pg_backup_archiver.c

PostgreSQL 8.1.4的源码 适用于Linux下的开源数据库系统

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

	AH->currUser = strdup(user);
}

/*
 * Become the owner of the the given TOC entry object.	If
 * changes in ownership are not allowed, this doesn't do anything.
 */
static void
_becomeOwner(ArchiveHandle *AH, TocEntry *te)
{
	if (AH->ropt && (AH->ropt->noOwner || !AH->ropt->use_setsessauth))
		return;

	_becomeUser(AH, te->owner);
}


/*
 * Set the proper default_with_oids value for the table.
 */
static void
_setWithOids(ArchiveHandle *AH, TocEntry *te)
{
	if (AH->currWithOids != te->withOids)
	{
		_doSetWithOids(AH, te->withOids);
		AH->currWithOids = te->withOids;
	}
}


/*
 * Issue the commands to select the specified schema as the current schema
 * in the target database.
 */
static void
_selectOutputSchema(ArchiveHandle *AH, const char *schemaName)
{
	PQExpBuffer qry;

	if (!schemaName || *schemaName == '\0' ||
		strcmp(AH->currSchema, schemaName) == 0)
		return;					/* no need to do anything */

	qry = createPQExpBuffer();

	appendPQExpBuffer(qry, "SET search_path = %s",
					  fmtId(schemaName));
	if (strcmp(schemaName, "pg_catalog") != 0)
		appendPQExpBuffer(qry, ", pg_catalog");

	if (RestoringToDB(AH))
	{
		PGresult   *res;

		res = PQexec(AH->connection, qry->data);

		if (!res || PQresultStatus(res) != PGRES_COMMAND_OK)
			warn_or_die_horribly(AH, modulename,
								 "could not set search_path to \"%s\": %s",
								 schemaName, PQerrorMessage(AH->connection));

		PQclear(res);
	}
	else
		ahprintf(AH, "%s;\n\n", qry->data);

	if (AH->currSchema)
		free(AH->currSchema);
	AH->currSchema = strdup(schemaName);

	destroyPQExpBuffer(qry);
}

/*
 * Issue the commands to select the specified tablespace as the current one
 * in the target database.
 */
static void
_selectTablespace(ArchiveHandle *AH, const char *tablespace)
{
	PQExpBuffer qry;
	const char *want,
			   *have;

	have = AH->currTablespace;
	want = tablespace;

	/* no need to do anything for non-tablespace object */
	if (!want)
		return;

	if (have && strcmp(want, have) == 0)
		return;					/* no need to do anything */

	qry = createPQExpBuffer();

	if (strcmp(want, "") == 0)
	{
		/* We want the tablespace to be the database's default */
		appendPQExpBuffer(qry, "SET default_tablespace = ''");
	}
	else
	{
		/* We want an explicit tablespace */
		appendPQExpBuffer(qry, "SET default_tablespace = %s", fmtId(want));
	}

	if (RestoringToDB(AH))
	{
		PGresult   *res;

		res = PQexec(AH->connection, qry->data);

		if (!res || PQresultStatus(res) != PGRES_COMMAND_OK)
			warn_or_die_horribly(AH, modulename,
								 "could not set default_tablespace to %s: %s",
								 fmtId(want), PQerrorMessage(AH->connection));

		PQclear(res);
	}
	else
		ahprintf(AH, "%s;\n\n", qry->data);

	if (AH->currTablespace)
		free(AH->currTablespace);
	AH->currTablespace = strdup(want);

	destroyPQExpBuffer(qry);
}

/*
 * Extract an object description for a TOC entry, and append it to buf.
 *
 * This is not quite as general as it may seem, since it really only
 * handles constructing the right thing to put into ALTER ... OWNER TO.
 *
 * The whole thing is pretty grotty, but we are kind of stuck since the
 * information used is all that's available in older dump files.
 */
static void
_getObjectDescription(PQExpBuffer buf, TocEntry *te, ArchiveHandle *AH)
{
	const char *type = te->desc;

	/* Use ALTER TABLE for views and sequences */
	if (strcmp(type, "VIEW") == 0 ||
		strcmp(type, "SEQUENCE") == 0)
		type = "TABLE";

