diff options
Diffstat (limited to 'src/backend/access/transam/xact.c')
| -rw-r--r-- | src/backend/access/transam/xact.c | 65 |
1 files changed, 61 insertions, 4 deletions
diff --git a/src/backend/access/transam/xact.c b/src/backend/access/transam/xact.c index 046486a6ccc..4687578fedd 100644 --- a/src/backend/access/transam/xact.c +++ b/src/backend/access/transam/xact.c @@ -8,7 +8,7 @@ * * * IDENTIFICATION - * $Header: /cvsroot/pgsql/src/backend/access/transam/xact.c,v 1.133 2002/10/21 19:46:45 tgl Exp $ + * $Header: /cvsroot/pgsql/src/backend/access/transam/xact.c,v 1.134 2002/10/21 22:06:18 tgl Exp $ * * NOTES * Transaction aborts can now occur two ways: @@ -1280,9 +1280,12 @@ CommitTransactionCommand(bool forceCommit) * * Autocommit mode is forced by either a true forceCommit * parameter to me, or a true preventChain parameter to the - * preceding StartTransactionCommand call. This is needed so - * that commands like VACUUM can ensure that the right things - * happen. + * preceding StartTransactionCommand call, or a + * PreventTransactionChain call during the transaction. + * (The parameters could be omitted, but it turns out most + * callers of StartTransactionCommand/CommitTransactionCommand + * want to force autocommit, so making them all call + * PreventTransactionChain would just be extra notation.) */ case TBLOCK_DEFAULT: if (autocommit || forceCommit || suppressChain) @@ -1429,6 +1432,60 @@ AbortCurrentTransaction(void) } } +/* -------------------------------- + * PreventTransactionChain + * + * This routine is to be called by statements that must not run inside + * a transaction block, typically because they have non-rollback-able + * side effects or do internal commits. + * + * If we have already started a transaction block, issue an error; also issue + * an error if we appear to be running inside a user-defined function (which + * could issue more commands and possibly cause a failure after the statement + * completes). In autocommit-off mode, we allow the statement if a block is + * not already started, and force the statement to be autocommitted despite + * the mode. + * + * stmtNode: pointer to parameter block for statement; this is used in + * a very klugy way to determine whether we are inside a function. + * stmtType: statement type name for error messages. + * -------------------------------- + */ +void +PreventTransactionChain(void *stmtNode, const char *stmtType) +{ + /* + * xact block already started? + */ + if (IsTransactionBlock()) + { + /* translator: %s represents an SQL statement name */ + elog(ERROR, "%s cannot run inside a transaction block", stmtType); + } + /* + * Are we inside a function call? If the statement's parameter block + * was allocated in QueryContext, assume it is an interactive command. + * Otherwise assume it is coming from a function. + */ + if (!MemoryContextContains(QueryContext, stmtNode)) + { + /* translator: %s represents an SQL statement name */ + elog(ERROR, "%s cannot be executed from a function", stmtType); + } + /* If we got past IsTransactionBlock test, should be in default state */ + if (CurrentTransactionState->blockState != TBLOCK_DEFAULT) + elog(ERROR, "PreventTransactionChain: can't prevent chain"); + /* okay to set the flag */ + suppressChain = true; + /* If we're in autocommit-off node, generate a notice */ + if (!autocommit) + { + /* translator: %s represents an SQL statement name */ + elog(NOTICE, "%s will be committed automatically", stmtType); + } +} + + /* ---------------------------------------------------------------- * transaction block support * ---------------------------------------------------------------- |