1 == p1_end) && (p2 == p2_end))
segment = 0; // All segments are duplicates
for (ULONG i = segment + 1; i <= segments; i++)
duplicatesList[segments - i]++;
}
// check if this is a duplicate node
duplicate = (!newNode.length && prefix == leafKey->key_length);
if (duplicate && (count > 1))
++duplicates;
// Update the length of the page.
bucket->btr_length = pointer - (UCHAR*) bucket;
if (bucket->btr_length > dbb->dbb_page_size)
BUGCHECK(205); // msg 205 index bucket overfilled
// Remember the last key inserted to compress the next one.
leafKey->key_length = isr->isr_key_length;
memcpy(leafKey->key_data, record, leafKey->key_length);
if (leafLevel->newAreaPointer < pointer)
{
// Create a jumpnode
IndexJumpNode jumpNode;
jumpNode.prefix = IndexNode::computePrefix(leafJumpKey->key_data,
leafJumpKey->key_length, leafKey->key_data, newNode.prefix);
jumpNode.length = newNode.prefix - jumpNode.prefix;
const USHORT jumpNodeSize = jumpNode.getJumpNodeSize();
// Ensure the new jumpnode fits in the bucket
if (bucket->btr_length + leafLevel->totalJumpSize + jumpNodeSize < lp_fill_limit)
{
// Initialize the rest of the jumpnode
jumpNode.offset = (newNode.nodePointer - (UCHAR*) bucket);
jumpNode.data = FB_NEW_POOL(pool) UCHAR[jumpNode.length];
memcpy(jumpNode.data, leafKey->key_data + jumpNode.prefix, jumpNode.length);
// Push node on end in list
leafJumpNodes->add(jumpNode);
// Store new data in leafJumpKey, so a new jump node can calculate prefix
memcpy(leafJumpKey->key_data + jumpNode.prefix, jumpNode.data, jumpNode.length);
leafJumpKey->key_length = jumpNode.length + jumpNode.prefix;
// Set new position for generating jumpnode
leafLevel->newAreaPointer += jumpAreaSize;
leafLevel->totalJumpSize += jumpNodeSize;
}
}
// If there wasn't a split, we're done. If there was, propagate the
// split upward
for (unsigned level = 1; levels[level - 1].splitPage; level++)
{
if (level == MAX_LEVELS)
{
// Maximum level depth reached
status_exception::raise(Arg::Gds(isc_imp_exc) <<
Arg::Gds(isc_max_idx_depth) << Arg::Num(MAX_LEVELS));
}
if (level == levels.getCount())
levels.resize(level + 1);
FastLoadLevel* const currLevel = &levels[level];
FastLoadLevel* const priorLevel = &levels[level - 1];
// Initialize the current pointers for this level
window = &currLevel->window;
currLevel->splitPage = 0;
UCHAR* levelPointer = currLevel->pointer;
// If there isn't already a bucket at this level, make one. Remember to
// shorten the index id to a byte
if (!(bucket = currLevel->bucket))
{
// Initialize new level
currLevel->window.win_page.setPageSpaceID(pageSpaceID);
currLevel->bucket = bucket = (btree_page*) DPM_allocate(tdbb, window);
bucket->btr_header.pag_type = pag_index;
bucket->btr_relation = relation->rel_id;
bucket->btr_id = (UCHAR)(idx->idx_id % 256);
fb_assert(level <= MAX_UCHAR);
bucket->btr_level = (UCHAR) level;
bucket->btr_jump_interval = jumpAreaSize;
bucket->btr_jump_size = 0;
bucket->btr_jump_count = 0;
#ifdef DEBUG_BTR_PAGES
sprintf(debugtext, "\t new page (%d)", window->win_page);
gds__log(debugtext);
#endif
// since this is the beginning of the level, we propagate the lower-level
// page with a "degenerate" zero-length node indicating that this page holds
// any key value less than the next node
levelPointer = bucket->btr_nodes;
// First record-number of level must be zero
currLevel->levelNode.setNode(0, 0, RecordNumber(0), priorLevel->splitPage);
levelPointer = currLevel->levelNode.writeNode(levelPointer, false);
bucket->btr_length = levelPointer - (UCHAR*) bucket;
currLevel->jumpNodes = FB_NEW_POOL(pool) JumpNodeList(pool);
currLevel->newAreaPointer = levelPointer + jumpAreaSize;
}
temporary_key* const pageKey = &currLevel->key;
temporary_key* const pageJumpKey = &currLevel->jumpKey;
JumpNodeList* const pageJumpNodes = currLevel->jumpNodes;
// Compute the prefix in preparation of insertion
prefix = IndexNode::computePrefix(pageKey->key_data, pageKey->key_length,
split_key.key_data, split_key.key_length);
// Remember the last key inserted to compress the next one.
copy_key(&split_key, &temp_key);
// Save current node if we need to split.
tempNode = currLevel->levelNode;
// Set new node values.
currLevel->levelNode.setNode(prefix, temp_key.key_length - prefix,
priorLevel->splitRecordNumber, priorLevel->window.win_page.getPageNum());
currLevel->levelNode.data = temp_key.key_data + prefix;
// See if the new node fits in the current bucket.
// If not, split the bucket.
if (bucket->btr_length + currLevel->totalJumpSize +
currLevel->levelNode.getNodeSize(false) > pp_fill_limit)
{
// mark the end of the page; note that the end_bucket marker must
// contain info about the first node on the next page
const ULONG lastPageNumber = tempNode.pageNumber;
tempNode.readNode(tempNode.nodePointer, false);
tempNode.setEndBucket();
levelPointer = tempNode.writeNode(tempNode.nodePointer, false, false);
bucket->btr_length = levelPointer - (UCHAR*) bucket;
if (currLevel->totalJumpSize)
{
// Slide down current nodes;
// CVC: Warning, this may overlap. It seems better to use
// memmove or to ensure manually that leafLevel->totalJumpSize > l
// Also, "sliding down" here is moving contents higher in memory.
const USHORT l = bucket->btr_length - BTR_SIZE;
memmove(bucket->btr_nodes + currLevel->totalJumpSize, bucket->btr_nodes, l);
// Update JumpInfo
if (pageJumpNodes->getCount() > MAX_UCHAR)
BUGCHECK(205); // msg 205 index bucket overfilled
bucket->btr_jump_interval = jumpAreaSize;
bucket->btr_jump_size = currLevel->totalJumpSize;
bucket->btr_jump_count = (UCHAR) pageJumpNodes->getCount();
// Write jumpnodes on page.
levelPointer = bucket->btr_nodes;
IndexJumpNode* walkJumpNode = pageJumpNodes->begin();
for (size_t i = 0; i < pageJumpNodes->getCount(); i++)
{
// Update offset position first.
walkJumpNode[i].offset += currLevel->totalJumpSize;
levelPointer = walkJumpNode[i].writeJumpNode(levelPointer);
}
bucket->btr_length += currLevel->totalJumpSize;
}
if (bucket->btr_length > dbb->dbb_page_size)
BUGCHECK(205); // msg 205 index bucket overfilled
btree_page* split = (btree_page*) DPM_allocate(tdbb, &split_window);
bucket->btr_sibling = split_window.win_page.getPageNum();
split->btr_left_sibling = window->win_page.getPageNum();
split->btr_header.pag_type = pag_index;
split->btr_relation = bucket->btr_relation;
split->btr_level = bucket->btr_level;
split->btr_id = bucket->btr_id;
split->btr_jump_interval = bucket->btr_jump_interval;
split->btr_jump_size = 0;
split->btr_jump_count = 0;
#ifdef DEBUG_BTR_PAGES
sprintf(debugtext, "\t new page (%d), left page (%d)",
split_window.win_page, split->btr_left_sibling);
gds__log(debugtext);
#endif
levelPointer = split->btr_nodes;
// Reset position and size for generating jumpnode
currLevel->newAreaPointer = levelPointer + jumpAreaSize;
currLevel->totalJumpSize = 0;
pageJumpKey->key_length = 0;
// insert the new node in the new bucket
IndexNode splitNode;
splitNode.setNode(0, pageKey->key_length, tempNode.recordNumber, lastPageNumber);
splitNode.data = pageKey->key_data;
levelPointer = splitNode.writeNode(levelPointer, false);
tempNode = splitNode;
// indicate to propagate the page we just split from
currLevel->splitPage = window->win_page.getPageNum();
currLevel->splitRecordNumber = splitNode.recordNumber;
CCH_RELEASE(tdbb, window);
#ifdef DEBUG_BTR_PAGES
sprintf(debugtext, "\t release page (%d), left page (%d), right page (%d)",
window->win_page,
((btr*)window->win_buffer)->btr_left_sibling,
((btr*)window->win_buffer)->btr_sibling);
gds__log(debugtext);
#endif
// and make the new page the current page
*window = split_window;
currLevel->bucket = bucket = split;
copy_key(pageKey, &split_key);
// Clear jumplist.
IndexJumpNode* walkJumpNode = pageJumpNodes->begin();
for (size_t i = 0; i < pageJumpNodes->getCount(); i++)
delete[] walkJumpNode[i].data;
pageJumpNodes->clear();
}
// Now propagate up the lower-level bucket by storing a "pointer" to it.
bucket->btr_prefix_total += prefix;
levelPointer = currLevel->levelNode.writeNode(levelPointer, false);
// Update the length of the page.
bucket->btr_length = levelPointer - (UCHAR*) bucket;
if (bucket->btr_length > dbb->dbb_page_size)
BUGCHECK(205); // msg 205 index bucket overfilled
if (currLevel->newAreaPointer < levelPointer)
{
// Create a jumpnode
IndexJumpNode jumpNode;
jumpNode.prefix = IndexNode::computePrefix(pageJumpKey->key_data,
pageJumpKey->key_length,
temp_key.key_data,
currLevel->levelNode.prefix);
jumpNode.length = currLevel->levelNode.prefix - jumpNode.prefix;
const USHORT jumpNodeSize = jumpNode.getJumpNodeSize();
// Ensure the new jumpnode fits in the bucket
if (bucket->btr_length + currLevel->totalJumpSize + jumpNodeSize < pp_fill_limit)
{
// Initialize the rest of the jumpnode
jumpNode.offset = (currLevel->levelNode.nodePointer - (UCHAR*) bucket);
jumpNode.data = FB_NEW_POOL(pool) UCHAR[jumpNode.length];
memcpy(jumpNode.data, temp_key.key_data + jumpNode.prefix, jumpNode.length);
// Push node on end in list
pageJumpNodes->add(jumpNode);
// Store new data in jumpKey, so a new jump node can calculate prefix
memcpy(pageJumpKey->key_data + jumpNode.prefix, jumpNode.data, jumpNode.length);
pageJumpKey->key_length = jumpNode.length + jumpNode.prefix;
// Set new position for generating jumpnode
currLevel->newAreaPointer += jumpAreaSize;
currLevel->totalJumpSize += jumpNodeSize;
}
}
// Now restore the current key value and save this node as the
// current node on this level; also calculate the new page length.
copy_key(&temp_key, pageKey);
currLevel->pointer = levelPointer;
}
if (--tdbb->tdbb_quantum < 0)
error = JRD_reschedule(tdbb, 0, false);
}
// To finish up, put an end of level marker on the last bucket
// of each level.
for (unsigned i = 0; i < levels.getCount(); i++)
{
FastLoadLevel* const currLevel = &levels[i];
bucket = currLevel->bucket;
if (!bucket)
break;
// retain the top level window for returning to the calling routine
const bool leafPage = (bucket->btr_level == 0);
window = &currLevel->window;
// store the end of level marker
pointer = (UCHAR*) bucket + bucket->btr_length;
currLevel->levelNode.setEndLevel();
pointer = currLevel->levelNode.writeNode(pointer, leafPage);
// and update the final page length
bucket->btr_length = pointer - (UCHAR*) bucket;
if (bucket->btr_length > dbb->dbb_page_size)
BUGCHECK(205); // msg 205 index bucket overfilled
// Store jump nodes on page if needed.
