int64
FileSeek(File file, int64 offset, int whence)
{
int returnCode;
Assert(FileIsValid(file));
DO_DB(elog(LOG, "FileSeek: %d (%s) " INT64_FORMAT " " INT64_FORMAT " %d",
file, VfdCache[file].fileName,
VfdCache[file].seekPos, offset, whence));
if (FileIsNotOpen(file))
{
switch (whence)
{
case SEEK_SET:
Assert(offset >= INT64CONST(0));
VfdCache[file].seekPos = offset;
break;
case SEEK_CUR:
VfdCache[file].seekPos += offset;
break;
case SEEK_END:
returnCode = FileAccess(file);
if (returnCode < 0)
return returnCode;
VfdCache[file].seekPos = pg_lseek64(VfdCache[file].fd,
offset, whence);
break;
default:
Assert(!"invalid whence");
break;
}
}
else
{
switch (whence)
{
case SEEK_SET:
Assert(offset >= INT64CONST(0));
if (VfdCache[file].seekPos != offset)
VfdCache[file].seekPos = pg_lseek64(VfdCache[file].fd,
offset, whence);
break;
case SEEK_CUR:
if (offset != 0 || VfdCache[file].seekPos == FileUnknownPos)
VfdCache[file].seekPos = pg_lseek64(VfdCache[file].fd,
offset, whence);
break;
case SEEK_END:
VfdCache[file].seekPos = pg_lseek64(VfdCache[file].fd,
offset, whence);
break;
default:
Assert(!"invalid whence");
break;
}
}
return VfdCache[file].seekPos;
}
/*
* XXX not actually used but here for completeness
*/
long
FileTell(File file)
{
DO_DB(printf("DEBUG: FileTell %d (%s)\n",
file, VfdCache[file].fileName));
return VfdCache[file].seekPos;
}
/* returns 0 on success, -1 on re-open failure (with errno set) */
static int
FileAccess(File file)
{
int returnValue;
DO_DB(elog(LOG, "FileAccess %d (%s)",
file, VfdCache[file].fileName));
/*
* Is the file open? If not, open it and put it at the head of the LRU
* ring (possibly closing the least recently used file to get an FD).
*/
if (FileIsNotOpen(file))
{
returnValue = LruInsert(file);
if (returnValue != 0)
return returnValue;
}
else if (VfdCache[0].lruLessRecently != file)
{
/*
* We now know that the file is open and that it is not the last one
* accessed, so we need to move it to the head of the Lru ring.
*/
Delete(file);
Insert(file);
}
return 0;
}
long
FileSeek(File file, long offset, int whence)
{
int returnCode;
DO_DB(printf("DEBUG: FileSeek: %d (%s) %d %d\n",
file, VfdCache[file].fileName, offset, whence));
if (FileIsNotOpen(file)) {
switch(whence) {
case SEEK_SET:
VfdCache[file].seekPos = offset;
return offset;
case SEEK_CUR:
VfdCache[file].seekPos = VfdCache[file].seekPos +offset;
return VfdCache[file].seekPos;
case SEEK_END:
FileAccess(file);
returnCode = VfdCache[file].seekPos =
lseek(VfdCache[file].fd, offset, whence);
return returnCode;
default:
elog(WARN, "FileSeek: invalid whence: %d", whence);
break;
}
} else {
returnCode = VfdCache[file].seekPos =
lseek(VfdCache[file].fd, offset, whence);
return returnCode;
}
/*NOTREACHED*/
return(-1L);
}
static void
LruDelete(File file)
{
Vfd *vfdP;
Assert(file != 0);
DO_DB(elog(LOG, "LruDelete %d (%s)",
file, VfdCache[file].fileName));
vfdP = &VfdCache[file];
