BACKED OUT.

> Regression tests opr_sanity and sanity_check are now failing.

Um, Bruce, I've said several times that I didn't think Perchine's large
object changes should be applied until someone had actually reviewed
them.

src/backend/catalog/Makefile

@@ -2,7 +2,7 @@
 #
 # Makefile for catalog
 #
-# $Header: /cvsroot/pgsql/src/backend/catalog/Makefile,v 1.29 2000/10/21 15:55:21 momjian Exp $
+# $Header: /cvsroot/pgsql/src/backend/catalog/Makefile,v 1.30 2000/10/22 05:27:10 momjian Exp $
 #
 #-------------------------------------------------------------------------
 
@@ -11,8 +11,7 @@ top_builddir = ../../..
 include $(top_builddir)/src/Makefile.global
 
 OBJS = catalog.o heap.o index.o indexing.o aclchk.o \
-       pg_aggregate.o pg_largeobject.o pg_operator.o pg_proc.o \
-       pg_type.o
+       pg_aggregate.o pg_operator.o pg_proc.o pg_type.o
 
 BKIFILES = global.bki template1.bki global.description template1.description
 
@@ -30,7 +29,7 @@ TEMPLATE1_BKI_SRCS := $(addprefix $(top_srcdir)/src/include/catalog/,\
 	pg_proc.h pg_type.h pg_attribute.h pg_class.h \
 	pg_inherits.h pg_index.h pg_statistic.h \
 	pg_operator.h pg_opclass.h pg_am.h pg_amop.h pg_amproc.h \
-	pg_language.h pg_largeobject.h \
+	pg_language.h \
 	pg_aggregate.h pg_ipl.h pg_inheritproc.h \
 	pg_rewrite.h pg_listener.h pg_description.h indexing.h \
     )

src/backend/catalog/indexing.c

@@ -9,7 +9,7 @@
  *
  *
  * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/backend/catalog/indexing.c,v 1.70 2000/10/21 15:55:21 momjian Exp $
+ *	  $Header: /cvsroot/pgsql/src/backend/catalog/indexing.c,v 1.71 2000/10/22 05:27:10 momjian Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -51,8 +51,6 @@ char	   *Name_pg_inherits_indices[Num_pg_inherits_indices] =
 {InheritsRelidSeqnoIndex};
 char	   *Name_pg_language_indices[Num_pg_language_indices] =
 {LanguageOidIndex, LanguageNameIndex};
-char	   *Name_pg_largeobject_indices[Num_pg_largeobject_indices] =
-{LargeobjectLOIdIndex, LargeobjectLOIdPNIndex};
 char	   *Name_pg_listener_indices[Num_pg_listener_indices] =
 {ListenerPidRelnameIndex};
 char	   *Name_pg_opclass_indices[Num_pg_opclass_indices] =

src/backend/catalog/pg_largeobject.c

-/*-------------------------------------------------------------------------
- *
- * pg_largeobject.c
- *	  routines to support manipulation of the pg_largeobject relation
- *
- * Portions Copyright (c) 1996-2000, PostgreSQL, Inc
- * Portions Copyright (c) 1994, Regents of the University of California
- *
- *
- * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/backend/catalog/pg_largeobject.c,v 1.3 2000/10/21 15:55:21 momjian Exp $
- *
- *-------------------------------------------------------------------------
- */
-#include "postgres.h"
-
-#include "access/genam.h"
-#include "access/heapam.h"
-#include "catalog/catname.h"
-#include "catalog/indexing.h"
-#include "catalog/pg_largeobject.h"
-#include "miscadmin.h"
-#include "utils/fmgroids.h"
-
-bytea *_byteain(const char *data, int32 size);
-
-bytea *_byteain(const char *data, int32 size) {
-	bytea	*result;
-
-	result = (bytea *)palloc(size + VARHDRSZ);
-	result->vl_len = size + VARHDRSZ;
-	if (size > 0)
-		memcpy(result->vl_dat, data, size);
-	
-	return result;
-}
-
-Oid LargeobjectCreate(Oid loid) {
-	Oid		retval;
-  	Relation        	pg_largeobject;
-	HeapTuple	ntup = (HeapTuple) palloc(sizeof(HeapTupleData));
-	Relation		idescs[Num_pg_largeobject_indices];
-	Datum		values[Natts_pg_largeobject];
-	char		nulls[Natts_pg_largeobject];
-	int		i;
-
-	for (i=0; i<Natts_pg_largeobject; i++) {
-		nulls[i] = ' ';
-		values[i] = (Datum)NULL;
-	}
-
-	i = 0;
-	values[i++] = ObjectIdGetDatum(loid);
-	values[i++] = Int32GetDatum(0);
-	values[i++] = (Datum) _byteain(NULL, 0);
-	
-	pg_largeobject = heap_openr(LargeobjectRelationName, RowExclusiveLock);
-	ntup = heap_formtuple(pg_largeobject->rd_att, values, nulls);
-	retval = heap_insert(pg_largeobject, ntup);
-
-	if (!IsIgnoringSystemIndexes()) {
-		CatalogOpenIndices(Num_pg_largeobject_indices, Name_pg_largeobject_indices, idescs);
-		CatalogIndexInsert(idescs, Num_pg_largeobject_indices, pg_largeobject, ntup);
-		CatalogCloseIndices(Num_pg_largeobject_indices, idescs);
-	}
-	
-	heap_close(pg_largeobject, RowExclusiveLock);
-	heap_freetuple(ntup);
-	
-	CommandCounterIncrement();
-
-	return retval;
-}
-
-void LargeobjectDrop(Oid loid) {
-	Relation	pg_largeobject;
-	Relation	pg_lo_id;
-	ScanKeyData	skey;
-	IndexScanDesc	sd = (IndexScanDesc) NULL;
-	RetrieveIndexResult	indexRes;
-	int	found = 0;
-
-	ScanKeyEntryInitialize(&skey,
-					    (bits16) 0x0,
-					    (AttrNumber) 1,
-					    (RegProcedure) F_OIDEQ,
-					    ObjectIdGetDatum(loid));
-
-	pg_largeobject = heap_openr(LargeobjectRelationName, RowShareLock);
-	pg_lo_id = index_openr(LargeobjectLOIdIndex);
-
-	sd = index_beginscan(pg_lo_id, false, 1, &skey);
-
-	while((indexRes = index_getnext(sd, ForwardScanDirection))) {
-		found++;
-		heap_delete(pg_largeobject, &indexRes->heap_iptr, NULL);
-		pfree(indexRes);
-	}
-
-	index_endscan(sd);
-
-	index_close(pg_lo_id);
-	heap_close(pg_largeobject, RowShareLock);
-	if (found == 0)
-		elog(ERROR, "LargeobjectDrop: large object %d not found", loid);
-}
-
-int LargeobjectFind(Oid loid) {
-	int	retval = 0;
-	Relation	pg_lo_id;
-	ScanKeyData	skey;
-	IndexScanDesc	sd = (IndexScanDesc) NULL;
-	RetrieveIndexResult	indexRes;
-
-	ScanKeyEntryInitialize(&skey,
-					    (bits16) 0x0,
-					    (AttrNumber) 1,
-					    (RegProcedure) F_OIDEQ,
-					    ObjectIdGetDatum(loid));
-
-	pg_lo_id = index_openr(LargeobjectLOIdIndex);
-
-	sd = index_beginscan(pg_lo_id, false, 1, &skey);
-
-	if ((indexRes = index_getnext(sd, ForwardScanDirection))) {
-		retval = 1;
-		pfree(indexRes);
-	}
-
-	index_endscan(sd);
-
-	index_close(pg_lo_id);
-	return retval;
-}
-

src/backend/libpq/be-fsstubs.c

@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/backend/libpq/be-fsstubs.c,v 1.53 2000/10/21 15:55:22 momjian Exp $
+ *	  $Header: /cvsroot/pgsql/src/backend/libpq/be-fsstubs.c,v 1.54 2000/10/22 05:27:12 momjian Exp $
  *
  * NOTES
  *	  This should be moved to a more appropriate place.  It is here
@@ -267,7 +267,7 @@ lo_creat(PG_FUNCTION_ARGS)
 		PG_RETURN_OID(InvalidOid);
 	}
 
-	lobjId = lobjDesc->id;
+	lobjId = RelationGetRelid(lobjDesc->heap_r);
 
 	inv_close(lobjDesc);
 
@@ -512,10 +512,8 @@ lo_commit(bool isCommit)
 	{
 		if (cookies[i] != NULL)
 		{
-/*
 			if (isCommit)
 				inv_cleanindex(cookies[i]);
-*/
 			cookies[i] = NULL;
 		}
 	}

src/backend/storage/large_object/inv_api.c

@@ -9,7 +9,7 @@
  *
  *
  * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/backend/storage/large_object/inv_api.c,v 1.77 2000/10/21 15:55:24 momjian Exp $
+ *	  $Header: /cvsroot/pgsql/src/backend/storage/large_object/inv_api.c,v 1.78 2000/10/22 05:27:15 momjian Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -22,34 +22,58 @@
 #include "access/genam.h"
 #include "access/heapam.h"
 #include "access/nbtree.h"
-#include "access/htup.h"
 #include "catalog/catalog.h"
-#include "catalog/catname.h"
 #include "catalog/heap.h"
 #include "catalog/index.h"
-#include "catalog/indexing.h"
 #include "catalog/pg_opclass.h"
-#include "catalog/pg_largeobject.h"
 #include "catalog/pg_type.h"
 #include "libpq/libpq-fs.h"
 #include "miscadmin.h"
 #include "storage/large_object.h"
 #include "storage/smgr.h"
 #include "utils/fmgroids.h"
-#include "utils/builtins.h"
+#include "utils/relcache.h"
 
