Code review: minor cleanups, make the world safe for unsigned OIDs.

Improve documentation, too.

contrib/pg_dumplo/README.pg_dumplo

+$Header: /cvsroot/pgsql/contrib/pg_dumplo/Attic/README.pg_dumplo,v 1.2 2000/11/22 00:00:55 tgl Exp $
+
+pg_dumplo - PostgreSQL large object dumper
+==========================================        
+
+By Karel Zak <zakkr@zf.jcu.cz>
+
+
+Compilation:
+===========
+
+	* run master ./configure in the PG source top directory  
+	* gmake all
+	* gmake install
+	
+THANKS:
+====== 
+
+	<??? I lost his e-mail ???>
+		* option '--all' and pg_class usage
+
+	Pavel Janík ml. <Pavel.Janik@linux.cz>
+		* HOWTO (the rest of this file)
+
 
 How to use pg_dumplo?
 =====================
@@ -19,7 +43,7 @@ CREATE DATABASE
 
 Ok, our database with the name 'test' is created. Now we should create demo
 table which will contain only one column with the name 'id' which will hold
-the oid number of Large Object:
+the OID number of a Large Object:
 
 SnowWhite:$ psql test
 Welcome to psql, the PostgreSQL interactive terminal.
@@ -49,12 +73,12 @@ Object" - the file /etc/aliases. It has an oid of 19338 so we have inserted
 this oid number to the database table lo to the column id. The final SELECT
 shows that we have one record in the table.
 
-Now we can demonstrate the work of pg_dumplo. We will create dump directory
+Now we can demonstrate the work of pg_dumplo. We will create a dump directory
 which will contain the whole dump of large objects (/tmp/dump):
 
 mkdir -p /tmp/dump
 
-Now we can dump all large objects from the database `test' which has an oid
+Now we can dump all large objects from the database `test' which have OIDs
 stored in the column `id' in the table `lo':
 
 SnowWhite:$ pg_dumplo -s /tmp/dump -d test -l lo.id
@@ -73,45 +97,52 @@ SnowWhite:$ tree /tmp/dump/
 3 directories, 2 files
 SnowWhite:$ 
 
-Isn't it nice :-) Yes, it is, but we are on the half of our way. We should
-also be able to recreate the contents of the table lo and the Large Object
-database when something went wrong. It is very easy, we will demonstrate
-this via dropping the database and recreating it from scratch with
-pg_dumplo:
+In practice, we'd probably use
 
-SnowwWite:$ dropdb test
-DROP DATABASE
+SnowWhite:$ pg_dumplo -s /tmp/dump -d test -e
 
-SnowWhite:$ createdb test
-CREATE DATABASE
+to export all large objects that are referenced by any OID-type column
+in the database.  Calling out specific column(s) with -l is only needed
+for a selective dump.
 
-Ok, our database with the name `test' is created again. We should also
-create the table `lo' again:
+For routine backup purposes, the dump directory could now be converted into
+an archive file with tar and stored on tape.  Notice that a single dump
+directory can hold the dump of multiple databases.
 
-SnowWhite:$ psql test
-Welcome to psql, the PostgreSQL interactive terminal.
+Now, how can we recreate the contents of the table lo and the Large Object
+database when something went wrong?  To do this, we expect that pg_dump is
+also used to store the definition and contents of the regular tables in
+the database.
 
-Type:  \copyright for distribution terms
-       \h for help with SQL commands
-       \? for help on internal slash commands
-       \g or terminate with semicolon to execute query
-       \q to quit
+SnowWhite:$ pg_dump test >test.backup
 
-test=# CREATE TABLE lo (id oid);
-CREATE
-test=# \q
-SnowWhite:$
+Now, if we lose the database:
 
-Now the database with the table `lo' is created again, but we do not have
-any information stored in it. But have the dump of complete Large Object
-database, so we can recreate the contents of the whole database from the
-directory /tmp/dump:
+SnowWhite:$ dropdb test
+DROP DATABASE
+
+we can recreate it and reload the regular tables from the dump file:
+
+SnowWhite:$ createdb test
+CREATE DATABASE
+
+SnowWhite:$ psql test <test.backup
+
+But at this point our database has no large objects in it.  What's more,
+the large-object-referencing columns contain the OIDs of the old large
+objects, which will not be the OIDs they'll have when reloaded.  Never
+fear: pg_dumplo will fix the large object references at the same time
+it reloads the large objects.  We reload the LO data from the dump
+directory like this:
 
 SnowWhite:$ pg_dumplo -s /tmp/dump -d test -i
 19338	lo	id	test/lo/id/19338
 SnowWhite:$
 
-And this is everything.
+And this is everything.  The contents of table lo will be automatically
+updated to refer to the new large object OIDs.
 