JumpNodeList* const pageJumpNodes = currLevel->jumpNodes;
if (currLevel->totalJumpSize)
{
// Slide down current nodes;
// CVC: Warning, this may overlap. It seems better to use
// memmove or to ensure manually that leafLevel->totalJumpSize > l
// Also, "sliding down" here is moving contents higher in memory.
const USHORT l = bucket->btr_length - BTR_SIZE;
memmove(bucket->btr_nodes + currLevel->totalJumpSize, bucket->btr_nodes, l);
// Update JumpInfo
if (pageJumpNodes->getCount() > MAX_UCHAR)
BUGCHECK(205); // msg 205 index bucket overfilled
bucket->btr_jump_interval = jumpAreaSize;
bucket->btr_jump_size = currLevel->totalJumpSize;
bucket->btr_jump_count = (UCHAR) pageJumpNodes->getCount();
// Write jumpnodes on page.
pointer = bucket->btr_nodes;
IndexJumpNode* walkJumpNode = pageJumpNodes->begin();
for (size_t i = 0; i < pageJumpNodes->getCount(); i++)
{
// Update offset position first.
walkJumpNode[i].offset += currLevel->totalJumpSize;
pointer = walkJumpNode[i].writeJumpNode(pointer);
}
bucket->btr_length += currLevel->totalJumpSize;
}
if (bucket->btr_length > dbb->dbb_page_size)
BUGCHECK(205); // msg 205 index bucket overfilled
CCH_RELEASE(tdbb, &currLevel->window);
#ifdef DEBUG_BTR_PAGES
sprintf(debugtext, "\t release page (%d), left page (%d), right page (%d)",
currLevel->window.win_page,
((btr*) currLevel->window.win_buffer)->btr_left_sibling,
((btr*) currLevel->window.win_buffer)->btr_sibling);
gds__log(debugtext);
#endif
}
// Finally clean up dynamic memory used.
for (unsigned i = 0; i < levels.getCount(); i++)
{
JumpNodeList* const freeJumpNodes = levels[i].jumpNodes;
if (freeJumpNodes)
{
IndexJumpNode* walkJumpNode = freeJumpNodes->begin();
for (size_t i = 0; i < freeJumpNodes->getCount(); i++)
delete[] walkJumpNode[i].data;
delete freeJumpNodes;
}
}
} // try
catch (const Exception& ex)
{
ex.stuffException(tdbb->tdbb_status_vector);
error = true;
}
tdbb->tdbb_flags &= ~TDBB_no_cache_unwind;
// do some final housekeeping
creation.sort.reset();
// If index flush fails, try to delete the index tree.
// If the index delete fails, just go ahead and punt.
try
{
if (error)
ERR_punt();
if (!relation->isTemporary())
CCH_flush(tdbb, FLUSH_ALL, 0);
// Calculate selectivity, also per segment when newer ODS
selectivity.grow(segments);
if (segments > 1)
{
for (ULONG i = 0; i < segments; i++)
selectivity[i] = (float) (count ? 1.0 / (float) (count - duplicatesList[i]) : 0.0);
}
else
selectivity[0] = (float) (count ? (1.0 / (float) (count - duplicates)) : 0.0);
} // try
catch (const Exception& ex)
{
ex.stuffException(tdbb->tdbb_status_vector);
// CCH_unwind does not released page buffers (as we
// set TDBB_no_cache_unwind flag), do it now
for (unsigned i = 0; i < levels.getCount(); i++)
{
if (levels[i].window.win_bdb)
CCH_RELEASE(tdbb, &levels[i].window);
}
if (window)
{
delete_tree(tdbb, relation->rel_id, idx->idx_id,
window->win_page, PageNumber(window->win_page.getPageSpaceID(), 0));
}
throw;
}
return window->win_page.getPageNum();
}
static index_root_page* fetch_root(thread_db* tdbb, WIN* window, const jrd_rel* relation,
const RelationPages* relPages)
{
/**************************************
*
* f e t c h _ r o o t
*
**************************************
*
* Functional description
* Return descriptions of all indices for relation. If there isn't
* a known index root, assume we were called during optimization
* and return no indices.
*
**************************************/
SET_TDBB(tdbb);
if ((window->win_page = relPages->rel_index_root) == 0)
{
if (relation->rel_id == 0)
return NULL;
DPM_scan_pages(tdbb);
if (!relPages->rel_index_root)
return NULL;
window->win_page = relPages->rel_index_root;
}
return (index_root_page*) CCH_FETCH(tdbb, window, LCK_read, pag_root);
}
static UCHAR* find_node_start_point(btree_page* bucket, temporary_key* key,
UCHAR* value,
USHORT* return_value, bool descending,
bool retrieval, bool pointer_by_marker,
RecordNumber find_record_number)
{
/**************************************
*
* f i n d _ n o d e _ s t a r t _ p o i n t
*
**************************************
*
* Functional description
* Locate and return a pointer to the insertion point.
* If the key doesn't belong in this bucket, return NULL.
* A flag indicates the index is descending.
*
**************************************/
USHORT prefix = 0;
const UCHAR* const key_end = key->key_data + key->key_length;
bool firstPass = true;
const bool leafPage = (bucket->btr_level == 0);
const UCHAR* const endPointer = (UCHAR*) bucket + bucket->btr_length;
// Find point where we can start search.
UCHAR* pointer = find_area_start_point(bucket, key, value, &prefix, descending, retrieval,
find_record_number);
const UCHAR* p = key->key_data + prefix;
IndexNode node;
pointer = node.readNode(pointer, leafPage);
// Check if pointer is still valid
if (pointer > endPointer)
BUGCHECK(204); // msg 204 index inconsistent
// If this is an non-leaf bucket of a descending index, the dummy node on the
// front will trip us up. NOTE: This code may be apocryphal. I don't see
// anywhere that a dummy node is stored for a descending index. - deej
//
// AB: This node ("dummy" node) is inserted on every first page in a level.
// Because it's length and prefix is 0 a descending index would see it
// always as the first matching node.
if (!leafPage && descending &&
(node.nodePointer == bucket->btr_nodes + bucket->btr_jump_size) && (node.length == 0))
{
pointer = node.readNode(pointer, leafPage);
// Check if pointer is still valid
if (pointer > endPointer)
BUGCHECK(204); // msg 204 index inconsistent
}
while (true)
{
// Pick up data from node
if (value && node.length)
memcpy(value + node.prefix, node.data, node.length);
// If the record number is -1, the node is the last in the level
// and, by definition, is the insertion point. Otherwise, if the
// prefix of the current node is less than the running prefix, the
// node must have a value greater than the key, so it is the insertion
// point.
if (node.isEndLevel || node.prefix < prefix)
goto done;
// If the node prefix is greater than current prefix , it must be less
// than the key, so we can skip it. If it has zero length, then
// it is a duplicate, and can also be skipped.
if (node.prefix == prefix)
{
const UCHAR* q = node.data;
const UCHAR* const nodeEnd = q + node.length;
if (descending)
{
while (true)
{
if (q == nodeEnd || (retrieval && p == key_end))
goto done;
if (p == key_end || *p > *q)
break;
if (*p++ < *q++)
goto done;
}
}
else if (node.length > 0 || firstPass)
{
firstPass = false;
while (true)
{
if (p == key_end)
goto done;
if (q == nodeEnd || *p > *q)
break;
if (*p++ < *q++)
goto done;
}
}
prefix = (USHORT)(p - key->key_data);
}
if (node.isEndBucket)
{
if (pointer_by_marker && (prefix == key->key_length) &&
(prefix == node.prefix + node.length))
{
// AB: When storing equal nodes, recordnumbers should always
// be inserted on this page, because the first node on the next
// page could be a equal node with a higher recordnumber than
// this one and that would cause a overwrite of the first node
// in the next page, but the first node of a page must not change!!
goto done;
}
return NULL;
}
pointer = node.readNode(pointer, leafPage);
// Check if pointer is still valid
if (pointer > endPointer)
BUGCHECK(204); // msg 204 index inconsistent
}
done:
if (return_value)
*return_value = prefix;
return node.nodePointer;
}
static UCHAR* find_area_start_point(btree_page* bucket, const temporary_key* key,
UCHAR* value,
USHORT* return_prefix, bool descending,
bool retrieval, RecordNumber find_record_number)
{
/**************************************
*
* f i n d _ a r e a _ s t a r t _ p o i n t
*
**************************************
*
* Functional description
* Locate and return a pointer to a start area.
* The starting nodes for a area are
* defined with jump nodes. A jump node
* contains the prefix information for
* a node at a specific offset.
*
**************************************/
const bool useFindRecordNumber = (find_record_number != NO_VALUE);
const bool leafPage = (bucket->btr_level == 0);
const UCHAR* keyPointer = key->key_data;
const UCHAR* const keyEnd = keyPointer + key->key_length;
// Retrieve jump information.
UCHAR* pointer = bucket->btr_nodes;
UCHAR n = bucket->btr_jump_count;
// Set begin of page as default.
IndexJumpNode prevJumpNode;
prevJumpNode.offset = BTR_SIZE + bucket->btr_jump_size;
prevJumpNode.prefix = 0;
prevJumpNode.length = 0;
temporary_key jumpKey;
jumpKey.key_length = 0;
jumpKey.key_flags = 0;
USHORT prefix = 0;
USHORT testPrefix = 0;
while (n)
{
IndexJumpNode jumpNode;
pointer = jumpNode.readJumpNode(pointer);
IndexNode node;
node.readNode((UCHAR*) bucket + jumpNode.offset, leafPage);
// jumpKey will hold complete data off referenced node
memcpy(jumpKey.key_data + jumpNode.prefix, jumpNode.data, jumpNode.length);
memcpy(jumpKey.key_data + node.prefix, node.data, node.length);
jumpKey.key_length = node.prefix + node.length;
keyPointer = key->key_data + jumpNode.prefix;
const UCHAR* q = jumpKey.key_data + jumpNode.prefix;
const UCHAR* const nodeEnd = jumpKey.key_data + jumpKey.key_length;
bool done = false;
if ((jumpNode.prefix <= testPrefix) && descending)
{
while (true)
{
if (q == nodeEnd)
{
done = true;
// Check if this is a exact match or a duplicate.
// If the node is pointing to its end and the length is
// the same as the key then we have found a exact match.
// Now start walking between the jump nodes until we
// found a node reference that's not equal anymore
// or the record number is higher then the one we need.
if (useFindRecordNumber && (keyPointer == keyEnd))
{
n--;
while (n)
{
if (find_record_number <= node.recordNumber)
{
// If the record number from leaf is higer
// then we should be in our previous area.
break;
}
// Calculate new prefix to return right prefix.
prefix = jumpNode.length + jumpNode.prefix;
prevJumpNode = jumpNode;
pointer = jumpNode.readJumpNode(pointer);
node.readNode((UCHAR*) bucket + jumpNode.offset, leafPage);
if (node.length != 0 ||
node.prefix != prevJumpNode.prefix + prevJumpNode.length ||
node.prefix < jumpKey.key_length ||
jumpNode.prefix != prevJumpNode.prefix + prevJumpNode.length ||
node.isEndBucket || node.isEndLevel)
{
break;
}
n--;
}
}
break;
}
if (retrieval && keyPointer == keyEnd)
{
done = true;
break;
}
if (keyPointer == keyEnd) // End of key reached
break;
if (*keyPointer > *q) // Our key is bigger so check next node.
break;
if (*keyPointer++ < *q++)
{
done = true;
break;
}
}
testPrefix = (USHORT)(keyPointer - key->key_data);
}
else if (jumpNode.prefix <= testPrefix)
{
while (true)
{
if (keyPointer == keyEnd)
{
// Reached end of our key we're searching for.
done = true;
// Check if this is a exact match or a duplicate
// If the node is pointing to its end and the length is
// the same as the key then we have found a exact match.