	/* objects named by a schema and name */
	if (strcmp(type, "CONVERSION") == 0 ||
		strcmp(type, "DOMAIN") == 0 ||
		strcmp(type, "TABLE") == 0 ||
		strcmp(type, "TYPE") == 0)
	{
		appendPQExpBuffer(buf, "%s ", type);
		if (te->namespace && te->namespace[0])	/* is null pre-7.3 */
			appendPQExpBuffer(buf, "%s.", fmtId(te->namespace));

		/*
		 * Pre-7.3 pg_dump would sometimes (not always) put a fmtId'd name
		 * into te->tag for an index. This check is heuristic, so make its
		 * scope as narrow as possible.
		 */
		if (AH->version < K_VERS_1_7 &&
			te->tag[0] == '"' &&
			te->tag[strlen(te->tag) - 1] == '"' &&
			strcmp(type, "INDEX") == 0)
			appendPQExpBuffer(buf, "%s", te->tag);
		else
			appendPQExpBuffer(buf, "%s", fmtId(te->tag));
		return;
	}

	/* objects named by just a name */
	if (strcmp(type, "DATABASE") == 0 ||
		strcmp(type, "SCHEMA") == 0)
	{
		appendPQExpBuffer(buf, "%s %s", type, fmtId(te->tag));
		return;
	}

	/*
	 * These object types require additional decoration.  Fortunately, the
	 * information needed is exactly what's in the DROP command.
	 */
	if (strcmp(type, "AGGREGATE") == 0 ||
		strcmp(type, "FUNCTION") == 0 ||
		strcmp(type, "OPERATOR") == 0 ||
		strcmp(type, "OPERATOR CLASS") == 0)
	{
		/* Chop "DROP " off the front and make a modifiable copy */
		char	   *first = strdup(te->dropStmt + 5);
		char	   *last;

		/* point to last character in string */
		last = first + strlen(first) - 1;

		/* Strip off any ';' or '\n' at the end */
		while (last >= first && (*last == '\n' || *last == ';'))
			last--;
		*(last + 1) = '\0';

		appendPQExpBufferStr(buf, first);

		free(first);
		return;
	}

	write_msg(modulename, "WARNING: don't know how to set owner for object type %s\n",
			  type);
}

static void
_printTocEntry(ArchiveHandle *AH, TocEntry *te, RestoreOptions *ropt, bool isData, bool acl_pass)
{
	/* ACLs are dumped only during acl pass */
	if (acl_pass)
	{
		if (strcmp(te->desc, "ACL") != 0)
			return;
	}
	else
	{
		if (strcmp(te->desc, "ACL") == 0)
			return;
	}

	/*
	 * Avoid dumping the public schema, as it will already be created ...
	 * unless we are using --clean mode, in which case it's been deleted and
	 * we'd better recreate it.
	 */
	if (!ropt->dropSchema &&
		strcmp(te->desc, "SCHEMA") == 0 && strcmp(te->tag, "public") == 0)
		return;

	/* Select owner, schema, and tablespace as necessary */
	_becomeOwner(AH, te);
	_selectOutputSchema(AH, te->namespace);
	_selectTablespace(AH, te->tablespace);

	/* Set up OID mode too */
	if (strcmp(te->desc, "TABLE") == 0)
		_setWithOids(AH, te);

	/* Emit header comment for item */
	if (!AH->noTocComments)
	{
		const char *pfx;

		if (isData)
			pfx = "Data for ";
		else
			pfx = "";

		ahprintf(AH, "--\n");
		if (AH->public.verbose)
		{
			ahprintf(AH, "-- TOC entry %d (class %u OID %u)\n",
					 te->dumpId, te->catalogId.tableoid, te->catalogId.oid);
			if (te->nDeps > 0)
			{
				int			i;

				ahprintf(AH, "-- Dependencies:");
				for (i = 0; i < te->nDeps; i++)
					ahprintf(AH, " %d", te->dependencies[i]);
				ahprintf(AH, "\n");
			}
		}
		ahprintf(AH, "-- %sName: %s; Type: %s; Schema: %s; Owner: %s",
				 pfx, te->tag, te->desc,
				 te->namespace ? te->namespace : "-",
				 te->owner);
		if (te->tablespace)
			ahprintf(AH, "; Tablespace: %s", te->tablespace);
		ahprintf(AH, "\n");

		if (AH->PrintExtraTocPtr !=NULL)
			(*AH->PrintExtraTocPtr) (AH, te);
		ahprintf(AH, "--\n\n");
	}

