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2688 lines (2464 loc) · 79.9 KB
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/*
** 2004 May 22
**
** The author disclaims copyright to this source code. In place of
** a legal notice, here is a blessing:
**
** May you do good and not evil.
** May you find forgiveness for yourself and forgive others.
** May you share freely, never taking more than you give.
**
******************************************************************************
**
** This file contains code that is specific to windows.
*/
#include "sqliteInt.h"
#if SQLITE_OS_WIN /* This file is used for windows only */
/*
** A Note About Memory Allocation:
**
** This driver uses malloc()/free() directly rather than going through
** the SQLite-wrappers sqlite3_malloc()/sqlite3_free(). Those wrappers
** are designed for use on embedded systems where memory is scarce and
** malloc failures happen frequently. Win32 does not typically run on
** embedded systems, and when it does the developers normally have bigger
** problems to worry about than running out of memory. So there is not
** a compelling need to use the wrappers.
**
** But there is a good reason to not use the wrappers. If we use the
** wrappers then we will get simulated malloc() failures within this
** driver. And that causes all kinds of problems for our tests. We
** could enhance SQLite to deal with simulated malloc failures within
** the OS driver, but the code to deal with those failure would not
** be exercised on Linux (which does not need to malloc() in the driver)
** and so we would have difficulty writing coverage tests for that
** code. Better to leave the code out, we think.
**
** The point of this discussion is as follows: When creating a new
** OS layer for an embedded system, if you use this file as an example,
** avoid the use of malloc()/free(). Those routines work ok on windows
** desktops but not so well in embedded systems.
*/
#include <winbase.h>
#ifdef __CYGWIN__
# include <sys/cygwin.h>
#endif
/*
** Macros used to determine whether or not to use threads.
*/
#if defined(THREADSAFE) && THREADSAFE
# define SQLITE_W32_THREADS 1
#endif
/*
** Include code that is common to all os_*.c files
*/
#include "os_common.h"
/*
** Some microsoft compilers lack this definition.
*/
#ifndef INVALID_FILE_ATTRIBUTES
# define INVALID_FILE_ATTRIBUTES ((DWORD)-1)
#endif
/*
** Determine if we are dealing with WindowsCE - which has a much
** reduced API.
*/
#if SQLITE_OS_WINCE
# define AreFileApisANSI() 1
# define FormatMessageW(a,b,c,d,e,f,g) 0
#endif
/* Forward references */
typedef struct winShm winShm; /* A connection to shared-memory */
typedef struct winShmNode winShmNode; /* A region of shared-memory */
/*
** WinCE lacks native support for file locking so we have to fake it
** with some code of our own.
*/
#if SQLITE_OS_WINCE
typedef struct winceLock {
int nReaders; /* Number of reader locks obtained */
BOOL bPending; /* Indicates a pending lock has been obtained */
BOOL bReserved; /* Indicates a reserved lock has been obtained */
BOOL bExclusive; /* Indicates an exclusive lock has been obtained */
} winceLock;
#endif
/*
** The winFile structure is a subclass of sqlite3_file* specific to the win32
** portability layer.
*/
typedef struct winFile winFile;
struct winFile {
const sqlite3_io_methods *pMethod; /*** Must be first ***/
sqlite3_vfs *pVfs; /* The VFS used to open this file */
HANDLE h; /* Handle for accessing the file */
unsigned char locktype; /* Type of lock currently held on this file */
short sharedLockByte; /* Randomly chosen byte used as a shared lock */
DWORD lastErrno; /* The Windows errno from the last I/O error */
DWORD sectorSize; /* Sector size of the device file is on */
winShm *pShm; /* Instance of shared memory on this file */
const char *zPath; /* Full pathname of this file */
int szChunk; /* Chunk size configured by FCNTL_CHUNK_SIZE */
#if SQLITE_OS_WINCE
WCHAR *zDeleteOnClose; /* Name of file to delete when closing */
HANDLE hMutex; /* Mutex used to control access to shared lock */
HANDLE hShared; /* Shared memory segment used for locking */
winceLock local; /* Locks obtained by this instance of winFile */
winceLock *shared; /* Global shared lock memory for the file */
#endif
};