-#include <errno.h>
+/*
+ *	Warning, Will Robinson...  In order to pack data into an inversion
+ *	file as densely as possible, we violate the class abstraction here.
+ *	When we're appending a new tuple to the end of the table, we check
+ *	the last page to see how much data we can put on it.  If it's more
+ *	than IMINBLK, we write enough to fill the page.  This limits external
+ *	fragmentation.	In no case can we write more than IMAXBLK, since
+ *	the 8K postgres page size less overhead leaves only this much space
+ *	for data.
+ */
 
-#define	IBLKSIZE		(MaxTupleSize - MinHeapTupleBitmapSize - sizeof(int32) * 3)
+/*
+ *		In order to prevent buffer leak on transaction commit, large object
+ *		scan index handling has been modified. Indexes are persistant inside
+ *		a transaction but may be closed between two calls to this API (when
+ *		transaction is committed while object is opened, or when no
+ *		transaction is active). Scan indexes are thus now reinitialized using
+ *		the object current offset. [PA]
+ *
+ *		Some cleanup has been also done for non freed memory.
+ *
+ *		For subsequent notes, [PA] is Pascal Andr <andre@via.ecp.fr>
+ */
 
-/* Defined in backend/storage/catalog/large_object.c */
-bytea *_byteain(const char *data, int32 size);
-
-static int32 getbytealen(bytea *data) {
-	if (VARSIZE(data) < VARHDRSZ)
-		elog(ERROR, "getbytealen: VARSIZE(data) < VARHDRSZ. This is internal error.");
-  return (VARSIZE(data) - VARHDRSZ);
-}
+#define IFREESPC(p)		(PageGetFreeSpace(p) - \
+				 MAXALIGN(offsetof(HeapTupleHeaderData,t_bits)) - \
+				 MAXALIGN(sizeof(struct varlena) + sizeof(int32)) - \
+				 sizeof(double))
+#define IMAXBLK			8092
+#define IMINBLK			512
+
+/* non-export function prototypes */
+static HeapTuple inv_newtuple(LargeObjectDesc *obj_desc, Buffer buffer,
+			 Page page, char *dbuf, int nwrite);
+static void inv_fetchtup(LargeObjectDesc *obj_desc, HeapTuple tuple, Buffer *buffer);
+static int	inv_wrnew(LargeObjectDesc *obj_desc, char *buf, int nbytes);
+static int inv_wrold(LargeObjectDesc *obj_desc, char *dbuf, int nbytes,
+		  HeapTuple tuple, Buffer buffer);
+static void inv_indextup(LargeObjectDesc *obj_desc, HeapTuple tuple);
+static int	_inv_getsize(Relation hreln, TupleDesc hdesc, Relation ireln);
 
 /*
  *	inv_create -- create a new large object.
@@ -60,12 +84,18 @@ static int32 getbytealen(bytea *data) {
  *		Returns:
  *		  large object descriptor, appropriately filled in.
  */
-
 LargeObjectDesc *
 inv_create(int flags)
 {
-	int		file_oid;
 	LargeObjectDesc *retval;
+	Oid			file_oid;
+	Relation	r;
+	Relation	indr;
+	TupleDesc	tupdesc;
+	IndexInfo  *indexInfo;
+	Oid			classObjectId[1];
+	char		objname[NAMEDATALEN];
+	char		indname[NAMEDATALEN];
 
 	/*
 	 * add one here since the pg_class tuple created will have the next
@@ -74,25 +104,104 @@ inv_create(int flags)
 	 */
 	file_oid = newoid() + 1;
 
-	if (LargeobjectFind(file_oid) == 1)
-		elog(ERROR, "inv_create: large object %d already exists. This is internal error.", file_oid);
+	/* come up with some table names */
+	sprintf(objname, "xinv%u", file_oid);
+	sprintf(indname, "xinx%u", file_oid);
+
+	if (RelnameFindRelid(objname) != InvalidOid)
+		elog(ERROR,
+		  "internal error: %s already exists -- cannot create large obj",
+			 objname);
+	if (RelnameFindRelid(indname) != InvalidOid)
+		elog(ERROR,
+		  "internal error: %s already exists -- cannot create large obj",
+			 indname);
+
+	/* this is pretty painful...  want a tuple descriptor */
+	tupdesc = CreateTemplateTupleDesc(2);
+	TupleDescInitEntry(tupdesc, (AttrNumber) 1,
+					   "olastbye",
+					   INT4OID,
+					   -1, 0, false);
+	TupleDescInitEntry(tupdesc, (AttrNumber) 2,
+					   "odata",
+					   BYTEAOID,
+					   -1, 0, false);
+
+	/*
+	 * First create the table to hold the inversion large object.  It will
+	 * be located on whatever storage manager the user requested.
+	 */
+
+	heap_create_with_catalog(objname, tupdesc, RELKIND_LOBJECT,
+							 false, false);
+
+	/* make the relation visible in this transaction */
+	CommandCounterIncrement();
+
+	/*--------------------
+	 * We hold AccessShareLock on any large object we have open
+	 * by inv_create or inv_open; it is released by inv_close.
+	 * Note this will not conflict with ExclusiveLock or ShareLock
+	 * that we acquire when actually reading/writing; it just prevents
+	 * deletion of the large object while we have it open.
+	 *--------------------
+	 */
+	r = heap_openr(objname, AccessShareLock);
+
+	/*
+	 * Now create a btree index on the relation's olastbyte attribute to
+	 * make seeks go faster.
+	 */
+	indexInfo = makeNode(IndexInfo);
+	indexInfo->ii_NumIndexAttrs = 1;
+	indexInfo->ii_NumKeyAttrs = 1;
+	indexInfo->ii_KeyAttrNumbers[0] = 1;
+	indexInfo->ii_Predicate = NULL;
+	indexInfo->ii_FuncOid = InvalidOid;
+	indexInfo->ii_Unique = false;
+
+	classObjectId[0] = INT4_OPS_OID;
+
+	index_create(objname, indname, indexInfo,
+				 BTREE_AM_OID, classObjectId,
+				 false, false, false);
+
+	/* make the index visible in this transaction */
+	CommandCounterIncrement();
+
+	indr = index_openr(indname);
+
+	if (!RelationIsValid(indr))
+	{
+		elog(ERROR, "cannot create index for large obj on %s under inversion",
+			 DatumGetCString(DirectFunctionCall1(smgrout,
+							 Int16GetDatum(DEFAULT_SMGR))));
+	}
 
 	retval = (LargeObjectDesc *) palloc(sizeof(LargeObjectDesc));
 
-	if (flags & INV_WRITE) {
+	retval->heap_r = r;
+	retval->index_r = indr;
+	retval->iscan = (IndexScanDesc) NULL;
+	retval->hdesc = RelationGetDescr(r);
+	retval->idesc = RelationGetDescr(indr);
+	retval->offset = retval->lowbyte = retval->highbyte = 0;
+	ItemPointerSetInvalid(&(retval->htid));
+	retval->flags = 0;
+
+	if (flags & INV_WRITE)
+	{
+		LockRelation(r, ExclusiveLock);
 		retval->flags = IFS_WRLOCK | IFS_RDLOCK;
-		retval->heap_r = heap_openr(LargeobjectRelationName, RowExclusiveLock);
-	} else if (flags & INV_READ) {
+	}
+	else if (flags & INV_READ)
+	{
+		LockRelation(r, ShareLock);
 		retval->flags = IFS_RDLOCK;
-		retval->heap_r = heap_openr(LargeobjectRelationName, AccessShareLock);
-	} else
-		elog(ERROR, "inv_create: invalid flags: %d", flags);
+	}
+	retval->flags |= IFS_ATEOF;	/* since we know the object is empty */
 
-	retval->flags |= IFS_ATEOF;
-	retval->index_r = index_openr(LargeobjectLOIdPNIndex);
-	retval->offset = 0;
-	retval->id = file_oid;
-	(void)LargeobjectCreate(file_oid);
 	return retval;
 }
 
@@ -100,24 +209,46 @@ LargeObjectDesc *
 inv_open(Oid lobjId, int flags)
 {
 	LargeObjectDesc *retval;
+	Relation	r;
+	char	   *indname;
+	Relation	indrel;
+
+	r = heap_open(lobjId, AccessShareLock);
 
-	if (LargeobjectFind(lobjId) == 0)
-		elog(ERROR, "inv_open: large object %d not found", lobjId);
+	indname = pstrdup(RelationGetRelationName(r));
+
+	/*
+	 * hack hack hack...  we know that the fourth character of the
+	 * relation name is a 'v', and that the fourth character of the index
+	 * name is an 'x', and that they're otherwise identical.
+	 */
+	indname[3] = 'x';
+	indrel = index_openr(indname);
 
