1 files changed, 77 insertions, 0 deletions
diff --git a/contrib/spi/insert_username.c b/contrib/spi/insert_username.c
new file mode 100644
index 00000000000..92889c93487
--- /dev/null
+++ b/contrib/spi/insert_username.c
@@ -0,0 +1,77 @@
+/*
+ * insert_username.c
+ * $Modified: Thu Oct 16 08:13:42 1997 by brook $
+ *
+ * insert user name in response to a trigger
+ * usage:  insert_username (column_name)
+ */
+
+#include "executor/spi.h"		/* this is what you need to work with SPI */
+#include "commands/trigger.h"		/* -"- and triggers */
+#include "miscadmin.h"			/* for GetPgUserName() */
+
+HeapTuple	insert_username (void);
+
+HeapTuple
+insert_username ()
+{
+	Trigger		*trigger;		/* to get trigger name */
+	int			nargs;			/* # of arguments */
+	Datum		newval;			/* new value of column */
+	char		**args;			/* arguments */
+	char		*relname;		/* triggered relation name */
+	Relation	rel;			/* triggered relation */
+	HeapTuple	rettuple = NULL;
+	TupleDesc	tupdesc;		/* tuple description */
+	int			attnum;
+
+				/* sanity checks from autoinc.c */		
+	if (!CurrentTriggerData)
+		elog(WARN, "insert_username: triggers are not initialized");
+	if (TRIGGER_FIRED_FOR_STATEMENT(CurrentTriggerData->tg_event))
+		elog(WARN, "insert_username: can't process STATEMENT events");
+	if (TRIGGER_FIRED_AFTER(CurrentTriggerData->tg_event))
+		elog(WARN, "insert_username: must be fired before event");
+	
+	if (TRIGGER_FIRED_BY_INSERT(CurrentTriggerData->tg_event))
+		rettuple = CurrentTriggerData->tg_trigtuple;
+	else if (TRIGGER_FIRED_BY_UPDATE(CurrentTriggerData->tg_event))
+		rettuple = CurrentTriggerData->tg_newtuple;
+	else
+		elog(WARN, "insert_username: can't process DELETE events");
+	
+	rel = CurrentTriggerData->tg_relation;
+	relname = SPI_getrelname(rel);
+	
+	trigger = CurrentTriggerData->tg_trigger;
+
+	nargs = trigger->tgnargs;
+	if (nargs != 1)
+		elog(WARN, "insert_username (%s): one argument was expected", relname);
+	
+	args = trigger->tgargs;
+	tupdesc = rel->rd_att;
+	
+	CurrentTriggerData = NULL;
+	
+	attnum = SPI_fnumber (tupdesc, args[0]);
+		
+	if ( attnum < 0 )
+		elog(WARN, "insert_username (%s): there is no attribute %s", relname, args[0]);
+	if (SPI_gettypeid (tupdesc, attnum) != TEXTOID)
+		elog(WARN, "insert_username (%s): attribute %s must be of TEXT type", 
+				relname, args[0]);
+
+				/* create fields containing name */
+	newval = PointerGetDatum (textin (GetPgUserName ()));
+
+				/* construct new tuple */
+	rettuple = SPI_modifytuple (rel, rettuple, 1, &attnum, &newval, NULL);
+	if ( rettuple == NULL )
+		elog (WARN, "insert_username (%s): %d returned by SPI_modifytuple",
+			relname, SPI_result);
+	
+	pfree (relname);
+
+	return (rettuple);
+}