 Summary: In this small example we have shown that pg_dumplo can be used to
 completely dump the database's Large Objects very easily.
+
+For more information see the help ( pg_dumplo -h ).

contrib/pg_dumplo/lo_export.c

+/* -------------------------------------------------------------------------
+ * pg_dumplo
+ *
+ *	Portions Copyright (c) 1999-2000, PostgreSQL, Inc
+ *
+ * $Header: /cvsroot/pgsql/contrib/pg_dumplo/Attic/lo_export.c,v 1.4 2000/11/22 00:00:55 tgl Exp $
+ *
+ *					Karel Zak 1999-2000
+ * -------------------------------------------------------------------------
+ */
 
 #include <stdio.h>	
 #include <unistd.h>
@@ -16,15 +26,6 @@
 
 extern int 	errno;        
 
-#define LOAD_LOLIST_QUERY "\
-	SELECT c.relname, a.attname \
-	FROM pg_class c, pg_attribute a, pg_type t \
-	WHERE a.attnum > 0 \
-		AND a.attrelid = c.oid \
-		AND a.atttypid = t.oid \
-		AND t.typname = 'oid' \
-		AND c.relname NOT LIKE 'pg_%'"
-
 
 void 
 load_lolist( LODumpMaster *pgLO ) 
@@ -34,19 +35,33 @@ load_lolist( LODumpMaster *pgLO )
 	int		n;
 
  	/* ----------
- 	 * Now find any candidate tables who have columns of type oid (the
-   	 * column oid is ignored, as it has attnum < 1)
+	 * Now find any candidate tables who have columns of type oid.
+	 *
+	 * NOTE: System tables including pg_largeobject will be ignored.
+	 * Otherwise we'd end up dumping all LOs, referenced or not.
+	 *
+	 * NOTE: the system oid column is ignored, as it has attnum < 1.
+	 * This shouldn't matter for correctness, but it saves time.
  	 * ----------
  	 */	
-	if (!(pgLO->res = PQexec(pgLO->conn, LOAD_LOLIST_QUERY))) {
-		
-		fprintf(stderr, "%s: Select from pg_class failed.\n", progname);
-    		exit(RE_ERROR);
-  	}
-	
+	pgLO->res = PQexec(pgLO->conn,
+					   "SELECT c.relname, a.attname "
+					   "FROM pg_class c, pg_attribute a, pg_type t "
+					   "WHERE a.attnum > 0 "
+					   "    AND a.attrelid = c.oid "
+					   "    AND a.atttypid = t.oid "
+					   "    AND t.typname = 'oid' "
+					   "    AND c.relkind = 'r' "
+					   "    AND c.relname NOT LIKE 'pg_%'");
+
+	if (PQresultStatus(pgLO->res) != PGRES_TUPLES_OK) {
+		fprintf(stderr, "%s: Failed to get LO OIDs:\n%s", progname,
+				PQerrorMessage(pgLO->conn));
+		exit(RE_ERROR);
+	}
+
 	if ((n = PQntuples(pgLO->res)) == 0) {
-		
-		fprintf(stderr, "%s: No large objects in the database.\n", progname);
+		fprintf(stderr, "%s: No OID columns in the database.\n", progname);
 		exit(RE_ERROR);
  	}
 	
@@ -61,10 +76,9 @@ load_lolist( LODumpMaster *pgLO )
 		ll->lo_table = strdup(PQgetvalue(pgLO->res, i, 0));
 		ll->lo_attr  = strdup(PQgetvalue(pgLO->res, i, 1));
 	}
+ 	ll->lo_table = ll->lo_attr = (char *) NULL;
 	
