pg_backup_archiver.c

PostgreSQL7.4.6 for Linux

	va_start(ap, fmt);
	_die_horribly(AH, modulename, fmt, ap);
}


static void
_moveAfter(ArchiveHandle *AH, TocEntry *pos, TocEntry *te)
{
	te->prev->next = te->next;
	te->next->prev = te->prev;

	te->prev = pos;
	te->next = pos->next;

	pos->next->prev = te;
	pos->next = te;

	te->_moved = 1;
}

static void
_moveBefore(ArchiveHandle *AH, TocEntry *pos, TocEntry *te)
{
	te->prev->next = te->next;
	te->next->prev = te->prev;

	te->prev = pos->prev;
	te->next = pos;
	pos->prev->next = te;
	pos->prev = te;

	te->_moved = 1;
}

static TocEntry *
_getTocEntry(ArchiveHandle *AH, int id)
{
	TocEntry   *te;

	te = AH->toc->next;
	while (te != AH->toc)
	{
		if (te->id == id)
			return te;
		te = te->next;
	}
	return NULL;
}

int
TocIDRequired(ArchiveHandle *AH, int id, RestoreOptions *ropt)
{
	TocEntry   *te = _getTocEntry(AH, id);

	if (!te)
		return 0;

	return _tocEntryRequired(te, ropt);
}

size_t
WriteOffset(ArchiveHandle *AH, off_t o, int wasSet)
{
	int			off;

	/* Save the flag */
	(*AH->WriteBytePtr) (AH, wasSet);

	/* Write out off_t smallest byte first, prevents endian mismatch */
	for (off = 0; off < sizeof(off_t); off++)
	{
		(*AH->WriteBytePtr) (AH, o & 0xFF);
		o >>= 8;
	}
	return sizeof(off_t) + 1;
}

int
ReadOffset(ArchiveHandle *AH, off_t *o)
{
	int			i;
	int			off;
	int			offsetFlg;

	/* Initialize to zero */
	*o = 0;

	/* Check for old version */
	if (AH->version < K_VERS_1_7)
	{
		/* Prior versions wrote offsets using WriteInt */
		i = ReadInt(AH);
		/* -1 means not set */
		if (i < 0)
			return K_OFFSET_POS_NOT_SET;
		else if (i == 0)
			return K_OFFSET_NO_DATA;

		/* Cast to off_t because it was written as an int. */
		*o = (off_t) i;
		return K_OFFSET_POS_SET;
	}

	/*
	 * Read the flag indicating the state of the data pointer. Check if
	 * valid and die if not.
	 *
	 * This used to be handled by a negative or zero pointer, now we use an
	 * extra byte specifically for the state.
	 */
	offsetFlg = (*AH->ReadBytePtr) (AH) & 0xFF;

	switch (offsetFlg)
	{
		case K_OFFSET_POS_NOT_SET:
		case K_OFFSET_NO_DATA:
		case K_OFFSET_POS_SET:

			break;

		default:
			die_horribly(AH, modulename, "Unexpected data offset flag %d\n", offsetFlg);
	}

	/*
	 * Read the bytes
	 */
	for (off = 0; off < AH->offSize; off++)
	{
		if (off < sizeof(off_t))
			*o |= ((off_t) ((*AH->ReadBytePtr) (AH))) << (off * 8);
		else
		{
			if ((*AH->ReadBytePtr) (AH) != 0)
				die_horribly(AH, modulename, "file offset in dump file is too large\n");
		}
	}

	return offsetFlg;
}

size_t
WriteInt(ArchiveHandle *AH, int i)
{
	int			b;

	/*
	 * This is a bit yucky, but I don't want to make the binary format
	 * very dependent on representation, and not knowing much about it, I
	 * write out a sign byte. If you change this, don't forget to change
	 * the file version #, and modify readInt to read the new format AS
	 * WELL AS the old formats.
	 */