-	retval = (LargeObjectDesc *)palloc(sizeof(LargeObjectDesc));
+	if (!RelationIsValid(indrel))
+		return (LargeObjectDesc *) NULL;
 
-	if (flags & INV_WRITE) {
+	retval = (LargeObjectDesc *) palloc(sizeof(LargeObjectDesc));
+
+	retval->heap_r = r;
+	retval->index_r = indrel;
+	retval->iscan = (IndexScanDesc) NULL;
+	retval->hdesc = RelationGetDescr(r);
+	retval->idesc = RelationGetDescr(indrel);
+	retval->offset = retval->lowbyte = retval->highbyte = 0;
+	ItemPointerSetInvalid(&(retval->htid));
+	retval->flags = 0;
+
+	if (flags & INV_WRITE)
+	{
+		LockRelation(r, ExclusiveLock);
 		retval->flags = IFS_WRLOCK | IFS_RDLOCK;
-		retval->heap_r = heap_openr(LargeobjectRelationName, RowExclusiveLock);
-	} else if (flags & INV_READ) {
+	}
+	else if (flags & INV_READ)
+	{
+		LockRelation(r, ShareLock);
 		retval->flags = IFS_RDLOCK;
-		retval->heap_r = heap_openr(LargeobjectRelationName, AccessShareLock);
-	} else
-		elog(ERROR, "inv_open: invalid flags: %d", flags);
-
-	retval->index_r = index_openr(LargeobjectLOIdPNIndex);
-	retval->offset = 0;
-	retval->id = lobjId;
+	}
 
 	return retval;
 }
@@ -130,11 +261,15 @@ inv_close(LargeObjectDesc *obj_desc)
 {
 	Assert(PointerIsValid(obj_desc));
 
-	if (obj_desc->flags & IFS_WRLOCK)
-		heap_close(obj_desc->heap_r, RowExclusiveLock);
-	else if (obj_desc->flags & IFS_RDLOCK)
-		heap_close(obj_desc->heap_r, AccessShareLock);
+	if (obj_desc->iscan != (IndexScanDesc) NULL)
+	{
+		index_endscan(obj_desc->iscan);
+		obj_desc->iscan = NULL;
+	}
+
 	index_close(obj_desc->index_r);
+	heap_close(obj_desc->heap_r, AccessShareLock);
+
 	pfree(obj_desc);
 }
 
@@ -146,7 +281,24 @@ inv_close(LargeObjectDesc *obj_desc)
 int
 inv_drop(Oid lobjId)
 {
-	LargeobjectDrop(lobjId);
+	Relation	r;
+
+	r = RelationIdGetRelation(lobjId);
+	if (!RelationIsValid(r))
+		return -1;
+
+	if (r->rd_rel->relkind != RELKIND_LOBJECT)
+	{
+		/* drop relcache refcount from RelationIdGetRelation */
+		RelationDecrementReferenceCount(r);
+		return -1;
+	}
+
+	/*
+	 * Since heap_drop_with_catalog will destroy the relcache entry,
+	 * there's no need to drop the refcount in this path.
+	 */
+	heap_drop_with_catalog(RelationGetRelationName(r), false);
 	return 1;
 }
 
@@ -212,75 +364,71 @@ inv_stat(LargeObjectDesc *obj_desc, struct pgstat * stbuf)
 
 #endif
 
-static uint32 inv_getsize(LargeObjectDesc *obj_desc) {
-	uint32			found = 0;
-	uint32			lastbyte = 0;
+int
+inv_seek(LargeObjectDesc *obj_desc, int offset, int whence)
+{
+	int			oldOffset;
+	Datum		d;
 	ScanKeyData skey;
-	IndexScanDesc		sd = (IndexScanDesc) NULL;
-	RetrieveIndexResult	indexRes;
-	HeapTupleData		tuple;
-	Buffer			buffer;
-	Form_pg_largeobject	data;
 
 	Assert(PointerIsValid(obj_desc));
 
-	ScanKeyEntryInitialize(&skey,
-					    (bits16) 0x0,
-					    (AttrNumber) 1,
-					    (RegProcedure) F_OIDEQ,
-					    ObjectIdGetDatum(obj_desc->id));
-
-	sd = index_beginscan(obj_desc->index_r, true, 1, &skey);
-	tuple.t_datamcxt = CurrentMemoryContext;
-	tuple.t_data = NULL;
-	while ((indexRes = index_getnext(sd, ForwardScanDirection))) {
-		tuple.t_self = indexRes->heap_iptr;
-		heap_fetch(obj_desc->heap_r, SnapshotNow, &tuple, &buffer);
-		pfree(indexRes);
-		if (tuple.t_data == NULL)
-			continue;
-		found++;
-		data = (Form_pg_largeobject) GETSTRUCT(&tuple);
-		lastbyte = data->pageno * IBLKSIZE + getbytealen(&(data->data));
-		ReleaseBuffer(buffer);
-		break;
+	if (whence == SEEK_CUR)
+	{
+		offset += obj_desc->offset;		/* calculate absolute position */
+	}
+	else if (whence == SEEK_END)
+	{
+		/* need read lock for getsize */
+		if (!(obj_desc->flags & IFS_RDLOCK))
+		{
+			LockRelation(obj_desc->heap_r, ShareLock);
+			obj_desc->flags |= IFS_RDLOCK;
 		}
+		offset += _inv_getsize(obj_desc->heap_r,
+							   obj_desc->hdesc,
+							   obj_desc->index_r);
+	}
+	/* now we can assume that the operation is SEEK_SET */
 
-	index_endscan(sd);
+	/*
+	 * Whenever we do a seek, we turn off the EOF flag bit to force
+	 * ourselves to check for real on the next read.
+	 */
 
-	if (found == 0)
-		elog(ERROR, "inv_getsize: large object %d not found", obj_desc->id);
-	return lastbyte;
-}
+	obj_desc->flags &= ~IFS_ATEOF;
+	oldOffset = obj_desc->offset;
+	obj_desc->offset = offset;
 
-int
-inv_seek(LargeObjectDesc *obj_desc, int offset, int whence)
-{
-	Assert(PointerIsValid(obj_desc));
+	/* try to avoid doing any work, if we can manage it */
+	if (offset >= obj_desc->lowbyte
+		&& offset <= obj_desc->highbyte
+		&& oldOffset <= obj_desc->highbyte
+		&& obj_desc->iscan != (IndexScanDesc) NULL)
+		return offset;
 
-	switch (whence) {
-		case SEEK_SET:
-			if (offset < 0)
-				elog(ERROR, "inv_seek: invalid offset: %d", offset);
-			obj_desc->offset = offset;
-			break;
-		case SEEK_CUR:
-			if ((obj_desc->offset + offset) < 0)
-				elog(ERROR, "inv_seek: invalid offset: %d", offset);
-			obj_desc->offset += offset;
-			break;
-		case SEEK_END:
+	/*
+	 * To do a seek on an inversion file, we start an index scan that will
+	 * bring us to the right place.  Each tuple in an inversion file
+	 * stores the offset of the last byte that appears on it, and we have
+	 * an index on this.
+	 */
+	if (obj_desc->iscan != (IndexScanDesc) NULL)
 	{
-				int4 size = inv_getsize(obj_desc);
-				if (offset > size)
-					elog(ERROR, "inv_seek: invalid offset");
-				obj_desc->offset = size - offset;
+		d = Int32GetDatum(offset);
+		btmovescan(obj_desc->iscan, d);
 	}
-			break;
-		default:
-			elog(ERROR, "inv_seek: invalid whence: %d", whence);
+	else
+	{
+		ScanKeyEntryInitialize(&skey, 0x0, 1, F_INT4GE,
+							   Int32GetDatum(offset));
+
+		obj_desc->iscan = index_beginscan(obj_desc->index_r,
+										  (bool) 0, (uint16) 1,
+										  &skey);
 	}
-	return obj_desc->offset;
+
+	return offset;
 }
 
 int
@@ -294,259 +442,862 @@ inv_tell(LargeObjectDesc *obj_desc)
 int
 inv_read(LargeObjectDesc *obj_desc, char *buf, int nbytes)
 {
-	uint32			nread = 0;
-	uint32			n;
-	uint32			off;
-	uint32			len;
-	uint32			found = 0;
-	uint32			pageno = obj_desc->offset / IBLKSIZE; 
-	ScanKeyData		skey[2];
-	IndexScanDesc		sd = (IndexScanDesc) NULL;
-	RetrieveIndexResult	indexRes;
 	HeapTupleData tuple;
-	Buffer			buffer;
-	Form_pg_largeobject	data;
+	int			nread;
+	int			off;
+	int			ncopy;
+	Datum		d;
+	struct varlena *fsblock;
+	bool		isNull;
 
 	Assert(PointerIsValid(obj_desc));
 	Assert(buf != NULL);
 
