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mirror of https://github.com/FirebirdSQL/firebird.git synced 2025-01-31 12:43:02 +01:00
firebird-mirror/src/common/classes/TempFile.cpp
2006-06-05 14:22:56 +00:00

339 lines
6.5 KiB
C++

/*
* The contents of this file are subject to the Initial
* Developer's 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.ibphoenix.com/main.nfs?a=ibphoenix&page=ibp_idpl.
*
* Software distributed under the License is distributed AS IS,
* 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 Dmitry Yemanov
* for the Firebird Open Source RDBMS project.
*
* Copyright (c) 2006 Dmitry Yemanov <dimitr@users.sf.net>
* and all contributors signed below.
*
* All Rights Reserved.
* Contributor(s): ______________________________________.
*/
#include "firebird.h"
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <errno.h>
#if defined(WIN_NT)
#include <fcntl.h>
#include <io.h>
#include <process.h>
#include <share.h>
#include <sys/stat.h>
#include <sys/types.h>
#include <sys/timeb.h>
#include <windows.h>
#elif defined(HAVE_UNISTD_H)
#include <unistd.h>
#endif
#include "../jrd/gdsassert.h"
#include "../jrd/os/path_utils.h"
#include "../common/classes/TempFile.h"
// Const definitions
static const char* ENV_VAR = "FIREBIRD_TMP";
static const char* DEFAULT_PATH =
#if defined(UNIX)
"/tmp/";
#elif defined(WIN_NT)
"c:\\temp\\";
#elif defined(VMS)
"SYS$SCRATCH:";
#else
NULL;
#endif
static const char* const NAME_PATTERN = "XXXXXX";
static const char* const NAME_LETTERS = "abcdefghijklmnopqrstuvwxyz0123456789";
static const size_t MAX_TRIES = 256;
//
// TempFile::getTempPath
//
// Returns a pathname to the system temporary directory
//
Firebird::PathName TempFile::getTempPath()
{
const char* env_temp = getenv(ENV_VAR);
Firebird::PathName path = env_temp ? env_temp : "";
if (path.empty())
{
#if defined(WIN_NT)
char temp_dir[MAXPATHLEN];
// this checks "TEMP" and "TMP" environment variables
const int len = GetTempPath(sizeof(temp_dir), temp_dir);
if (len && len < sizeof(temp_dir))
{
path = temp_dir;
}
#else
env_temp = getenv("TMP");
path = env_temp ? env_temp : "";
#endif
}
if (path.empty())
{
path = DEFAULT_PATH;
}
fb_assert(path.length());
return path;
}
//
// TempFile::create
//
// Creates a temporary file and returns its name
//
Firebird::PathName TempFile::create(const Firebird::PathName& prefix)
{
Firebird::PathName filename;
try {
TempFile file(prefix, false);
filename = file.getName();
}
catch (const Firebird::Exception&) {
// do nothing
}
return filename;
}
//
// TempFile::init
//
// Creates temporary file with a unique filename
//
void TempFile::init(const Firebird::PathName& directory,
const Firebird::PathName& prefix)
{
// set up temporary directory, if not specified
filename = directory;
if (filename.empty())
{
filename = getTempPath();
}
#if defined(WIN_NT)
_timeb t;
_ftime(&t);
__int64 randomness = t.time;
randomness *= 1000;
randomness += t.millitm;
Firebird::PathName suffix = NAME_PATTERN;
for (int tries = 0; tries < MAX_TRIES; tries++)
{
Firebird::PathName name = filename + prefix;
__int64 temp = randomness;
for (int i = 0; i < suffix.length(); i++)
{
suffix[i] = NAME_LETTERS[temp % (strlen(NAME_LETTERS))];
temp /= strlen(NAME_LETTERS);
}
name += suffix;
DWORD attributes = FILE_ATTRIBUTE_NORMAL |
FILE_ATTRIBUTE_TEMPORARY |
FILE_FLAG_RANDOM_ACCESS;
if (doUnlink)
{
attributes |= FILE_FLAG_DELETE_ON_CLOSE;
}
handle = CreateFile(name.c_str(), GENERIC_READ | GENERIC_WRITE,
0, NULL, CREATE_NEW, attributes, NULL);
if (handle != INVALID_HANDLE_VALUE)
{
filename = name;
break;
}
randomness++;
}
if (handle == INVALID_HANDLE_VALUE)
{
Firebird::system_call_failed::raise("CreateFile");
}
#else
filename += prefix;
filename += NAME_PATTERN;
#ifdef HAVE_MKSTEMP
handle = (IPTR) mkstemp(filename.begin());
#else
if (!mktemp(filename.begin()))
{
Firebird::system_call_failed::raise("mktemp");
}
do {
handle = open(filename.c_str(), O_RDWR | O_EXCL | O_CREAT);
} while (handle == -1 && errno == EINTR);
#endif
if (handle == -1)
{
Firebird::system_call_failed::raise("open");
}
if (doUnlink)
{
::unlink(filename.c_str());
}
#endif
doUnlink = false;
}
//
// TempFile::~TempFile
//
// Destructor
//
TempFile::~TempFile()
{
#if defined(WIN_NT)
CloseHandle(handle);
#else
::close(handle);
#endif
if (doUnlink)
{
::unlink(filename.c_str());
}
}
//
// TempFile::seek
//
// Performs a positioning operation
//
void TempFile::seek(offset_t offset)
{
if (position == offset)
return;
#if defined(WIN_NT)
LARGE_INTEGER liOffset;
liOffset.QuadPart = offset;
const DWORD seek = SetFilePointer(handle, (LONG) liOffset.LowPart,
&liOffset.HighPart, FILE_BEGIN);
if (seek == INVALID_SET_FILE_POINTER && GetLastError() != NO_ERROR)
{
Firebird::system_call_failed::raise("SetFilePointer");
}
#else
const off_t seek = ::lseek(handle, (off_t) offset, SEEK_SET);
if (seek == (off_t) -1)
{
Firebird::system_call_failed::raise("lseek");
}
#endif
position = offset;
if (position > size)
size = position;
}
//
// TempFile::extend
//
// Increases the file size
//
void TempFile::extend(size_t delta)
{
seek(size + delta);
}
//
// TempFile::read
//
// Reads bytes from file
//
size_t TempFile::read(offset_t offset, void* buffer, size_t length)
{
fb_assert(offset + length <= size);
seek(offset);
#if defined(WIN_NT)
DWORD bytes = 0;
if (!ReadFile(handle, buffer, length, &bytes, NULL) ||
bytes != length)
{
Firebird::system_call_failed::raise("ReadFile");
}
#else
const int bytes = ::read(handle, buffer, length);
if (bytes != length)
{
Firebird::system_call_failed::raise("read");
}
#endif
position += bytes;
return bytes;
}
//
// TempFile::write
//
// Writes bytes to file
//
size_t TempFile::write(offset_t offset, void* buffer, size_t length)
{
fb_assert(offset <= size);
seek(offset);
#if defined(WIN_NT)
DWORD bytes = 0;
if (!WriteFile(handle, buffer, length, &bytes, NULL) ||
bytes != length)
{
Firebird::system_call_failed::raise("WriteFile");
}
#else
const int bytes = ::write(handle, buffer, length);
if (bytes != length)
{
Firebird::system_call_failed::raise("write");
}
#endif
position += bytes;
if (position > size)
size = position;
return bytes;
}
//
// TempFile::unlink
//
// Unlinks the file
//
void TempFile::unlink()
{
#if defined(WIN_NT)
doUnlink = true;
#else
::unlink(filename.c_str());
#endif
}