pg_dump can now dump large objects even in plain-text output mode, by

using the recently added lo_create() function.  The restore logic in
pg_restore is greatly simplified as well, since there's no need anymore
to try to adjust database references to match a new set of blob OIDs.

1 files changed, 110 insertions, 5 deletions

diff --git a/src/bin/pg_dump/pg_backup_null.c b/src/bin/pg_dump/pg_backup_null.c
index 82bc5d121fa..7e0b6ffe117 100644
--- a/src/bin/pg_dump/pg_backup_null.c
+++ b/src/bin/pg_dump/pg_backup_null.c
@@ -3,7 +3,7 @@
  * pg_backup_null.c
  *
  *	Implementation of an archive that is never saved; it is used by
- *	pg_dump to output a plain text SQL script instead of save
+ *	pg_dump to output a plain text SQL script instead of saving
  *	a real archive.
  *
  *	See the headers to pg_restore for more details.
@@ -17,7 +17,7 @@
  *
  *
  * IDENTIFICATION
- *		$PostgreSQL: pgsql/src/bin/pg_dump/pg_backup_null.c,v 1.14 2003/12/08 16:39:05 tgl Exp $
+ *		$PostgreSQL: pgsql/src/bin/pg_dump/pg_backup_null.c,v 1.15 2005/06/21 20:45:44 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -27,12 +27,21 @@
 
 #include <unistd.h>				/* for dup */
 
+#include "libpq/libpq-fs.h"
+
+
 static size_t _WriteData(ArchiveHandle *AH, const void *data, size_t dLen);
+static size_t _WriteBlobData(ArchiveHandle *AH, const void *data, size_t dLen);
 static void _EndData(ArchiveHandle *AH, TocEntry *te);
 static int	_WriteByte(ArchiveHandle *AH, const int i);
 static size_t _WriteBuf(ArchiveHandle *AH, const void *buf, size_t len);
 static void _CloseArchive(ArchiveHandle *AH);
 static void _PrintTocData(ArchiveHandle *AH, TocEntry *te, RestoreOptions *ropt);
+static void _StartBlobs(ArchiveHandle *AH, TocEntry *te);
+static void _StartBlob(ArchiveHandle *AH, TocEntry *te, Oid oid);
+static void _EndBlob(ArchiveHandle *AH, TocEntry *te, Oid oid);
+static void _EndBlobs(ArchiveHandle *AH, TocEntry *te);
+
 
 /*
  *	Initializer
@@ -48,6 +57,17 @@ InitArchiveFmt_Null(ArchiveHandle *AH)
 	AH->ClosePtr = _CloseArchive;
 	AH->PrintTocDataPtr = _PrintTocData;
 
+	AH->StartBlobsPtr = _StartBlobs;
+	AH->StartBlobPtr = _StartBlob;
+	AH->EndBlobPtr = _EndBlob;
+	AH->EndBlobsPtr = _EndBlobs;
+
+	/* Initialize LO buffering */
+	AH->lo_buf_size = LOBBUFSIZE;
+	AH->lo_buf = (void *) malloc(LOBBUFSIZE);
+	if (AH->lo_buf == NULL)
+		die_horribly(AH, NULL, "out of memory\n");
+
 	/*
 	 * Now prevent reading...
 	 */
@@ -59,10 +79,8 @@ InitArchiveFmt_Null(ArchiveHandle *AH)
  * - Start a new TOC entry
  */
 
-/*------
+/*
  * Called by dumper via archiver from within a data dump routine
- * As at V1.3, this is only called for COPY FROM dfata, and BLOB data
- *------
  */
 static size_t
 _WriteData(ArchiveHandle *AH, const void *data, size_t dLen)
@@ -72,12 +90,91 @@ _WriteData(ArchiveHandle *AH, const void *data, size_t dLen)
 	return dLen;
 }
 
+/*
+ * Called by dumper via archiver from within a data dump routine
+ * We substitute this for _WriteData while emitting a BLOB
+ */
+static size_t
+_WriteBlobData(ArchiveHandle *AH, const void *data, size_t dLen)
+{
+	if (dLen > 0)
+	{
+		unsigned char *str;
+		size_t	len;
+
+		str = PQescapeBytea((const unsigned char *) data, dLen, &len);
+		if (!str)
+			die_horribly(AH, NULL, "out of memory\n");
+
+		ahprintf(AH, "SELECT lowrite(0, '%s');\n", str);
+
+		free(str);
+	}
+	return dLen;
+}
+
 static void
 _EndData(ArchiveHandle *AH, TocEntry *te)
 {
 	ahprintf(AH, "\n\n");
 }
 
+/*
+ * Called by the archiver when starting to save all BLOB DATA (not schema).
+ * This routine should save whatever format-specific information is needed
+ * to read the BLOBs back into memory.
+ *
+ * It is called just prior to the dumper's DataDumper routine.
+ *
+ * Optional, but strongly recommended.
+ */
+static void
+_StartBlobs(ArchiveHandle *AH, TocEntry *te)
+{
+	ahprintf(AH, "BEGIN;\n\n");
+}
+
+/*
+ * Called by the archiver when the dumper calls StartBlob.
+ *
+ * Mandatory.
+ *
+ * Must save the passed OID for retrieval at restore-time.
+ */
+static void
+_StartBlob(ArchiveHandle *AH, TocEntry *te, Oid oid)
+{
+	if (oid == 0)
+		die_horribly(AH, NULL, "invalid OID for large object\n");
+
+	ahprintf(AH, "SELECT lo_open(lo_create(%u), %d);\n", oid, INV_WRITE);
+
+	AH->WriteDataPtr = _WriteBlobData;
+}
+
+/*
+ * Called by the archiver when the dumper calls EndBlob.
+ *
+ * Optional.
+ */
+static void
+_EndBlob(ArchiveHandle *AH, TocEntry *te, Oid oid)
+{
+	AH->WriteDataPtr = _WriteData;
+	ahprintf(AH, "SELECT lo_close(0);\n\n");
+}
+
+/*
+ * Called by the archiver when finishing saving all BLOB DATA.
+ *
+ * Optional.
+ */
+static void
+_EndBlobs(ArchiveHandle *AH, TocEntry *te)
+{
+	ahprintf(AH, "COMMIT;\n\n");
+}
+
 /*------
  * Called as part of a RestoreArchive call; for the NULL archive, this
  * just sends the data for a given TOC entry to the output.
@@ -89,7 +186,15 @@ _PrintTocData(ArchiveHandle *AH, TocEntry *te, RestoreOptions *ropt)
 	if (te->dataDumper)
 	{
 		AH->currToc = te;
+
+		if (strcmp(te->desc, "BLOBS") == 0)
+			_StartBlobs(AH, te);
+
 		(*te->dataDumper) ((Archive *) AH, te->dataDumperArg);
+
+		if (strcmp(te->desc, "BLOBS") == 0)
+			_EndBlobs(AH, te);
+
 		AH->currToc = NULL;
 	}
 }