-	ScanKeyEntryInitialize(&skey[0],
-					    (bits16) 0x0,
-					    (AttrNumber) 1,
-					    (RegProcedure) F_OIDEQ,
-					    ObjectIdGetDatum(obj_desc->id));
+	/* if we're already at EOF, we don't need to do any work here */
+	if (obj_desc->flags & IFS_ATEOF)
+		return 0;
 
-	ScanKeyEntryInitialize(&skey[1],
-					    (bits16) 0x0,
-					    (AttrNumber) 2,
-					    (RegProcedure) F_INT4GE,
-					    Int32GetDatum(pageno));
+	/* make sure we obey two-phase locking */
+	if (!(obj_desc->flags & IFS_RDLOCK))
+	{
+		LockRelation(obj_desc->heap_r, ShareLock);
+		obj_desc->flags |= IFS_RDLOCK;
+	}
 
-	sd = index_beginscan(obj_desc->index_r, false, 2, skey);
-	tuple.t_datamcxt = CurrentMemoryContext;
-	tuple.t_data = NULL;
-	while ((indexRes = index_getnext(sd, ForwardScanDirection))) {
-		tuple.t_self = indexRes->heap_iptr;
-		heap_fetch(obj_desc->heap_r, SnapshotNow, &tuple, &buffer);
-		pfree(indexRes);
+	nread = 0;
 
-		if (tuple.t_data == NULL)
-			continue;
+	/* fetch a block at a time */
+	while (nread < nbytes)
+	{
+		Buffer		buffer;
 
-		found++;
-		data = (Form_pg_largeobject) GETSTRUCT(&tuple);
-		if (data->pageno != pageno) {
-			ReleaseBuffer(buffer);
-			index_endscan(sd);
-			return 0;
-		}
+		/* fetch an inversion file system block */
+		inv_fetchtup(obj_desc, &tuple, &buffer);
 
-		len = getbytealen(&(data->data));
-		off = obj_desc->offset % IBLKSIZE;
-		if (off == len) {
-			ReleaseBuffer(buffer);
+		if (tuple.t_data == NULL)
+		{
+			obj_desc->flags |= IFS_ATEOF;
 			break;
 		}
-		if (off > len) {
-			ReleaseBuffer(buffer);
-			index_endscan(sd);
-			return 0;
-		}
-		n = len - off;
-
-		n = (n < (nbytes - nread)) ? n : (nbytes - nread);
-		memcpy(buf + nread, VARDATA(&(data->data)) + off, n);
-		nread += n;
-		obj_desc->offset += n;
 
+		/* copy the data from this block into the buffer */
+		d = heap_getattr(&tuple, 2, obj_desc->hdesc, &isNull);
+		fsblock = (struct varlena *) DatumGetPointer(d);
 		ReleaseBuffer(buffer);
-		pageno++;
-		if (nread == nbytes)
+
+		/*
+		 * If block starts beyond current seek point, then we are looking
+		 * at a "hole" (unwritten area) in the object.  Return zeroes for
+		 * the "hole".
+		 */
+		if (obj_desc->offset < obj_desc->lowbyte)
+		{
+			int		nzeroes = obj_desc->lowbyte - obj_desc->offset;
+
+			if (nzeroes > (nbytes - nread))
+				nzeroes = (nbytes - nread);
+			MemSet(buf, 0, nzeroes);
+			buf += nzeroes;
+			nread += nzeroes;
+			obj_desc->offset += nzeroes;
+			if (nread >= nbytes)
 				break;
 		}
 
-	index_endscan(sd);
+		off = obj_desc->offset - obj_desc->lowbyte;
+		ncopy = obj_desc->highbyte - obj_desc->offset + 1;
+		if (ncopy > (nbytes - nread))
+			ncopy = (nbytes - nread);
+		memmove(buf, &(fsblock->vl_dat[off]), ncopy);
 
-	if (found == 0)
-		return 0;
+		/* move pointers past the amount we just read */
+		buf += ncopy;
+		nread += ncopy;
+		obj_desc->offset += ncopy;
+	}
 
 	return nread;
 }
 
-static int inv_write_existing(LargeObjectDesc *obj_desc, char *buf, int nbytes, int *found) {
-	uint32			n = 0;
-	uint32			off;
-	uint32			len;
-	int			i;
+int
+inv_write(LargeObjectDesc *obj_desc, char *buf, int nbytes)
+{
 	HeapTupleData tuple;
-	HeapTuple		newtup;
-	Buffer			buffer;
-	Form_pg_largeobject	data;
-	ScanKeyData		skey[2];
-	IndexScanDesc		sd = (IndexScanDesc) NULL;
-	RetrieveIndexResult	indexRes;
-	Relation		idescs[Num_pg_largeobject_indices];
-	Datum			values[Natts_pg_largeobject];
-	char			nulls[Natts_pg_largeobject];
-	char			replace[Natts_pg_largeobject];
+	int			nwritten;
+	int			tuplen;
 
 	Assert(PointerIsValid(obj_desc));
 	Assert(buf != NULL);
 
-	ScanKeyEntryInitialize(&skey[0],
-					    (bits16) 0,
-					    (AttrNumber) 1,
-					    (RegProcedure) F_OIDEQ,
-					    ObjectIdGetDatum(obj_desc->id));
-
-	ScanKeyEntryInitialize(&skey[1],
-					    (bits16) 0x0,
-					    (AttrNumber) 2,
-					    (RegProcedure) F_INT4EQ,
-					    Int32GetDatum(obj_desc->offset / IBLKSIZE));
+	/*
+	 * Make sure we obey two-phase locking.  A write lock entitles you to
+	 * read the relation, as well.
+	 */
 
-	CommandCounterIncrement();
-	sd = index_beginscan(obj_desc->index_r, false, 2, skey);
-	tuple.t_datamcxt = CurrentMemoryContext;
-	tuple.t_data = NULL;
-	while ((indexRes = index_getnext(sd, ForwardScanDirection))) {
-		tuple.t_self = indexRes->heap_iptr;
-		heap_fetch(obj_desc->heap_r, SnapshotNow, &tuple, &buffer);
-		pfree(indexRes);
-		if (tuple.t_data != NULL)
-			break;
+	if (!(obj_desc->flags & IFS_WRLOCK))
+	{
+		LockRelation(obj_desc->heap_r, ExclusiveLock);
+		obj_desc->flags |= (IFS_WRLOCK | IFS_RDLOCK);
 	}
 
-	index_endscan(sd);
-	if (tuple.t_data == NULL)
-		return 0;
+	nwritten = 0;
+
+	/* write a block at a time */
+	while (nwritten < nbytes)
+	{
+		Buffer		buffer;
+
+		/*
+		 * Fetch the current inversion file system block.  We can skip
+		 * the work if we already know we are at EOF.
+		 */
 
-	(*found)++;
-	data = (Form_pg_largeobject) GETSTRUCT(&tuple);
-	off = obj_desc->offset % IBLKSIZE;
-	len = getbytealen(&(data->data));
+		if (obj_desc->flags & IFS_ATEOF)
+			tuple.t_data = NULL;
+		else
+			inv_fetchtup(obj_desc, &tuple, &buffer);
 
-	if (len > IBLKSIZE) {
+		/* either append or replace a block, as required */
+		if (tuple.t_data == NULL)
+			tuplen = inv_wrnew(obj_desc, buf, nbytes - nwritten);
+		else
+		{
+			if (obj_desc->offset > obj_desc->highbyte)
+			{
+				tuplen = inv_wrnew(obj_desc, buf, nbytes - nwritten);
 				ReleaseBuffer(buffer);
-		elog(FATAL, "Internal error: len > IBLKSIZE");
+			}
+			else
+				tuplen = inv_wrold(obj_desc, buf, nbytes - nwritten, &tuple, buffer);
+
+			/*
+			 * inv_wrold() has already issued WriteBuffer() which has
+			 * decremented local reference counter (LocalRefCount). So we
+			 * should not call ReleaseBuffer() here. -- Tatsuo 99/2/4
+			 */
 		}
 
-	for (i=0; i<Natts_pg_largeobject; i++) {
-		nulls[i] = ' ';
-		replace[i] = ' ';
-		values[i] = (Datum)NULL;
+		/* move pointers past the amount we just wrote */
+		buf += tuplen;
+		nwritten += tuplen;
+		obj_desc->offset += tuplen;
 	}
 