/* delete the vfd record from the LRU ring */
Delete(file);
/* save the seek position */
vfdP->seekPos = (long) lseek(vfdP->fd, 0L, SEEK_CUR);
Assert(vfdP->seekPos != -1L);
/* close the file */
if (close(vfdP->fd))
elog(ERROR, "could not close file \"%s\": %m", vfdP->fileName);
--nfile;
vfdP->fd = VFD_CLOSED;
}
void
AllocateFile()
{
int fd;
int fdleft;
while ((fd = open(Nulldev,O_WRONLY,0)) < 0) {
if (errno == EMFILE) {
errno = 0;
FreeFd = 0;
AssertLruRoom();
} else {
elog(WARN,"Open: %s in %s line %d\n", Nulldev,
__FILE__, __LINE__);
}
}
close(fd);
++allocatedFiles;
fdleft = MAXFILES - allocatedFiles;
if (fdleft < 6) {
elog(DEBUG,"warning: few usable file descriptors left (%d)", fdleft);
}
DO_DB(printf("DEBUG: AllocatedFile. FreeFd = %d\n",
FreeFd));
}
/*
* close a file when done with it
*/
void
FileClose(File file)
{
Vfd *vfdP;
struct stat filestats;
Assert(FileIsValid(file));
DO_DB(elog(LOG, "FileClose: %d (%s)",
file, VfdCache[file].fileName));
vfdP = &VfdCache[file];
if (!FileIsNotOpen(file))
{
/* remove the file from the lru ring */
Delete(file);
/* close the file */
if (close(vfdP->fd))
elog(ERROR, "could not close file \"%s\": %m", vfdP->fileName);
--nfile;
vfdP->fd = VFD_CLOSED;
}
/*
* Delete the file if it was temporary
*/
if (vfdP->fdstate & FD_TEMPORARY)
{
/* reset flag so that die() interrupt won't cause problems */
vfdP->fdstate &= ~FD_TEMPORARY;
if (log_temp_files >= 0)
{
if (stat(vfdP->fileName, &filestats) == 0)
{
if (filestats.st_size >= log_temp_files)
ereport(LOG,
(errmsg("temporary file: path \"%s\", size %lu",
vfdP->fileName,
(unsigned long) filestats.st_size)));
}
else
elog(LOG, "could not stat file \"%s\": %m", vfdP->fileName);
}
if (unlink(vfdP->fileName))
elog(LOG, "could not unlink file \"%s\": %m", vfdP->fileName);
}
/* Unregister it from the resource owner */
if (vfdP->resowner)
ResourceOwnerForgetFile(vfdP->resowner, file);
/*
* Return the Vfd slot to the free list
*/
FreeVfd(file);
}
int64
FileTell(File file)
{
Assert(FileIsValid(file));
DO_DB(elog(LOG, "FileTell %d (%s)",
file, VfdCache[file].fileName));
return VfdCache[file].seekPos;
}
int
FileRead(File file, char *buffer, int amount)
{
int returnCode;
Assert(FileIsValid(file));
DO_DB(elog(LOG, "FileRead: %d (%s) " INT64_FORMAT " %d %p",
file, VfdCache[file].fileName,
VfdCache[file].seekPos, amount, buffer));
if (Debug_filerep_print)
(elog(LOG, "FileRead: %d (%s) " INT64_FORMAT " %d %p",
file, VfdCache[file].fileName,
VfdCache[file].seekPos, amount, buffer));
returnCode = FileAccess(file);
if (returnCode < 0)
return returnCode;
retry:
returnCode = read(VfdCache[file].fd, buffer, amount);
if (returnCode >= 0)
VfdCache[file].seekPos += returnCode;
else
{
/*
* Windows may run out of kernel buffers and return "Insufficient
* system resources" error. Wait a bit and retry to solve it.
*
* It is rumored that EINTR is also possible on some Unix filesystems,
* in which case immediate retry is indicated.