	/*
	 * Actually print the definition.
	 *
	 * Really crude hack for suppressing AUTHORIZATION clause that old pg_dump
	 * versions put into CREATE SCHEMA.  We have to do this when --no-owner
	 * mode is selected.  This is ugly, but I see no other good way ...
	 */
	if (ropt->noOwner && strcmp(te->desc, "SCHEMA") == 0)
	{
		ahprintf(AH, "CREATE SCHEMA %s;\n\n\n", fmtId(te->tag));
	}
	else
	{
		if (strlen(te->defn) > 0)
			ahprintf(AH, "%s\n\n", te->defn);
	}

	/*
	 * If we aren't using SET SESSION AUTH to determine ownership, we must
	 * instead issue an ALTER OWNER command.  We assume that anything without
	 * a DROP command is not a separately ownable object.  All the categories
	 * with DROP commands must appear in one list or the other.
	 */
	if (!ropt->noOwner && !ropt->use_setsessauth &&
		strlen(te->owner) > 0 && strlen(te->dropStmt) > 0)
	{
		if (strcmp(te->desc, "AGGREGATE") == 0 ||
			strcmp(te->desc, "CONVERSION") == 0 ||
			strcmp(te->desc, "DATABASE") == 0 ||
			strcmp(te->desc, "DOMAIN") == 0 ||
			strcmp(te->desc, "FUNCTION") == 0 ||
			strcmp(te->desc, "OPERATOR") == 0 ||
			strcmp(te->desc, "OPERATOR CLASS") == 0 ||
			strcmp(te->desc, "SCHEMA") == 0 ||
			strcmp(te->desc, "TABLE") == 0 ||
			strcmp(te->desc, "TYPE") == 0 ||
			strcmp(te->desc, "VIEW") == 0 ||
			strcmp(te->desc, "SEQUENCE") == 0)
		{
			PQExpBuffer temp = createPQExpBuffer();

			appendPQExpBuffer(temp, "ALTER ");
			_getObjectDescription(temp, te, AH);
			appendPQExpBuffer(temp, " OWNER TO %s;", fmtId(te->owner));
			ahprintf(AH, "%s\n\n", temp->data);
			destroyPQExpBuffer(temp);
		}
		else if (strcmp(te->desc, "CAST") == 0 ||
				 strcmp(te->desc, "CHECK CONSTRAINT") == 0 ||
				 strcmp(te->desc, "CONSTRAINT") == 0 ||
				 strcmp(te->desc, "DEFAULT") == 0 ||
				 strcmp(te->desc, "FK CONSTRAINT") == 0 ||
				 strcmp(te->desc, "INDEX") == 0 ||
				 strcmp(te->desc, "PROCEDURAL LANGUAGE") == 0 ||
				 strcmp(te->desc, "RULE") == 0 ||
				 strcmp(te->desc, "TRIGGER") == 0)
		{
			/* these object types don't have separate owners */
		}
		else
		{
			write_msg(modulename, "WARNING: don't know how to set owner for object type %s\n",
					  te->desc);
		}
	}

	/*
	 * If it's an ACL entry, it might contain SET SESSION AUTHORIZATION
	 * commands, so we can no longer assume we know the current auth setting.
	 */
	if (strncmp(te->desc, "ACL", 3) == 0)
	{
		if (AH->currUser)
			free(AH->currUser);
		AH->currUser = NULL;
	}
}

void
WriteHead(ArchiveHandle *AH)
{
	struct tm	crtm;

	(*AH->WriteBufPtr) (AH, "PGDMP", 5);		/* Magic code */
	(*AH->WriteBytePtr) (AH, AH->vmaj);
	(*AH->WriteBytePtr) (AH, AH->vmin);
	(*AH->WriteBytePtr) (AH, AH->vrev);
	(*AH->WriteBytePtr) (AH, AH->intSize);
	(*AH->WriteBytePtr) (AH, AH->offSize);
	(*AH->WriteBytePtr) (AH, AH->format);

#ifndef HAVE_LIBZ
	if (AH->compression != 0)
		write_msg(modulename, "WARNING: requested compression not available in this "
				  "installation -- archive will be uncompressed\n");

