Restrict pgrowlocks function to superusers. (This might be too strict,

but no permissions check at all is certainly no good.)  Clean up usage
of some deprecated APIs.

Author: tglsfdc

contrib/pgrowlocks/README.pgrowlocks

@@ -1,21 +1,19 @@
-$PostgreSQL: pgsql/contrib/pgrowlocks/README.pgrowlocks,v 1.1 2006/04/23 01:12:58 ishii Exp $
+$PostgreSQL: pgsql/contrib/pgrowlocks/README.pgrowlocks,v 1.2 2007/08/27 00:13:51 tgl Exp $
 
 pgrowlocks README			Tatsuo Ishii
 
 1. What is pgrowlocks?
 
    pgrowlocks shows row locking information for specified table.
 
-   pgrowlocks returns following data type:
+   pgrowlocks returns following columns:
 
-CREATE TYPE pgrowlocks_type AS (
 	locked_row TID,		-- row TID
 	lock_type TEXT,		-- lock type
 	locker XID,		-- locking XID
 	multi bool,		-- multi XID?
 	xids xid[],		-- multi XIDs
 	pids INTEGER[]		-- locker's process id
-);
 
   Here is a sample execution of pgrowlocks:
 
@@ -62,14 +60,6 @@ test=# SELECT * FROM pgrowlocks('t1');
 
 3. How to use pgrowlocks
 
-   The calling sequence for pgrowlocks is as follows:
-
-   CREATE OR REPLACE FUNCTION pgrowlocks(text) RETURNS pgrowlocks_type
-     AS 'MODULE_PATHNAME', 'pgrowlocks'
-     LANGUAGE 'c' WITH (isstrict);
-
-   The parameter is a name of table. pgrowlocks returns type pgrowlocks_type.
-
    pgrowlocks grab AccessShareLock for the target table and read each
    row one by one to get the row locking information. You should
    notice that:

contrib/pgrowlocks/pgrowlocks.c

@@ -1,5 +1,5 @@
 /*
- * $PostgreSQL: pgsql/contrib/pgrowlocks/pgrowlocks.c,v 1.5 2006/10/04 00:29:46 momjian Exp $
+ * $PostgreSQL: pgsql/contrib/pgrowlocks/pgrowlocks.c,v 1.6 2007/08/27 00:13:51 tgl Exp $
  *
  * Copyright (c) 2005-2006	Tatsuo Ishii
  *
@@ -24,19 +24,15 @@
 
 #include "postgres.h"
 
-#include "funcapi.h"
 #include "access/heapam.h"
-#include "access/transam.h"
+#include "access/multixact.h"
 #include "access/xact.h"
 #include "catalog/namespace.h"
-#include "catalog/pg_type.h"
-#include "storage/proc.h"
+#include "funcapi.h"
+#include "miscadmin.h"
+#include "storage/procarray.h"
 #include "utils/builtins.h"
 
-#ifdef HEAP_XMAX_SHARED_LOCK
-#include "access/multixact.h"
-#include "storage/procarray.h"
-#endif
 
 PG_MODULE_MAGIC;
 
@@ -47,22 +43,11 @@ extern Datum pgrowlocks(PG_FUNCTION_ARGS);
 /* ----------
  * pgrowlocks:
  * returns tids of rows being locked
- *
- * C FUNCTION definition
- * pgrowlocks(text) returns set of pgrowlocks_type
- * see pgrowlocks.sql for pgrowlocks_type
  * ----------
  */
 
-#define DUMMY_TUPLE "public.pgrowlocks_type"
 #define NCHARS 32
 
-/*
- * define this if makeRangeVarFromNameList() has two arguments. As far
- * as I know, this only happens in 8.0.x.
- */
-#undef MAKERANGEVARFROMNAMELIST_HAS_TWO_ARGS
-
 typedef struct
 {
 	Relation	rel;
@@ -82,6 +67,11 @@ pgrowlocks(PG_FUNCTION_ARGS)
 	MyData	   *mydata;
 	Relation	rel;
 
+	if (!superuser())
+		ereport(ERROR,
+				(errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),
+				 (errmsg("must be superuser to use pgrowlocks"))));
+
 	if (SRF_IS_FIRSTCALL())
 	{
 		text	   *relname;
@@ -91,17 +81,17 @@ pgrowlocks(PG_FUNCTION_ARGS)
 		funcctx = SRF_FIRSTCALL_INIT();
 		oldcontext = MemoryContextSwitchTo(funcctx->multi_call_memory_ctx);
 