*/
#ifdef WIN32
DWORD error = GetLastError();
switch (error)
{
case ERROR_NO_SYSTEM_RESOURCES:
pg_usleep(1000L);
errno = EINTR;
break;
default:
_dosmaperr(error);
break;
}
#endif
/* OK to retry if interrupted */
if (errno == EINTR)
goto retry;
/* Trouble, so assume we don't know the file position anymore */
VfdCache[file].seekPos = FileUnknownPos;
}
return returnCode;
}
static void
FreeVfd(File file)
{
DO_DB(printf("DB: FreeVfd: %d (%s)\n",
file, VfdCache[file].fileName));
VfdCache[file].nextFree = VfdCache[0].nextFree;
VfdCache[0].nextFree = file;
}
static void
Insert(File file)
{
Vfd *vfdP;
DO_DB(printf("DEBUG: Insert %d (%s)\n",
file, VfdCache[file].fileName));
DO_DB(_dump_lru());
vfdP = &VfdCache[file];
vfdP->lruMoreRecently = 0;
vfdP->lruLessRecently = VfdCache[0].lruLessRecently;
VfdCache[0].lruLessRecently = file;
VfdCache[vfdP->lruLessRecently].lruMoreRecently = file;
DO_DB(_dump_lru());
}
static void
Delete(File file)
{
Vfd *vfdP;
Assert(file != 0);
DO_DB(elog(LOG, "Delete %d (%s)",
file, VfdCache[file].fileName));
DO_DB(_dump_lru());
vfdP = &VfdCache[file];
VfdCache[vfdP->lruLessRecently].lruMoreRecently = vfdP->lruMoreRecently;
VfdCache[vfdP->lruMoreRecently].lruLessRecently = vfdP->lruLessRecently;
DO_DB(_dump_lru());
}
static File
AllocateVfd(void)
{
Index i;
File file;
DO_DB(elog(LOG, "AllocateVfd. Size %lu", SizeVfdCache));
Assert(SizeVfdCache > 0); /* InitFileAccess not called? */
if (VfdCache[0].nextFree == 0)
{
/*
* The free list is empty so it is time to increase the size of the
* array. We choose to double it each time this happens. However,
* there's not much point in starting *real* small.
*/
Size newCacheSize = SizeVfdCache * 2;
Vfd *newVfdCache;
if (newCacheSize < 32)
newCacheSize = 32;
/*
* Be careful not to clobber VfdCache ptr if realloc fails.
*/
newVfdCache = (Vfd *) realloc(VfdCache, sizeof(Vfd) * newCacheSize);
if (newVfdCache == NULL)
ereport(ERROR,
(errcode(ERRCODE_OUT_OF_MEMORY),
errmsg("out of memory")));
VfdCache = newVfdCache;
/*
* Initialize the new entries and link them into the free list.
*/
for (i = SizeVfdCache; i < newCacheSize; i++)
{
MemSet((char *) &(VfdCache[i]), 0, sizeof(Vfd));
VfdCache[i].nextFree = i + 1;
VfdCache[i].fd = VFD_CLOSED;
}
VfdCache[newCacheSize - 1].nextFree = 0;
VfdCache[0].nextFree = SizeVfdCache;
/*
* Record the new size
*/
SizeVfdCache = newCacheSize;
}
file = VfdCache[0].nextFree;
VfdCache[0].nextFree = VfdCache[file].nextFree;
return file;
}
static void
AssertLruRoom()
{
DO_DB(printf("DEBUG: AssertLruRoom (FreeFd = %d)\n",
FreeFd));
if (FreeFd <= 0 || nfile >= MAXFILES) {
LruDelete(VfdCache[0].lruMoreRecently);
}
}
/*
* XXX What happens if FreeFile() is called without a previous
* AllocateFile()?