-	i = 0;
+	/* that's it */
+	return nwritten;
+}
+
+/*
+ * inv_cleanindex
+ *		 Clean opened indexes for large objects, and clears current result.
+ *		 This is necessary on transaction commit in order to prevent buffer
+ *		 leak.
+ *		 This function must be called for each opened large object.
+ *		 [ PA, 7/17/98 ]
+ */
+void
+inv_cleanindex(LargeObjectDesc *obj_desc)
+{
+	Assert(PointerIsValid(obj_desc));
+
+	if (obj_desc->iscan == (IndexScanDesc) NULL)
+		return;
+
+	index_endscan(obj_desc->iscan);
+	obj_desc->iscan = (IndexScanDesc) NULL;
+
+	ItemPointerSetInvalid(&(obj_desc->htid));
+}
+
+/*
+ *	inv_fetchtup -- Fetch an inversion file system block.
+ *
+ *		This routine finds the file system block containing the offset
+ *		recorded in the obj_desc structure.  Later, we need to think about
+ *		the effects of non-functional updates (can you rewrite the same
+ *		block twice in a single transaction?), but for now, we won't bother.
+ *
+ *		Parameters:
+ *				obj_desc -- the object descriptor.
+ *				bufP -- pointer to a buffer in the buffer cache; caller
+ *						must free this.
+ *
+ *		Returns:
+ *				A heap tuple containing the desired block, or NULL if no
+ *				such tuple exists.
+ */
+static void
+inv_fetchtup(LargeObjectDesc *obj_desc, HeapTuple tuple, Buffer *buffer)
+{
+	RetrieveIndexResult res;
+	Datum		d;
+	int			firstbyte,
+				lastbyte;
+	struct varlena *fsblock;
+	bool		isNull;
+
+	/*
+	 * If we've exhausted the current block, we need to get the next one.
+	 * When we support time travel and non-functional updates, we will
+	 * need to loop over the blocks, rather than just have an 'if', in
+	 * order to find the one we're really interested in.
+	 */
+
+	if (obj_desc->offset > obj_desc->highbyte
+		|| obj_desc->offset < obj_desc->lowbyte
+		|| !ItemPointerIsValid(&(obj_desc->htid)))
 	{
-		char b[IBLKSIZE];
-		int4 rest = len - off;
+		ScanKeyData skey;
 
-		memset(b, 0, IBLKSIZE); /* Can optimize later */
-		if ((off > 0) && (len > 0)) /* We start in the middle of the tuple */
-			memcpy(b, VARDATA(&(data->data)), (off > len) ? len : off);
+		ScanKeyEntryInitialize(&skey, 0x0, 1, F_INT4GE,
+							   Int32GetDatum(obj_desc->offset));
 
-		if ((nbytes <= rest) || (len == IBLKSIZE)) {
-			/* We will update inside existing tuple size */
-			if (nbytes < rest)
-				n = rest;
+		/* initialize scan key if not done */
+		if (obj_desc->iscan == (IndexScanDesc) NULL)
+		{
+
+			/*
+			 * As scan index may be prematurely closed (on commit), we
+			 * must use object current offset (was 0) to reinitialize the
+			 * entry [ PA ].
+			 */
+			obj_desc->iscan = index_beginscan(obj_desc->index_r,
+											  (bool) 0, (uint16) 1,
+											  &skey);
+		}
 		else
-				n = nbytes;
-			memcpy(b + off, buf, n);
-			if (n < rest) /* There's a rest of the tuple left */
-				memcpy(b + off + n, VARDATA(&(data->data)) + off + n, rest - n);
-			/* Update data only */
-			replace[2] = 'r';
-			values[2] = (Datum) _byteain(b, len);
-		 } else {
-			/* We will extend tuple */
-			/* Do we fit into max tuple size */
-			if (nbytes <= (IBLKSIZE - off))
-				len = off + nbytes;
+			index_rescan(obj_desc->iscan, false, &skey);
+
+		do
+		{
+			res = index_getnext(obj_desc->iscan, ForwardScanDirection);
+
+			if (res == (RetrieveIndexResult) NULL)
+			{
+				ItemPointerSetInvalid(&(obj_desc->htid));
+				tuple->t_datamcxt = NULL;
+				tuple->t_data = NULL;
+				return;
+			}
+
+			/*
+			 * For time travel, we need to use the actual time qual here,
+			 * rather that NowTimeQual.  We currently have no way to pass
+			 * a time qual in.
+			 *
+			 * This is now valid for snapshot !!! And should be fixed in some
+			 * way...	- vadim 07/28/98
+			 *
+			 */
+			tuple->t_self = res->heap_iptr;
+			heap_fetch(obj_desc->heap_r, SnapshotNow, tuple, buffer);
+			pfree(res);
+		} while (tuple->t_data == NULL);
+
+		/* remember this tid -- we may need it for later reads/writes */
+		ItemPointerCopy(&(tuple->t_self), &obj_desc->htid);
+	}
 	else
-				len = IBLKSIZE;
-			n = len - off;
-			memcpy(b + off, buf, n);
-			/* Update data */
-			replace[2] = 'r';
-			values[2] = (Datum) _byteain(b, len);
+	{
+		tuple->t_self = obj_desc->htid;
+		heap_fetch(obj_desc->heap_r, SnapshotNow, tuple, buffer);
+		if (tuple->t_data == NULL)
+			elog(ERROR, "inv_fetchtup: heap_fetch failed");
 	}
 
-		newtup = heap_modifytuple(&tuple, obj_desc->heap_r,
-					  values, nulls, replace);
+	/*
+	 * By here, we have the heap tuple we're interested in.  We cache the
+	 * upper and lower bounds for this block in the object descriptor and
+	 * return the tuple.
+	 */
+
+	d = heap_getattr(tuple, 1, obj_desc->hdesc, &isNull);
+	lastbyte = (int32) DatumGetInt32(d);
+	d = heap_getattr(tuple, 2, obj_desc->hdesc, &isNull);
+	fsblock = (struct varlena *) DatumGetPointer(d);
+
+	/*
+	 * order of + and - is important -- these are unsigned quantites near
+	 * 0
+	 */
+	firstbyte = (lastbyte + 1 + sizeof(fsblock->vl_len)) - fsblock->vl_len;
+
+	obj_desc->lowbyte = firstbyte;
+	obj_desc->highbyte = lastbyte;
+
+	return;
+}
+
+/*
+ *	inv_wrnew() -- append a new filesystem block tuple to the inversion
+ *					file.
+ *
+ *		In response to an inv_write, we append one or more file system
+ *		blocks to the class containing the large object.  We violate the
+ *		class abstraction here in order to pack things as densely as we
+ *		are able.  We examine the last page in the relation, and write
+ *		just enough to fill it, assuming that it has above a certain
+ *		threshold of space available.  If the space available is less than
+ *		the threshold, we allocate a new page by writing a big tuple.
+ *
+ *		By the time we get here, we know all the parameters passed in
+ *		are valid, and that we hold the appropriate lock on the heap
+ *		relation.
+ *
+ *		Parameters:
+ *				obj_desc: large object descriptor for which to append block.
+ *				buf: buffer containing data to write.
+ *				nbytes: amount to write
+ *
+ *		Returns:
+ *				number of bytes actually written to the new tuple.
+ */
+static int
+inv_wrnew(LargeObjectDesc *obj_desc, char *buf, int nbytes)
+{
+	Relation	hr;
+	HeapTuple	ntup;
+	Buffer		buffer;
+	Page		page;
+	int			nblocks;
+	int			nwritten;
+
+	hr = obj_desc->heap_r;
+
+	/*
+	 * Get the last block in the relation.	If there's no data in the
+	 * relation at all, then we just get a new block.  Otherwise, we check
+	 * the last block to see whether it has room to accept some or all of
+	 * the data that the user wants to write.  If it doesn't, then we
+	 * allocate a new block.
+	 */
+
+	nblocks = RelationGetNumberOfBlocks(hr);
 
-		heap_update(obj_desc->heap_r, &newtup->t_self, newtup, NULL);
-		if (!IsIgnoringSystemIndexes()) {
-			CatalogOpenIndices(Num_pg_largeobject_indices, Name_pg_largeobject_indices, idescs);
-			CatalogIndexInsert(idescs, Num_pg_largeobject_indices, obj_desc->heap_r, newtup);
-			CatalogCloseIndices(Num_pg_largeobject_indices, idescs);
+	if (nblocks > 0)
+	{
+		buffer = ReadBuffer(hr, nblocks - 1);
+		page = BufferGetPage(buffer);
 	}
-		heap_freetuple(newtup);
+	else
+	{
+		buffer = ReadBuffer(hr, P_NEW);
+		page = BufferGetPage(buffer);
+		PageInit(page, BufferGetPageSize(buffer), 0);
 	}
+
+	/*
+	 * If the last page is too small to hold all the data, and it's too
+	 * small to hold IMINBLK, then we allocate a new page.	If it will
+	 * hold at least IMINBLK, but less than all the data requested, then
+	 * we write IMINBLK here.  The caller is responsible for noticing that
+	 * less than the requested number of bytes were written, and calling
+	 * this routine again.
+	 */
+
+	nwritten = IFREESPC(page);
+	if (nwritten < nbytes)
+	{
+		if (nwritten < IMINBLK)
+		{
 			ReleaseBuffer(buffer);
+			buffer = ReadBuffer(hr, P_NEW);
+			page = BufferGetPage(buffer);
+			PageInit(page, BufferGetPageSize(buffer), 0);
+			if (nbytes > IMAXBLK)
+				nwritten = IMAXBLK;
+			else
+				nwritten = nbytes;
+		}
+	}
+	else
+		nwritten = nbytes;
 
-	return n;
+	/*
+	 * Insert a new file system block tuple, index it, and write it out.
+	 */
+
+	ntup = inv_newtuple(obj_desc, buffer, page, buf, nwritten);
+	inv_indextup(obj_desc, ntup);
+	heap_freetuple(ntup);
+
+	/* new tuple is inserted */
+	WriteBuffer(buffer);
+
+	return nwritten;
 }
 
