Rename TransactionChain functions

We call this thing a "transaction block" everywhere except in a few
functions, where it is mysteriously called a "transaction chain".  In
the SQL standard, a transaction chain is something different.  So rename
these functions to match the common terminology.
Reviewed-by: Alvaro Herrera <alvherre@alvh.no-ip.org>

src/backend/access/transam/xact.c

@@ -310,7 +310,7 @@ static void CallSubXactCallbacks(SubXactEvent event,
 					 SubTransactionId mySubid,
 					 SubTransactionId parentSubid);
 static void CleanupTransaction(void);
-static void CheckTransactionChain(bool isTopLevel, bool throwError,
+static void CheckTransactionBlock(bool isTopLevel, bool throwError,
 					  const char *stmtType);
 static void CommitTransaction(void);
 static TransactionId RecordTransactionAbort(bool isSubXact);
@@ -3134,7 +3134,7 @@ AbortCurrentTransaction(void)
 }
 
 /*
- *	PreventTransactionChain
+ *	PreventInTransactionBlock
  *
  *	This routine is to be called by statements that must not run inside
  *	a transaction block, typically because they have non-rollback-able
@@ -3151,7 +3151,7 @@ AbortCurrentTransaction(void)
  *	stmtType: statement type name, for error messages.
  */
 void
-PreventTransactionChain(bool isTopLevel, const char *stmtType)
+PreventInTransactionBlock(bool isTopLevel, const char *stmtType)
 {
 	/*
 	 * xact block already started?
@@ -3190,8 +3190,8 @@ PreventTransactionChain(bool isTopLevel, const char *stmtType)
 }
 
 /*
- *	WarnNoTranactionChain
- *	RequireTransactionChain
+ *	WarnNoTranactionBlock
+ *	RequireTransactionBlock
  *
  *	These two functions allow for warnings or errors if a command is executed
  *	outside of a transaction block.  This is useful for commands that have no
@@ -3204,29 +3204,29 @@ PreventTransactionChain(bool isTopLevel, const char *stmtType)
  *	If we appear to be running inside a user-defined function, we do not
  *	issue anything, since the function could issue more commands that make
  *	use of the current statement's results.  Likewise subtransactions.
- *	Thus these are inverses for PreventTransactionChain.
+ *	Thus these are inverses for PreventInTransactionBlock.
  *
  *	isTopLevel: passed down from ProcessUtility to determine whether we are
  *	inside a function.
  *	stmtType: statement type name, for warning or error messages.
  */
 void
-WarnNoTransactionChain(bool isTopLevel, const char *stmtType)
+WarnNoTransactionBlock(bool isTopLevel, const char *stmtType)
 {
-	CheckTransactionChain(isTopLevel, false, stmtType);
+	CheckTransactionBlock(isTopLevel, false, stmtType);
 }
 
 void
-RequireTransactionChain(bool isTopLevel, const char *stmtType)
+RequireTransactionBlock(bool isTopLevel, const char *stmtType)
 {
-	CheckTransactionChain(isTopLevel, true, stmtType);
+	CheckTransactionBlock(isTopLevel, true, stmtType);
 }
 
 /*
  * This is the implementation of the above two.
  */
 static void
-CheckTransactionChain(bool isTopLevel, bool throwError, const char *stmtType)
+CheckTransactionBlock(bool isTopLevel, bool throwError, const char *stmtType)
 {
 	/*
 	 * xact block already started?
@@ -3255,7 +3255,7 @@ CheckTransactionChain(bool isTopLevel, bool throwError, const char *stmtType)
 }
 
 /*
- *	IsInTransactionChain
+ *	IsInTransactionBlock
  *
  *	This routine is for statements that need to behave differently inside
  *	a transaction block than when running as single commands.  ANALYZE is
@@ -3265,10 +3265,10 @@ CheckTransactionChain(bool isTopLevel, bool throwError, const char *stmtType)
  *	inside a function.
  */
 bool
-IsInTransactionChain(bool isTopLevel)
+IsInTransactionBlock(bool isTopLevel)
 {
 	/*
-	 * Return true on same conditions that would make PreventTransactionChain
+	 * Return true on same conditions that would make PreventInTransactionBlock
 	 * error out
 	 */
 	if (IsTransactionBlock())

src/backend/commands/cluster.c

@@ -202,7 +202,7 @@ cluster(ClusterStmt *stmt, bool isTopLevel)
 		 * We cannot run this form of CLUSTER inside a user transaction block;
 		 * we'd be holding locks way too long.
 		 */
-		PreventTransactionChain(isTopLevel, "CLUSTER");
+		PreventInTransactionBlock(isTopLevel, "CLUSTER");
 