 	PQclear(pgLO->res);
- 	ll++;
- 	ll->lo_table = ll->lo_attr = (char *) NULL;
 }
 
 void 
@@ -91,24 +105,25 @@ pglo_export(LODumpMaster *pgLO)
 	for(ll=pgLO->lolist; ll->lo_table != NULL; ll++) {
 		
 		/* ----------
-		 * Query
+		 * Query: find the LOs referenced by this column
 		 * ----------
 		 */
-		sprintf(Qbuff, "SELECT DISTINCT x.\"%s\" FROM \"%s\" x, pg_largeobject l WHERE x.\"%s\" = l.loid",
-			ll->lo_attr, ll->lo_table, ll->lo_attr);
+		sprintf(Qbuff, "SELECT DISTINCT l.loid FROM \"%s\" x, pg_largeobject l WHERE x.\"%s\" = l.loid",
+				ll->lo_table, ll->lo_attr);
 		
 		/* puts(Qbuff); */
 			
 		pgLO->res = PQexec(pgLO->conn, Qbuff);
-	
-		if ((tuples = PQntuples(pgLO->res)) == 0) {
-		
+
+        if (PQresultStatus(pgLO->res) != PGRES_TUPLES_OK) {
+			fprintf(stderr, "%s: Failed to get LO OIDs:\n%s", progname,
+					PQerrorMessage(pgLO->conn));
+        }
+		else if ((tuples = PQntuples(pgLO->res)) == 0) {
 			if (!pgLO->quiet && pgLO->action == ACTION_EXPORT_ATTR)
-				printf("%s: no large objects in '%s'\n",
-					   progname, ll->lo_table);	
-			continue;
-		
-		} else if (check_res(pgLO)) {
+				printf("%s: no large objects in \"%s\".\"%s\"\n",
+					   progname, ll->lo_table, ll->lo_attr);	
+		} else {
 		
 			int	t;
 			char	*val;
@@ -117,9 +132,10 @@ pglo_export(LODumpMaster *pgLO)
 			 * Create DIR/FILE
 			 * ----------
 			 */
-			if (tuples && pgLO->action != ACTION_SHOW) {
+			if (pgLO->action != ACTION_SHOW) {
 			
-				sprintf(path, "%s/%s/%s", pgLO->space, pgLO->db, ll->lo_table);          
+				sprintf(path, "%s/%s/%s", pgLO->space, pgLO->db,
+						ll->lo_table);
 
 				if (mkdir(path, DIR_UMASK) == -1) {
 					if (errno != EEXIST) {
@@ -127,8 +143,9 @@ pglo_export(LODumpMaster *pgLO)
 						exit(RE_ERROR);					
 					}	
 				}
-				
-				sprintf(path, "%s/%s", path, ll->lo_attr);          
+
+				sprintf(path, "%s/%s/%s/%s", pgLO->space, pgLO->db,
+						ll->lo_table, ll->lo_attr);          
 				
 				if (mkdir(path, DIR_UMASK) == -1) {
 					if (errno != EEXIST) {
@@ -145,19 +162,14 @@ pglo_export(LODumpMaster *pgLO)
 			pgLO->counter += tuples;
 			
 			for(t=0; t<tuples; t++) {
-				
-				Oid lo = (Oid) 0;
+				Oid lo;
 				
 				val = PQgetvalue(pgLO->res, t, 0);
 				
-				if (!val)
-					continue;
-				else
-					lo = (Oid) atol(val);
+				lo = atooid(val);
 				
 				if (pgLO->action == ACTION_SHOW) {
-					printf("%s.%s: %ld\n", ll->lo_table, 
-						ll->lo_attr, (long) lo);
+					printf("%s.%s: %u\n", ll->lo_table, ll->lo_attr, lo);
 					continue;
 				}
 				
@@ -165,13 +177,15 @@ pglo_export(LODumpMaster *pgLO)
 					pgLO->db, ll->lo_table, ll->lo_attr, val);
 				
 				if (lo_export(pgLO->conn, lo, path) < 0) 
-					fprintf(stderr, "%s: %s\n", PQerrorMessage(pgLO->conn), progname);
+					fprintf(stderr, "%s: lo_export failed:\n%s", progname,
+							PQerrorMessage(pgLO->conn));
 					
 				else 
 					fprintf(pgLO->index, "%s\t%s\t%s\t%s/%s/%s/%s\n", val, 
 						ll->lo_table, ll->lo_attr, pgLO->db, ll->lo_table, ll->lo_attr, val);
 			}
 		}
-	}	
- }
 
