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The attached patch cleans up the implementation of the TRUNCATE command;
in the current code, the authentication logic (check user, check the relation we're operating on, etc) is done in tcop/utility.c, whereas the actual TRUNCATE command in done in TruncateRelation() in commands/createinh.c (which is really just a wrapper over heap_truncate() in catalog/heap.c). This patch moves the authentication logic into TruncateRelation(), as well as making some minor code cleanups. Neil Conway
1 parent d8e70cd commit a9819ca

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5 files changed

+40
-36
lines changed

5 files changed

+40
-36
lines changed

‎src/backend/catalog/heap.c

Lines changed: 2 additions & 2 deletions
Original file line numberDiff line numberDiff line change
@@ -8,7 +8,7 @@
88
*
99
*
1010
* IDENTIFICATION
11-
* $Header: /cvsroot/pgsql/src/backend/catalog/heap.c,v 1.187 2002/03/19 02:18:14 momjian Exp $
11+
* $Header: /cvsroot/pgsql/src/backend/catalog/heap.c,v 1.188 2002/03/19 02:58:19 momjian Exp $
1212
*
1313
*
1414
* INTERFACE ROUTINES
@@ -1057,7 +1057,7 @@ RelationTruncateIndexes(Oid heapId)
10571057
*/
10581058

10591059
void
1060-
heap_truncate(char *relname)
1060+
heap_truncate(const char *relname)
10611061
{
10621062
Relation rel;
10631063
Oid rid;

‎src/backend/commands/creatinh.c

Lines changed: 30 additions & 5 deletions
Original file line numberDiff line numberDiff line change
@@ -8,14 +8,15 @@
88
*
99
*
1010
* IDENTIFICATION
11-
* $Header: /cvsroot/pgsql/src/backend/commands/Attic/creatinh.c,v 1.86 2002/03/19 02:18:15 momjian Exp $
11+
* $Header: /cvsroot/pgsql/src/backend/commands/Attic/creatinh.c,v 1.87 2002/03/19 02:58:19 momjian Exp $
1212
*
1313
*-------------------------------------------------------------------------
1414
*/
1515

1616
#include "postgres.h"
1717

1818
#include "access/heapam.h"
19+
#include "catalog/catalog.h"
1920
#include "catalog/catname.h"
2021
#include "catalog/indexing.h"
2122
#include "catalog/heap.h"
@@ -221,7 +222,7 @@ DefineRelation(CreateStmt *stmt, char relkind)
221222
* themselves will be destroyed, too.
222223
*/
223224
void
224-
RemoveRelation(char *name)
225+
RemoveRelation(const char *name)
225226
{
226227
AssertArg(name);
227228
heap_drop_with_catalog(name, allowSystemTableMods);
@@ -238,10 +239,34 @@ RemoveRelation(char *name)
238239
* Rows are removed, indices are truncated and reconstructed.
239240
*/
240241
void
241-
TruncateRelation(char *name)
242+
TruncateRelation(const char *relname)
242243
{
243-
AssertArg(name);
244-
heap_truncate(name);
244+
Relation rel;
245+
246+
AssertArg(relname);
247+
248+
if (!allowSystemTableMods && IsSystemRelationName(relname))
249+
elog(ERROR, "TRUNCATE cannot be used on system tables. '%s' is a system table",
250+
relname);
251+
252+
if (!pg_ownercheck(GetUserId(), relname, RELNAME))
253+
elog(ERROR, "you do not own relation \"%s\"", relname);
254+
255+
/* Grab exclusive lock in preparation for truncate */
256+
rel = heap_openr(relname, AccessExclusiveLock);
257+
258+
if (rel->rd_rel->relkind == RELKIND_SEQUENCE)
259+
elog(ERROR, "TRUNCATE cannot be used on sequences. '%s' is a sequence",
260+
relname);
261+
262+
if (rel->rd_rel->relkind == RELKIND_VIEW)
263+
elog(ERROR, "TRUNCATE cannot be used on views. '%s' is a view",
264+
relname);
265+
266+
/* Keep the lock until transaction commit */
267+
heap_close(rel, NoLock);
268+
269+
heap_truncate(relname);
245270
}
246271