/*
** Forward prototypes.
*/
static int getSectorSize(
sqlite3_vfs *pVfs,
const char *zRelative /* UTF-8 file name */
);
/*
** The following variable is (normally) set once and never changes
** thereafter. It records whether the operating system is Win95
** or WinNT.
**
** 0: Operating system unknown.
** 1: Operating system is Win95.
** 2: Operating system is WinNT.
**
** In order to facilitate testing on a WinNT system, the test fixture
** can manually set this value to 1 to emulate Win98 behavior.
*/
#ifdef SQLITE_TEST
int sqlite3_os_type = 0;
#else
static int sqlite3_os_type = 0;
#endif
/*
** Return true (non-zero) if we are running under WinNT, Win2K, WinXP,
** or WinCE. Return false (zero) for Win95, Win98, or WinME.
**
** Here is an interesting observation: Win95, Win98, and WinME lack
** the LockFileEx() API. But we can still statically link against that
** API as long as we don't call it when running Win95/98/ME. A call to
** this routine is used to determine if the host is Win95/98/ME or
** WinNT/2K/XP so that we will know whether or not we can safely call
** the LockFileEx() API.
*/
#if SQLITE_OS_WINCE
# define isNT() (1)
#else
static int isNT(void){
if( sqlite3_os_type==0 ){
OSVERSIONINFO sInfo;
sInfo.dwOSVersionInfoSize = sizeof(sInfo);
GetVersionEx(&sInfo);
sqlite3_os_type = sInfo.dwPlatformId==VER_PLATFORM_WIN32_NT ? 2 : 1;
}
return sqlite3_os_type==2;
}
#endif /* SQLITE_OS_WINCE */
/*
** Convert a UTF-8 string to microsoft unicode (UTF-16?).
**
** Space to hold the returned string is obtained from malloc.
*/
static WCHAR *utf8ToUnicode(const char *zFilename){
int nChar;
WCHAR *zWideFilename;
nChar = MultiByteToWideChar(CP_UTF8, 0, zFilename, -1, NULL, 0);
zWideFilename = malloc( nChar*sizeof(zWideFilename[0]) );
if( zWideFilename==0 ){
return 0;
}
nChar = MultiByteToWideChar(CP_UTF8, 0, zFilename, -1, zWideFilename, nChar);
if( nChar==0 ){
free(zWideFilename);
zWideFilename = 0;
}
return zWideFilename;
}
/*
** Convert microsoft unicode to UTF-8. Space to hold the returned string is
** obtained from malloc().
*/
static char *unicodeToUtf8(const WCHAR *zWideFilename){
int nByte;
char *zFilename;
nByte = WideCharToMultiByte(CP_UTF8, 0, zWideFilename, -1, 0, 0, 0, 0);
zFilename = malloc( nByte );
if( zFilename==0 ){
return 0;
}
nByte = WideCharToMultiByte(CP_UTF8, 0, zWideFilename, -1, zFilename, nByte,
0, 0);
if( nByte == 0 ){
free(zFilename);
zFilename = 0;
}
return zFilename;
}
/*
** Convert an ansi string to microsoft unicode, based on the
** current codepage settings for file apis.
**
** Space to hold the returned string is obtained
** from malloc.
*/
static WCHAR *mbcsToUnicode(const char *zFilename){
int nByte;
WCHAR *zMbcsFilename;
int codepage = AreFileApisANSI() ? CP_ACP : CP_OEMCP;
nByte = MultiByteToWideChar(codepage, 0, zFilename, -1, NULL,0)*sizeof(WCHAR);
zMbcsFilename = malloc( nByte*sizeof(zMbcsFilename[0]) );
if( zMbcsFilename==0 ){
return 0;
}
nByte = MultiByteToWideChar(codepage, 0, zFilename, -1, zMbcsFilename, nByte);
if( nByte==0 ){
free(zMbcsFilename);
zMbcsFilename = 0;
}
return zMbcsFilename;