+		PQclear(pgLO->res);
+	}
+}

contrib/pg_dumplo/lo_import.c

+/* -------------------------------------------------------------------------
+ * pg_dumplo
+ *
+ *	Portions Copyright (c) 1999-2000, PostgreSQL, Inc
+ *
+ * $Header: /cvsroot/pgsql/contrib/pg_dumplo/Attic/lo_import.c,v 1.2 2000/11/22 00:00:55 tgl Exp $
+ *
+ *					Karel Zak 1999-2000
+ * -------------------------------------------------------------------------
+ */
 
 #include <stdio.h>	
 #include <unistd.h>
@@ -20,7 +30,7 @@ void
 pglo_import(LODumpMaster *pgLO)
 {
 	LOlist		loa;
-	long 		new_oid;
+	Oid 		new_oid;
 	char		tab[MAX_TABLE_NAME], attr[MAX_ATTR_NAME],
 			path[BUFSIZ], lo_path[BUFSIZ],
 			Qbuff[QUERY_BUFSIZ];
@@ -33,7 +43,7 @@ pglo_import(LODumpMaster *pgLO)
 		if (! pgLO->remove && ! pgLO->quiet)
 			printf(Qbuff);
 		
-		sscanf(Qbuff, "%ld\t%s\t%s\t%s\n", &loa.lo_oid, tab, attr, path); 
+		sscanf(Qbuff, "%u\t%s\t%s\t%s\n", &loa.lo_oid, tab, attr, path); 
 		loa.lo_table = tab;
 		loa.lo_attr  = attr;
 
@@ -43,7 +53,7 @@ pglo_import(LODumpMaster *pgLO)
 		 * Import LO
 		 * ----------
 		 */
-		if ((new_oid = lo_import(pgLO->conn, lo_path)) <= 0) {
+		if ((new_oid = lo_import(pgLO->conn, lo_path)) == 0) {
 		
 			fprintf(stderr, "%s: %s\n", progname, PQerrorMessage(pgLO->conn));
 			
@@ -54,12 +64,12 @@ pglo_import(LODumpMaster *pgLO)
 
 		if (pgLO->remove) {
 			notice(pgLO, FALSE);
-			if (lo_unlink(pgLO->conn, (Oid) loa.lo_oid) < 0) 
-				fprintf(stderr, "%s: can't remove LO: %ld (%s)\n", 
+			if (lo_unlink(pgLO->conn, loa.lo_oid) < 0) 
+				fprintf(stderr, "%s: can't remove LO %u:\n%s", 
 					progname, loa.lo_oid, PQerrorMessage(pgLO->conn));
 					
 			else if (!pgLO->quiet)
-				printf("remove old %ld and create new %ld\n", 
+				printf("remove old %u and create new %u\n", 
 					loa.lo_oid, new_oid);	
 			notice(pgLO, TRUE);	
 		}
@@ -70,20 +80,20 @@ pglo_import(LODumpMaster *pgLO)
 		 * UPDATE oid in tab
 		 * ----------
 		 */
-		sprintf(Qbuff, "UPDATE %s SET %s=%ld WHERE %s=%ld", 
+		sprintf(Qbuff, "UPDATE \"%s\" SET \"%s\"=%u WHERE \"%s\"=%u", 
 			loa.lo_table, loa.lo_attr, new_oid, loa.lo_attr, loa.lo_oid);
 
 		/*fprintf(stderr, Qbuff);*/
 			
 		pgLO->res = PQexec(pgLO->conn, Qbuff);
 	