247272

‎src/backend/tcop/utility.c

Lines changed: 3 additions & 24 deletions
Original file line numberDiff line numberDiff line change
@@ -10,7 +10,7 @@
1010
*
1111
*
1212
* IDENTIFICATION
13-
* $Header: /cvsroot/pgsql/src/backend/tcop/utility.c,v 1.133 2002/03/19 02:18:20 momjian Exp $
13+
* $Header: /cvsroot/pgsql/src/backend/tcop/utility.c,v 1.134 2002/03/19 02:58:19 momjian Exp $
1414
*
1515
*-------------------------------------------------------------------------
1616
*/
@@ -216,9 +216,7 @@ ProcessUtility(Node *parsetree,
216216
break;
217217

218218
/*
219-
* ******************************** relation and attribute
220-
* manipulation ********************************
221-
*
219+
* relation and attribute manipulation
222220
*/
223221
case T_CreateStmt:
224222
DefineRelation((CreateStmt *) parsetree, RELKIND_RELATION);
@@ -301,26 +299,7 @@ ProcessUtility(Node *parsetree,
301299

302300
case T_TruncateStmt:
303301
{
304-
Relation rel;
305-
306-
relname = ((TruncateStmt *) parsetree)->relName;
307-
if (!allowSystemTableMods && IsSystemRelationName(relname))
308-
elog(ERROR, "TRUNCATE cannot be used on system tables. '%s' is a system table",
309-
relname);
310-
311-
/* Grab exclusive lock in preparation for truncate... */
312-
rel = heap_openr(relname, AccessExclusiveLock);
313-
if (rel->rd_rel->relkind == RELKIND_SEQUENCE)
314-
elog(ERROR, "TRUNCATE cannot be used on sequences. '%s' is a sequence",
315-
relname);
316-
if (rel->rd_rel->relkind == RELKIND_VIEW)
317-
elog(ERROR, "TRUNCATE cannot be used on views. '%s' is a view",
318-
relname);
319-
heap_close(rel, NoLock);
320-
321-
if (!pg_ownercheck(GetUserId(), relname, RELNAME))
322-
elog(ERROR, "you do not own class \"%s\"", relname);
323-
TruncateRelation(relname);
302+
TruncateRelation(((TruncateStmt *) parsetree)->relName);
324303
}
325304
break;
326305

‎src/include/catalog/heap.h

Lines changed: 2 additions & 2 deletions
Original file line numberDiff line numberDiff line change
@@ -7,7 +7,7 @@
77
* Portions Copyright (c) 1996-2001, PostgreSQL Global Development Group
88
* Portions Copyright (c) 1994, Regents of the University of California
99
*
10-
* $Id: heap.h,v 1.44 2002/03/19 02:18:22 momjian Exp $
10+
* $Id: heap.h,v 1.45 2002/03/19 02:58:19 momjian Exp $
1111
*
1212
*-------------------------------------------------------------------------
1313
*/
@@ -41,7 +41,7 @@ extern Oid heap_create_with_catalog(char *relname, TupleDesc tupdesc,
4141
extern void heap_drop_with_catalog(const char *relname,
4242
bool allow_system_table_mods);
4343

44-
extern void heap_truncate(char *relname);
44+
extern void heap_truncate(const char *relname);
4545

4646
extern void AddRelationRawConstraints(Relation rel,
4747
List *rawColDefaults,

‎src/include/commands/creatinh.h

Lines changed: 3 additions & 3 deletions
Original file line numberDiff line numberDiff line change
@@ -7,7 +7,7 @@
77
* Portions Copyright (c) 1996-2001, PostgreSQL Global Development Group
88
* Portions Copyright (c) 1994, Regents of the University of California
99
*
10-
* $Id: creatinh.h,v 1.17 2001/11/05 17:46:33 momjian Exp $
10+
* $Id: creatinh.h,v 1.18 2002/03/19 02:58:20 momjian Exp $
1111
*
1212
*-------------------------------------------------------------------------
1313
*/
@@ -17,7 +17,7 @@
1717
#include "nodes/parsenodes.h"
1818

1919
extern void DefineRelation(CreateStmt *stmt, char relkind);
20-
extern void RemoveRelation(char *name);
21-
extern void TruncateRelation(char *name);
20+
extern void RemoveRelation(const char *name);
21+
extern void TruncateRelation(const char *name);
2222

2323
#endif /* CREATINH_H */

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