// Now start walking between the jump nodes until we
// found a node reference that's not equal anymore
// or the record number is higher then the one we need.
if (useFindRecordNumber && q == nodeEnd)
{
n--;
while (n)
{
if (find_record_number <= node.recordNumber)
{
// If the record number from leaf is higer
// then we should be in our previous area.
break;
}
// Calculate new prefix to return right prefix.
prefix = jumpNode.length + jumpNode.prefix;
prevJumpNode = jumpNode;
pointer = jumpNode.readJumpNode(pointer);
node.readNode((UCHAR*) bucket + jumpNode.offset, leafPage);
if (node.length != 0 ||
node.prefix != prevJumpNode.prefix + prevJumpNode.length ||
jumpNode.prefix != prevJumpNode.prefix + prevJumpNode.length ||
node.isEndBucket || node.isEndLevel)
{
break;
}
n--;
}
}
break;
}
if (q == nodeEnd) // End of node data reached
break;
if (*keyPointer > *q) // Our key is bigger so check next node.
break;
if (*keyPointer++ < *q++)
{
done = true;
break;
}
}
testPrefix = (USHORT)(keyPointer - key->key_data);
}
if (done)
{
// We're done, go out of main loop.
break;
}
prefix = MIN(jumpNode.length + jumpNode.prefix, testPrefix);
if (value && (jumpNode.length + jumpNode.prefix))
{
// Copy prefix data from referenced node to value
memcpy(value, jumpKey.key_data, jumpNode.length + jumpNode.prefix);
}
prevJumpNode = jumpNode;
n--;
}
if (return_prefix)
*return_prefix = prefix;
return (UCHAR*) bucket + prevJumpNode.offset;
}
static ULONG find_page(btree_page* bucket, const temporary_key* key,
const index_desc* idx, RecordNumber find_record_number,
bool retrieval)
{
/**************************************
*
* f i n d _ p a g e
*
**************************************
*
* Functional description
* Find a page number in an index level. Return either the
* node equal to the key or the last node less than the key.
* Note that this routine can be called only for non-leaf
* pages, because it assumes the first node on page is
* a degenerate, zero-length node.
*
**************************************/
const bool leafPage = (bucket->btr_level == 0);
bool firstPass = true;
const bool descending = (idx->idx_flags & idx_descending);
const bool primary = (idx->idx_flags & idx_primary);
const bool unique = (idx->idx_flags & idx_unique);
const bool key_all_nulls = (key->key_nulls == (1 << idx->idx_count) - 1);
const bool validateDuplicates = (unique && !key_all_nulls) || primary;
if (validateDuplicates)
find_record_number = NO_VALUE;
const UCHAR* const endPointer = (UCHAR*) bucket + bucket->btr_length;
USHORT prefix = 0; // last computed prefix against processed node
// pointer where to start reading next node
UCHAR* pointer = find_area_start_point(bucket, key, 0, &prefix,
descending, retrieval, find_record_number);
IndexNode node;
pointer = node.readNode(pointer, leafPage);
// Check if pointer is still valid
if (pointer > endPointer)
BUGCHECK(204); // msg 204 index inconsistent
if (node.isEndBucket || node.isEndLevel)
{
pointer = bucket->btr_nodes + bucket->btr_jump_size;
pointer = node.readNode(pointer, leafPage);
// Check if pointer is still valid
if (pointer > endPointer)
BUGCHECK(204); // msg 204 index inconsistent
}
if (node.isEndLevel)
BUGCHECK(206); // msg 206 exceeded index level
ULONG previousNumber = node.pageNumber;
if (node.nodePointer == bucket->btr_nodes + bucket->btr_jump_size)
{
prefix = 0;
// Handle degenerating node, always generated at first
// page in a level.
if ((node.prefix == 0) && (node.length == 0))
{
// Compute common prefix of key and first node
previousNumber = node.pageNumber;
pointer = node.readNode(pointer, leafPage);
// Check if pointer is still valid
if (pointer > endPointer)
BUGCHECK(204); // msg 204 index inconsistent
}
}
const UCHAR* p = key->key_data + prefix; // pointer on key
const UCHAR* const keyEnd = key->key_data + key->key_length; // pointer on end of key
while (true)
{
// If the page/record number is -1, the node is the last in the level
// and, by definition, is the target node. Otherwise, if the
// prefix of the current node is less than the running prefix, its
// node must have a value greater than the key, which is the fb_insertion
// point.
if (node.isEndLevel || node.prefix < prefix)
return previousNumber;
// If the node prefix is greater than current prefix , it must be less
// than the key, so we can skip it. If it has zero length, then
// it is a duplicate, and can also be skipped.
const UCHAR* q = node.data; // pointer on processing node
const UCHAR* const nodeEnd = q + node.length; // pointer on end of processing node
if (node.prefix == prefix)
{
if (descending)
{
// Descending indexes
while (true)
{
// Check for exact match and if we need to do
// record number matching.
if (q == nodeEnd || p == keyEnd)
{
if (find_record_number != NO_VALUE && q == nodeEnd && p == keyEnd)
{
return IndexNode::findPageInDuplicates(bucket,
node.nodePointer, previousNumber, find_record_number);
}
if (q < nodeEnd && !retrieval)
break;
return previousNumber;
}
if (*p > *q)
break;
if (*p++ < *q++)
return previousNumber;
}
}
else if (node.length > 0 || firstPass)
{
firstPass = false;
// Ascending index
while (true)
{
if (p == keyEnd)
{
// Check for exact match and if we need to do
// record number matching.
if (find_record_number != NO_VALUE && q == nodeEnd)
{
return IndexNode::findPageInDuplicates(bucket,
node.nodePointer, previousNumber, find_record_number);
}
return previousNumber;
}
if (q == nodeEnd || *p > *q)
break;
if (*p++ < *q++)
return previousNumber;
}
}
}
prefix = p - key->key_data;
// If this is the end of bucket, return node. Somebody else can deal with this.
if (node.isEndBucket)
return node.pageNumber;
previousNumber = node.pageNumber;
pointer = node.readNode(pointer, leafPage);
// Check if pointer is still valid
if (pointer > endPointer)
BUGCHECK(204); // msg 204 index inconsistent
}
// NOTREACHED
return ~0; // superfluous return to shut lint up
}
static contents garbage_collect(thread_db* tdbb, WIN* window, ULONG parent_number)
{
/**************************************
*
* g a r b a g e _ c o l l e c t
*
**************************************
*
* Functional description
* Garbage collect an index page. This requires
* care so that we don't step on other processes
* that might be traversing the tree forwards,
* backwards, or top to bottom. We must also
* keep in mind that someone might be adding a node
* at the same time we are deleting. Therefore we
* must lock all the pages involved to prevent
* such operations while we are garbage collecting.
*
**************************************/
SET_TDBB(tdbb);
const Database* dbb = tdbb->getDatabase();
CHECK_DBB(dbb);
const USHORT pageSpaceID = window->win_page.getPageSpaceID();
btree_page* gc_page = (btree_page*) window->win_buffer;
contents result = contents_above_threshold;
// check to see if the page was marked not to be garbage collected
if ( !BtrPageGCLock::isPageGCAllowed(tdbb, window->win_page) )
{
CCH_RELEASE(tdbb, window);
return contents_above_threshold;
}
// record the left sibling now since this is the only way to
// get to it quickly; don't worry if it's not accurate now or
// is changed after we release the page, since we will fetch
// it in a fault-tolerant way anyway.
const ULONG left_number = gc_page->btr_left_sibling;
// if the left sibling is blank, that indicates we are the leftmost page,
// so don't garbage-collect the page; do this for several reasons:
// 1. The leftmost page needs a degenerate zero length node as its first node
// (for a non-leaf, non-top-level page).
// 2. The parent page would need to be fixed up to have a degenerate node
// pointing to the right sibling.
// 3. If we remove all pages on the level, we would need to re-add it next
// time a record is inserted, so why constantly garbage-collect and re-create
// this page?
if (!left_number)
{
CCH_RELEASE(tdbb, window);
return contents_above_threshold;
}
// record some facts for later validation
const USHORT relation_number = gc_page->btr_relation;
const UCHAR index_id = gc_page->btr_id;
const UCHAR index_level = gc_page->btr_level;
// we must release the page we are attempting to garbage collect;
// this is necessary to avoid deadlocks when we fetch the parent page
CCH_RELEASE(tdbb, window);
// fetch the parent page, but we have to be careful, because it could have
// been garbage-collected when we released it--make checks so that we know it
// is the parent page; there is a minute possibility that it could have been
// released and reused already as another page on this level, but if so, it
// won't really matter because we won't find the node on it
WIN parent_window(pageSpaceID, parent_number);
btree_page* parent_page = (btree_page*) CCH_FETCH(tdbb, &parent_window, LCK_write, pag_undefined);
if ((parent_page->btr_header.pag_type != pag_index) ||
(parent_page->btr_relation != relation_number) ||
(parent_page->btr_id != (UCHAR)(index_id % 256)) ||
(parent_page->btr_level != index_level + 1))
{
CCH_RELEASE(tdbb, &parent_window);
return contents_above_threshold;
}
if (parent_page->btr_header.pag_flags & btr_released)
{
CCH_RELEASE(tdbb, &parent_window);
#ifdef DEBUG_BTR
gds__log("BTR/garbage_collect : parent page is released.");
#endif
return contents_above_threshold;
}
// Find the node on the parent's level--the parent page could
// have split while we didn't have it locked
UCHAR* parentPointer = parent_page->btr_nodes + parent_page->btr_jump_size;
IndexNode parentNode;
while (true)
{
parentPointer = parentNode.readNode(parentPointer, false);
if (parentNode.isEndBucket)
{
parent_page = (btree_page*) CCH_HANDOFF(tdbb, &parent_window,
parent_page->btr_sibling, LCK_write, pag_index);
parentPointer = parent_page->btr_nodes + parent_page->btr_jump_size;
continue;
}
if (parentNode.pageNumber == window->win_page.getPageNum() || parentNode.isEndLevel)
break;
}
// we should always find the node, but just in case we don't, bow out gracefully
if (parentNode.isEndLevel)
{
CCH_RELEASE(tdbb, &parent_window);
#ifdef DEBUG_BTR
CORRUPT(204); // msg 204 index inconsistent
#endif
return contents_above_threshold;
}
// Fix for ARINC database corruption bug: in most cases we update the END_BUCKET
// marker of the left sibling page to contain the END_BUCKET of the garbage-collected
// page. However, when this page is the first page on its parent, then the left
// sibling page is the last page on its parent. That means if we update its END_BUCKET
// marker, its bucket of values will extend past that of its parent, causing trouble
// down the line.