 		/*
 		 * Create special memory context for cross-transaction storage.

src/backend/commands/dbcommands.c

@@ -1476,7 +1476,7 @@ AlterDatabase(ParseState *pstate, AlterDatabaseStmt *stmt, bool isTopLevel)
 							dtablespace->defname),
 					 parser_errposition(pstate, dtablespace->location)));
 		/* this case isn't allowed within a transaction block */
-		PreventTransactionChain(isTopLevel, "ALTER DATABASE SET TABLESPACE");
+		PreventInTransactionBlock(isTopLevel, "ALTER DATABASE SET TABLESPACE");
 		movedb(stmt->dbname, defGetString(dtablespace));
 		return InvalidOid;
 	}

src/backend/commands/discard.c

@@ -63,7 +63,7 @@ DiscardAll(bool isTopLevel)
 	 * DISCARD ALL inside a transaction block would leave the transaction
 	 * still uncommitted.
 	 */
-	PreventTransactionChain(isTopLevel, "DISCARD ALL");
+	PreventInTransactionBlock(isTopLevel, "DISCARD ALL");
 
 	/* Closing portals might run user-defined code, so do that first. */
 	PortalHashTableDeleteAll();

src/backend/commands/portalcmds.c

@@ -63,7 +63,7 @@ PerformCursorOpen(DeclareCursorStmt *cstmt, ParamListInfo params,
 	 * user-visible effect).
 	 */
 	if (!(cstmt->options & CURSOR_OPT_HOLD))
-		RequireTransactionChain(isTopLevel, "DECLARE CURSOR");
+		RequireTransactionBlock(isTopLevel, "DECLARE CURSOR");
 
 	/*
 	 * Parse analysis was done already, but we still have to run the rule

src/backend/commands/subscriptioncmds.c

@@ -339,7 +339,7 @@ CreateSubscription(CreateSubscriptionStmt *stmt, bool isTopLevel)
 	 * replication slot.
 	 */
 	if (create_slot)
-		PreventTransactionChain(isTopLevel, "CREATE SUBSCRIPTION ... WITH (create_slot = true)");
+		PreventInTransactionBlock(isTopLevel, "CREATE SUBSCRIPTION ... WITH (create_slot = true)");
 
 	if (!superuser())
 		ereport(ERROR,
@@ -897,7 +897,7 @@ DropSubscription(DropSubscriptionStmt *stmt, bool isTopLevel)
 	 * don't have the proper facilities for that.
 	 */
 	if (slotname)
-		PreventTransactionChain(isTopLevel, "DROP SUBSCRIPTION");
+		PreventInTransactionBlock(isTopLevel, "DROP SUBSCRIPTION");
 
 
 	ObjectAddressSet(myself, SubscriptionRelationId, subid);

src/backend/commands/typecmds.c

@@ -1321,7 +1321,7 @@ AlterEnum(AlterEnumStmt *stmt, bool isTopLevel)
 			!(tup->t_data->t_infomask & HEAP_UPDATED))
 			 /* safe to do inside transaction block */ ;
 		else
-			PreventTransactionChain(isTopLevel, "ALTER TYPE ... ADD");
+			PreventInTransactionBlock(isTopLevel, "ALTER TYPE ... ADD");
 
 		AddEnumLabel(enum_type_oid, stmt->newVal,
 					 stmt->newValNeighbor, stmt->newValIsAfter,

src/backend/commands/vacuum.c

@@ -186,11 +186,11 @@ vacuum(int options, List *relations, VacuumParams *params,
 	 */
 	if (options & VACOPT_VACUUM)
 	{
-		PreventTransactionChain(isTopLevel, stmttype);
+		PreventInTransactionBlock(isTopLevel, stmttype);
 		in_outer_xact = false;
 	}
 	else
-		in_outer_xact = IsInTransactionChain(isTopLevel);
+		in_outer_xact = IsInTransactionBlock(isTopLevel);
 