}
/*
** Convert microsoft unicode to multibyte character string, based on the
** user's Ansi codepage.
**
** Space to hold the returned string is obtained from
** malloc().
*/
static char *unicodeToMbcs(const WCHAR *zWideFilename){
int nByte;
char *zFilename;
int codepage = AreFileApisANSI() ? CP_ACP : CP_OEMCP;
nByte = WideCharToMultiByte(codepage, 0, zWideFilename, -1, 0, 0, 0, 0);
zFilename = malloc( nByte );
if( zFilename==0 ){
return 0;
}
nByte = WideCharToMultiByte(codepage, 0, zWideFilename, -1, zFilename, nByte,
0, 0);
if( nByte == 0 ){
free(zFilename);
zFilename = 0;
}
return zFilename;
}
/*
** Convert multibyte character string to UTF-8. Space to hold the
** returned string is obtained from malloc().
*/
char *sqlite3_win32_mbcs_to_utf8(const char *zFilename){
char *zFilenameUtf8;
WCHAR *zTmpWide;
zTmpWide = mbcsToUnicode(zFilename);
if( zTmpWide==0 ){
return 0;
}
zFilenameUtf8 = unicodeToUtf8(zTmpWide);
free(zTmpWide);
return zFilenameUtf8;
}
/*
** Convert UTF-8 to multibyte character string. Space to hold the
** returned string is obtained from malloc().
*/
static char *utf8ToMbcs(const char *zFilename){
char *zFilenameMbcs;
WCHAR *zTmpWide;
zTmpWide = utf8ToUnicode(zFilename);
if( zTmpWide==0 ){
return 0;
}
zFilenameMbcs = unicodeToMbcs(zTmpWide);
free(zTmpWide);
return zFilenameMbcs;
}
#if SQLITE_OS_WINCE
/*************************************************************************
** This section contains code for WinCE only.
*/
/*
** WindowsCE does not have a localtime() function. So create a
** substitute.
*/
#include <time.h>
struct tm *__cdecl localtime(const time_t *t)
{
static struct tm y;
FILETIME uTm, lTm;
SYSTEMTIME pTm;
sqlite3_int64 t64;
t64 = *t;
t64 = (t64 + 11644473600)*10000000;
uTm.dwLowDateTime = (DWORD)(t64 & 0xFFFFFFFF);
uTm.dwHighDateTime= (DWORD)(t64 >> 32);
FileTimeToLocalFileTime(&uTm,&lTm);
FileTimeToSystemTime(&lTm,&pTm);
y.tm_year = pTm.wYear - 1900;
y.tm_mon = pTm.wMonth - 1;
y.tm_wday = pTm.wDayOfWeek;
y.tm_mday = pTm.wDay;
y.tm_hour = pTm.wHour;
y.tm_min = pTm.wMinute;
y.tm_sec = pTm.wSecond;
return &y;
}
/* This will never be called, but defined to make the code compile */
#define GetTempPathA(a,b)
#define LockFile(a,b,c,d,e) winceLockFile(&a, b, c, d, e)
#define UnlockFile(a,b,c,d,e) winceUnlockFile(&a, b, c, d, e)
#define LockFileEx(a,b,c,d,e,f) winceLockFileEx(&a, b, c, d, e, f)
#define HANDLE_TO_WINFILE(a) (winFile*)&((char*)a)[-(int)offsetof(winFile,h)]
/*
** Acquire a lock on the handle h
*/
static void winceMutexAcquire(HANDLE h){
DWORD dwErr;
do {
dwErr = WaitForSingleObject(h, INFINITE);
} while (dwErr != WAIT_OBJECT_0 && dwErr != WAIT_ABANDONED);
}
/*
** Release a lock acquired by winceMutexAcquire()
*/
#define winceMutexRelease(h) ReleaseMutex(h)
/*
** Create the mutex and shared memory used for locking in the file
** descriptor pFile
*/
static BOOL winceCreateLock(const char *zFilename, winFile *pFile){
WCHAR *zTok;
WCHAR *zName = utf8ToUnicode(zFilename);
BOOL bInit = TRUE;
/* Initialize the local lockdata */
ZeroMemory(&pFile->local, sizeof(pFile->local));
/* Replace the backslashes from the filename and lowercase it
** to derive a mutex name. */
zTok = CharLowerW(zName);
for (;*zTok;zTok++){
if (*zTok == '\\') *zTok = '_';
}
/* Create/open the named mutex */
pFile->hMutex = CreateMutexW(NULL, FALSE, zName);
if (!pFile->hMutex){
pFile->lastErrno = GetLastError();
free(zName);
return FALSE;
}
/* Acquire the mutex before continuing */
winceMutexAcquire(pFile->hMutex);