// So we never garbage-collect a page which is the first one on its parent. This page
// will have to wait until the parent page gets collapsed with the page to its left,
// in which case this page itself will then be garbage-collectable. Since there are
// no more keys on this page, it will not be garbage-collected itself. When the page
// to the right falls below the threshold for garbage collection, it will be merged with
// this page.
if (parentNode.nodePointer == parent_page->btr_nodes + parent_page->btr_jump_size)
{
CCH_RELEASE(tdbb, &parent_window);
return contents_above_threshold;
}
// find the left sibling page by going one page to the left,
// but if it does not recognize us as its right sibling, keep
// going to the right until we find the page that is our real
// left sibling
WIN left_window(pageSpaceID, left_number);
btree_page* left_page = (btree_page*) CCH_FETCH(tdbb, &left_window, LCK_write, pag_undefined);
if (left_page->btr_header.pag_type != pag_index ||
left_page->btr_relation != relation_number ||
left_page->btr_id != UCHAR(index_id % 256) ||
left_page->btr_level != index_level)
{
CCH_RELEASE(tdbb, &parent_window);
CCH_RELEASE(tdbb, &left_window);
return contents_above_threshold;
}
if (left_page->btr_header.pag_flags & btr_released)
{
CCH_RELEASE(tdbb, &parent_window);
CCH_RELEASE(tdbb, &left_window);
#ifdef DEBUG_BTR
gds__log("BTR/garbage_collect : left page is released.");
#endif
return contents_above_threshold;
}
while (left_page->btr_sibling != window->win_page.getPageNum())
{
#ifdef DEBUG_BTR
CCH_RELEASE(tdbb, &parent_window);
CCH_RELEASE(tdbb, &left_window);
CORRUPT(204); // msg 204 index inconsistent
#endif
// If someone garbage collects the index page before we can, it
// won't be found by traversing the right sibling chain. This means
// scanning index pages until the end-of-level bucket is hit.
if (!left_page->btr_sibling)
{
CCH_RELEASE(tdbb, &parent_window);
CCH_RELEASE(tdbb, &left_window);
return contents_above_threshold;
}
left_page = (btree_page*) CCH_HANDOFF(tdbb, &left_window,
left_page->btr_sibling, LCK_write, pag_index);
}
// now refetch the original page and make sure it is still
// below the threshold for garbage collection.
gc_page = (btree_page*) CCH_FETCH(tdbb, window, LCK_write, pag_index);
if (gc_page->btr_length >= GARBAGE_COLLECTION_BELOW_THRESHOLD ||
!BtrPageGCLock::isPageGCAllowed(tdbb, window->win_page))
{
CCH_RELEASE(tdbb, &parent_window);
CCH_RELEASE(tdbb, &left_window);
CCH_RELEASE(tdbb, window);
return contents_above_threshold;
}
if (gc_page->btr_header.pag_flags & btr_released)
{
CCH_RELEASE(tdbb, &parent_window);
CCH_RELEASE(tdbb, &left_window);
CCH_RELEASE(tdbb, window);
#ifdef DEBUG_BTR
gds__log("BTR/garbage_collect : gc_page is released.");
CORRUPT(204); // msg 204 index inconsistent
#endif
return contents_above_threshold;
}
// fetch the right sibling page
btree_page* right_page = NULL;
WIN right_window(pageSpaceID, gc_page->btr_sibling);
if (right_window.win_page.getPageNum())
{
// right_window.win_flags = 0; redundant, made by the constructor
right_page = (btree_page*) CCH_FETCH(tdbb, &right_window, LCK_write, pag_index);
if (right_page->btr_left_sibling != window->win_page.getPageNum())
{
CCH_RELEASE(tdbb, &parent_window);
if (left_page)
CCH_RELEASE(tdbb, &left_window);
CCH_RELEASE(tdbb, window);
CCH_RELEASE(tdbb, &right_window);
#ifdef DEBUG_BTR
CORRUPT(204); // msg 204 index inconsistent
#endif
return contents_above_threshold;
}
}
const bool leafPage = (gc_page->btr_level == 0);
UCHAR* leftPointer = left_page->btr_nodes + left_page->btr_jump_size;
temporary_key lastKey;
lastKey.key_flags = 0;
lastKey.key_length = 0;
IndexNode leftNode;
UCHAR* pointer = left_page->btr_nodes;
// Walk trough node jumpers.
UCHAR n = left_page->btr_jump_count;
IndexJumpNode jumpNode;
while (n)
{
pointer = jumpNode.readJumpNode(pointer);
leftNode.readNode((UCHAR*) left_page + jumpNode.offset, leafPage);
if (!(leftNode.isEndBucket || leftNode.isEndLevel))
{
memcpy(lastKey.key_data + jumpNode.prefix, jumpNode.data, jumpNode.length);
leftPointer = (UCHAR*) left_page + jumpNode.offset;
lastKey.key_length = jumpNode.prefix + jumpNode.length;
}
else
break;
n--;
}
while (true)
{
leftPointer = leftNode.readNode(leftPointer, leafPage);
// If it isn't a recordnumber were done
if (leftNode.isEndBucket || leftNode.isEndLevel)
break;
// Save data
if (leftNode.length)
{
memcpy(lastKey.key_data + leftNode.prefix, leftNode.data, leftNode.length);
lastKey.key_length = leftNode.prefix + leftNode.length;
}
}
leftPointer = leftNode.nodePointer;
// see if there's enough space on the left page to move all the nodes to it
// and leave some extra space for expansion (at least one key length)
UCHAR* gcPointer = gc_page->btr_nodes + gc_page->btr_jump_size;
IndexNode gcNode;
gcNode.readNode(gcPointer, leafPage);
const USHORT prefix = IndexNode::computePrefix(lastKey.key_data, lastKey.key_length,
gcNode.data, gcNode.length);
// Get pointer for calculating gcSize (including jump nodes).
gcPointer = gc_page->btr_nodes;
const USHORT gcSize = gc_page->btr_length - (gcPointer - (UCHAR*) gc_page);
const USHORT leftAssumedSize = left_page->btr_length + gcSize - prefix;
// If the new page will be larger then the thresholds don't gc.
const USHORT max_threshold = GARBAGE_COLLECTION_NEW_PAGE_MAX_THRESHOLD;
if (leftAssumedSize > max_threshold)
{
CCH_RELEASE(tdbb, &parent_window);
CCH_RELEASE(tdbb, &left_window);
CCH_RELEASE(tdbb, window);
if (right_page)
CCH_RELEASE(tdbb, &right_window);
return contents_above_threshold;
}
// First copy left page to scratch page.
SLONG scratchPage[OVERSIZE];
btree_page* const newBucket = (btree_page*) scratchPage;
pointer = left_page->btr_nodes;
const USHORT jumpersOriginalSize = left_page->btr_jump_size;
const USHORT jumpAreaSize = left_page->btr_jump_interval;
// Copy header and data
memcpy(newBucket, left_page, BTR_SIZE);
memcpy(newBucket->btr_nodes, left_page->btr_nodes + left_page->btr_jump_size,
left_page->btr_length - left_page->btr_jump_size - BTR_SIZE);
// Update leftPointer to scratch page.
leftPointer = (UCHAR*) newBucket + (leftPointer - (UCHAR*) left_page) - jumpersOriginalSize;
gcPointer = gc_page->btr_nodes + gc_page->btr_jump_size;
//
leftNode.readNode(leftPointer, leafPage);
// Calculate the total amount of compression on page as the combined
// totals of the two pages, plus the compression of the first node
// on the g-c'ed page, minus the prefix of the END_BUCKET node to
// be deleted.
newBucket->btr_prefix_total += gc_page->btr_prefix_total + prefix - leftNode.prefix;
// Get first node from gc-page.
gcPointer = gcNode.readNode(gcPointer, leafPage);
// Write first node with prefix compression on left page.
leftNode.setNode(prefix, gcNode.length - prefix, gcNode.recordNumber,
gcNode.pageNumber, gcNode.isEndBucket, gcNode.isEndLevel);
leftNode.data = gcNode.data + prefix;
leftPointer = leftNode.writeNode(leftPointer, leafPage);
// Update page-size.
newBucket->btr_length = leftPointer - (UCHAR*) newBucket;
// copy over the remainder of the page to be garbage-collected.
const USHORT l = gc_page->btr_length - (gcPointer - (UCHAR*) gc_page);
memcpy(leftPointer, gcPointer, l);
// update page size.
newBucket->btr_length += l;
if (newBucket->btr_length > dbb->dbb_page_size)
BUGCHECK(205); // msg 205 index bucket overfilled
// Generate new jump nodes.
JumpNodeList jumpNodes;
USHORT jumpersNewSize = 0;
// Update jump information on scratch page, so generate_jump_nodes
// can deal with it.
newBucket->btr_jump_interval = jumpAreaSize;
newBucket->btr_jump_size = 0;
newBucket->btr_jump_count = 0;
generate_jump_nodes(tdbb, newBucket, &jumpNodes, 0, &jumpersNewSize, NULL, NULL, 0);
// Now we know exact how big our updated left page is, so check size
// again to be sure it all will fit.
// If the new page will be larger then the page size don't gc ofcourse.
if (newBucket->btr_length + jumpersNewSize > dbb->dbb_page_size)
{
CCH_RELEASE(tdbb, &parent_window);
CCH_RELEASE(tdbb, &left_window);
CCH_RELEASE(tdbb, window);
if (right_page)
CCH_RELEASE(tdbb, &right_window);
IndexJumpNode* walkJumpNode = jumpNodes.begin();
for (size_t i = 0; i < jumpNodes.getCount(); i++)
delete[] walkJumpNode[i].data;
return contents_above_threshold;
}
#ifdef DEBUG_BTR_SPLIT
string s;
s.printf("node with page %ld removed from parent page %ld",
parentNode.pageNumber, parent_window.win_page.getPageNum());
gds__trace(s.c_str());
#endif
// Update the parent first. If the parent is not written out first,
// we will be pointing to a page which is not in the doubly linked
// sibling list, and therefore navigation back and forth won't work.
// AB: Parent is always a index pointer page.
result = delete_node(tdbb, &parent_window, parentNode.nodePointer);
CCH_RELEASE(tdbb, &parent_window);
// Update the right sibling page next, since it does not really
// matter that the left sibling pointer points to the page directly
// to the left, only that it point to some page to the left.