 	/*
 	 * Due to static variables vac_context, anl_context and vac_strategy,

src/backend/replication/walsender.c

@@ -1516,7 +1516,7 @@ exec_replication_command(const char *cmd_string)
 			break;
 
 		case T_BaseBackupCmd:
-			PreventTransactionChain(true, "BASE_BACKUP");
+			PreventInTransactionBlock(true, "BASE_BACKUP");
 			SendBaseBackup((BaseBackupCmd *) cmd_node);
 			break;
 
@@ -1532,7 +1532,7 @@ exec_replication_command(const char *cmd_string)
 			{
 				StartReplicationCmd *cmd = (StartReplicationCmd *) cmd_node;
 
-				PreventTransactionChain(true, "START_REPLICATION");
+				PreventInTransactionBlock(true, "START_REPLICATION");
 
 				if (cmd->kind == REPLICATION_KIND_PHYSICAL)
 					StartReplication(cmd);
@@ -1542,7 +1542,7 @@ exec_replication_command(const char *cmd_string)
 			}
 
 		case T_TimeLineHistoryCmd:
-			PreventTransactionChain(true, "TIMELINE_HISTORY");
+			PreventInTransactionBlock(true, "TIMELINE_HISTORY");
 			SendTimeLineHistory((TimeLineHistoryCmd *) cmd_node);
 			break;
 

src/backend/tcop/utility.c

@@ -453,13 +453,13 @@ standard_ProcessUtility(PlannedStmt *pstmt,
 						break;
 
 					case TRANS_STMT_COMMIT_PREPARED:
-						PreventTransactionChain(isTopLevel, "COMMIT PREPARED");
+						PreventInTransactionBlock(isTopLevel, "COMMIT PREPARED");
 						PreventCommandDuringRecovery("COMMIT PREPARED");
 						FinishPreparedTransaction(stmt->gid, true);
 						break;
 
 					case TRANS_STMT_ROLLBACK_PREPARED:
-						PreventTransactionChain(isTopLevel, "ROLLBACK PREPARED");
+						PreventInTransactionBlock(isTopLevel, "ROLLBACK PREPARED");
 						PreventCommandDuringRecovery("ROLLBACK PREPARED");
 						FinishPreparedTransaction(stmt->gid, false);
 						break;
@@ -473,7 +473,7 @@ standard_ProcessUtility(PlannedStmt *pstmt,
 							ListCell   *cell;
 							char	   *name = NULL;
 
-							RequireTransactionChain(isTopLevel, "SAVEPOINT");
+							RequireTransactionBlock(isTopLevel, "SAVEPOINT");
 
 							foreach(cell, stmt->options)
 							{
@@ -490,12 +490,12 @@ standard_ProcessUtility(PlannedStmt *pstmt,
 						break;
 
 					case TRANS_STMT_RELEASE:
-						RequireTransactionChain(isTopLevel, "RELEASE SAVEPOINT");
+						RequireTransactionBlock(isTopLevel, "RELEASE SAVEPOINT");
 						ReleaseSavepoint(stmt->options);
 						break;
 
 					case TRANS_STMT_ROLLBACK_TO:
-						RequireTransactionChain(isTopLevel, "ROLLBACK TO SAVEPOINT");
+						RequireTransactionBlock(isTopLevel, "ROLLBACK TO SAVEPOINT");
 						RollbackToSavepoint(stmt->options);
 
 						/*
@@ -536,13 +536,13 @@ standard_ProcessUtility(PlannedStmt *pstmt,
 
 		case T_CreateTableSpaceStmt:
 			/* no event triggers for global objects */
-			PreventTransactionChain(isTopLevel, "CREATE TABLESPACE");
+			PreventInTransactionBlock(isTopLevel, "CREATE TABLESPACE");
 			CreateTableSpace((CreateTableSpaceStmt *) parsetree);
 			break;
 
 		case T_DropTableSpaceStmt:
 			/* no event triggers for global objects */
-			PreventTransactionChain(isTopLevel, "DROP TABLESPACE");
+			PreventInTransactionBlock(isTopLevel, "DROP TABLESPACE");
 			DropTableSpace((DropTableSpaceStmt *) parsetree);
 			break;
 