	AH->compression = 0;
#endif

	WriteInt(AH, AH->compression);

	crtm = *localtime(&AH->createDate);
	WriteInt(AH, crtm.tm_sec);
	WriteInt(AH, crtm.tm_min);
	WriteInt(AH, crtm.tm_hour);
	WriteInt(AH, crtm.tm_mday);
	WriteInt(AH, crtm.tm_mon);
	WriteInt(AH, crtm.tm_year);
	WriteInt(AH, crtm.tm_isdst);
	WriteStr(AH, PQdb(AH->connection));
	WriteStr(AH, AH->public.remoteVersionStr);
	WriteStr(AH, PG_VERSION);
}

void
ReadHead(ArchiveHandle *AH)
{
	char		tmpMag[7];
	int			fmt;
	struct tm	crtm;

	/* If we haven't already read the header... */
	if (!AH->readHeader)
	{

		(*AH->ReadBufPtr) (AH, tmpMag, 5);

		if (strncmp(tmpMag, "PGDMP", 5) != 0)
			die_horribly(AH, modulename, "did not find magic string in file header\n");

		AH->vmaj = (*AH->ReadBytePtr) (AH);
		AH->vmin = (*AH->ReadBytePtr) (AH);

		if (AH->vmaj > 1 || ((AH->vmaj == 1) && (AH->vmin > 0)))		/* Version > 1.0 */
			AH->vrev = (*AH->ReadBytePtr) (AH);
		else
			AH->vrev = 0;

		AH->version = ((AH->vmaj * 256 + AH->vmin) * 256 + AH->vrev) * 256 + 0;


		if (AH->version < K_VERS_1_0 || AH->version > K_VERS_MAX)
			die_horribly(AH, modulename, "unsupported version (%d.%d) in file header\n",
						 AH->vmaj, AH->vmin);

		AH->intSize = (*AH->ReadBytePtr) (AH);
		if (AH->intSize > 32)
			die_horribly(AH, modulename, "sanity check on integer size (%lu) failed\n",
						 (unsigned long) AH->intSize);

		if (AH->intSize > sizeof(int))
			write_msg(modulename, "WARNING: archive was made on a machine with larger integers, some operations may fail\n");

		if (AH->version >= K_VERS_1_7)
			AH->offSize = (*AH->ReadBytePtr) (AH);
		else
			AH->offSize = AH->intSize;

		fmt = (*AH->ReadBytePtr) (AH);

		if (AH->format != fmt)
			die_horribly(AH, modulename, "expected format (%d) differs from format found in file (%d)\n",
						 AH->format, fmt);
	}

	if (AH->version >= K_VERS_1_2)
	{
		if (AH->version < K_VERS_1_4)
			AH->compression = (*AH->ReadBytePtr) (AH);
		else
			AH->compression = ReadInt(AH);
	}
	else
		AH->compression = Z_DEFAULT_COMPRESSION;

#ifndef HAVE_LIBZ
	if (AH->compression != 0)
		write_msg(modulename, "WARNING: archive is compressed, but this installation does not support compression -- no data will be available\n");
#endif

	if (AH->version >= K_VERS_1_4)
	{
		crtm.tm_sec = ReadInt(AH);
		crtm.tm_min = ReadInt(AH);
		crtm.tm_hour = ReadInt(AH);
		crtm.tm_mday = ReadInt(AH);
		crtm.tm_mon = ReadInt(AH);
		crtm.tm_year = ReadInt(AH);
		crtm.tm_isdst = ReadInt(AH);

		AH->archdbname = ReadStr(AH);

		AH->createDate = mktime(&crtm);

		if (AH->createDate == (time_t) -1)
			write_msg(modulename, "WARNING: invalid creation date in header\n");
	}

	if (AH->version >= K_VERS_1_10)
	{
		AH->archiveRemoteVersion = ReadStr(AH);
		AH->archiveDumpVersion = ReadStr(AH);
	}

}


/*
 * checkSeek
 *	  check to see if fseek can be performed.
 */

bool
checkSeek(FILE *fp)
{

	if (fseeko(fp, 0, SEEK_CUR) != 0)
		return false;
	else if (sizeof(off_t) > sizeof(long))

		/*
		 * At this point, off_t is too large for long, so we return based on
		 * whether an off_t version of fseek is available.
		 */
#ifdef HAVE_FSEEKO
		return true;
#else
		return false;
#endif
	else
		return true;
}


/*
 * dumpTimestamp
 */
static void
dumpTimestamp(ArchiveHandle *AH, const char *msg, time_t tim)
{
	char		buf[256];

	if (strftime(buf, 256, "%Y-%m-%d %H:%M:%S %Z", localtime(&tim)) != 0)
		ahprintf(AH, "-- %s %s\n\n", msg, buf);
}