*/
void
FreeFile()
{
DO_DB(printf("DEBUG: FreeFile. FreeFd now %d\n",
FreeFd));
FreeFd++;
nfile++; /* dangerous */
Assert(allocatedFiles > 0);
--allocatedFiles;
}
static void
Delete(File file)
{
Vfd *fileP;
DO_DB(printf("DEBUG: Delete %d (%s)\n",
file, VfdCache[file].fileName));
DO_DB(_dump_lru());
Assert(file != 0);
fileP = &VfdCache[file];
VfdCache[fileP->lruLessRecently].lruMoreRecently =
VfdCache[file].lruMoreRecently;
VfdCache[fileP->lruMoreRecently].lruLessRecently =
VfdCache[file].lruLessRecently;
DO_DB(_dump_lru());
}
int
FileWrite(File file, char *buffer, int amount)
{
int returnCode;
Assert(FileIsValid(file));
DO_DB(elog(LOG, "FileWrite: %d (%s) %ld %d %p",
file, VfdCache[file].fileName,
VfdCache[file].seekPos, amount, buffer));
returnCode = FileAccess(file);
if (returnCode < 0)
return returnCode;
retry:
errno = 0;
returnCode = write(VfdCache[file].fd, buffer, amount);
/* if write didn't set errno, assume problem is no disk space */
if (returnCode != amount && errno == 0)
errno = ENOSPC;
if (returnCode >= 0)
VfdCache[file].seekPos += returnCode;
else
{
/*
* See comments in FileRead()
*/
#ifdef WIN32
DWORD error = GetLastError();
switch (error)
{
case ERROR_NO_SYSTEM_RESOURCES:
pg_usleep(1000L);
errno = EINTR;
break;
default:
_dosmaperr(error);
break;
}
#endif
/* OK to retry if interrupted */
if (errno == EINTR)
goto retry;
/* Trouble, so assume we don't know the file position anymore */
VfdCache[file].seekPos = FileUnknownPos;
}
return returnCode;
}
static void
Insert(File file)
{
Vfd *vfdP;
Assert(file != 0);
DO_DB(elog(LOG, "Insert %d (%s)",
file, VfdCache[file].fileName));
DO_DB(_dump_lru());
vfdP = &VfdCache[file];
vfdP->lruMoreRecently = 0;
vfdP->lruLessRecently = VfdCache[0].lruLessRecently;
VfdCache[0].lruLessRecently = file;
VfdCache[vfdP->lruLessRecently].lruMoreRecently = file;
DO_DB(_dump_lru());
}
int
FileTruncate(File file, int offset)
{
int returnCode;
DO_DB(printf("DEBUG: FileTruncate %d (%s)\n",
file, VfdCache[file].fileName));
(void) FileSync(file);
(void) FileAccess(file);
returnCode = ftruncate(VfdCache[file].fd, offset);
return(returnCode);
}
/*
* close a file and forcibly delete the underlying Unix file
*/
void
FileUnlink(File file)
{
Assert(FileIsValid(file));
DO_DB(elog(LOG, "FileUnlink: %d (%s)",
file, VfdCache[file].fileName));
/* force FileClose to delete it */
VfdCache[file].fdstate |= FD_TEMPORARY;
FileClose(file);
}
int
FileRead(File file, char *buffer, int amount)
{
int returnCode;
DO_DB(printf("DEBUG: FileRead: %d (%s) %d 0x%x\n",
file, VfdCache[file].fileName, amount, buffer));
FileAccess(file);
returnCode = read(VfdCache[file].fd, buffer, amount);
if (returnCode > 0) {
VfdCache[file].seekPos += returnCode;
}
return returnCode;
}
int
FileSync(File file)
{
int returnCode;
Assert(FileIsValid(file));
DO_DB(elog(LOG, "FileSync: %d (%s)",
file, VfdCache[file].fileName));
returnCode = FileAccess(file);
if (returnCode < 0)
return returnCode;
return pg_fsync(VfdCache[file].fd);
}
int
FileTruncate(File file, long offset)
{
int returnCode;
Assert(FileIsValid(file));
DO_DB(elog(LOG, "FileTruncate %d (%s)",
file, VfdCache[file].fileName));
returnCode = FileAccess(file);
if (returnCode < 0)
return returnCode;
returnCode = ftruncate(VfdCache[file].fd, (size_t) offset);
return returnCode;
}
static bool
ReleaseLruFile(void)
{
DO_DB(elog(LOG, "ReleaseLruFile. Opened %d", nfile));
if (nfile > 0)
{
/*
* There are opened files and so there should be at least one used vfd
* in the ring.