-static int inv_write_append(LargeObjectDesc *obj_desc, char *buf, int nbytes) {
-	HeapTuple	ntup = (HeapTuple) palloc(sizeof(HeapTupleData));
-	Relation		idescs[Num_pg_largeobject_indices];
-	Datum		values[Natts_pg_largeobject];
-	char		nulls[Natts_pg_largeobject];
-	int		i;
-	uint32		len;
+static int
+inv_wrold(LargeObjectDesc *obj_desc,
+		  char *dbuf,
+		  int nbytes,
+		  HeapTuple tuple,
+		  Buffer buffer)
+{
+	Relation	hr;
+	HeapTuple	ntup;
+	Buffer		newbuf;
+	Page		page;
+	Page		newpage;
+	int			tupbytes;
+	Datum		d;
+	struct varlena *fsblock;
+	int			nwritten,
+				nblocks,
+				freespc;
+	bool		isNull;
+	int			keep_offset;
+	RetrieveIndexResult res;
+
+	/*
+	 * Since we're using a no-overwrite storage manager, the way we
+	 * overwrite blocks is to mark the old block invalid and append a new
+	 * block.  First mark the old block invalid.  This violates the tuple
+	 * abstraction.
+	 */
+
+	TransactionIdStore(GetCurrentTransactionId(), &(tuple->t_data->t_xmax));
+	tuple->t_data->t_cmax = GetCurrentCommandId();
+	tuple->t_data->t_infomask &= ~(HEAP_XMAX_COMMITTED | HEAP_XMAX_INVALID);
+
+	/*
+	 * If we're overwriting the entire block, we're lucky.	All we need to
+	 * do is to insert a new block.
+	 */
+
+	if (obj_desc->offset == obj_desc->lowbyte
+		&& obj_desc->lowbyte + nbytes >= obj_desc->highbyte)
+	{
+		WriteBuffer(buffer);
+		return inv_wrnew(obj_desc, dbuf, nbytes);
+	}
+
+	/*
+	 * By here, we need to overwrite part of the data in the current
+	 * tuple.  In order to reduce the degree to which we fragment blocks,
+	 * we guarantee that no block will be broken up due to an overwrite.
+	 * This means that we need to allocate a tuple on a new page, if
+	 * there's not room for the replacement on this one.
+	 */
+
+	newbuf = buffer;
+	page = BufferGetPage(buffer);
+	newpage = BufferGetPage(newbuf);
+	hr = obj_desc->heap_r;
+	freespc = IFREESPC(page);
+	d = heap_getattr(tuple, 2, obj_desc->hdesc, &isNull);
+	fsblock = (struct varlena *) DatumGetPointer(d);
+	tupbytes = fsblock->vl_len - sizeof(fsblock->vl_len);
+
+	if (freespc < tupbytes)
+	{
+
+		/*
+		 * First see if there's enough space on the last page of the table
+		 * to put this tuple.
+		 */
+
+		nblocks = RelationGetNumberOfBlocks(hr);
+
+		if (nblocks > 0)
+		{
+			newbuf = ReadBuffer(hr, nblocks - 1);
+			newpage = BufferGetPage(newbuf);
+		}
+		else
+		{
+			newbuf = ReadBuffer(hr, P_NEW);
+			newpage = BufferGetPage(newbuf);
+			PageInit(newpage, BufferGetPageSize(newbuf), 0);
+		}
+
+		freespc = IFREESPC(newpage);
 
-	for (i=0; i<Natts_pg_largeobject; i++) {
-		nulls[i] = ' ';
-		values[i] = (Datum)NULL;
+		/*
+		 * If there's no room on the last page, allocate a new last page
+		 * for the table, and put it there.
+		 */
+
+		if (freespc < tupbytes)
+		{
+			ReleaseBuffer(newbuf);
+			newbuf = ReadBuffer(hr, P_NEW);
+			newpage = BufferGetPage(newbuf);
+			PageInit(newpage, BufferGetPageSize(newbuf), 0);
 		}
+	}
+
+	nwritten = nbytes;
+	if (nwritten > obj_desc->highbyte - obj_desc->offset + 1)
+		nwritten = obj_desc->highbyte - obj_desc->offset + 1;
+	memmove(VARDATA(fsblock) + (obj_desc->offset - obj_desc->lowbyte),
+			dbuf, nwritten);
 
-	i = 0;
-	values[i++] = ObjectIdGetDatum(obj_desc->id);
-	len = (nbytes > IBLKSIZE) ? IBLKSIZE : nbytes;
+	/*
+	 * we are rewriting the entire old block, therefore we reset offset to
+	 * the lowbyte of the original block before jumping into
+	 * inv_newtuple()
+	 */
+	keep_offset = obj_desc->offset;
+	obj_desc->offset = obj_desc->lowbyte;
+	ntup = inv_newtuple(obj_desc, newbuf, newpage, VARDATA(fsblock),
+						tupbytes);
+	/* after we are done, we restore to the true offset */
+	obj_desc->offset = keep_offset;
+
+	/*
+	 * By here, we have a page (newpage) that's guaranteed to have enough
+	 * space on it to put the new tuple.  Call inv_newtuple to do the
+	 * work.  Passing NULL as a buffer to inv_newtuple() keeps it from
+	 * copying any data into the new tuple.  When it returns, the tuple is
+	 * ready to receive data from the old tuple and the user's data
+	 * buffer.
+	 */
+/*
+	ntup = inv_newtuple(obj_desc, newbuf, newpage, (char *) NULL, tupbytes);
+	dptr = ((char *) ntup) + ntup->t_hoff -
+				(sizeof(HeapTupleData) - offsetof(HeapTupleData, t_bits)) +
+				sizeof(int4)
+				+ sizeof(fsblock->vl_len);
+
+	if (obj_desc->offset > obj_desc->lowbyte) {
+		memmove(dptr,
+				&(fsblock->vl_dat[0]),
+				obj_desc->offset - obj_desc->lowbyte);
+		dptr += obj_desc->offset - obj_desc->lowbyte;
+	}
 
-	values[i++] = Int32GetDatum(obj_desc->offset / IBLKSIZE);
-	values[i++] = (Datum) _byteain(buf, len);
 
-	ntup = heap_formtuple(obj_desc->heap_r->rd_att, values, nulls);
-	heap_insert(obj_desc->heap_r, ntup);
+	nwritten = nbytes;
+	if (nwritten > obj_desc->highbyte - obj_desc->offset + 1)
+		nwritten = obj_desc->highbyte - obj_desc->offset + 1;
 
-	if (!IsIgnoringSystemIndexes()) {
-		CatalogOpenIndices(Num_pg_largeobject_indices, Name_pg_largeobject_indices, idescs);
-		CatalogIndexInsert(idescs, Num_pg_largeobject_indices, obj_desc->heap_r, ntup);
-		CatalogCloseIndices(Num_pg_largeobject_indices, idescs);
+	memmove(dptr, dbuf, nwritten);
+	dptr += nwritten;
+
+	if (obj_desc->offset + nwritten < obj_desc->highbyte + 1) {
+*/
+/*
+		loc = (obj_desc->highbyte - obj_desc->offset)
+				+ nwritten;
+		sz = obj_desc->highbyte - (obj_desc->lowbyte + loc);
+
+		what's going on here?? - jolly
+*/
+/*
+		sz = (obj_desc->highbyte + 1) - (obj_desc->offset + nwritten);
+		memmove(&(fsblock->vl_dat[0]), dptr, sz);
 	}
+*/
+
 
+	/* index the new tuple */
+	inv_indextup(obj_desc, ntup);
 	heap_freetuple(ntup);
 
-	return len;
-}
+	/*
+	 * move the scandesc forward so we don't reread the newly inserted
+	 * tuple on the next index scan
+	 */
+	res = NULL;
+	if (obj_desc->iscan)
+		res = index_getnext(obj_desc->iscan, ForwardScanDirection);
 
-static int inv_write_int(LargeObjectDesc *obj_desc, char *buf, int nbytes) {
-	int			nwritten = 0;
-	int			found = 0;
+	if (res)
+		pfree(res);
 
-	if (nbytes == 0)
-		return 0;
+	/*
+	 * Okay, by here, a tuple for the new block is correctly placed,
+	 * indexed, and filled.  Write the changed pages out.
+	 */
+
+	WriteBuffer(buffer);
+	if (newbuf != buffer)
+		WriteBuffer(newbuf);
 