/* Since the names of named mutexes, semaphores, file mappings etc are
** case-sensitive, take advantage of that by uppercasing the mutex name
** and using that as the shared filemapping name.
*/
CharUpperW(zName);
pFile->hShared = CreateFileMappingW(INVALID_HANDLE_VALUE, NULL,
PAGE_READWRITE, 0, sizeof(winceLock),
zName);
/* Set a flag that indicates we're the first to create the memory so it
** must be zero-initialized */
if (GetLastError() == ERROR_ALREADY_EXISTS){
bInit = FALSE;
}
free(zName);
/* If we succeeded in making the shared memory handle, map it. */
if (pFile->hShared){
pFile->shared = (winceLock*)MapViewOfFile(pFile->hShared,
FILE_MAP_READ|FILE_MAP_WRITE, 0, 0, sizeof(winceLock));
/* If mapping failed, close the shared memory handle and erase it */
if (!pFile->shared){
pFile->lastErrno = GetLastError();
CloseHandle(pFile->hShared);
pFile->hShared = NULL;
}
}
/* If shared memory could not be created, then close the mutex and fail */
if (pFile->hShared == NULL){
winceMutexRelease(pFile->hMutex);
CloseHandle(pFile->hMutex);
pFile->hMutex = NULL;
return FALSE;
}
/* Initialize the shared memory if we're supposed to */
if (bInit) {
ZeroMemory(pFile->shared, sizeof(winceLock));
}
winceMutexRelease(pFile->hMutex);
return TRUE;
}
/*
** Destroy the part of winFile that deals with wince locks
*/
static void winceDestroyLock(winFile *pFile){
if (pFile->hMutex){
/* Acquire the mutex */
winceMutexAcquire(pFile->hMutex);
/* The following blocks should probably assert in debug mode, but they
are to cleanup in case any locks remained open */
if (pFile->local.nReaders){
pFile->shared->nReaders --;
}
if (pFile->local.bReserved){
pFile->shared->bReserved = FALSE;
}
if (pFile->local.bPending){
pFile->shared->bPending = FALSE;
}
if (pFile->local.bExclusive){
pFile->shared->bExclusive = FALSE;
}
/* De-reference and close our copy of the shared memory handle */
UnmapViewOfFile(pFile->shared);
CloseHandle(pFile->hShared);
/* Done with the mutex */
winceMutexRelease(pFile->hMutex);
CloseHandle(pFile->hMutex);
pFile->hMutex = NULL;
}
}
/*
** An implementation of the LockFile() API of windows for wince
*/
static BOOL winceLockFile(
HANDLE *phFile,
DWORD dwFileOffsetLow,
DWORD dwFileOffsetHigh,
DWORD nNumberOfBytesToLockLow,
DWORD nNumberOfBytesToLockHigh
){
winFile *pFile = HANDLE_TO_WINFILE(phFile);
BOOL bReturn = FALSE;
UNUSED_PARAMETER(dwFileOffsetHigh);
UNUSED_PARAMETER(nNumberOfBytesToLockHigh);
if (!pFile->hMutex) return TRUE;
winceMutexAcquire(pFile->hMutex);
/* Wanting an exclusive lock? */
if (dwFileOffsetLow == (DWORD)SHARED_FIRST
&& nNumberOfBytesToLockLow == (DWORD)SHARED_SIZE){
if (pFile->shared->nReaders == 0 && pFile->shared->bExclusive == 0){
pFile->shared->bExclusive = TRUE;
pFile->local.bExclusive = TRUE;
bReturn = TRUE;
}
}
/* Want a read-only lock? */
else if (dwFileOffsetLow == (DWORD)SHARED_FIRST &&
