Major overhaul of large-object implementation, by Denis Perchine with

kibitzing from Tom Lane.  Large objects are now all stored in a single
system relation "pg_largeobject" --- no more xinv or xinx files, no more
relkind 'l'.  This should offer substantial performance improvement for
large numbers of LOs, since there won't be directory bloat anymore.
It'll also fix problems like running out of locktable space when you
access thousands of LOs in one transaction.
Also clean up cruft in read/write routines.  LOs with "holes" in them
(never-written byte ranges) now work just like Unix files with holes do:
a hole reads as zeroes but doesn't occupy storage space.
INITDB forced!

1 files changed, 20 insertions, 26 deletions

diff --git a/src/backend/libpq/be-fsstubs.c b/src/backend/libpq/be-fsstubs.c
index bb5c7f6e556..7eff84e5d33 100644
--- a/src/backend/libpq/be-fsstubs.c
+++ b/src/backend/libpq/be-fsstubs.c
@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/backend/libpq/be-fsstubs.c,v 1.54 2000/10/22 05:27:12 momjian Exp $
+ *	  $Header: /cvsroot/pgsql/src/backend/libpq/be-fsstubs.c,v 1.55 2000/10/24 01:38:26 tgl Exp $
  *
  * NOTES
  *	  This should be moved to a more appropriate place.  It is here
@@ -32,13 +32,13 @@
  *-------------------------------------------------------------------------
  */
 
+#include "postgres.h"
+
 #include <fcntl.h>
 #include <sys/types.h>
 #include <sys/stat.h>
 #include <unistd.h>
 
-#include "postgres.h"
-
 #include "catalog/pg_shadow.h"
 #include "libpq/be-fsstubs.h"
 #include "libpq/libpq-fs.h"
@@ -50,8 +50,7 @@
 
 /*#define FSDB 1*/
 #define MAX_LOBJ_FDS	256
-#define BUFSIZE			1024
-#define FNAME_BUFSIZE	8192
+#define BUFSIZE			8192
 
 /*
  * LO "FD"s are indexes into this array.
@@ -141,10 +140,10 @@ lo_close(PG_FUNCTION_ARGS)
 
 	inv_close(cookies[fd]);
 
-	MemoryContextSwitchTo(currentContext);
-
 	deleteLOfd(fd);
 
+	MemoryContextSwitchTo(currentContext);
+
 	PG_RETURN_INT32(0);
 }
 
@@ -267,7 +266,7 @@ lo_creat(PG_FUNCTION_ARGS)
 		PG_RETURN_OID(InvalidOid);
 	}
 
-	lobjId = RelationGetRelid(lobjDesc->heap_r);
+	lobjId = lobjDesc->id;
 
 	inv_close(lobjDesc);
 
@@ -310,8 +309,8 @@ lo_unlink(PG_FUNCTION_ARGS)
 	 * any LO-specific data structures at all.	(Again, that's probably
 	 * more than this module ought to be assuming.)
 	 *
-	 * XXX there ought to be some code to clean up any open LOs that
-	 * reference the specified relation... as is, they remain "open".
+	 * XXX there ought to be some code to clean up any open LO FDs that
+	 * reference the specified LO... as is, they remain "open".
 	 */
 	PG_RETURN_INT32(inv_drop(lobjId));
 }
@@ -367,7 +366,7 @@ lo_import(PG_FUNCTION_ARGS)
 	int			nbytes,
 				tmp;
 	char		buf[BUFSIZE];
-	char		fnamebuf[FNAME_BUFSIZE];
+	char		fnamebuf[MAXPGPATH];
 	LargeObjectDesc *lobj;
 	Oid			lobjOid;
 
@@ -382,8 +381,8 @@ lo_import(PG_FUNCTION_ARGS)
 	 * open the file to be read in
 	 */
 	nbytes = VARSIZE(filename) - VARHDRSZ;
-	if (nbytes >= FNAME_BUFSIZE)
-		nbytes = FNAME_BUFSIZE-1;
+	if (nbytes >= MAXPGPATH)
+		nbytes = MAXPGPATH-1;
 	memcpy(fnamebuf, VARDATA(filename), nbytes);
 	fnamebuf[nbytes] = '\0';
 	fd = PathNameOpenFile(fnamebuf, O_RDONLY | PG_BINARY, 0666);
@@ -398,12 +397,7 @@ lo_import(PG_FUNCTION_ARGS)
 	if (lobj == NULL)
 		elog(ERROR, "lo_import: can't create inv object for \"%s\"",
 			 fnamebuf);
-
-	/*
-	 * the oid for the large object is just the oid of the relation
-	 * XInv??? which contains the data.
-	 */
-	lobjOid = RelationGetRelid(lobj->heap_r);
+	lobjOid = lobj->id;
 
 	/*
 	 * read in from the Unix file and write to the inversion file
@@ -411,7 +405,7 @@ lo_import(PG_FUNCTION_ARGS)
 	while ((nbytes = FileRead(fd, buf, BUFSIZE)) > 0)
 	{
 		tmp = inv_write(lobj, buf, nbytes);
-		if (tmp < nbytes)
+		if (tmp != nbytes)
 			elog(ERROR, "lo_import: error while reading \"%s\"",
 				 fnamebuf);
 	}
@@ -435,7 +429,7 @@ lo_export(PG_FUNCTION_ARGS)
 	int			nbytes,
 				tmp;
 	char		buf[BUFSIZE];
-	char		fnamebuf[FNAME_BUFSIZE];
+	char		fnamebuf[MAXPGPATH];
 	LargeObjectDesc *lobj;
 	mode_t		oumask;
 
@@ -461,8 +455,8 @@ lo_export(PG_FUNCTION_ARGS)
 	 * world-writable export files doesn't seem wise.
 	 */
 	nbytes = VARSIZE(filename) - VARHDRSZ;
-	if (nbytes >= FNAME_BUFSIZE)
-		nbytes = FNAME_BUFSIZE-1;
+	if (nbytes >= MAXPGPATH)
+		nbytes = MAXPGPATH-1;
 	memcpy(fnamebuf, VARDATA(filename), nbytes);
 	fnamebuf[nbytes] = '\0';
 	oumask = umask((mode_t) 0022);
@@ -473,12 +467,12 @@ lo_export(PG_FUNCTION_ARGS)
 			 fnamebuf);
 
 	/*
-	 * read in from the Unix file and write to the inversion file
+	 * read in from the inversion file and write to the Unix file
 	 */
 	while ((nbytes = inv_read(lobj, buf, BUFSIZE)) > 0)
 	{
 		tmp = FileWrite(fd, buf, nbytes);
-		if (tmp < nbytes)
+		if (tmp != nbytes)
 			elog(ERROR, "lo_export: error while writing \"%s\"",
 				 fnamebuf);
 	}
@@ -513,7 +507,7 @@ lo_commit(bool isCommit)
 		if (cookies[i] != NULL)
 		{
 			if (isCommit)
-				inv_cleanindex(cookies[i]);
+				inv_close(cookies[i]);
 			cookies[i] = NULL;
 		}
 	}