	/* SIGN byte */
	if (i < 0)
	{
		(*AH->WriteBytePtr) (AH, 1);
		i = -i;
	}
	else
		(*AH->WriteBytePtr) (AH, 0);

	for (b = 0; b < AH->intSize; b++)
	{
		(*AH->WriteBytePtr) (AH, i & 0xFF);
		i >>= 8;
	}

	return AH->intSize + 1;
}

int
ReadInt(ArchiveHandle *AH)
{
	int			res = 0;
	int			bv,
				b;
	int			sign = 0;		/* Default positive */
	int			bitShift = 0;

	if (AH->version > K_VERS_1_0)
		/* Read a sign byte */
		sign = (*AH->ReadBytePtr) (AH);

	for (b = 0; b < AH->intSize; b++)
	{
		bv = (*AH->ReadBytePtr) (AH) & 0xFF;
		if (bv != 0)
			res = res + (bv << bitShift);
		bitShift += 8;
	}

	if (sign)
		res = -res;

	return res;
}

size_t
WriteStr(ArchiveHandle *AH, const char *c)
{
	size_t		res;

	if (c)
	{
		res = WriteInt(AH, strlen(c));
		res += (*AH->WriteBufPtr) (AH, c, strlen(c));
	}
	else
		res = WriteInt(AH, -1);

	return res;
}

char *
ReadStr(ArchiveHandle *AH)
{
	char	   *buf;
	int			l;

	l = ReadInt(AH);
	if (l == -1)
		buf = NULL;
	else
	{
		buf = (char *) malloc(l + 1);
		if (!buf)
			die_horribly(AH, modulename, "out of memory\n");

		(*AH->ReadBufPtr) (AH, (void *) buf, l);
		buf[l] = '\0';
	}

	return buf;
}

static int
_discoverArchiveFormat(ArchiveHandle *AH)
{
	FILE	   *fh;
	char		sig[6];			/* More than enough */
	size_t		cnt;
	int			wantClose = 0;

#if 0
	write_msg(modulename, "attempting to ascertain archive format\n");
#endif

	if (AH->lookahead)
		free(AH->lookahead);

	AH->lookaheadSize = 512;
	AH->lookahead = calloc(1, 512);
	AH->lookaheadLen = 0;
	AH->lookaheadPos = 0;

	if (AH->fSpec)
	{
		wantClose = 1;
		fh = fopen(AH->fSpec, PG_BINARY_R);
	}
	else
		fh = stdin;

	if (!fh)
		die_horribly(AH, modulename, "could not open input file: %s\n", strerror(errno));

	cnt = fread(sig, 1, 5, fh);

	if (cnt != 5)
	{
		if (ferror(fh))
			die_horribly(AH, modulename, "could not read input file: %s\n", strerror(errno));
		else
			die_horribly(AH, modulename, "input file is too short (read %lu, expected 5)\n",
						 (unsigned long) cnt);
	}

	/* Save it, just in case we need it later */
	strncpy(&AH->lookahead[0], sig, 5);
	AH->lookaheadLen = 5;

	if (strncmp(sig, "PGDMP", 5) == 0)
	{
		AH->vmaj = fgetc(fh);
		AH->vmin = fgetc(fh);

		/* Save these too... */
		AH->lookahead[AH->lookaheadLen++] = AH->vmaj;
		AH->lookahead[AH->lookaheadLen++] = AH->vmin;

		/* Check header version; varies from V1.0 */
		if (AH->vmaj > 1 || ((AH->vmaj == 1) && (AH->vmin > 0)))		/* Version > 1.0 */
		{
			AH->vrev = fgetc(fh);
			AH->lookahead[AH->lookaheadLen++] = AH->vrev;
		}
		else
			AH->vrev = 0;

		/* Make a convenient integer <maj><min><rev>00 */
		AH->version = ((AH->vmaj * 256 + AH->vmin) * 256 + AH->vrev) * 256 + 0;

		AH->intSize = fgetc(fh);
		AH->lookahead[AH->lookaheadLen++] = AH->intSize;

		if (AH->version >= K_VERS_1_7)
		{
			AH->offSize = fgetc(fh);
			AH->lookahead[AH->lookaheadLen++] = AH->offSize;
		}
		else
			AH->offSize = AH->intSize;

		AH->format = fgetc(fh);
		AH->lookahead[AH->lookaheadLen++] = AH->format;
	}
	else
	{
		/*
		 * *Maybe* we have a tar archive format file... So, read first 512
		 * byte header...
		 */
		cnt = fread(&AH->lookahead[AH->lookaheadLen], 1, 512 - AH->lookaheadLen, fh);
		AH->lookaheadLen += cnt;

		if (AH->lookaheadLen != 512)
			die_horribly(AH, modulename, "input file does not appear to be a valid archive (too short?)\n");

		if (!isValidTarHeader(AH->lookahead))
			die_horribly(AH, modulename, "input file does not appear to be a valid archive\n");