nNumberOfBytesToLockLow == 1){
if (pFile->shared->bExclusive == 0){
pFile->local.nReaders ++;
if (pFile->local.nReaders == 1){
pFile->shared->nReaders ++;
}
bReturn = TRUE;
}
}
/* Want a pending lock? */
else if (dwFileOffsetLow == (DWORD)PENDING_BYTE && nNumberOfBytesToLockLow == 1){
/* If no pending lock has been acquired, then acquire it */
if (pFile->shared->bPending == 0) {
pFile->shared->bPending = TRUE;
pFile->local.bPending = TRUE;
bReturn = TRUE;
}
}
/* Want a reserved lock? */
else if (dwFileOffsetLow == (DWORD)RESERVED_BYTE && nNumberOfBytesToLockLow == 1){
if (pFile->shared->bReserved == 0) {
pFile->shared->bReserved = TRUE;
pFile->local.bReserved = TRUE;
bReturn = TRUE;
}
}
winceMutexRelease(pFile->hMutex);
return bReturn;
}
/*
** An implementation of the UnlockFile API of windows for wince
*/
static BOOL winceUnlockFile(
HANDLE *phFile,
DWORD dwFileOffsetLow,
DWORD dwFileOffsetHigh,
DWORD nNumberOfBytesToUnlockLow,
DWORD nNumberOfBytesToUnlockHigh
){
winFile *pFile = HANDLE_TO_WINFILE(phFile);
BOOL bReturn = FALSE;
UNUSED_PARAMETER(dwFileOffsetHigh);
UNUSED_PARAMETER(nNumberOfBytesToUnlockHigh);
if (!pFile->hMutex) return TRUE;
winceMutexAcquire(pFile->hMutex);
/* Releasing a reader lock or an exclusive lock */
if (dwFileOffsetLow == (DWORD)SHARED_FIRST){
/* Did we have an exclusive lock? */
if (pFile->local.bExclusive){
assert(nNumberOfBytesToUnlockLow == (DWORD)SHARED_SIZE);
pFile->local.bExclusive = FALSE;
pFile->shared->bExclusive = FALSE;
bReturn = TRUE;
}
/* Did we just have a reader lock? */
else if (pFile->local.nReaders){
assert(nNumberOfBytesToUnlockLow == (DWORD)SHARED_SIZE || nNumberOfBytesToUnlockLow == 1);
pFile->local.nReaders --;
if (pFile->local.nReaders == 0)
{
pFile->shared->nReaders --;
}
bReturn = TRUE;
}
}
/* Releasing a pending lock */
else if (dwFileOffsetLow == (DWORD)PENDING_BYTE && nNumberOfBytesToUnlockLow == 1){
if (pFile->local.bPending){
pFile->local.bPending = FALSE;
pFile->shared->bPending = FALSE;
bReturn = TRUE;
}
}
/* Releasing a reserved lock */
else if (dwFileOffsetLow == (DWORD)RESERVED_BYTE && nNumberOfBytesToUnlockLow == 1){
if (pFile->local.bReserved) {
pFile->local.bReserved = FALSE;
pFile->shared->bReserved = FALSE;
bReturn = TRUE;
}
}
winceMutexRelease(pFile->hMutex);
return bReturn;
}
/*
** An implementation of the LockFileEx() API of windows for wince
*/
static BOOL winceLockFileEx(
HANDLE *phFile,
DWORD dwFlags,
DWORD dwReserved,
DWORD nNumberOfBytesToLockLow,
DWORD nNumberOfBytesToLockHigh,
LPOVERLAPPED lpOverlapped
){
UNUSED_PARAMETER(dwReserved);
UNUSED_PARAMETER(nNumberOfBytesToLockHigh);
/* If the caller wants a shared read lock, forward this call
** to winceLockFile */
if (lpOverlapped->Offset == (DWORD)SHARED_FIRST &&
dwFlags == 1 &&
nNumberOfBytesToLockLow == (DWORD)SHARED_SIZE){
return winceLockFile(phFile, SHARED_FIRST, 0, 1, 0);
}
return FALSE;
