1996-07-09 08:22:35 +02:00
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/*-------------------------------------------------------------------------
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*
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* be-fsstubs.c--
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* support for filesystem operations on large objects
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*
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* Copyright (c) 1994, Regents of the University of California
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*
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*
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* IDENTIFICATION
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1997-04-21 06:28:59 +02:00
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* $Header: /cvsroot/pgsql/src/backend/libpq/be-fsstubs.c,v 1.8 1997/04/21 04:28:59 vadim Exp $
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1996-07-09 08:22:35 +02:00
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*
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* NOTES
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* This should be moved to a more appropriate place. It is here
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* for lack of a better place.
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*
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* Builtin functions for open/close/read/write operations on large objects.
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*
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* These functions operate in the current portal variable context, which
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* means the large object descriptors hang around between transactions and
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* are not deallocated until explicitly closed, or until the portal is
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* closed.
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*-------------------------------------------------------------------------
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*/
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1996-11-06 09:48:33 +01:00
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#include <fcntl.h>
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#include <sys/types.h>
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1996-11-15 19:38:20 +01:00
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#include <sys/stat.h>
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1996-11-06 09:48:33 +01:00
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#include <unistd.h>
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1997-04-21 06:28:59 +02:00
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#include <string.h>
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1996-07-09 08:22:35 +02:00
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1996-11-06 09:48:33 +01:00
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#include <postgres.h>
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#include <lib/dllist.h>
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#include <libpq/libpq.h>
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#include <libpq/libpq-fs.h>
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#include <nodes/nodes.h>
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#include <utils/memutils.h>
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#include <lib/fstack.h>
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#include <utils/mcxt.h>
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#include <storage/fd.h> /* for O_ */
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#include <storage/large_object.h>
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#include <libpq/be-fsstubs.h>
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1996-07-09 08:22:35 +02:00
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/*#define FSDB 1*/
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#define MAX_LOBJ_FDS 256
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static LargeObjectDesc *cookies[MAX_LOBJ_FDS];
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static GlobalMemory fscxt = NULL;
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static int newLOfd(LargeObjectDesc *lobjCookie);
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static void deleteLOfd(int fd);
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/*****************************************************************************
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* File Interfaces for Large Objects
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*****************************************************************************/
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int
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lo_open(Oid lobjId, int mode)
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{
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LargeObjectDesc *lobjDesc;
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int fd;
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MemoryContext currentContext;
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#if FSDB
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elog(NOTICE,"LOopen(%d,%d)",lobjId,mode);
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#endif
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if (fscxt == NULL) {
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fscxt = CreateGlobalMemory("Filesystem");
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}
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currentContext = MemoryContextSwitchTo((MemoryContext)fscxt);
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lobjDesc = inv_open(lobjId, mode);
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if (lobjDesc == NULL) { /* lookup failed */
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MemoryContextSwitchTo(currentContext);
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#if FSDB
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elog(NOTICE,"cannot open large object %d", lobjId);
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#endif
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return -1;
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}
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fd = newLOfd(lobjDesc);
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/* switch context back to orig. */
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MemoryContextSwitchTo(currentContext);
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return fd;
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}
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int
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lo_close(int fd)
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{
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MemoryContext currentContext;
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if (fd >= MAX_LOBJ_FDS) {
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elog(WARN,"lo_close: large obj descriptor (%d) out of range", fd);
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return -2;
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}
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if (cookies[fd] == NULL) {
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elog(WARN,"lo_close: invalid large obj descriptor (%d)", fd);
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return -3;
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}
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#if FSDB
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elog(NOTICE,"LOclose(%d)",fd);
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#endif
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Assert(fscxt != NULL);
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currentContext = MemoryContextSwitchTo((MemoryContext)fscxt);
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inv_close(cookies[fd]);
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MemoryContextSwitchTo(currentContext);
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deleteLOfd(fd);
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return 0;
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}
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/*
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* We assume the large object supports byte oriented reads and seeks so
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* that our work is easier.