-	nwritten = inv_write_existing(obj_desc, buf, nbytes, &found);
-	if (found > 0) {
-		obj_desc->offset += nwritten;
+	/* Tuple id is no longer valid */
+	ItemPointerSetInvalid(&(obj_desc->htid));
+
+	/* done */
 	return nwritten;
+}
+
+static HeapTuple
+inv_newtuple(LargeObjectDesc *obj_desc,
+			 Buffer buffer,
+			 Page page,
+			 char *dbuf,
+			 int nwrite)
+{
+	HeapTuple	ntup = (HeapTuple) palloc(sizeof(HeapTupleData));
+	PageHeader	ph;
+	int			tupsize;
+	int			hoff;
+	Offset		lower;
+	Offset		upper;
+	ItemId		itemId;
+	OffsetNumber off;
+	OffsetNumber limit;
+	char	   *attptr;
+
+	/* compute tuple size -- no nulls */
+	hoff = offsetof(HeapTupleHeaderData, t_bits);
+	hoff = MAXALIGN(hoff);
+
+	/* add in olastbyte, varlena.vl_len, varlena.vl_dat */
+	tupsize = hoff + (2 * sizeof(int32)) + nwrite;
+	tupsize = MAXALIGN(tupsize);
+
+	/*
+	 * Allocate the tuple on the page, violating the page abstraction.
+	 * This code was swiped from PageAddItem().
+	 */
+
+	ph = (PageHeader) page;
+	limit = OffsetNumberNext(PageGetMaxOffsetNumber(page));
+
+	/* look for "recyclable" (unused & deallocated) ItemId */
+	for (off = FirstOffsetNumber; off < limit; off = OffsetNumberNext(off))
+	{
+		itemId = &ph->pd_linp[off - 1];
+		if ((((*itemId).lp_flags & LP_USED) == 0) &&
+			((*itemId).lp_len == 0))
+			break;
 	}
-	/* Looks like we are beyond the end of the file */
-	nwritten = inv_write_append(obj_desc, buf, nbytes);
-	obj_desc->offset += nwritten;
-	return nwritten;
+
+	if (off > limit)
+		lower = (Offset) (((char *) (&ph->pd_linp[off])) - ((char *) page));
+	else if (off == limit)
+		lower = ph->pd_lower + sizeof(ItemIdData);
+	else
+		lower = ph->pd_lower;
+
+	upper = ph->pd_upper - tupsize;
+
+	itemId = &ph->pd_linp[off - 1];
+	(*itemId).lp_off = upper;
+	(*itemId).lp_len = tupsize;
+	(*itemId).lp_flags = LP_USED;
+	ph->pd_lower = lower;
+	ph->pd_upper = upper;
+
+	ntup->t_datamcxt = NULL;
+	ntup->t_data = (HeapTupleHeader) ((char *) page + upper);
+
+	/*
+	 * Tuple is now allocated on the page.	Next, fill in the tuple
+	 * header.	This block of code violates the tuple abstraction.
+	 */
+
+	ntup->t_len = tupsize;
+	ItemPointerSet(&ntup->t_self, BufferGetBlockNumber(buffer), off);
+	ntup->t_data->t_oid = newoid();
+	TransactionIdStore(GetCurrentTransactionId(), &(ntup->t_data->t_xmin));
+	ntup->t_data->t_cmin = GetCurrentCommandId();
+	StoreInvalidTransactionId(&(ntup->t_data->t_xmax));
+	ntup->t_data->t_cmax = 0;
+	ntup->t_data->t_infomask = HEAP_XMAX_INVALID;
+	ntup->t_data->t_natts = 2;
+	ntup->t_data->t_hoff = hoff;
+
+	/* if a NULL is passed in, avoid the calculations below */
+	if (dbuf == NULL)
+		return ntup;
+
+	/*
+	 * Finally, copy the user's data buffer into the tuple.  This violates
+	 * the tuple and class abstractions.
+	 */
+
+	attptr = ((char *) ntup->t_data) + hoff;
+	*((int32 *) attptr) = obj_desc->offset + nwrite - 1;
+	attptr += sizeof(int32);
+
+	/*
+	 * *  mer fixed disk layout of varlenas to get rid of the need for
+	 * this. *
+	 *
+	 * ((int32 *) attptr) = nwrite + sizeof(int32); *  attptr +=
+	 * sizeof(int32);
+	 */
+
+	*((int32 *) attptr) = nwrite + sizeof(int32);
+	attptr += sizeof(int32);
+
+	/*
+	 * If a data buffer was passed in, then copy the data from the buffer
+	 * to the tuple.  Some callers (eg, inv_wrold()) may not pass in a
+	 * buffer, since they have to copy part of the old tuple data and part
+	 * of the user's new data into the new tuple.
+	 */
+
+	if (dbuf != (char *) NULL)
+		memmove(attptr, dbuf, nwrite);
+
+	/* keep track of boundary of current tuple */
+	obj_desc->lowbyte = obj_desc->offset;
+	obj_desc->highbyte = obj_desc->offset + nwrite - 1;
+
+	/* new tuple is filled -- return it */
+	return ntup;
 }
 
-static int count = 0;
+static void
+inv_indextup(LargeObjectDesc *obj_desc, HeapTuple tuple)
+{
+	InsertIndexResult res;
+	Datum		v[1];
+	char		n[1];
 
-int
-inv_write(LargeObjectDesc *obj_desc, char *buf, int nbytes) {
-	int nwritten = 0;
-	while (nwritten < nbytes)
-		nwritten += inv_write_int(obj_desc, buf + nwritten, nbytes - nwritten);
+	n[0] = ' ';
+	v[0] = Int32GetDatum(obj_desc->highbyte);
+	res = index_insert(obj_desc->index_r, &v[0], &n[0],
+					   &(tuple->t_self), obj_desc->heap_r);
 
-	return nwritten;
+	if (res)
+		pfree(res);
+}
+
+#ifdef NOT_USED
+
+static void
+DumpPage(Page page, int blkno)
+{
+		ItemId			lp;
+		HeapTuple		tup;
+		int				flags, i, nline;
+		ItemPointerData pointerData;
+
+		printf("\t[subblock=%d]:lower=%d:upper=%d:special=%d\n", 0,
+				((PageHeader)page)->pd_lower, ((PageHeader)page)->pd_upper,
+				((PageHeader)page)->pd_special);
+
+		printf("\t:MaxOffsetNumber=%d\n",
+			   (int16) PageGetMaxOffsetNumber(page));
+
+		nline = (int16) PageGetMaxOffsetNumber(page);
+
+{
+		int		i;
+		char	*cp;
+
+		i = PageGetSpecialSize(page);
+		cp = PageGetSpecialPointer(page);
+
+		printf("\t:SpecialData=");
+
+		while (i > 0) {
+				printf(" 0x%02x", *cp);
+				cp += 1;
+				i -= 1;
+		}
+		printf("\n");
+}
+		for (i = 0; i < nline; i++) {
+				lp = ((PageHeader)page)->pd_linp + i;
+				flags = (*lp).lp_flags;
+				ItemPointerSet(&pointerData, blkno, 1 + i);
+				printf("%s:off=%d:flags=0x%x:len=%d",
+						ItemPointerFormExternal(&pointerData), (*lp).lp_off,
+						flags, (*lp).lp_len);
+
+				if (flags & LP_USED) {
+						HeapTupleData	htdata;
+
+						printf(":USED");
+
+						memmove((char *) &htdata,
+								(char *) &((char *)page)[(*lp).lp_off],
+								sizeof(htdata));
+
+						tup = &htdata;
+
+						printf("\n\t:ctid=%s:oid=%d",
+								ItemPointerFormExternal(&tup->t_ctid),
+								tup->t_oid);
+						printf(":natts=%d:thoff=%d:",
+								tup->t_natts,
+								tup->t_hoff);
+
+						printf("\n\t:cmin=%u:",
+								tup->t_cmin);
+
+						printf("xmin=%u:", tup->t_xmin);
+
+						printf("\n\t:cmax=%u:",
+								tup->t_cmax);
+
+						printf("xmax=%u:\n", tup->t_xmax);
+
+				} else
+						putchar('\n');
+		}
+}
+
+static char*
+ItemPointerFormExternal(ItemPointer pointer)
+{
+		static char		itemPointerString[32];
+
+		if (!ItemPointerIsValid(pointer)) {
+			memmove(itemPointerString, "<-,-,->", sizeof "<-,-,->");
+		} else {
+			sprintf(itemPointerString, "<%u,%u>",
+					ItemPointerGetBlockNumber(pointer),
+					ItemPointerGetOffsetNumber(pointer));
+		}
+
+		return itemPointerString;
+}
+
+#endif
+
+static int
+_inv_getsize(Relation hreln, TupleDesc hdesc, Relation ireln)
+{
+	IndexScanDesc iscan;
+	RetrieveIndexResult res;
+	HeapTupleData tuple;
+	Datum		d;
+	long		size;
+	bool		isNull;
+	Buffer		buffer;
+
+	/* scan backwards from end */
+	iscan = index_beginscan(ireln, (bool) 1, 0, (ScanKey) NULL);
+
+	do
+	{
+		res = index_getnext(iscan, BackwardScanDirection);
+
+		/*
+		 * If there are no more index tuples, then the relation is empty,
+		 * so the file's size is zero.
+		 */
+
+		if (res == (RetrieveIndexResult) NULL)
+		{
+			index_endscan(iscan);
+			return 0;
+		}
+
+		/*
+		 * For time travel, we need to use the actual time qual here,
+		 * rather that NowTimeQual.  We currently have no way to pass a
+		 * time qual in.
+		 */
+		tuple.t_self = res->heap_iptr;
+		heap_fetch(hreln, SnapshotNow, &tuple, &buffer);
+		pfree(res);
+	} while (tuple.t_data == NULL);
+
+	/* don't need the index scan anymore */
+	index_endscan(iscan);
+
+	/* get olastbyte attribute */
+	d = heap_getattr(&tuple, 1, hdesc, &isNull);
+	size = DatumGetInt32(d) + 1;
+	ReleaseBuffer(buffer);
+
+	return size;
 }

src/bin/pg_dump/pg_dump.c

@@ -22,7 +22,7 @@
  *
  *
  * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/bin/pg_dump/pg_dump.c,v 1.171 2000/10/21 15:55:26 momjian Exp $
+ *	  $Header: /cvsroot/pgsql/src/bin/pg_dump/pg_dump.c,v 1.172 2000/10/22 05:27:18 momjian Exp $
  *
  * Modifications - 6/10/96 - dave@bensoft.com - version 1.13.dhb
  *
@@ -1104,7 +1104,7 @@ dumpBlobs(Archive *AH, char* junkOid, void *junkVal)
 		fprintf(stderr, "%s saving BLOBs\n", g_comment_start);
 