*/
Assert(VfdCache[0].lruMoreRecently != 0);
LruDelete(VfdCache[0].lruMoreRecently);
return true; /* freed a file */
}
return false; /* no files available to free */
}
int64
FileNonVirtualCurSeek(File file)
{
int returnCode;
Assert(FileIsValid(file));
DO_DB(elog(LOG, "FileNonVirtualCurSeek: %d (%s) virtual position" INT64_FORMAT,
file, VfdCache[file].fileName,
VfdCache[file].seekPos));
returnCode = FileAccess(file);
if (returnCode < 0)
return returnCode;
return pg_lseek64(VfdCache[file].fd, 0, SEEK_CUR);
}
int
FileSync(File file)
{
int returnCode;
FileRepGpmonRecord_s gpmonRecord;
FileRepGpmonStatType_e whichStat;
if (fileRepRole == FileRepPrimaryRole)
{
whichStat = FileRepGpmonStatType_PrimaryFsyncSyscall;
FileRepGpmonStat_OpenRecord(whichStat, &gpmonRecord);
} else
{
whichStat = FileRepGpmonStatType_MirrorFsyncSyscall;
FileRepGpmonStat_OpenRecord(whichStat, &gpmonRecord);
}
Assert(FileIsValid(file));
DO_DB(elog(LOG, "FileSync: %d (%s)",
file, VfdCache[file].fileName));
returnCode = FileAccess(file);
if (returnCode < 0)
return returnCode;
#ifdef FAULT_INJECTOR
FaultInjector_InjectFaultIfSet(
FileRepFlush,
DDLNotSpecified,
"", //databaseName
""); // tableName
#endif
returnCode = pg_fsync(VfdCache[file].fd);
if (returnCode >= 0)
{
//only include stats if successful
if ((fileRepRole == FileRepPrimaryRole) ||
(fileRepRole == FileRepMirrorRole))
{
FileRepGpmonStat_CloseRecord(whichStat, &gpmonRecord);
}
}
return returnCode;
}
/*
* Routines that want to use stdio (ie, FILE*) should use AllocateFile
* rather than plain fopen(). This lets fd.c deal with freeing FDs if
* necessary to open the file. When done, call FreeFile rather than fclose.
*
* Note that files that will be open for any significant length of time
* should NOT be handled this way, since they cannot share kernel file
* descriptors with other files; there is grave risk of running out of FDs
* if anyone locks down too many FDs. Most callers of this routine are
* simply reading a config file that they will read and close immediately.
*
* fd.c will automatically close all files opened with AllocateFile at
* transaction commit or abort; this prevents FD leakage if a routine
* that calls AllocateFile is terminated prematurely by ereport(ERROR).
*
* Ideally this should be the *only* direct call of fopen() in the backend.
*/
FILE *
AllocateFile(const char *name, const char *mode)
{
FILE *file;
DO_DB(elog(LOG, "AllocateFile: Allocated %d (%s)",
numAllocatedDescs, name));
/*
* The test against MAX_ALLOCATED_DESCS prevents us from overflowing
* allocatedFiles[]; the test against max_safe_fds prevents AllocateFile
* from hogging every one of the available FDs, which'd lead to infinite
* looping.
