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

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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.
This commit is contained in:
Tom Lane
2005-06-21 20:45:44 +00:00
parent b49d871f6a
commit 7a28de2052
15 changed files with 254 additions and 585 deletions
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115
src/bin/pg_dump/pg_backup_null.c
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@@ -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;
}
}