}
/*
** End of the special code for wince
*****************************************************************************/
#endif /* SQLITE_OS_WINCE */
/*****************************************************************************
** The next group of routines implement the I/O methods specified
** by the sqlite3_io_methods object.
******************************************************************************/
/*
** Some microsoft compilers lack this definition.
*/
#ifndef INVALID_SET_FILE_POINTER
# define INVALID_SET_FILE_POINTER ((DWORD)-1)
#endif
/*
** Move the current position of the file handle passed as the first
** argument to offset iOffset within the file. If successful, return 0.
** Otherwise, set pFile->lastErrno and return non-zero.
*/
static int seekWinFile(winFile *pFile, sqlite3_int64 iOffset){
LONG upperBits; /* Most sig. 32 bits of new offset */
LONG lowerBits; /* Least sig. 32 bits of new offset */
DWORD dwRet; /* Value returned by SetFilePointer() */
upperBits = (LONG)((iOffset>>32) & 0x7fffffff);
lowerBits = (LONG)(iOffset & 0xffffffff);
/* API oddity: If successful, SetFilePointer() returns a dword
** containing the lower 32-bits of the new file-offset. Or, if it fails,
** it returns INVALID_SET_FILE_POINTER. However according to MSDN,
** INVALID_SET_FILE_POINTER may also be a valid new offset. So to determine
** whether an error has actually occured, it is also necessary to call
** GetLastError().
*/
dwRet = SetFilePointer(pFile->h, lowerBits, &upperBits, FILE_BEGIN);
if( (dwRet==INVALID_SET_FILE_POINTER && GetLastError()!=NO_ERROR) ){
pFile->lastErrno = GetLastError();
return 1;
}
return 0;
}
/*
** Close a file.
**
** It is reported that an attempt to close a handle might sometimes
** fail. This is a very unreasonable result, but windows is notorious
** for being unreasonable so I do not doubt that it might happen. If
** the close fails, we pause for 100 milliseconds and try again. As
** many as MX_CLOSE_ATTEMPT attempts to close the handle are made before
** giving up and returning an error.
*/
#define MX_CLOSE_ATTEMPT 3
static int winClose(sqlite3_file *id){
int rc, cnt = 0;
winFile *pFile = (winFile*)id;
assert( id!=0 );
assert( pFile->pShm==0 );
OSTRACE(("CLOSE %d\n", pFile->h));
do{
rc = CloseHandle(pFile->h);
/* SimulateIOError( rc=0; cnt=MX_CLOSE_ATTEMPT; ); */
}while( rc==0 && ++cnt < MX_CLOSE_ATTEMPT && (Sleep(100), 1) );
#if SQLITE_OS_WINCE
#define WINCE_DELETION_ATTEMPTS 3
winceDestroyLock(pFile);
if( pFile->zDeleteOnClose ){
int cnt = 0;
while(
DeleteFileW(pFile->zDeleteOnClose)==0
&& GetFileAttributesW(pFile->zDeleteOnClose)!=0xffffffff
&& cnt++ < WINCE_DELETION_ATTEMPTS
){
Sleep(100); /* Wait a little before trying again */
}
free(pFile->zDeleteOnClose);
}
#endif
OSTRACE(("CLOSE %d %s\n", pFile->h, rc ? "ok" : "failed"));
OpenCounter(-1);
return rc ? SQLITE_OK : SQLITE_IOERR;
}
/*
** Read data from a file into a buffer. Return SQLITE_OK if all
** bytes were read successfully and SQLITE_IOERR if anything goes
** wrong.
*/
static int winRead(
sqlite3_file *id, /* File to read from */
void *pBuf, /* Write content into this buffer */
int amt, /* Number of bytes to read */
sqlite3_int64 offset /* Begin reading at this offset */
){
winFile *pFile = (winFile*)id; /* file handle */
DWORD nRead; /* Number of bytes actually read from file */
assert( id!=0 );
SimulateIOError(return SQLITE_IOERR_READ);
OSTRACE(("READ %d lock=%d\n", pFile->h, pFile->locktype));
if( seekWinFile(pFile, offset) ){
return SQLITE_FULL;
}
if( !ReadFile(pFile->h, pBuf, amt, &nRead, 0) ){
pFile->lastErrno = GetLastError();
return SQLITE_IOERR_READ;
}
if( nRead<(DWORD)amt ){
/* Unread parts of the buffer must be zero-filled */
memset(&((char*)pBuf)[nRead], 0, amt-nRead);
return SQLITE_IOERR_SHORT_READ;
}
return SQLITE_OK;