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*/
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int
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lo_read(int fd, char *buf, int len)
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{
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Assert(cookies[fd]!=NULL);
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return inv_read(cookies[fd], buf, len);
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}
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int
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lo_write(int fd, char *buf, int len)
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{
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Assert(cookies[fd]!=NULL);
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return inv_write(cookies[fd], buf, len);
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}
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int
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lo_lseek(int fd, int offset, int whence)
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{
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1997-03-18 22:30:41 +01:00
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MemoryContext currentContext;
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int ret;
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1996-07-09 08:22:35 +02:00
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if (fd >= MAX_LOBJ_FDS) {
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elog(WARN,"lo_seek: large obj descriptor (%d) out of range", fd);
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return -2;
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}
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1997-03-18 22:30:41 +01:00
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currentContext = MemoryContextSwitchTo((MemoryContext)fscxt);
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ret = inv_seek(cookies[fd], offset, whence);
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MemoryContextSwitchTo(currentContext);
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return ret;
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1996-07-09 08:22:35 +02:00
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}
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Oid
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lo_creat(int mode)
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{
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LargeObjectDesc *lobjDesc;
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MemoryContext currentContext;
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Oid lobjId;
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if (fscxt == NULL) {
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fscxt = CreateGlobalMemory("Filesystem");
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}
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currentContext = MemoryContextSwitchTo((MemoryContext)fscxt);
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lobjDesc = inv_create(mode);
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if (lobjDesc == NULL) {
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MemoryContextSwitchTo(currentContext);
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return InvalidOid;
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}
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lobjId = lobjDesc->heap_r->rd_id;
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inv_close(lobjDesc);
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/* switch context back to original memory context */
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MemoryContextSwitchTo(currentContext);
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return lobjId;
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}
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int
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lo_tell(int fd)
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{
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if (fd >= MAX_LOBJ_FDS) {
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elog(WARN,"lo_tell: large object descriptor (%d) out of range",fd);
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return -2;
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}
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if (cookies[fd] == NULL) {
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elog(WARN,"lo_tell: invalid large object descriptor (%d)",fd);
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return -3;
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}
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return inv_tell(cookies[fd]);
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}
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int
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lo_unlink(Oid lobjId)
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{
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return (inv_destroy(lobjId));
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}
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/*****************************************************************************
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* Read/Write using varlena
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*****************************************************************************/
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struct varlena *
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LOread(int fd, int len)
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{
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struct varlena *retval;
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int totalread = 0;
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retval = (struct varlena *)palloc(sizeof(int32) + len);
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totalread = lo_read(fd, VARDATA(retval), len);
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VARSIZE(retval) = totalread + sizeof(int32);
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return retval;
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}
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int LOwrite(int fd, struct varlena *wbuf)
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{
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int totalwritten;
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int bytestowrite;
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bytestowrite = VARSIZE(wbuf) - sizeof(int32);
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totalwritten = lo_write(fd, VARDATA(wbuf), bytestowrite);
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return totalwritten;
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}
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/*****************************************************************************
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* Import/Export of Large Object
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*****************************************************************************/
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/*
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* lo_import -
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* imports a file as an (inversion) large object.
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*/
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Oid
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lo_import(text *filename)
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{
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int fd;
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int nbytes, tmp;
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#define BUFSIZE 1024
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char buf[BUFSIZE];
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1997-04-17 22:39:31 +02:00
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char fnamebuf[8192];
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1996-07-09 08:22:35 +02:00
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LargeObjectDesc *lobj;
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Oid lobjOid;
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1996-11-15 19:38:20 +01:00
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1996-07-09 08:22:35 +02:00
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/*
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* open the file to be read in
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*/
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1997-04-17 22:39:31 +02:00
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strncpy(fnamebuf, VARDATA(filename), VARSIZE(filename));
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fnamebuf[VARSIZE(filename)] = '\0';
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fd = open(fnamebuf, O_RDONLY, 0666);
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1996-07-09 08:22:35 +02:00
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if (fd < 0) { /* error */
|
1996-09-23 10:29:52 +02:00
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elog(WARN, "lo_import: can't open unix file\"%s\"\n",
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1997-04-17 22:39:31 +02:00
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fnamebuf);
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1996-07-09 08:22:35 +02:00
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}
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/*
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* create an inversion "object"
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*/
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lobj = inv_create(INV_READ|INV_WRITE);
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if (lobj == NULL) {
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elog(WARN, "lo_import: can't create inv object for \"%s\"",
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1997-04-17 22:39:31 +02:00
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fnamebuf);
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1996-07-09 08:22:35 +02:00
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}
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/*
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* the oid for the large object is just the oid of the relation
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* XInv??? which contains the data.