-		tupdesc = RelationNameGetTupleDesc(DUMMY_TUPLE);
+		/* Build a tuple descriptor for our result type */
+		if (get_call_result_type(fcinfo, NULL, &tupdesc) != TYPEFUNC_COMPOSITE)
+			elog(ERROR, "return type must be a row type");
+
 		attinmeta = TupleDescGetAttInMetadata(tupdesc);
 		funcctx->attinmeta = attinmeta;
 
 		relname = PG_GETARG_TEXT_P(0);
-#ifdef MAKERANGEVARFROMNAMELIST_HAS_TWO_ARGS
-		relrv = makeRangeVarFromNameList(textToQualifiedNameList(relname, "pgrowlocks"));
-#else
 		relrv = makeRangeVarFromNameList(textToQualifiedNameList(relname));
-#endif
 		rel = heap_openrv(relrv, AccessShareLock);
+
 		scan = heap_beginscan(rel, SnapshotNow, 0, NULL);
 		mydata = palloc(sizeof(*mydata));
 		mydata->rel = rel;
@@ -135,17 +125,12 @@ pgrowlocks(PG_FUNCTION_ARGS)
 			i = 0;
 			values[i++] = (char *) DirectFunctionCall1(tidout, PointerGetDatum(&tuple->t_self));
 
-#ifdef HEAP_XMAX_SHARED_LOCK
 			if (tuple->t_data->t_infomask & HEAP_XMAX_SHARED_LOCK)
 				values[i++] = pstrdup("Shared");
 			else
 				values[i++] = pstrdup("Exclusive");
-#else
-			values[i++] = pstrdup("Exclusive");
-#endif
 			values[i] = palloc(NCHARS * sizeof(char));
 			snprintf(values[i++], NCHARS, "%d", HeapTupleHeaderGetXmax(tuple->t_data));
-#ifdef HEAP_XMAX_SHARED_LOCK
 			if (tuple->t_data->t_infomask & HEAP_XMAX_IS_MULTI)
 			{
 				TransactionId *xids;
@@ -198,11 +183,6 @@ pgrowlocks(PG_FUNCTION_ARGS)
 				values[i] = palloc(NCHARS * sizeof(char));
 				snprintf(values[i++], NCHARS, "{%d}", BackendXidGetPid(HeapTupleHeaderGetXmax(tuple->t_data)));
 			}
-#else
-			values[i++] = pstrdup("false");
-			values[i++] = pstrdup("{}");
-			values[i++] = pstrdup("{}");
-#endif
 
 			LockBuffer(scan->rs_cbuf, BUFFER_LOCK_UNLOCK);
 

contrib/pgrowlocks/pgrowlocks.sql.in

@@ -1,16 +1,13 @@
 -- Adjust this setting to control where the objects get created.
 SET search_path = public;
 
-CREATE TYPE pgrowlocks_type AS (
-	locked_row TID,		-- row TID
-	lock_type TEXT,		-- lock type
-	locker XID,		-- locking XID
-	multi bool,		-- multi XID?
-	xids xid[],		-- multi XIDs
-	pids INTEGER[]		-- locker's process id
-);
-
-CREATE OR REPLACE FUNCTION pgrowlocks(text)
-RETURNS setof pgrowlocks_type
+CREATE OR REPLACE FUNCTION pgrowlocks(IN relname text,
+    OUT locked_row TID,		-- row TID
+    OUT lock_type TEXT,		-- lock type
+    OUT locker XID,		-- locking XID
+    OUT multi bool,		-- multi XID?
+    OUT xids xid[],		-- multi XIDs
+    OUT pids INTEGER[])		-- locker's process id
+RETURNS SETOF record
 AS 'MODULE_PATHNAME', 'pgrowlocks'
-LANGUAGE 'C' STRICT;
+LANGUAGE C STRICT;

contrib/pgrowlocks/uninstall_pgrowlocks.sql

@@ -1,5 +1,3 @@
 SET search_path = public;
 
 DROP FUNCTION pgrowlocks(text);
-
-DROP TYPE pgrowlocks_type;