}
/*
** Write data from a buffer into a file. Return SQLITE_OK on success
** or some other error code on failure.
*/
static int winWrite(
sqlite3_file *id, /* File to write into */
const void *pBuf, /* The bytes to be written */
int amt, /* Number of bytes to write */
sqlite3_int64 offset /* Offset into the file to begin writing at */
){
int rc; /* True if error has occured, else false */
winFile *pFile = (winFile*)id; /* File handle */
assert( amt>0 );
assert( pFile );
SimulateIOError(return SQLITE_IOERR_WRITE);
SimulateDiskfullError(return SQLITE_FULL);
OSTRACE(("WRITE %d lock=%d\n", pFile->h, pFile->locktype));
rc = seekWinFile(pFile, offset);
if( rc==0 ){
u8 *aRem = (u8 *)pBuf; /* Data yet to be written */
int nRem = amt; /* Number of bytes yet to be written */
DWORD nWrite; /* Bytes written by each WriteFile() call */
while( nRem>0 && WriteFile(pFile->h, aRem, nRem, &nWrite, 0) && nWrite>0 ){
aRem += nWrite;
nRem -= nWrite;
}
if( nRem>0 ){
pFile->lastErrno = GetLastError();
rc = 1;
}
}
if( rc ){
if( pFile->lastErrno==ERROR_HANDLE_DISK_FULL ){
return SQLITE_FULL;
}
return SQLITE_IOERR_WRITE;
}
return SQLITE_OK;
}
/*
** Truncate an open file to a specified size
*/
static int winTruncate(sqlite3_file *id, sqlite3_int64 nByte){
winFile *pFile = (winFile*)id; /* File handle object */
int rc = SQLITE_OK; /* Return code for this function */
assert( pFile );
OSTRACE(("TRUNCATE %d %lld\n", pFile->h, nByte));
SimulateIOError(return SQLITE_IOERR_TRUNCATE);
/* If the user has configured a chunk-size for this file, truncate the
** file so that it consists of an integer number of chunks (i.e. the
** actual file size after the operation may be larger than the requested
** size).
*/
if( pFile->szChunk ){
nByte = ((nByte + pFile->szChunk - 1)/pFile->szChunk) * pFile->szChunk;
}
/* SetEndOfFile() returns non-zero when successful, or zero when it fails. */
if( seekWinFile(pFile, nByte) ){
rc = SQLITE_IOERR_TRUNCATE;
}else if( 0==SetEndOfFile(pFile->h) ){
pFile->lastErrno = GetLastError();
rc = SQLITE_IOERR_TRUNCATE;
}
OSTRACE(("TRUNCATE %d %lld %s\n", pFile->h, nByte, rc ? "failed" : "ok"));
return rc;
}
#ifdef SQLITE_TEST
/*
** Count the number of fullsyncs and normal syncs. This is used to test
** that syncs and fullsyncs are occuring at the right times.
*/
int sqlite3_sync_count = 0;
int sqlite3_fullsync_count = 0;
#endif
/*
** Make sure all writes to a particular file are committed to disk.
*/
static int winSync(sqlite3_file *id, int flags){
#if !defined(NDEBUG) || !defined(SQLITE_NO_SYNC) || defined(SQLITE_DEBUG)
winFile *pFile = (winFile*)id;
#else
UNUSED_PARAMETER(id);
#endif
assert( pFile );
/* Check that one of SQLITE_SYNC_NORMAL or FULL was passed */
assert((flags&0x0F)==SQLITE_SYNC_NORMAL
|| (flags&0x0F)==SQLITE_SYNC_FULL
);
OSTRACE(("SYNC %d lock=%d\n", pFile->h, pFile->locktype));
#ifndef SQLITE_TEST
UNUSED_PARAMETER(flags);
#else
if( flags & SQLITE_SYNC_FULL ){
sqlite3_fullsync_count++;
}
sqlite3_sync_count++;
#endif
/* Unix cannot, but some systems may return SQLITE_FULL from here. This
** line is to test that doing so does not cause any problems.
*/
SimulateDiskfullError( return SQLITE_FULL );
SimulateIOError( return SQLITE_IOERR; );
/* If we compiled with the SQLITE_NO_SYNC flag, then syncing is a
** no-op
*/
#ifdef SQLITE_NO_SYNC
return SQLITE_OK;
#else
if( FlushFileBuffers(pFile->h) ){
return SQLITE_OK;
}else{
pFile->lastErrno = GetLastError();
return SQLITE_IOERR;
}
#endif
}
/*
** Determine the current size of a file in bytes
*/
static int winFileSize(sqlite3_file *id, sqlite3_int64 *pSize){
DWORD upperBits;
DWORD lowerBits;
winFile *pFile = (winFile*)id;
DWORD error;
assert( id!=0 );
SimulateIOError(return SQLITE_IOERR_FSTAT);
lowerBits = GetFileSize(pFile->h, &upperBits);
if( (lowerBits == INVALID_FILE_SIZE)
&& ((error = GetLastError()) != NO_ERROR) )
{
pFile->lastErrno = error;
return SQLITE_IOERR_FSTAT;
}
*pSize = (((sqlite3_int64)upperBits)<<32) + lowerBits;
return SQLITE_OK;
