/*
* Opens an existing file as BufFile
*
* If create is true, the file is created if it doesn't exist.
*
* Does not add the pgsql_tmp/ prefix to the file path before opening.
*
*/
BufFile *
BufFileOpenFile(const char *fileName, bool create, bool delOnClose, bool interXact)
{
bool closeAtEOXact = !interXact;
File pfile = OpenNamedFile(fileName,
create,
delOnClose,
closeAtEOXact); /* closeAtEOXact */
/*
* If we are trying to open an existing file and it failed,
* signal this to the caller.
*/
if (!create && pfile <= 0)
{
return NULL;
}
Assert(pfile >= 0);
BufFile *file = makeBufFile(pfile);
file->isTemp = delOnClose;
if (!create)
{
/* Open existing file, initialize its size */
file->maxoffset = FileDiskSize(file->file);
}
return file;
}
/*
* Open a temporary file that will (optionally) disappear when we close it.
*
* If 'makenameunique' is true, this function generates a file name which
* should be unique to this particular OpenTemporaryFile() request and
* distinct from any others in concurrent use on the same host. As a
* convenience for monitoring and debugging, the given 'fileName' string
* and 'extentseqnum' are embedded in the file name.
*
* If 'makenameunique' is false, then 'fileName' and 'extentseqnum' identify a
* new or existing temporary file which other processes also could open and
* share.
*
* If 'create' is true, a new file is created. If successful, a valid vfd
* index (>0) is returned; otherwise an error is thrown.
*
* If 'create' is false, an existing file is opened. If successful, a valid
* vfd index (>0) is returned. If the file does not exist or cannot be
* opened, an invalid vfd index (<= 0) is returned.
*
* If 'delOnClose' is true, then the file is removed when you call
* FileClose(); or when the process exits; or (provided 'closeAtEOXact' is
* true) when the transaction ends.
*
* If 'closeAtEOXact' is true, the vfd is closed automatically at end of
* transaction unless you have called FileClose() to close it before then.
* If 'closeAtEOXact' is false, the vfd state is not changed at end of
* transaction.
*
* In most cases, you don't want temporary files to outlive the transaction
* that created them, so you should specify 'true' for both 'delOnClose' and
* 'closeAtEOXact'.
*/
File
OpenTemporaryFile(const char *fileName,
int extentseqnum,
bool makenameunique,
bool create,
bool delOnClose,
bool closeAtEOXact)
{
char tempfilepath[MAXPGPATH];
Assert(fileName);
AssertImply(makenameunique, create && delOnClose);
char tempfileprefix[MAXPGPATH];
int len = GetTempFilePrefix(tempfileprefix, MAXPGPATH, fileName);
insist_log(len <= MAXPGPATH - 1, "could not generate temporary file name");
if (makenameunique)
{
/*
* Generate a tempfile name that should be unique within the current
* database instance.
*/
snprintf(tempfilepath, sizeof(tempfilepath),
"%s_%d_%04d.%ld",
tempfileprefix,
MyProcPid,
extentseqnum,
tempFileCounter++);
}
else
{
snprintf(tempfilepath, sizeof(tempfilepath),
"%s.%04d",
tempfileprefix,
extentseqnum);
}
return OpenNamedFile(tempfilepath, create, delOnClose, closeAtEOXact);
} /* OpenTemporaryFile */
