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firebird-mirror/src/jrd/blb.h

119 lines
4.3 KiB
C++

/*
* PROGRAM: JRD Access Method
* MODULE: blb.h
* DESCRIPTION: Blob handling definitions
*
* 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): ______________________________________.
*
* 2002.10.28 Sean Leyne - Code cleanup, removed obsolete "DecOSF" port
*
*/
#ifndef JRD_BLB_H
#define JRD_BLB_H
namespace Jrd {
/* Blob id. A blob has two states -- temporary and permanent. In each
case, the blob id is 8 bytes (2 longwords) long. In the case of a
temporary blob, the first word is NULL and the second word points to
an internal blob block. In the case of a permanent blob, the first
word contains the relation id of the blob and the second the record
number of the first segment-clump. The two types of blobs can be
reliably distinguished by a zero or non-zero relation id. */
class BlobControl;
class jrd_req;
class jrd_tra;
struct bid {
ULONG bid_relation_id; /* Relation id (or null) */
union union_bid_stuff {
ULONG bid_temp_id; /* Temporary ID of blob or array. Used for newly created objects (bid_relation_id==0) */
ULONG bid_number; /* Record number */
} bid_stuff;
bool isEmpty() const { return bid_relation_id == 0 && bid_stuff.bid_number == 0; }
};
/* Your basic blob block. */
class blb : public pool_alloc_rpt<UCHAR, type_blb>
{
public:
Attachment* blb_attachment; /* database attachment */
jrd_rel* blb_relation; /* Relation, if known */
jrd_tra* blb_transaction; /* Parent transaction block */
blb* blb_next; /* Next blob in transaction */
UCHAR* blb_segment; /* Next segment to be addressed */
BlobControl* blb_filter; /* Blob filter control block, if any */
bid blb_blob_id; /* Id of materialized blob */
jrd_req* blb_request; /* request that assigned temporary blob */
vcl* blb_pages; /* Vector of pages */
USHORT blb_pointers; /* Max pointer on a page */
USHORT blb_level; /* Storage type */
USHORT blb_max_segment; /* Longest segment */
USHORT blb_flags; /* Interesting stuff (see below) */
USHORT blb_clump_size; /* Size of data clump */
USHORT blb_space_remaining; /* Data space left */
USHORT blb_max_pages; /* Max pages in vector */
USHORT blb_fragment_size; /* Residual fragment size */
USHORT blb_source_interp; /* source interp (for writing) */
USHORT blb_target_interp; /* destination interp (for reading) */
SSHORT blb_sub_type; /* Blob's declared sub-type */
ULONG blb_sequence; /* Blob page sequence */
ULONG blb_max_sequence; /* Number of data pages */
ULONG blb_count; /* Number of segments */
ULONG blb_length; /* Total length of data sans segments */
ULONG blb_lead_page; /* First page number */
ULONG blb_seek; /* Seek location */
ULONG blb_temp_id; // ID of newly created blob in transaction
/* blb_data must be longword aligned */
UCHAR blb_data[1]; /* A page's worth of blob */
};
#define BLB_temporary 1 /* Newly created blob */
#define BLB_eof 2 /* This blob is exhausted */
#define BLB_stream 4 /* Stream style blob */
#define BLB_closed 8 /* Temporary blob has been closed */
#define BLB_damaged 16 /* Blob is busted */
#define BLB_seek 32 /* Seek is pending */
#define BLB_user_def 64 /* Blob is user created */
#define BLB_large_scan 128 /* Blob is larger than page buffer cache */
/* Blob levels are:
0 small blob -- blob "record" is actual data
1 medium blob -- blob "record" is pointer to pages
2 large blob -- blob "record" is pointer to pages of pointers
*/
// mapping blob ids for REPLAY
// Useful only with REPLAY_OSRI_API_CALLS_SUBSYSTEM defined.
class blb_map : public pool_alloc<type_map>
{
public:
blb_map* map_next;
blb* map_old_blob;
blb* map_new_blob;
};
} //namespace Jrd
#endif // JRD_BLB_H