-		if (!pgLO->res && PQresultStatus(pgLO->res) != PGRES_COMMAND_OK) {
-		
-        		fprintf(stderr, "%s: %s\n",progname, PQerrorMessage(pgLO->conn));
-                	PQclear(pgLO->res);
-                	PQexec(pgLO->conn, "ROLLBACK");
+		if (PQresultStatus(pgLO->res) != PGRES_COMMAND_OK) {
+			fprintf(stderr, "%s: %s\n",progname, PQerrorMessage(pgLO->conn));
+			PQclear(pgLO->res);
+			PQexec(pgLO->conn, "ROLLBACK");
 			fprintf(stderr, "\n%s: ROLLBACK\n", progname);
 			exit(RE_ERROR);
-        	}	
+		}	
+		PQclear(pgLO->res);
 	}	
  }

contrib/pg_dumplo/main.c

-
 /* -------------------------------------------------------------------------
  * pg_dumplo
  *
  *	Portions Copyright (c) 1999-2000, PostgreSQL, Inc
  *
- * $Header: /cvsroot/pgsql/contrib/pg_dumplo/Attic/main.c,v 1.3 2000/07/03 16:03:22 momjian Exp $
+ * $Header: /cvsroot/pgsql/contrib/pg_dumplo/Attic/main.c,v 1.4 2000/11/22 00:00:55 tgl Exp $
  *
  *					Karel Zak 1999-2000
  * -------------------------------------------------------------------------
  */
 
-
 #include <stdio.h>	
 #include <unistd.h>
 #include <stdlib.h>
 #include <string.h>
 #include <errno.h>                            
 
+/* We import postgres.h mostly to get the HAVE_GETOPT_LONG configure result. */
 #ifndef OUT_OF_PG
-	#include "postgres.h"
+#include "postgres.h"
 #endif
 
 #include <libpq-fe.h>
 #include <libpq/libpq-fs.h>
 
+#include "pg_dumplo.h" 
+
 #ifdef HAVE_GETOPT_LONG
 	#include <getopt.h>
 	#define no_argument 0
@@ -34,8 +35,6 @@ extern int 	errno;
 
 char	*progname = NULL;
 
-#include "pg_dumplo.h" 
-
 int main(int argc, char **argv);
 static void usage(void);
 static void parse_lolist (LODumpMaster *pgLO);
@@ -97,11 +96,11 @@ main(int argc, char **argv)
 #else
 		while((arg = getopt(argc, argv, "?aehu:p:qd:l:t:irs:w")) != -1) {                
 #endif
-        		switch(arg) {
+			switch(arg) {
       			case '?':
       			case 'h':
       				usage();
-        		    	exit(RE_OK);
+					exit(RE_OK);
         		case 'u':    	
         			pgLO->user = strdup(optarg);
         			break;	 
@@ -127,11 +126,11 @@ main(int argc, char **argv)
         			break;
         		case 'e':	
         		case 'a':
- 				pgLO->action = ACTION_EXPORT_ALL;
- 				break;
- 			case 'w':
- 				pgLO->action = ACTION_SHOW;
- 				break;	
+					pgLO->action = ACTION_EXPORT_ALL;
+					break;
+				case 'w':
+					pgLO->action = ACTION_SHOW;
+					break;	
         		case 'r':
         			pgLO->remove = TRUE;
         			break;
@@ -139,10 +138,10 @@ main(int argc, char **argv)
         			pgLO->quiet = TRUE;	
         			break;
         		default:
-        			fprintf(stderr, "%s: bad arg!\n", progname);
+        			fprintf(stderr, "%s: bad arg -%c\n", progname, arg);
         			usage();
         			exit(RE_ERROR);
-        		}
+			}
 		}	
 	} else {
 		usage();
@@ -172,12 +171,12 @@ main(int argc, char **argv)
 	pgLO->conn = PQsetdbLogin(pgLO->host, NULL, NULL, NULL, pgLO->db, 
 			pgLO->user, pwd);
         
-        if (PQstatus(pgLO->conn) == CONNECTION_BAD) {
-                fprintf(stderr, "%s (connection): %s\n", progname, PQerrorMessage(pgLO->conn));
-                exit(RE_ERROR);
-        }  
-        pgLO->host = PQhost(pgLO->conn) ? PQhost(pgLO->conn) : "localhost";
-        pgLO->db   = PQdb(pgLO->conn); 
+	if (PQstatus(pgLO->conn) == CONNECTION_BAD) {
+		fprintf(stderr, "%s (connection): %s\n", progname, PQerrorMessage(pgLO->conn));
+		exit(RE_ERROR);
+	}  
+	pgLO->host = PQhost(pgLO->conn) ? PQhost(pgLO->conn) : "localhost";
+	pgLO->db   = PQdb(pgLO->conn); 
 	pgLO->user = PQuser(pgLO->conn);	
 	