// Set up the precedence so that the parent will be written first.
if (right_page)
{
if (parent_page)
CCH_precedence(tdbb, &right_window, parent_window.win_page);
CCH_MARK(tdbb, &right_window);
right_page->btr_left_sibling = left_window.win_page.getPageNum();
CCH_RELEASE(tdbb, &right_window);
}
// Now update the left sibling, effectively removing the garbage-collected page
// from the tree. Set the precedence so the right sibling will be written first.
if (right_page)
CCH_precedence(tdbb, &left_window, right_window.win_page);
else if (parent_page)
CCH_precedence(tdbb, &left_window, parent_window.win_page);
CCH_MARK(tdbb, &left_window);
if (right_page)
left_page->btr_sibling = right_window.win_page.getPageNum();
else
left_page->btr_sibling = 0;
// Finally write all data to left page.
left_page->btr_jump_interval = jumpAreaSize;
left_page->btr_jump_size = jumpersNewSize;
left_page->btr_jump_count = (UCHAR) jumpNodes.getCount();
// Write jump nodes.
pointer = left_page->btr_nodes;
IndexJumpNode* walkJumpNode = jumpNodes.begin();
for (size_t i = 0; i < jumpNodes.getCount(); i++)
{
// Update offset to real position with new jump nodes.
walkJumpNode[i].offset += jumpersNewSize;
pointer = walkJumpNode[i].writeJumpNode(pointer);
delete[] walkJumpNode[i].data;
}
// Copy data.
memcpy(pointer, newBucket->btr_nodes, newBucket->btr_length - BTR_SIZE);
// Update page header information.
left_page->btr_prefix_total = newBucket->btr_prefix_total;
left_page->btr_length = newBucket->btr_length + jumpersNewSize;
#ifdef DEBUG_BTR
if (left_page->btr_length > dbb->dbb_page_size)
{
CCH_RELEASE(tdbb, &left_window);
CCH_RELEASE(tdbb, window);
CORRUPT(204); // msg 204 index inconsistent
return contents_above_threshold;
}
#endif
CCH_RELEASE(tdbb, &left_window);
#ifdef DEBUG_BTR_SPLIT
string s;
s.printf("page %ld is removed from index. parent %ld, left %ld, right %ld",
window->win_page.getPageNum(), parent_window.win_page.getPageNum(),
left_page ? left_window.win_page.getPageNum() : 0,
right_page ? right_window.win_page.getPageNum() : 0 );
gds__trace(s.c_str());
#endif
// finally, release the page, and indicate that we should write the
// previous page out before we write the TIP page out
CCH_MARK(tdbb, window);
gc_page->btr_header.pag_flags |= btr_released;
CCH_RELEASE(tdbb, window);
PAG_release_page(tdbb, window->win_page, left_page ? left_window.win_page :
right_page ? right_window.win_page : parent_window.win_page);
// if the parent page needs to be garbage collected, that means we need to
// re-fetch the parent and check to see whether it is still garbage-collectable;
// make sure that the page is still a btree page in this index and in this level--
// there is a miniscule chance that it was already reallocated as another page
// on this level which is already below the threshold, in which case it doesn't
// hurt anything to garbage-collect it anyway
if (result != contents_above_threshold)
{
window->win_page = parent_window.win_page;
parent_page = (btree_page*) CCH_FETCH(tdbb, window, LCK_write, pag_undefined);
if ((parent_page->btr_header.pag_type != pag_index) ||
(parent_page->btr_relation != relation_number) || (parent_page->btr_id != index_id) ||
(parent_page->btr_level != index_level + 1))
{
CCH_RELEASE(tdbb, window);
return contents_above_threshold;
}
// check whether it is empty
parentPointer = parent_page->btr_nodes + parent_page->btr_jump_size;
IndexNode parentNode2;
parentPointer = parentNode2.readNode(parentPointer, false);
if (parentNode2.isEndBucket || parentNode2.isEndLevel)
return contents_empty;
// check whether there is just one node
parentPointer = parentNode2.readNode(parentPointer, false);
if (parentNode2.isEndBucket || parentNode2.isEndLevel)
return contents_single;
// check to see if the size of the page is below the garbage collection threshold
if (parent_page->btr_length < GARBAGE_COLLECTION_BELOW_THRESHOLD)
return contents_below_threshold;
// the page must have risen above the threshold; release the window since
// someone else added a node while the page was released
CCH_RELEASE(tdbb, window);
return contents_above_threshold;
}
return result;
}
static void generate_jump_nodes(thread_db* tdbb, btree_page* page,
JumpNodeList* jumpNodes,
USHORT excludeOffset, USHORT* jumpersSize,
USHORT* splitIndex, USHORT* splitPrefix, USHORT keyLen)
{
/**************************************
*
* g e n e r a t e _ j u m p _ n o d e s
*
**************************************
*
* Functional description
*
**************************************/
SET_TDBB(tdbb);
const Database* dbb = tdbb->getDatabase();
fb_assert(page);
fb_assert(jumpNodes);
fb_assert(jumpersSize);
const bool leafPage = (page->btr_level == 0);
const USHORT jumpAreaSize = page->btr_jump_interval;
*jumpersSize = 0;
UCHAR* pointer = page->btr_nodes + page->btr_jump_size;
temporary_key jumpKey, currentKey;
jumpKey.key_flags = 0;
jumpKey.key_length = 0;
currentKey.key_flags = 0;
currentKey.key_length = 0;
UCHAR* jumpData = jumpKey.key_data;
USHORT jumpLength = 0;
UCHAR* currentData = currentKey.key_data;
if (splitIndex)
*splitIndex = 0;
if (splitPrefix)
*splitPrefix = 0;
const UCHAR* newAreaPosition = pointer + jumpAreaSize;
const UCHAR* const startpoint = page->btr_nodes + page->btr_jump_size;
const UCHAR* const endpoint = (UCHAR*) page + page->btr_length;
const UCHAR* halfpoint = (UCHAR*) page + (BTR_SIZE + page->btr_jump_size + page->btr_length) / 2;
const UCHAR* const excludePointer = (UCHAR*) page + excludeOffset;
IndexJumpNode jumpNode;
IndexNode node;
ULONG leftPageSize = 0;
ULONG splitPageSize = 0;
while (pointer < endpoint && newAreaPosition < endpoint)
{
pointer = node.readNode(pointer, leafPage);
if (node.isEndBucket || node.isEndLevel)
break;
if (node.length)
{
UCHAR* q = currentData + node.prefix;
memcpy(q, node.data, node.length);
}
if (splitIndex && splitPrefix && !*splitIndex)
{
*splitPrefix += node.prefix;
leftPageSize = BTR_SIZE + *jumpersSize + (pointer - startpoint);
if (leftPageSize + keyLen >= dbb->dbb_page_size)
halfpoint = newAreaPosition = node.nodePointer - 1;
}
if (node.nodePointer > newAreaPosition)
{
// Create a jumpnode, but it may not point to the new
// insert pointer or any MARKER else we make split
// more difficult then needed.
jumpNode.offset = node.nodePointer - (UCHAR*) page;
jumpNode.prefix = IndexNode::computePrefix(jumpData, jumpLength,
currentData, node.prefix);
jumpNode.length = node.prefix - jumpNode.prefix;
// make sure split page has enough space for new jump node
if (splitIndex && *splitIndex)
{
ULONG splitSize = splitPageSize + jumpNode.getJumpNodeSize();
if (*splitIndex == jumpNodes->getCount())
splitSize += jumpNode.prefix;
if (splitSize > dbb->dbb_page_size)
break;
}
if (jumpNode.length)
{
jumpNode.data = FB_NEW_POOL(*tdbb->getDefaultPool()) UCHAR[jumpNode.length];
const UCHAR* const q = currentData + jumpNode.prefix;
memcpy(jumpNode.data, q, jumpNode.length);
}
else
jumpNode.data = NULL;
// Push node on end in list
jumpNodes->add(jumpNode);
// Store new data in jumpKey, so a new jump node can calculate prefix
memcpy(jumpData + jumpNode.prefix, jumpNode.data, jumpNode.length);
jumpLength = jumpNode.length + jumpNode.prefix;
// Check if this could be our split point (if we need to split)
if (splitIndex && !*splitIndex && (pointer > halfpoint))
{
*splitIndex = jumpNodes->getCount();
splitPageSize = BTR_SIZE + (endpoint - node.nodePointer) + node.prefix + 4;
}
// Set new position for generating jumpnode
newAreaPosition += jumpAreaSize;
*jumpersSize += jumpNode.getJumpNodeSize();
if (splitIndex && *splitIndex < jumpNodes->getCount())
{
splitPageSize += jumpNode.getJumpNodeSize();
if (*splitIndex + 1 == jumpNodes->getCount())
splitPageSize += jumpNode.prefix;
}
}
}
}
static ULONG insert_node(thread_db* tdbb,
WIN* window,
index_insertion* insertion,
temporary_key* new_key,
RecordNumber* new_record_number,
ULONG* original_page,
ULONG* sibling_page)
{
/**************************************
*
* i n s e r t _ n o d e
*
**************************************
*
* Functional description
* Insert a node in a index leaf page.
* If this isn't the right bucket, return NO_VALUE.
* If it splits, return the split page number and
* leading string. This is the workhorse for add_node.
*
**************************************/
SET_TDBB(tdbb);
const Database* dbb = tdbb->getDatabase();
CHECK_DBB(dbb);
const USHORT pageSpaceID = window->win_page.getPageSpaceID();
// find the insertion point for the specified key
btree_page* bucket = (btree_page*) window->win_buffer;
temporary_key* key = insertion->iib_key;
const index_desc* const idx = insertion->iib_descriptor;
const bool unique = (idx->idx_flags & idx_unique);
const bool primary = (idx->idx_flags & idx_primary);
const bool key_all_nulls = (key->key_nulls == (1 << idx->idx_count) - 1);
const bool leafPage = (bucket->btr_level == 0);
// hvlad: don't check unique index if key has only null values
const bool validateDuplicates = (unique && !key_all_nulls) || primary;
USHORT prefix = 0;
const RecordNumber newRecordNumber = leafPage ?
insertion->iib_number : *new_record_number;
// For checking on duplicate nodes we should find the first matching key.
UCHAR* pointer = find_node_start_point(bucket, key, 0, &prefix,
idx->idx_flags & idx_descending,
false, true, validateDuplicates ? NO_VALUE : newRecordNumber);
if (!pointer)
return NO_VALUE_PAGE;
if ((UCHAR*) pointer - (UCHAR*) bucket > dbb->dbb_page_size)
BUGCHECK(205); // msg 205 index bucket overfilled
IndexNode beforeInsertNode;
pointer = beforeInsertNode.readNode(pointer, leafPage);
// loop through the equivalent nodes until the correct insertion
// point is found; for leaf level this will be the first node
USHORT newPrefix, newLength;
USHORT nodeOffset;
while (true)
{
nodeOffset = (USHORT) (beforeInsertNode.nodePointer - (UCHAR*) bucket);
newPrefix = beforeInsertNode.prefix;
newLength = beforeInsertNode.length;
// update the newPrefix and newLength against the node (key) that will
// be inserted before it.
const UCHAR* p = key->key_data + newPrefix;
const UCHAR* q = beforeInsertNode.data;
USHORT l = MIN(key->key_length - newPrefix, newLength);
while (l)
{
if (*p++ != *q++)
break;
--newLength;
newPrefix++;
l--;
}
// check if the inserted node has the same value as the next node
if (newPrefix != key->key_length ||
newPrefix != beforeInsertNode.length + beforeInsertNode.prefix)
{
break;
}
// We have a equal node, so find the correct insertion point.
if (beforeInsertNode.isEndBucket)
{
if (validateDuplicates)
return NO_VALUE_PAGE;
if (newRecordNumber < beforeInsertNode.recordNumber)
break;
return NO_VALUE_PAGE;
}
if (beforeInsertNode.isEndLevel)
break;
if (leafPage && validateDuplicates)
{
// Save the duplicate so the main caller can validate them.
RBM_SET(tdbb->getDefaultPool(), &insertion->iib_duplicates,
beforeInsertNode.recordNumber.getValue());
}
// AB: Never insert a duplicate node with the same record number.
// This would lead to nodes which will never be deleted.
/*if (leafPage && (newRecordNumber == beforeInsertNode.recordNumber))
{
// AB: It seems this is not enough, because on mass duplicate
// update to many nodes are deleted, possible staying and
// going are wrong checked before BTR_remove is called.
CCH_RELEASE(tdbb, window);
return 0;
}*/
//else
if (!validateDuplicates)
{
// if recordnumber is higher we need to insert before it.
if (newRecordNumber <= beforeInsertNode.recordNumber)
break;
}
else if (!unique)
break;
prefix = newPrefix;
pointer = beforeInsertNode.readNode(pointer, leafPage);
}
if (nodeOffset > dbb->dbb_page_size)
BUGCHECK(205); // msg 205 index bucket overfilled
const USHORT beforeInsertOriginalSize = beforeInsertNode.getNodeSize(leafPage);
const USHORT orginalPrefix = beforeInsertNode.prefix;
// Update the values for the next node after our new node.