		AH->format = archTar;
	}

	/* If we can't seek, then mark the header as read */
	if (fseeko(fh, 0, SEEK_SET) != 0)
	{
		/*
		 * NOTE: Formats that use the lookahead buffer can unset this in
		 * their Init routine.
		 */
		AH->readHeader = 1;
	}
	else
		AH->lookaheadLen = 0;	/* Don't bother since we've reset the file */

#if 0
	write_msg(modulename, "read %lu bytes into lookahead buffer\n",
			  (unsigned long) AH->lookaheadLen);
#endif

	/* Close the file */
	if (wantClose)
		if (fclose(fh) != 0)
			die_horribly(AH, modulename, "could not close the input file after reading header: %s\n",
						 strerror(errno));

	return AH->format;
}


/*
 * Allocate an archive handle
 */
static ArchiveHandle *
_allocAH(const char *FileSpec, const ArchiveFormat fmt,
		 const int compression, ArchiveMode mode)
{
	ArchiveHandle *AH;

#if 0
	write_msg(modulename, "allocating AH for %s, format %d\n", FileSpec, fmt);
#endif

	AH = (ArchiveHandle *) calloc(1, sizeof(ArchiveHandle));
	if (!AH)
		die_horribly(AH, modulename, "out of memory\n");

	/* AH->debugLevel = 100; */

	AH->vmaj = K_VERS_MAJOR;
	AH->vmin = K_VERS_MINOR;
	AH->vrev = K_VERS_REV;

	AH->createDate = time(NULL);

	AH->intSize = sizeof(int);
	AH->offSize = sizeof(off_t);
	AH->lastID = 0;
	if (FileSpec)
	{
		AH->fSpec = strdup(FileSpec);

		/*
		 * Not used; maybe later....
		 *
		 * AH->workDir = strdup(FileSpec); for(i=strlen(FileSpec) ; i > 0 ;
		 * i--) if (AH->workDir[i-1] == '/')
		 */
	}
	else
		AH->fSpec = NULL;

	AH->currUser = strdup("");	/* So it's valid, but we can free() it
								 * later if necessary */
	AH->currSchema = strdup("");	/* ditto */

	AH->toc = (TocEntry *) calloc(1, sizeof(TocEntry));
	if (!AH->toc)
		die_horribly(AH, modulename, "out of memory\n");

	AH->toc->next = AH->toc;
	AH->toc->prev = AH->toc;

	AH->mode = mode;
	AH->compression = compression;

	AH->pgCopyBuf = createPQExpBuffer();
	AH->sqlBuf = createPQExpBuffer();

	/* Open stdout with no compression for AH output handle */
	AH->gzOut = 0;
	AH->OF = stdout;

#if 0
	write_msg(modulename, "archive format is %d\n", fmt);
#endif

	if (fmt == archUnknown)
		AH->format = _discoverArchiveFormat(AH);
	else
		AH->format = fmt;

	switch (AH->format)
	{

		case archCustom:
			InitArchiveFmt_Custom(AH);
			break;

		case archFiles:
			InitArchiveFmt_Files(AH);
			break;

		case archNull:
			InitArchiveFmt_Null(AH);
			break;

		case archTar:
			InitArchiveFmt_Tar(AH);
			break;

		default:
			die_horribly(AH, modulename, "unrecognized file format \"%d\"\n", fmt);
	}

	return AH;
}


void
WriteDataChunks(ArchiveHandle *AH)
{
	TocEntry   *te = AH->toc->next;
	StartDataPtr startPtr;
	EndDataPtr	endPtr;

	while (te != AH->toc)
	{
		if (te->dataDumper != NULL)
		{
			AH->currToc = te;
			/* printf("Writing data for %d (%x)\n", te->id, te); */

			if (strcmp(te->desc, "BLOBS") == 0)
			{
				startPtr = AH->StartBlobsPtr;
				endPtr = AH->EndBlobsPtr;
			}
			else
			{
				startPtr = AH->StartDataPtr;
				endPtr = AH->EndDataPtr;
			}

			if (startPtr != NULL)
				(*startPtr) (AH, te);

			/*
			 * printf("Dumper arg for %d is %x\n", te->id,
			 * te->dataDumperArg);
			 */