 	/* Cursor to get all BLOB tables */
-    appendPQExpBuffer(oidQry, "Declare blobOid Cursor for SELECT loid from pg_largeobject");
+    appendPQExpBuffer(oidQry, "Declare blobOid Cursor for SELECT oid from pg_class where relkind = '%c'", RELKIND_LOBJECT);
 
 	res = PQexec(g_conn, oidQry->data);
 	if (!res || PQresultStatus(res) != PGRES_COMMAND_OK)

src/include/catalog/catname.h

@@ -7,7 +7,7 @@
  * Portions Copyright (c) 1996-2000, PostgreSQL, Inc
  * Portions Copyright (c) 1994, Regents of the University of California
  *
- * $Id: catname.h,v 1.15 2000/10/21 15:55:28 momjian Exp $
+ * $Id: catname.h,v 1.16 2000/10/22 05:27:20 momjian Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -29,7 +29,6 @@
 #define  InheritsRelationName "pg_inherits"
 #define  InheritancePrecidenceListRelationName "pg_ipl"
 #define  LanguageRelationName "pg_language"
-#define  LargeobjectRelationName "pg_largeobject"
 #define  ListenerRelationName "pg_listener"
 #define  LogRelationName "pg_log"
 #define  OperatorClassRelationName "pg_opclass"

src/include/catalog/indexing.h

@@ -8,7 +8,7 @@
  * Portions Copyright (c) 1996-2000, PostgreSQL, Inc
  * Portions Copyright (c) 1994, Regents of the University of California
  *
- * $Id: indexing.h,v 1.43 2000/10/21 15:55:28 momjian Exp $
+ * $Id: indexing.h,v 1.44 2000/10/22 05:27:20 momjian Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -31,7 +31,6 @@
 #define Num_pg_index_indices		2
 #define Num_pg_inherits_indices		1
 #define Num_pg_language_indices		2
-#define Num_pg_largeobject_indices		2
 #define Num_pg_listener_indices		1
 #define Num_pg_opclass_indices		2
 #define Num_pg_operator_indices		2
@@ -63,8 +62,6 @@
 #define InheritsRelidSeqnoIndex		"pg_inherits_relid_seqno_index"
 #define LanguageNameIndex			"pg_language_name_index"
 #define LanguageOidIndex			"pg_language_oid_index"
-#define LargeobjectLOIdIndex			"pg_largeobject_loid_index"
-#define LargeobjectLOIdPNIndex			"pg_largeobject_loid_pn_index"
 #define ListenerPidRelnameIndex		"pg_listener_pid_relname_index"
 #define OpclassDeftypeIndex			"pg_opclass_deftype_index"
 #define OpclassNameIndex			"pg_opclass_name_index"
@@ -95,7 +92,6 @@ extern char *Name_pg_group_indices[];
 extern char *Name_pg_index_indices[];
 extern char *Name_pg_inherits_indices[];
 extern char *Name_pg_language_indices[];
-extern char *Name_pg_largeobject_indices[];
 extern char *Name_pg_listener_indices[];
 extern char *Name_pg_opclass_indices[];
 extern char *Name_pg_operator_indices[];
@@ -195,8 +191,6 @@ DECLARE_UNIQUE_INDEX(pg_index_indexrelid_index on pg_index using btree(indexreli
 DECLARE_UNIQUE_INDEX(pg_inherits_relid_seqno_index on pg_inherits using btree(inhrelid oid_ops, inhseqno int4_ops));
 DECLARE_UNIQUE_INDEX(pg_language_name_index on pg_language using btree(lanname name_ops));
 DECLARE_UNIQUE_INDEX(pg_language_oid_index on pg_language using btree(oid oid_ops));
-DECLARE_INDEX(pg_largeobject_loid_index on pg_largeobject using btree(loid oid_ops));
-DECLARE_UNIQUE_INDEX(pg_largeobject_loid_pn_index on pg_largeobject using btree(loid oid_ops, pageno int4_ops));
 DECLARE_UNIQUE_INDEX(pg_listener_pid_relname_index on pg_listener using btree(listenerpid int4_ops, relname name_ops));
 /* This column needs to allow multiple zero entries, but is in the cache */
 DECLARE_INDEX(pg_opclass_deftype_index on pg_opclass using btree(opcdeftype oid_ops));

src/include/catalog/pg_largeobject.h

-/*-------------------------------------------------------------------------
- *
- * pg_largeobject.h
- *	  definition of the system "largeobject" relation (pg_largeobject)
- *	  along with the relation's initial contents.
- *
- *
- * Portions Copyright (c) 1996-2000, PostgreSQL, Inc
- * Portions Copyright (c) 1994, Regents of the University of California
- *
- * $Id: pg_largeobject.h,v 1.3 2000/10/21 15:55:28 momjian Exp $
- *
- * NOTES
- *	  the genbki.sh script reads this file and generates .bki
- *	  information from the DATA() statements.
- *
- *-------------------------------------------------------------------------
- */
-#ifndef PG_LARGEOBJECT_H
-#define PG_LARGEOBJECT_H
-
-/* ----------------
- *		postgres.h contains the system type definintions and the
- *		CATALOG(), BOOTSTRAP and DATA() sugar words so this file
- *		can be read by both genbki.sh and the C compiler.
- * ----------------
- */
-
-/* ----------------
- *		pg_largeobject definition.  cpp turns this into
- *		typedef struct FormData_pg_largeobject. Large object id
- *		is stored in loid;
- * ----------------
- */
-
-CATALOG(pg_largeobject)
-{
-	Oid			loid;
-	int4			pageno;
-	bytea			data;
-} FormData_pg_largeobject;
-
-/* ----------------
- *		Form_pg_largeobject corresponds to a pointer to a tuple with
- *		the format of pg_largeobject relation.
- * ----------------
- */
-typedef FormData_pg_largeobject *Form_pg_largeobject;
-
-/* ----------------
- *		compiler constants for pg_largeobject
- * ----------------
- */
-#define Natts_pg_largeobject			3
-#define Anum_pg_largeobject_loid		1
-#define Anum_pg_largeobject_pageno		2
-#define Anum_pg_largeobject_data		3
-
-Oid LargeobjectCreate(Oid loid);
-void LargeobjectDrop(Oid loid);
-int LargeobjectFind(Oid loid);
-
-#endif	 /* PG_LARGEOBJECT_H */

src/include/storage/large_object.h

@@ -8,7 +8,7 @@
  * Portions Copyright (c) 1996-2000, PostgreSQL, Inc
  * Portions Copyright (c) 1994, Regents of the University of California
  *
- * $Id: large_object.h,v 1.16 2000/10/21 15:55:29 momjian Exp $
+ * $Id: large_object.h,v 1.17 2000/10/22 05:27:23 momjian Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -22,11 +22,17 @@
 /*
  * This structure will eventually have lots more stuff associated with it.
  */
-typedef struct LargeObjectDesc {
-	Relation	heap_r;
-	Relation	index_r;
+typedef struct LargeObjectDesc
+{
+	Relation	heap_r;			/* heap relation */
+	Relation	index_r;		/* index relation on seqno attribute */
+	IndexScanDesc iscan;		/* index scan we're using */
+	TupleDesc	hdesc;			/* heap relation tuple desc */
+	TupleDesc	idesc;			/* index relation tuple desc */
+	uint32		lowbyte;		/* low byte on the current page */
+	uint32		highbyte;		/* high byte on the current page */
 	uint32		offset;			/* current seek pointer */
-	Oid		id;
+	ItemPointerData htid;		/* tid of current heap tuple */
 
 #define IFS_RDLOCK		(1 << 0)
 #define IFS_WRLOCK		(1 << 1)
@@ -49,4 +55,7 @@ extern int	inv_tell(LargeObjectDesc *obj_desc);
 extern int	inv_read(LargeObjectDesc *obj_desc, char *buf, int nbytes);
 extern int	inv_write(LargeObjectDesc *obj_desc, char *buf, int nbytes);
 
+/* added for buffer leak prevention [ PA ] */
+extern void inv_cleanindex(LargeObjectDesc *obj_desc);
+
 #endif	 /* LARGE_OBJECT_H */