// First, store needed data for beforeInsertNode into tempData.
HalfStaticArray<UCHAR, MAX_KEY> tempBuf;
UCHAR* tempData = tempBuf.getBuffer(newLength);
memcpy(tempData, beforeInsertNode.data + newPrefix - beforeInsertNode.prefix, newLength);
beforeInsertNode.prefix = newPrefix;
beforeInsertNode.length = newLength;
const USHORT beforeInsertSize = beforeInsertNode.getNodeSize(leafPage);
// Set values for our new node.
IndexNode newNode;
newNode.setNode(prefix, key->key_length - prefix, newRecordNumber);
newNode.data = key->key_data + prefix;
if (!leafPage)
newNode.pageNumber = insertion->iib_number.getValue();
// Compute the delta between current and new page.
const USHORT delta = newNode.getNodeSize(leafPage) +
beforeInsertSize - beforeInsertOriginalSize;
// Copy data up to insert point to scratch page.
SLONG scratchPage[OVERSIZE];
memcpy(scratchPage, bucket, nodeOffset);
btree_page* const newBucket = (btree_page*) scratchPage;
// Set pointer of new node to right place.
pointer = ((UCHAR*) newBucket + nodeOffset);
// Insert the new node.
pointer = newNode.writeNode(pointer, leafPage);
newBucket->btr_prefix_total += prefix - orginalPrefix;
// Recompress and rebuild the next node.
beforeInsertNode.data = tempData;
pointer = beforeInsertNode.writeNode(pointer, leafPage);
newBucket->btr_prefix_total += newPrefix;
beforeInsertNode.data = 0;
// Copy remaining data to scratch page.
if ((nodeOffset + beforeInsertOriginalSize) < bucket->btr_length)
{
memcpy(pointer, (UCHAR*) bucket + nodeOffset + beforeInsertOriginalSize,
bucket->btr_length - (nodeOffset + beforeInsertOriginalSize));
}
// Update bucket size.
newBucket->btr_length += delta;
// figure out whether this node was inserted at the end of the page
const bool endOfPage = (beforeInsertNode.isEndBucket || beforeInsertNode.isEndLevel);
// Initialize variables needed for generating jump information
bool fragmentedOffset = false;
USHORT newPrefixTotalBySplit = 0;
USHORT splitJumpNodeIndex = 0;
JumpNodeList tmpJumpNodes;
JumpNodeList* jumpNodes = &tmpJumpNodes;
USHORT ensureEndInsert = 0;
if (endOfPage)
{
// If we're adding a node at the end we don't want that a page
// splits in the middle, but at the end. We can never be sure
// that this will happen, but at least give it a bigger chance.
ensureEndInsert = 6 + key->key_length;
}
// Get the total size of the jump nodes currently in use.
pointer = newBucket->btr_nodes;
const USHORT jumpAreaSize = newBucket->btr_jump_interval;
const USHORT jumpersOriginalSize = newBucket->btr_jump_size;
const UCHAR jumpersOriginalCount = newBucket->btr_jump_count;
// Allow some fragmentation, 10% below or above actual point.
USHORT jumpersNewSize = jumpersOriginalSize;
UCHAR n = jumpersOriginalCount;
USHORT index = 1;
const USHORT fragmentedThreshold = jumpAreaSize / 5;
IndexJumpNode jumpNode;
while (n)
{
pointer = jumpNode.readJumpNode(pointer);
if (jumpNode.offset == nodeOffset)
{
fragmentedOffset = true;
break;
}
if (jumpNode.offset > nodeOffset)
jumpNode.offset += delta;
const USHORT minOffset = BTR_SIZE + jumpersOriginalSize +
(index * jumpAreaSize) - fragmentedThreshold;
if (jumpNode.offset < minOffset)
{
fragmentedOffset = true;
break;
}
const USHORT maxOffset = BTR_SIZE + jumpersOriginalSize +
(index * jumpAreaSize) + fragmentedThreshold;
if (jumpNode.offset > maxOffset)
{
fragmentedOffset = true;
break;
}
jumpNodes->add(jumpNode);
index++;
n--;
}
// Rebuild jump nodes if new node is inserted after last
// jump node offset + jumpAreaSize.
if (nodeOffset >= (BTR_SIZE + jumpersOriginalSize +
((jumpersOriginalCount + 1) * jumpAreaSize)))
{
fragmentedOffset = true;
}
// Rebuild jump nodes if we gona split.
if (newBucket->btr_length + ensureEndInsert > dbb->dbb_page_size)
fragmentedOffset = true;
if (fragmentedOffset)
{
// Clean up any previous nodes.
jumpNodes->clear();
// Generate new jump nodes.
generate_jump_nodes(tdbb, newBucket, jumpNodes,
(USHORT)(newNode.nodePointer - (UCHAR*) newBucket),
&jumpersNewSize, &splitJumpNodeIndex, &newPrefixTotalBySplit,
BTR_key_length(tdbb, insertion->iib_relation, insertion->iib_descriptor));
}
// If the bucket still fits on a page, we're almost done.
if (newBucket->btr_length + ensureEndInsert +
jumpersNewSize - jumpersOriginalSize <= dbb->dbb_page_size)
{
// if we are a pointer page, make sure that the page we are
// pointing to gets written before we do for on-disk integrity
if (!leafPage)
CCH_precedence(tdbb, window, insertion->iib_number.getValue());
// Mark page as dirty.
CCH_MARK(tdbb, window);
// Put all data back into bucket (= window->win_buffer).
// Write jump information header.
bucket->btr_jump_interval = jumpAreaSize;
bucket->btr_jump_size = jumpersNewSize;
bucket->btr_jump_count = (UCHAR) jumpNodes->getCount();
// Write jump nodes.
pointer = bucket->btr_nodes;
IndexJumpNode* walkJumpNode = jumpNodes->begin();
for (size_t i = 0; i < jumpNodes->getCount(); i++)
{
// Update offset to real position with new jump nodes.
walkJumpNode[i].offset += jumpersNewSize - jumpersOriginalSize;
pointer = walkJumpNode[i].writeJumpNode(pointer);
if (fragmentedOffset) {
delete[] walkJumpNode[i].data;
}
}
pointer = bucket->btr_nodes + bucket->btr_jump_size;
// Copy data block.
memcpy(pointer, newBucket->btr_nodes + jumpersOriginalSize,
newBucket->btr_length - BTR_SIZE - jumpersOriginalSize);
// Update header information.
bucket->btr_prefix_total = newBucket->btr_prefix_total;
bucket->btr_length = newBucket->btr_length + jumpersNewSize - jumpersOriginalSize;
CCH_RELEASE(tdbb, window);
jumpNodes->clear();
return NO_SPLIT;
}
// We've a bucket split in progress. We need to determine the split point.
// Set it halfway through the page, unless we are at the end of the page,
// in which case put only the new node on the new page. This will ensure
// that pages get filled in the case of a monotonically increasing key.
// Make sure that the original page has room, in case the END_BUCKET marker
// is now longer because it is pointing at the new node.
//
// Note! : newBucket contains still old jump nodes and info.
SLONG prefix_total = 0;
UCHAR* splitpoint = NULL;
USHORT jumpersSplitSize = 0;
IndexNode node;
if (splitJumpNodeIndex)
{
// Get pointer after new inserted node.
splitpoint = node.readNode(newNode.nodePointer, leafPage);
IndexNode dummyNode = newNode;
dummyNode.setEndBucket();
const USHORT deltaSize = dummyNode.getNodeSize(leafPage) - newNode.getNodeSize(leafPage);
if (endOfPage && ((splitpoint + jumpersNewSize - jumpersOriginalSize) <=
(UCHAR*) newBucket + dbb->dbb_page_size - deltaSize))
{
// Copy data from inserted key and this key will we the END_BUCKET marker
// as the first key on the next page.
const USHORT l = new_key->key_length = key->key_length;
memcpy(new_key->key_data, key->key_data, l);
prefix_total = newBucket->btr_prefix_total - beforeInsertNode.prefix;
splitJumpNodeIndex = 0;
}
else
{
jumpersNewSize = 0;
// splitJumpNodeIndex should always be 1 or higher
if (splitJumpNodeIndex < 1)
BUGCHECK(205); // msg 205 index bucket overfilled
// First get prefix data from jump node.
USHORT index = 1;
IndexJumpNode* jn = 0;
IndexJumpNode* walkJumpNode = jumpNodes->begin();
for (size_t i = 0; i < jumpNodes->getCount(); i++, index++)
{
UCHAR* q = new_key->key_data + walkJumpNode[i].prefix;
memcpy(q, walkJumpNode[i].data, walkJumpNode[i].length);
if (index == splitJumpNodeIndex)
{
jn = &walkJumpNode[i];
break;
}
}
// Get data from node.
splitpoint = (UCHAR*) newBucket + jn->offset;
splitpoint = node.readNode(splitpoint, leafPage);
memcpy(new_key->key_data + node.prefix, node.data, node.length);
new_key->key_length = node.prefix + node.length;
prefix_total = newPrefixTotalBySplit;
// Rebuild first jumpnode on splitpage
index = 1;
walkJumpNode = jumpNodes->begin();
for (size_t i = 0; i < jumpNodes->getCount(); i++, index++)
{
if (index > splitJumpNodeIndex)
{
const USHORT length = walkJumpNode[i].prefix + walkJumpNode[i].length;
UCHAR* newData = FB_NEW_POOL(*tdbb->getDefaultPool()) UCHAR[length];
memcpy(newData, new_key->key_data, walkJumpNode[i].prefix);
memcpy(newData + walkJumpNode[i].prefix, walkJumpNode[i].data,
walkJumpNode[i].length);
delete[] walkJumpNode[i].data;
walkJumpNode[i].prefix = 0;
walkJumpNode[i].length = length;
walkJumpNode[i].data = newData;
break;
}
}
// Initalize new offsets for original page and split page.
index = 1;
walkJumpNode = jumpNodes->begin();
for (size_t i = 0; i < jumpNodes->getCount(); i++, index++)
{
// The jump node where the split is done isn't included anymore!
if (index < splitJumpNodeIndex) {
jumpersNewSize += walkJumpNode[i].getJumpNodeSize();
}
else if (index > splitJumpNodeIndex) {
jumpersSplitSize += walkJumpNode[i].getJumpNodeSize();
}
}
}
}
else
{
const UCHAR* midpoint = NULL;
splitpoint = newNode.readNode(newNode.nodePointer, leafPage);
IndexNode dummyNode = newNode;
dummyNode.setEndBucket();
const USHORT deltaSize = dummyNode.getNodeSize(leafPage) - newNode.getNodeSize(leafPage);
if (endOfPage && ((UCHAR*) splitpoint <= (UCHAR*) newBucket + dbb->dbb_page_size - deltaSize))
{
midpoint = splitpoint;
}
else {
midpoint = (UCHAR*) newBucket +
(dbb->dbb_page_size - BTR_SIZE - newBucket->btr_jump_size) / 2;
}
// Start from the begin of the nodes
splitpoint = newBucket->btr_nodes + newBucket->btr_jump_size;
// Copy the bucket up to the midpoint, restructing the full midpoint key
while (splitpoint < midpoint)
{
splitpoint = node.readNode(splitpoint, leafPage);
prefix_total += node.prefix;
new_key->key_length = node.prefix + node.length;
memcpy(new_key->key_data + node.prefix, node.data, node.length);
}
}
// Allocate and format the overflow page
WIN split_window(pageSpaceID, -1);
btree_page* split = (btree_page*) DPM_allocate(tdbb, &split_window);
// if we're a pointer page, make sure the child page is written first
if (!leafPage)
{
if (newNode.nodePointer < splitpoint)
CCH_precedence(tdbb, window, insertion->iib_number.getValue());
else
CCH_precedence(tdbb, &split_window, insertion->iib_number.getValue());
}
// format the new page to look like the old page
const ULONG right_sibling = bucket->btr_sibling;
split->btr_header.pag_type = bucket->btr_header.pag_type;
split->btr_relation = bucket->btr_relation;
split->btr_id = bucket->btr_id;
split->btr_level = bucket->btr_level;
split->btr_sibling = right_sibling;
split->btr_left_sibling = window->win_page.getPageNum();
// Format the first node on the overflow page
newNode.setNode(0, new_key->key_length, node.recordNumber, node.pageNumber);
// Return first record number on split page to caller.
newNode.data = new_key->key_data;
*new_record_number = newNode.recordNumber;
const USHORT firstSplitNodeSize = newNode.getNodeSize(leafPage);
// Format the first node on the overflow page
split->btr_jump_interval = jumpAreaSize;
split->btr_jump_size = jumpersSplitSize;
split->btr_jump_count = (splitJumpNodeIndex > 0) ?