 	
@@ -195,6 +194,7 @@ main(int argc, char **argv)
 		case ACTION_SHOW:
 		case ACTION_EXPORT_ALL:
 			load_lolist(pgLO);
+			/* FALL THROUGH */
 				
 		case ACTION_EXPORT_ATTR:
 			pglo_export(pgLO);

contrib/pg_dumplo/pg_dumplo.h

+/* -------------------------------------------------------------------------
+ * pg_dumplo
+ *
+ *	Portions Copyright (c) 1999-2000, PostgreSQL, Inc
+ *
+ * $Header: /cvsroot/pgsql/contrib/pg_dumplo/Attic/pg_dumplo.h,v 1.2 2000/11/22 00:00:55 tgl Exp $
+ *
+ *					Karel Zak 1999-2000
+ * -------------------------------------------------------------------------
+ */
+
+#ifndef PG_DUMPLO_H
+#define PG_DUMPLO_H
 
-#ifndef _PG_LODUMP_H_
-#define _PG_LODUMP_H_
+#include "postgres_ext.h"
 
-#define VERSION "0.0.5"
+#define VERSION "7.1.0"
 
 /* ----------
  * Define
@@ -10,7 +22,7 @@
  */        
 #define QUERY_BUFSIZ	(8*1024)
 #define DIR_UMASK	0755
-#define FILE_UMASK	0666 
+#define FILE_UMASK	0644
 
 #define	TRUE		1
 #define FALSE		0
@@ -20,16 +32,16 @@
 #define MAX_TABLE_NAME	128
 #define MAX_ATTR_NAME	128
 
-extern char *progname;
+#define atooid(x)  ((Oid) strtoul((x), NULL, 10))
 
 /* ----------
  * LO struct
  * ----------
  */
 typedef struct { 
-	char		*lo_table,
+	char	*lo_table,
 			*lo_attr;
-	long		lo_oid;
+	Oid		lo_oid;
 } LOlist;
 
 typedef struct {
@@ -58,11 +70,12 @@ typedef enum {
 	ACTION_IMPORT
 } PGLODUMP_ACTIONS;
 
+extern char *progname;
+
 extern void	notice		(LODumpMaster *pgLO, int set);
-extern int	check_res	(LODumpMaster *pgLO);
 extern void	index_file	(LODumpMaster *pgLO);
 extern void	load_lolist	(LODumpMaster *pgLO);
 extern void	pglo_export	(LODumpMaster *pgLO);
 extern void	pglo_import	(LODumpMaster *pgLO);
 
-#endif /* _PG_LODUMP_H */
+#endif /* PG_DUMPLO_H */

contrib/pg_dumplo/utils.c

+/* -------------------------------------------------------------------------
+ * pg_dumplo
+ *
+ *	Portions Copyright (c) 1999-2000, PostgreSQL, Inc
+ *
+ * $Header: /cvsroot/pgsql/contrib/pg_dumplo/Attic/utils.c,v 1.2 2000/11/22 00:00:55 tgl Exp $
+ *
+ *					Karel Zak 1999-2000
+ * -------------------------------------------------------------------------
+ */
 
 #include <stdio.h>	
 #include <unistd.h>
@@ -58,22 +68,6 @@ index_file(LODumpMaster *pgLO)
 	}
 }
 
-int 
-check_res(LODumpMaster *pgLO) 
-{
-	if (!pgLO->res && PQresultStatus(pgLO->res) != PGRES_COMMAND_OK) {
-        	fprintf(stderr, "%s: %s\n", progname, PQerrorMessage(pgLO->conn));
-                PQclear(pgLO->res);
-                return FALSE;
-        }
-        if (PQresultStatus(pgLO->res) != PGRES_TUPLES_OK) {
-                fprintf(stderr, "%s: Tuples is not OK.\n", progname);
-                PQclear(pgLO->res);
-                return FALSE;
-        }
-        return TRUE;        
-}
-
 static 
 void Dummy_NoticeProcessor(void * arg, const char * message)
 {