*/
if (numAllocatedDescs >= MAX_ALLOCATED_DESCS ||
numAllocatedDescs >= max_safe_fds - 1)
elog(ERROR, "too many private files demanded");
TryAgain:
if ((file = fopen(name, mode)) != NULL)
{
AllocateDesc *desc = &allocatedDescs[numAllocatedDescs];
desc->kind = AllocateDescFile;
desc->desc.file = file;
desc->create_subid = GetCurrentSubTransactionId();
numAllocatedDescs++;
return desc->desc.file;
}
if (errno == EMFILE || errno == ENFILE)
{
int save_errno = errno;
ereport(LOG,
(errcode(ERRCODE_INSUFFICIENT_RESOURCES),
errmsg("out of file descriptors: %m; release and retry")));
errno = 0;
if (ReleaseLruFile())
goto TryAgain;
errno = save_errno;
}
return NULL;
}
/*
* Routines that want to use <dirent.h> (ie, DIR*) should use AllocateDir
* rather than plain opendir(). This lets fd.c deal with freeing FDs if
* necessary to open the directory, and with closing it after an elog.
* When done, call FreeDir rather than closedir.
*
* Ideally this should be the *only* direct call of opendir() in the backend.
*/
DIR *
AllocateDir(const char *dirname)
{
DIR *dir;
DO_DB(elog(LOG, "AllocateDir: Allocated %d (%s)",
numAllocatedDescs, dirname));
/*
* The test against MAX_ALLOCATED_DESCS prevents us from overflowing
* allocatedDescs[]; the test against max_safe_fds prevents AllocateDir
* from hogging every one of the available FDs, which'd lead to infinite
* looping.
*/
if (numAllocatedDescs >= MAX_ALLOCATED_DESCS ||
numAllocatedDescs >= max_safe_fds - 1)
elog(ERROR, "could not allocate directory: out of file handles");
TryAgain:
if ((dir = opendir(dirname)) != NULL)
{
AllocateDesc *desc = &allocatedDescs[numAllocatedDescs];
desc->kind = AllocateDescDir;
desc->desc.dir = dir;
desc->create_subid = GetCurrentSubTransactionId();
numAllocatedDescs++;
return desc->desc.dir;
}
if (errno == EMFILE || errno == ENFILE)
{
int save_errno = errno;
ereport(LOG,
(errcode(ERRCODE_INSUFFICIENT_RESOURCES),
errmsg("out of file handles: %m; release and retry")));
errno = 0;
if (ReleaseLruFile())
goto TryAgain;
errno = save_errno;
}
return NULL;
}
static void
FreeVfd(File file)
{
Vfd *vfdP = &VfdCache[file];
DO_DB(elog(LOG, "FreeVfd: %d (%s)",
file, vfdP->fileName ? vfdP->fileName : ""));
if (vfdP->fileName != NULL)
{
free(vfdP->fileName);
vfdP->fileName = NULL;
}
vfdP->fdstate = 0x0;
vfdP->nextFree = VfdCache[0].nextFree;
VfdCache[0].nextFree = file;
}
/*
* close a file when done with it
*/
void
FileClose(File file)
{
Vfd *vfdP;
Assert(FileIsValid(file));
DO_DB(elog(LOG, "FileClose: %d (%s)",
file, VfdCache[file].fileName));
vfdP = &VfdCache[file];
if (!FileIsNotOpen(file))
{
/* remove the file from the lru ring */
Delete(file);
/* close the file */
if (gp_retry_close(vfdP->fd))
elog(ERROR, "could not close file \"%s\": %m",
vfdP->fileName);
--nfile;
vfdP->fd = VFD_CLOSED;
}
/*
* Delete the file if it was temporary
*/
if (vfdP->fdstate & FD_TEMPORARY)
{
/* reset flag so that die() interrupt won't cause problems */
vfdP->fdstate &= ~FD_TEMPORARY;
if (unlink(vfdP->fileName))
elog(DEBUG1, "failed to unlink \"%s\": %m",
vfdP->fileName);
}
/*
* Return the Vfd slot to the free list
*/
FreeVfd(file);
}