(UCHAR) (jumpNodes->getCount() - splitJumpNodeIndex) : 0;
pointer = split->btr_nodes;
if (splitJumpNodeIndex > 0)
{
// Write jump nodes to split page.
USHORT index = 1;
// Calculate size that's between header and splitpoint.
const USHORT splitOffset = splitpoint - (UCHAR*) newBucket;
IndexJumpNode* walkJumpNode = jumpNodes->begin();
for (size_t i = 0; i < jumpNodes->getCount(); i++, index++)
{
if (index > splitJumpNodeIndex)
{
// Update offset to correct position.
walkJumpNode[i].offset = walkJumpNode[i].offset - splitOffset +
BTR_SIZE + split->btr_jump_size + firstSplitNodeSize;
pointer = walkJumpNode[i].writeJumpNode(pointer);
}
}
}
pointer = split->btr_nodes + split->btr_jump_size;
if (BTR_SIZE + split->btr_jump_size + newNode.getNodeSize(leafPage) > dbb->dbb_page_size)
BUGCHECK(205); // msg 205 index bucket overfilled
pointer = newNode.writeNode(pointer, leafPage);
// Copy down the remaining data from scratch page.
const USHORT l = newBucket->btr_length - (splitpoint - (UCHAR*) newBucket);
const ULONG splitLen = ((pointer + l) - (UCHAR*) split);
if (splitLen > dbb->dbb_page_size)
BUGCHECK(205); // msg 205 index bucket overfilled
memcpy(pointer, splitpoint, l);
split->btr_length = splitLen;
// the sum of the prefixes on the split page is the previous total minus
// the prefixes found on the original page; the sum of the prefixes on the
// original page must exclude the split node
split->btr_prefix_total = newBucket->btr_prefix_total - prefix_total;
const ULONG split_page = split_window.win_page.getPageNum();
CCH_RELEASE(tdbb, &split_window);
CCH_precedence(tdbb, window, split_window.win_page);
CCH_MARK_MUST_WRITE(tdbb, window);
// The split bucket is still residing in the scratch page. Copy it
// back to the original buffer. After cleaning up the last node,
// we're done!
// mark the end of the page; note that the end_bucket marker must
// contain info about the first node on the next page. So we don't
// overwrite the existing data.
node.setEndBucket();
pointer = node.writeNode(node.nodePointer, leafPage, false);
newBucket->btr_length = pointer - (UCHAR*) newBucket;
// Write jump information.
bucket->btr_jump_interval = jumpAreaSize;
bucket->btr_jump_size = jumpersNewSize;
const ULONG newLen = newBucket->btr_length + jumpersNewSize - jumpersOriginalSize;
if (newLen > dbb->dbb_page_size)
BUGCHECK(205); // msg 205 index bucket overfilled
bucket->btr_jump_count = (splitJumpNodeIndex > 0) ?
(UCHAR) (splitJumpNodeIndex - 1) : (UCHAR) jumpNodes->getCount();
pointer = bucket->btr_nodes;
// Write jump nodes.
index = 1;
IndexJumpNode* walkJumpNode = jumpNodes->begin();
for (size_t i = 0; i < jumpNodes->getCount(); i++, index++)
{
if (index <= bucket->btr_jump_count)
{
// Update offset to correct position.
walkJumpNode[i].offset = walkJumpNode[i].offset + jumpersNewSize - jumpersOriginalSize;
pointer = walkJumpNode[i].writeJumpNode(pointer);
}
}
pointer = bucket->btr_nodes + bucket->btr_jump_size;
memcpy(pointer, newBucket->btr_nodes + jumpersOriginalSize,
newBucket->btr_length - BTR_SIZE - jumpersOriginalSize);
bucket->btr_length = newLen;
if (fragmentedOffset)
{
IndexJumpNode* walkJumpNode2 = jumpNodes->begin();
for (size_t i = 0; i < jumpNodes->getCount(); i++, index++)
delete[] walkJumpNode2[i].data;
}
// Update page information.
bucket->btr_sibling = split_window.win_page.getPageNum();
bucket->btr_prefix_total = prefix_total;
// mark the bucket as non garbage-collectable until we can propagate
// the split page up to the parent; otherwise its possible that the
// split page we just created will be lost.
insertion->iib_dont_gc_lock->disablePageGC(tdbb, window->win_page);
if (original_page)
*original_page = window->win_page.getPageNum();
// now we need to go to the right sibling page and update its
// left sibling pointer to point to the newly split page
if (right_sibling)
{
bucket = (btree_page*) CCH_HANDOFF(tdbb, window, right_sibling, LCK_write, pag_index);
CCH_MARK(tdbb, window);
bucket->btr_left_sibling = split_window.win_page.getPageNum();
}
CCH_RELEASE(tdbb, window);
// return the page number of the right sibling page
if (sibling_page)
*sibling_page = right_sibling;
jumpNodes->clear();
new_key->key_nulls = 0;
if (unique)
{
// hvlad: it is important to set correct bitmap for all-NULL's key
// else insert_node() at upper level will validate duplicates and
// insert node into the end of duplicates chain instead of correct
// place (in order of record numbers).
temporary_key nullKey;
BTR_make_null_key(tdbb, idx, &nullKey);
if (new_key->key_length == nullKey.key_length &&
memcmp(new_key->key_data, nullKey.key_data, nullKey.key_length) == 0)
{
new_key->key_nulls = nullKey.key_nulls;
}
}
return split_page;
}
static INT64_KEY make_int64_key(SINT64 q, SSHORT scale)
{
/**************************************
*
* m a k e _ i n t 6 4 _ k e y
*
**************************************
*
* Functional description
* Make an Index key for a 64-bit Integer value.
*
**************************************/
// Following structure declared above in the modules global section
//
// static const struct {
// FB_UINT64 limit; --- if abs(q) is >= this, ...
// SINT64 factor; --- then multiply by this, ...
// SSHORT scale_change; --- and add this to the scale.
// } int64_scale_control[];
//
// Before converting the scaled int64 to a double, multiply it by the
// largest power of 10 which will NOT cause an overflow, and adjust
// the scale accordingly. This ensures that two different
// representations of the same value, entered at times when the
// declared scale of the column was different, actually wind up
// being mapped to the same key.
int n = 0;
const FB_UINT64 uq = (FB_UINT64) ((q >= 0) ? q : -q); // absolute value
while (uq < int64_scale_control[n].limit)
n++;
q *= int64_scale_control[n].factor;
scale -= int64_scale_control[n].scale_change;
INT64_KEY key;
key.d_part = ((double) (q / 10000)) / powerof10(scale);
key.s_part = (SSHORT) (q % 10000);
return key;
}
#ifdef DEBUG_INDEXKEY
static void print_int64_key(SINT64 value, SSHORT scale, INT64_KEY key)
{
/**************************************
*
* p r i n t _ i n t 6 4 _ k e y
*
**************************************
*
* Functional description
* Debugging function to print a key created out of an int64
* quantify.
*
**************************************/
fprintf(stderr, "%20" QUADFORMAT"d %4d %.15e %6d ", value, scale, key.d_part, key.s_part);
const UCHAR* p = (UCHAR*) &key;
for (int n = 10; n--; n > 0)
fprintf(stderr, "%02x ", *p++);
fprintf(stderr, "\n");
return;
}
#endif // DEBUG_INDEXKEY
string print_key(thread_db* tdbb, jrd_rel* relation, index_desc* idx, Record* record)
{
/**************************************
*
* p r i n t _ k e y
*
**************************************
*
* Functional description
* Convert index key into textual representation.
*
**************************************/
fb_assert(relation && idx && record);
if (!(relation->rel_flags & REL_scanned) ||
(relation->rel_flags & REL_being_scanned))
{
MET_scan_relation(tdbb, relation);
}
class Printer
{
public:
explicit Printer(thread_db* tdbb, const dsc* desc)
{
const int MAX_KEY_STRING_LEN = 250;
const char* const NULL_KEY_STRING = "NULL";
if (!desc)
{
value = NULL_KEY_STRING;
return;
}
fb_assert(!desc->isBlob());
value = MOV_make_string2(tdbb, desc, ttype_dynamic);
const int len = (int) value.length();
const char* const str = value.c_str();
if (desc->isText() || desc->isDateTime())
{
if (desc->dsc_dtype == dtype_text)
{
const char* const pad = (desc->dsc_sub_type == ttype_binary) ? "\0": " ";
value.rtrim(pad);
}
if (desc->isText() && desc->getTextType() == ttype_binary)
{
string hex;
char* s = hex.getBuffer(2 * len);
for (int i = 0; i < len; i++)
{
sprintf(s, "%02X", (int) (unsigned char) str[i]);
s += 2;
}
value = "x'" + hex + "'";
}
else
{
value = "'" + value + "'";
}
}
if (value.length() > MAX_KEY_STRING_LEN)
{
fb_assert(desc->isText());
value.resize(MAX_KEY_STRING_LEN);
const CharSet* const cs = INTL_charset_lookup(tdbb, desc->getCharSet());
while (value.hasData() && !cs->wellFormed(value.length(), (const UCHAR*) value.c_str()))
value.resize(value.length() - 1);
value += "...";
}
}
const string& get() const
{
return value;
}
private:
string value;
};
string key, value;
try
{
if (idx->idx_flags & idx_expressn)
{
bool notNull = false;
const dsc* const desc = BTR_eval_expression(tdbb, idx, record, notNull);
value = Printer(tdbb, notNull ? desc : NULL).get();
key += "<expression> = " + value;
}
else
{
for (USHORT i = 0; i < idx->idx_count; i++)
{
const USHORT field_id = idx->idx_rpt[i].idx_field;
const jrd_fld* const field = MET_get_field(relation, field_id);
if (field)
value.printf("\"%s\"", field->fld_name.c_str());
else
value.printf("<field #%d>", field_id);
key += value;
dsc desc;
const bool notNull = EVL_field(relation, record, field_id, &desc);
value = Printer(tdbb, notNull ? &desc : NULL).get();
key += " = " + value;
if (i < idx->idx_count - 1)
key += ", ";
}
}
}
catch (const Exception&)
{
return "";
}
return "(" + key + ")";
}
static contents remove_node(thread_db* tdbb, index_insertion* insertion, WIN* window)
{
/**************************************
*
* r e m o v e _ n o d e
*
**************************************
*
* Functional description
* Remove an index node from a b-tree,
* recursing down through the levels in case
* we need to garbage collect pages.