@@ -592,7 +592,7 @@ standard_ProcessUtility(PlannedStmt *pstmt,
 
 		case T_CreatedbStmt:
 			/* no event triggers for global objects */
-			PreventTransactionChain(isTopLevel, "CREATE DATABASE");
+			PreventInTransactionBlock(isTopLevel, "CREATE DATABASE");
 			createdb(pstate, (CreatedbStmt *) parsetree);
 			break;
 
@@ -611,7 +611,7 @@ standard_ProcessUtility(PlannedStmt *pstmt,
 				DropdbStmt *stmt = (DropdbStmt *) parsetree;
 
 				/* no event triggers for global objects */
-				PreventTransactionChain(isTopLevel, "DROP DATABASE");
+				PreventInTransactionBlock(isTopLevel, "DROP DATABASE");
 				dropdb(stmt->dbname, stmt->missing_ok);
 			}
 			break;
@@ -690,7 +690,7 @@ standard_ProcessUtility(PlannedStmt *pstmt,
 			break;
 
 		case T_AlterSystemStmt:
-			PreventTransactionChain(isTopLevel, "ALTER SYSTEM");
+			PreventInTransactionBlock(isTopLevel, "ALTER SYSTEM");
 			AlterSystemSetConfigFile((AlterSystemStmt *) parsetree);
 			break;
 
@@ -756,13 +756,13 @@ standard_ProcessUtility(PlannedStmt *pstmt,
 			 * Since the lock would just get dropped immediately, LOCK TABLE
 			 * outside a transaction block is presumed to be user error.
 			 */
-			RequireTransactionChain(isTopLevel, "LOCK TABLE");
+			RequireTransactionBlock(isTopLevel, "LOCK TABLE");
 			/* forbidden in parallel mode due to CommandIsReadOnly */
 			LockTableCommand((LockStmt *) parsetree);
 			break;
 
 		case T_ConstraintsSetStmt:
-			WarnNoTransactionChain(isTopLevel, "SET CONSTRAINTS");
+			WarnNoTransactionBlock(isTopLevel, "SET CONSTRAINTS");
 			AfterTriggerSetState((ConstraintsSetStmt *) parsetree);
 			break;
 
@@ -808,7 +808,7 @@ standard_ProcessUtility(PlannedStmt *pstmt,
 						 * start-transaction-command calls would not have the
 						 * intended effect!
 						 */
-						PreventTransactionChain(isTopLevel,
+						PreventInTransactionBlock(isTopLevel,
 												(stmt->kind == REINDEX_OBJECT_SCHEMA) ? "REINDEX SCHEMA" :
 												(stmt->kind == REINDEX_OBJECT_SYSTEM) ? "REINDEX SYSTEM" :
 												"REINDEX DATABASE");
@@ -1307,7 +1307,7 @@ ProcessUtilitySlow(ParseState *pstate,
 					List	   *inheritors = NIL;
 
 					if (stmt->concurrent)
-						PreventTransactionChain(isTopLevel,
+						PreventInTransactionBlock(isTopLevel,
 												"CREATE INDEX CONCURRENTLY");
 
 					/*
@@ -1715,7 +1715,7 @@ ExecDropStmt(DropStmt *stmt, bool isTopLevel)
 	{
 		case OBJECT_INDEX:
 			if (stmt->concurrent)
-				PreventTransactionChain(isTopLevel,
+				PreventInTransactionBlock(isTopLevel,
 										"DROP INDEX CONCURRENTLY");
 			/* fall through */
 

src/backend/utils/misc/guc.c

@@ -7348,7 +7348,7 @@ ExecSetVariableStmt(VariableSetStmt *stmt, bool isTopLevel)
 		case VAR_SET_VALUE:
 		case VAR_SET_CURRENT:
 			if (stmt->is_local)
-				WarnNoTransactionChain(isTopLevel, "SET LOCAL");
+				WarnNoTransactionBlock(isTopLevel, "SET LOCAL");
 			(void) set_config_option(stmt->name,
 									 ExtractSetVariableArgs(stmt),
 									 (superuser() ? PGC_SUSET : PGC_USERSET),
@@ -7368,7 +7368,7 @@ ExecSetVariableStmt(VariableSetStmt *stmt, bool isTopLevel)
 			{
 				ListCell   *head;
 