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*/
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lobjOid = lobj->heap_r->rd_id;
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/*
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* read in from the Unix file and write to the inversion file
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*/
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while ((nbytes = read(fd, buf, BUFSIZE)) > 0) {
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tmp = inv_write(lobj, buf, nbytes);
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if (tmp < nbytes) {
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elog(WARN, "lo_import: error while reading \"%s\"",
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1997-04-17 22:39:31 +02:00
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fnamebuf);
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1996-07-09 08:22:35 +02:00
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}
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}
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(void) close(fd);
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(void) inv_close(lobj);
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return lobjOid;
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}
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/*
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* lo_export -
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* exports an (inversion) large object.
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*/
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int4
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lo_export(Oid lobjId, text *filename)
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{
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int fd;
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int nbytes, tmp;
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#define BUFSIZE 1024
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char buf[BUFSIZE];
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1997-04-17 22:39:31 +02:00
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char fnamebuf[8192];
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1996-07-09 08:22:35 +02:00
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LargeObjectDesc *lobj;
|
1996-11-15 19:38:20 +01:00
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mode_t oumask;
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1996-07-09 08:22:35 +02:00
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/*
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* create an inversion "object"
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*/
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lobj = inv_open(lobjId, INV_READ);
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if (lobj == NULL) {
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elog(WARN, "lo_export: can't open inv object %d",
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lobjId);
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}
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/*
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* open the file to be written to
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*/
|
1996-11-15 19:38:20 +01:00
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oumask = umask((mode_t) 0);
|
1997-04-17 22:39:31 +02:00
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strncpy(fnamebuf, VARDATA(filename), VARSIZE(filename));
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fnamebuf[VARSIZE(filename)] = '\0';
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fd = open(fnamebuf, O_CREAT|O_WRONLY, 0666);
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1996-11-15 19:38:20 +01:00
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(void) umask(oumask);
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1996-07-09 08:22:35 +02:00
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if (fd < 0) { /* error */
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elog(WARN, "lo_export: can't open unix file\"%s\"",
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1997-04-17 22:39:31 +02:00
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fnamebuf);
|
1996-07-09 08:22:35 +02:00
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}
|
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|
|
/*
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|
|
|
* read in from the Unix file and write to the inversion file
|
|
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|
*/
|
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|
|
while ((nbytes = inv_read(lobj, buf, BUFSIZE)) > 0) {
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|
|
tmp = write(fd, buf, nbytes);
|
|
|
|
if (tmp < nbytes) {
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|
|
elog(WARN, "lo_export: error while writing \"%s\"",
|
1997-04-17 22:39:31 +02:00
|
|
|
fnamebuf);
|
1996-07-09 08:22:35 +02:00
|
|
|
}
|
|
|
|
}
|
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|
|
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|
(void) inv_close(lobj);
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|
|
(void) close(fd);
|
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|
|
return 1;
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|
|
|
}
|
|
|
|
|
|
|
|
|
|
|
|
/*****************************************************************************
|
|
|
|
* Support routines for this file
|
|
|
|
*****************************************************************************/
|
|
|
|
|
|
|
|
static int
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|
|
newLOfd(LargeObjectDesc *lobjCookie)
|
|
|
|
{
|
|
|
|
int i;
|
|
|
|
|
|
|
|
for (i = 0; i < MAX_LOBJ_FDS; i++) {
|
|
|
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|
|
|
|
if (cookies[i] == NULL) {
|
|
|
|
cookies[i] = lobjCookie;
|
|
|
|
return i;
|
|
|
|
}
|
|
|
|
}
|
|
|
|
return -1;
|
|
|
|
}
|
|
|
|
|
|
|
|
static void
|
|
|
|
deleteLOfd(int fd)
|
|
|
|
{
|
|
|
|
cookies[fd] = NULL;
|
|
|
|
}
|