*
**************************************/
SET_TDBB(tdbb);
//const Database* dbb = tdbb->getDatabase();
index_desc* idx = insertion->iib_descriptor;
btree_page* page = (btree_page*) window->win_buffer;
// if we are on a leaf page, remove the leaf node
if (page->btr_level == 0) {
return remove_leaf_node(tdbb, insertion, window);
}
while (true)
{
const ULONG number = find_page(page, insertion->iib_key, idx, insertion->iib_number);
// we should always find the node, but let's make sure
if (number == END_LEVEL)
{
CCH_RELEASE(tdbb, window);
#ifdef DEBUG_BTR
CORRUPT(204); // msg 204 index inconsistent
#endif
return contents_above_threshold;
}
// recurse to the next level down; if we are about to fetch a
// level 0 page, make sure we fetch it for write
if (number != END_BUCKET)
{
// handoff down to the next level, retaining the parent page number
const ULONG parent_number = window->win_page.getPageNum();
page = (btree_page*) CCH_HANDOFF(tdbb, window, number, (SSHORT)
((page->btr_level == 1) ? LCK_write : LCK_read), pag_index);
// if the removed node caused the page to go below the garbage collection
// threshold, and the database was created by a version of the engine greater
// than 8.2, then we can garbage-collect the page
const contents result = remove_node(tdbb, insertion, window);
if (result != contents_above_threshold)
return garbage_collect(tdbb, window, parent_number);
if (window->win_bdb)
CCH_RELEASE(tdbb, window);
return contents_above_threshold;
}
// we've hit end of bucket, so go to the sibling looking for the node
page = (btree_page*) CCH_HANDOFF(tdbb, window, page->btr_sibling, LCK_read, pag_index);
}
// NOTREACHED
return contents_empty; // superfluous return to shut lint up
}
static contents remove_leaf_node(thread_db* tdbb, index_insertion* insertion, WIN* window)
{
/**************************************
*
* r e m o v e _ l e a f _ n o d e
*
**************************************
*
* Functional description
* Remove an index node from the leaf level.
*
**************************************/
SET_TDBB(tdbb);
btree_page* page = (btree_page*) window->win_buffer;
temporary_key* key = insertion->iib_key;
const index_desc* const idx = insertion->iib_descriptor;
const bool primary = (idx->idx_flags & idx_primary);
const bool unique = (idx->idx_flags & idx_unique);
const bool key_all_nulls = (key->key_nulls == (1 << idx->idx_count) - 1);
const bool validateDuplicates = (unique && !key_all_nulls) || primary;
// Look for the first node with the value to be removed.
UCHAR* pointer;
USHORT prefix;
while (!(pointer = find_node_start_point(page, key, 0, &prefix,
(idx->idx_flags & idx_descending),
false, false,
(validateDuplicates ? NO_VALUE : insertion->iib_number))))
{
page = (btree_page*) CCH_HANDOFF(tdbb, window, page->btr_sibling, LCK_write, pag_index);
}
// Make sure first node looks ok
IndexNode node;
pointer = node.readNode(pointer, true);
if (prefix > node.prefix || key->key_length != node.length + node.prefix)
{
#ifdef DEBUG_BTR
CCH_RELEASE(tdbb, window);
CORRUPT(204); // msg 204 index inconsistent
#endif
return contents_above_threshold;
}
if (node.length && memcmp(node.data, key->key_data + node.prefix, node.length))
{
#ifdef DEBUG_BTR
CCH_RELEASE(tdbb, window);
CORRUPT(204); // msg 204 index inconsistent
#endif
return contents_above_threshold;
}
// *****************************************************
// AB: This becomes a very expensive task if there are
// many duplicates inside the index (non-unique index)!
// Therefore we also need to add the record-number to the
// non-leaf pages and sort duplicates by record-number.
// *****************************************************
// now look through the duplicate nodes to find the one
// with matching record number
ULONG pages = 0;
while (true)
{
// if we find the right one, quit
if (insertion->iib_number == node.recordNumber && !node.isEndBucket && !node.isEndLevel)
break;
if (node.isEndLevel)
{
#ifdef DEBUG_BTR
CCH_RELEASE(tdbb, window);
CORRUPT(204); // msg 204 index inconsistent
#endif
return contents_above_threshold;
}
// go to the next node and check that it is a duplicate
if (!node.isEndBucket)
{
pointer = node.readNode(pointer, true);
if (node.length != 0 || node.prefix != key->key_length)
{
#ifdef DEBUG_BTR
CCH_RELEASE(tdbb, window);
CORRUPT(204); // msg 204 index inconsistent
#endif
return contents_above_threshold;
}
continue;
}
// if we hit the end of bucket, go to the right sibling page,
// and check that the first node is a duplicate
++pages;
page = (btree_page*) CCH_HANDOFF(tdbb, window, page->btr_sibling, LCK_write, pag_index);
pointer = page->btr_nodes + page->btr_jump_size;
pointer = node.readNode(pointer, true);
const USHORT len = node.length;
if (len != key->key_length)
{
#ifdef DEBUG_BTR
CCH_RELEASE(tdbb, window);
CORRUPT(204); // msg 204 index inconsistent
#endif
return contents_above_threshold;
}
if (len && memcmp(node.data, key->key_data, len))
{
#ifdef DEBUG_BTR
CCH_RELEASE(tdbb, window);
CORRUPT(204); // msg 204 index inconsistent
#endif
return contents_above_threshold;
}
// Until deletion of duplicate nodes becomes efficient, limit
// leaf level traversal by rescheduling.
if (--tdbb->tdbb_quantum < 0)
JRD_reschedule(tdbb, 0, true);
}
// If we've needed to search thru a significant number of pages, warn the
// cache manager in case we come back this way
if (pages > 75)
CCH_expand(tdbb, pages + 25);
return delete_node(tdbb, window, node.nodePointer);
}
static bool scan(thread_db* tdbb, UCHAR* pointer, RecordBitmap** bitmap, RecordBitmap* bitmap_and,
index_desc* idx, const IndexRetrieval* retrieval, USHORT prefix,
temporary_key* key,
bool& skipLowerKey, const temporary_key& lowerKey)
{
/**************************************
*
* s c a n
*
**************************************
*
* Functional description
* Do an index scan.
* If we run over the bucket, return true.
* If we're completely done (passed END_LEVEL),
* return false.
*
**************************************/
SET_TDBB(tdbb);
if (--tdbb->tdbb_quantum < 0)
JRD_reschedule(tdbb, 0, true);
// if the search key is flagged to indicate a multi-segment index
// stuff the key to the stuff boundary
ULONG count;
USHORT flag = retrieval->irb_generic;
if ((flag & irb_partial) && (flag & irb_equality) &&
!(flag & irb_starting) && !(flag & irb_descending))
{
count = STUFF_COUNT - ((key->key_length + STUFF_COUNT) % (STUFF_COUNT + 1));
for (ULONG i = 0; i < count; i++)
key->key_data[key->key_length + i] = 0;
count += key->key_length;
}
else
count = key->key_length;
const USHORT to_segment = (idx->idx_count - retrieval->irb_upper_count);
const UCHAR* const end_key = key->key_data + count;
count -= key->key_length;
const bool descending = (flag & irb_descending);
const bool ignoreNulls = (flag & irb_ignore_null_value_key) && (idx->idx_count == 1);
bool done = false;
bool ignore = false;
const bool skipUpperKey = (flag & irb_exclude_upper);
const bool partLower = (retrieval->irb_lower_count < idx->idx_count);
const bool partUpper = (retrieval->irb_upper_count < idx->idx_count);
USHORT upperPrefix = prefix;
// reset irb_equality flag passed for optimization
flag &= ~(irb_equality | irb_ignore_null_value_key);
flag &= ~(irb_exclude_lower | irb_exclude_upper);
IndexNode node;
pointer = node.readNode(pointer, true);
const UCHAR* p = NULL;
while (true)
{
if (node.isEndLevel)
return false;
if (descending && done && (node.prefix < prefix))
return false;
if ((key->key_length == 0) && !(key->key_flags & key_empty))
{
// Scanning for NULL keys
if (to_segment == 0)
{
// All segments are expected to be NULL
if (node.prefix + node.length > 0)
return false;
}
else
{
// Up to (partial/starting) to_segment is expected to be NULL.
if (node.length && (node.prefix == 0))
{
const UCHAR* q = node.data;
if (*q > to_segment) {
// hvlad: for desc indexes we must use *q^-1 ?
return false;
}
}
}
}
else if (node.prefix <= prefix)
{
prefix = node.prefix;
upperPrefix = prefix;
p = key->key_data + prefix;
const UCHAR* q = node.data;
USHORT l = node.length;
for (; l; --l, prefix++)
{
if (skipUpperKey && partUpper)
{
if (upperPrefix >= key->key_length)
{
const USHORT segnum =
idx->idx_count - (UCHAR)(descending ? ((*q) ^ -1) : *q) + 1;
if (segnum >= retrieval->irb_upper_count)
return false;
}
if (*p == *q)
upperPrefix++;
}
if (p >= end_key)
{
if (flag)
break;
return false;
}
if (p > (end_key - count))
{
if (*p++ == *q++)
break;
continue;
}
if (*p < *q)
{
if ((flag & irb_starting) && (key->key_flags & key_empty))
break;
return false;
}
if (*p++ > *q++)
break;
}
if (p >= end_key)
{
done = true;
if ((l == 0) && skipUpperKey)
return false;
}
else if (descending && (l == 0))
return false;
}
if (node.isEndBucket)
{
// Our caller will fetch the next page
return true;
}
// Ignore NULL-values, this is currently only available for single segment indexes.
if (ignoreNulls)
{
ignore = false;
if (descending)
{
if ((node.prefix == 0) && (node.length >= 1) && (node.data[0] == 255))
return false;
}
else {
ignore = (node.prefix + node.length == 0); // Ascending (prefix + length == 0)
}
}
if (skipLowerKey)
checkForLowerKeySkip(skipLowerKey, partLower, node, lowerKey, *idx, retrieval);
if (!ignore && !skipLowerKey)
{
if ((flag & irb_starting) || !count)
{
if (!bitmap_and || bitmap_and->test(node.recordNumber.getValue()))
RBM_SET(tdbb->getDefaultPool(), bitmap, node.recordNumber.getValue());
}
else if (p > (end_key - count))
{
if (!bitmap_and || bitmap_and->test(node.recordNumber.getValue()))
RBM_SET(tdbb->getDefaultPool(), bitmap, node.recordNumber.getValue());
}
}
pointer = node.readNode(pointer, true);
}
// NOTREACHED
return false; // superfluous return to shut lint up
}
void update_selectivity(index_root_page* root, USHORT id, const SelectivityList& selectivity)
{
/**************************************
*
* u p d a t e _ s e l e c t i v i t y
*
**************************************
*
* Functional description
* Update selectivity on the index root page.
*
**************************************/
//const Database* dbb = GET_DBB();
index_root_page::irt_repeat* irt_desc = &root->irt_rpt[id];
const USHORT idx_count = irt_desc->irt_keys;
fb_assert(selectivity.getCount() == idx_count);
// dimitr: per-segment selectivities exist only for ODS11 and above
irtd* key_descriptor = (irtd*) ((UCHAR*) root + irt_desc->irt_desc);
for (int i = 0; i < idx_count; i++, key_descriptor++)
key_descriptor->irtd_selectivity = selectivity[i];
}
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