-				WarnNoTransactionChain(isTopLevel, "SET TRANSACTION");
+				WarnNoTransactionBlock(isTopLevel, "SET TRANSACTION");
 
 				foreach(head, stmt->args)
 				{
@@ -7419,7 +7419,7 @@ ExecSetVariableStmt(VariableSetStmt *stmt, bool isTopLevel)
 							(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
 							 errmsg("SET LOCAL TRANSACTION SNAPSHOT is not implemented")));
 
-				WarnNoTransactionChain(isTopLevel, "SET TRANSACTION");
+				WarnNoTransactionBlock(isTopLevel, "SET TRANSACTION");
 				Assert(nodeTag(&con->val) == T_String);
 				ImportSnapshot(strVal(&con->val));
 			}
@@ -7429,11 +7429,11 @@ ExecSetVariableStmt(VariableSetStmt *stmt, bool isTopLevel)
 			break;
 		case VAR_SET_DEFAULT:
 			if (stmt->is_local)
-				WarnNoTransactionChain(isTopLevel, "SET LOCAL");
+				WarnNoTransactionBlock(isTopLevel, "SET LOCAL");
 			/* fall through */
 		case VAR_RESET:
 			if (strcmp(stmt->name, "transaction_isolation") == 0)
-				WarnNoTransactionChain(isTopLevel, "RESET TRANSACTION");
+				WarnNoTransactionBlock(isTopLevel, "RESET TRANSACTION");
 
 			(void) set_config_option(stmt->name,
 									 NULL,

src/backend/utils/time/snapmgr.c

@@ -1171,7 +1171,7 @@ ExportSnapshot(Snapshot snapshot)
 	char		pathtmp[MAXPGPATH];
 
 	/*
-	 * It's tempting to call RequireTransactionChain here, since it's not very
+	 * It's tempting to call RequireTransactionBlock here, since it's not very
 	 * useful to export a snapshot that will disappear immediately afterwards.
 	 * However, we haven't got enough information to do that, since we don't
 	 * know if we're at top level or not.  For example, we could be inside a

src/bin/psql/common.c

@@ -2047,7 +2047,7 @@ command_no_begin(const char *query)
 
 	/*
 	 * Commands not allowed within transactions.  The statements checked for
-	 * here should be exactly those that call PreventTransactionChain() in the
+	 * here should be exactly those that call PreventInTransactionBlock() in the
 	 * backend.
 	 */
 	if (wordlen == 6 && pg_strncasecmp(query, "vacuum", 6) == 0)

src/include/access/xact.h

@@ -369,10 +369,10 @@ extern bool IsTransactionBlock(void);
 extern bool IsTransactionOrTransactionBlock(void);
 extern char TransactionBlockStatusCode(void);
 extern void AbortOutOfAnyTransaction(void);
-extern void PreventTransactionChain(bool isTopLevel, const char *stmtType);
-extern void RequireTransactionChain(bool isTopLevel, const char *stmtType);
-extern void WarnNoTransactionChain(bool isTopLevel, const char *stmtType);
-extern bool IsInTransactionChain(bool isTopLevel);
+extern void PreventInTransactionBlock(bool isTopLevel, const char *stmtType);
+extern void RequireTransactionBlock(bool isTopLevel, const char *stmtType);
+extern void WarnNoTransactionBlock(bool isTopLevel, const char *stmtType);
+extern bool IsInTransactionBlock(bool isTopLevel);
 extern void RegisterXactCallback(XactCallback callback, void *arg);
 extern void UnregisterXactCallback(XactCallback callback, void *arg);
 extern void RegisterSubXactCallback(SubXactCallback callback, void *arg);