}
/*
** LOCKFILE_FAIL_IMMEDIATELY is undefined on some Windows systems.
*/
#ifndef LOCKFILE_FAIL_IMMEDIATELY
# define LOCKFILE_FAIL_IMMEDIATELY 1
#endif
/*
** Acquire a reader lock.
** Different API routines are called depending on whether or not this
** is Win95 or WinNT.
*/
static int getReadLock(winFile *pFile){
int res;
if( isNT() ){
OVERLAPPED ovlp;
ovlp.Offset = SHARED_FIRST;
ovlp.OffsetHigh = 0;
ovlp.hEvent = 0;
res = LockFileEx(pFile->h, LOCKFILE_FAIL_IMMEDIATELY,
0, SHARED_SIZE, 0, &ovlp);
/* isNT() is 1 if SQLITE_OS_WINCE==1, so this else is never executed.
*/
#if SQLITE_OS_WINCE==0
}else{
int lk;
sqlite3_randomness(sizeof(lk), &lk);
pFile->sharedLockByte = (short)((lk & 0x7fffffff)%(SHARED_SIZE - 1));
res = LockFile(pFile->h, SHARED_FIRST+pFile->sharedLockByte, 0, 1, 0);
#endif
}
if( res == 0 ){
pFile->lastErrno = GetLastError();
}
return res;
}
/*
** Undo a readlock
*/
static int unlockReadLock(winFile *pFile){
int res;
if( isNT() ){
res = UnlockFile(pFile->h, SHARED_FIRST, 0, SHARED_SIZE, 0);
/* isNT() is 1 if SQLITE_OS_WINCE==1, so this else is never executed.
*/
#if SQLITE_OS_WINCE==0
}else{
res = UnlockFile(pFile->h, SHARED_FIRST + pFile->sharedLockByte, 0, 1, 0);
#endif
}
if( res == 0 ){
pFile->lastErrno = GetLastError();
}
return res;
}
/*
** Lock the file with the lock specified by parameter locktype - one
** of the following:
**
** (1) SHARED_LOCK
** (2) RESERVED_LOCK
** (3) PENDING_LOCK
** (4) EXCLUSIVE_LOCK
**
** Sometimes when requesting one lock state, additional lock states
** are inserted in between. The locking might fail on one of the later
** transitions leaving the lock state different from what it started but
** still short of its goal. The following chart shows the allowed
** transitions and the inserted intermediate states:
**
** UNLOCKED -> SHARED
** SHARED -> RESERVED
** SHARED -> (PENDING) -> EXCLUSIVE
** RESERVED -> (PENDING) -> EXCLUSIVE
** PENDING -> EXCLUSIVE
**
** This routine will only increase a lock. The winUnlock() routine
** erases all locks at once and returns us immediately to locking level 0.
** It is not possible to lower the locking level one step at a time. You
** must go straight to locking level 0.
*/
static int winLock(sqlite3_file *id, int locktype){
int rc = SQLITE_OK; /* Return code from subroutines */
int res = 1; /* Result of a windows lock call */
int newLocktype; /* Set pFile->locktype to this value before exiting */
int gotPendingLock = 0;/* True if we acquired a PENDING lock this time */
winFile *pFile = (winFile*)id;
DWORD error = NO_ERROR;
assert( id!=0 );
OSTRACE(("LOCK %d %d was %d(%d)\n",
pFile->h, locktype, pFile->locktype, pFile->sharedLockByte));
/* If there is already a lock of this type or more restrictive on the
** OsFile, do nothing. Don't use the end_lock: exit path, as
** sqlite3OsEnterMutex() hasn't been called yet.
*/
if( pFile->locktype>=locktype ){
return SQLITE_OK;
}
/* Make sure the locking sequence is correct
*/
assert( pFile->locktype!=NO_LOCK || locktype==SHARED_LOCK );
assert( locktype!=PENDING_LOCK );
assert( locktype!=RESERVED_LOCK || pFile->locktype==SHARED_LOCK );