			/*
			 * The user-provided DataDumper routine needs to call
			 * AH->WriteData
			 */
			(*te->dataDumper) ((Archive *) AH, te->oid, te->dataDumperArg);

			if (endPtr != NULL)
				(*endPtr) (AH, te);
			AH->currToc = NULL;
		}
		te = te->next;
	}
}

void
WriteToc(ArchiveHandle *AH)
{
	TocEntry   *te = AH->toc->next;
	const char *dep;
	int			i;

	/* printf("%d TOC Entries to save\n", AH->tocCount); */

	WriteInt(AH, AH->tocCount);
	while (te != AH->toc)
	{
		WriteInt(AH, te->id);
		WriteInt(AH, te->dataDumper ? 1 : 0);
		WriteStr(AH, te->oid);

		WriteStr(AH, te->tag);
		WriteStr(AH, te->desc);
		WriteStr(AH, te->defn);
		WriteStr(AH, te->dropStmt);
		WriteStr(AH, te->copyStmt);
		WriteStr(AH, te->namespace);
		WriteStr(AH, te->owner);

		/* Dump list of dependencies */
		if (te->depOid != NULL)
		{
			i = 0;
			while ((dep = (*te->depOid)[i++]) != NULL)
				WriteStr(AH, dep);
		}
		WriteStr(AH, NULL);		/* Terminate List */

		if (AH->WriteExtraTocPtr)
			(*AH->WriteExtraTocPtr) (AH, te);
		te = te->next;
	}
}

void
ReadToc(ArchiveHandle *AH)
{
	int			i;
	char	   *((*deps)[]);
	int			depIdx;
	int			depSize;

	TocEntry   *te = AH->toc->next;

	AH->tocCount = ReadInt(AH);

	for (i = 0; i < AH->tocCount; i++)
	{

		te = (TocEntry *) calloc(1, sizeof(TocEntry));
		te->id = ReadInt(AH);

		/* Sanity check */
		if (te->id <= 0 || te->id > AH->tocCount)
			die_horribly(AH, modulename, "entry ID %d out of range -- perhaps a corrupt TOC\n", te->id);

		te->hadDumper = ReadInt(AH);
		te->oid = ReadStr(AH);
		te->oidVal = atooid(te->oid);

		te->tag = ReadStr(AH);
		te->desc = ReadStr(AH);
		te->defn = ReadStr(AH);
		te->dropStmt = ReadStr(AH);

		if (AH->version >= K_VERS_1_3)
			te->copyStmt = ReadStr(AH);

		if (AH->version >= K_VERS_1_6)
			te->namespace = ReadStr(AH);

		te->owner = ReadStr(AH);

		/* Read TOC entry dependencies */
		if (AH->version >= K_VERS_1_5)
		{
			depSize = 100;
			deps = malloc(sizeof(char *) * depSize);
			depIdx = 0;
			do
			{
				if (depIdx >= depSize)
				{
					depSize *= 2;
					deps = realloc(deps, sizeof(char *) * depSize);
				}
				(*deps)[depIdx] = ReadStr(AH);
#if 0
				if ((*deps)[depIdx])
					write_msg(modulename, "read dependency for %s -> %s\n",
							  te->tag, (*deps)[depIdx]);
#endif
			} while ((*deps)[depIdx++] != NULL);

			if (depIdx > 1)		/* We have a non-null entry */
				te->depOid = realloc(deps, sizeof(char *) * depIdx);	/* trim it */
			else
			{
				free(deps);
				te->depOid = NULL;		/* no deps */
			}
		}
		else
			te->depOid = NULL;

		/* Set maxOidVal etc for use in sorting */
		_fixupOidInfo(te);

		if (AH->ReadExtraTocPtr)
			(*AH->ReadExtraTocPtr) (AH, te);

		ahlog(AH, 3, "read TOC entry %d (ID %d) for %s %s\n", i, te->id, te->desc, te->tag);

		te->prev = AH->toc->prev;
		AH->toc->prev->next = te;
		AH->toc->prev = te;
		te->next = AH->toc;
	}
}

static teReqs
_tocEntryRequired(TocEntry *te, RestoreOptions *ropt)
{
	teReqs		res = 3;		/* Schema = 1, Data = 2, Both = 3 */

	/* ENCODING objects are dumped specially, so always reject here */
	if (strcmp(te->desc, "ENCODING") == 0)
		return 0;

	/* If it's an ACL, maybe ignore it */
	if (ropt->aclsSkip && strcmp(te->desc, "ACL") == 0)
		return 0;

	if (!ropt->create && strcmp(te->desc, "DATABASE") == 0)
		return 0;