pgq/trigger: add when= argument to sqltriga/logutriga.

Similar to WHEN argument for CREATE TRIGGER in 9.0.

5 files changed, 86 insertions, 0 deletions

diff --git a/sql/pgq/expected/logutriga.out b/sql/pgq/expected/logutriga.out
index 18b81aac..65ebd544 100644
--- a/sql/pgq/expected/logutriga.out
+++ b/sql/pgq/expected/logutriga.out
@@ -110,3 +110,39 @@ CONTEXT:  SQL statement "select pgq.insert_event($1, $2, $3, $4, $5, $6, $7)"
 delete from custom_expr2;
 NOTICE:  insert_event(que3, bat, dat1=foo&dat2=2&dat3=bat, test=foo)
 CONTEXT:  SQL statement "select pgq.insert_event($1, $2, $3, $4, $5, $6, $7)"
+-- test when=
+create table when_test (
+    dat1 text not null primary key,
+    dat2 int2 not null,
+    dat3 text
+);
+NOTICE:  CREATE TABLE / PRIMARY KEY will create implicit index "when_test_pkey" for table "when_test"
+create trigger when_triga after insert or update or delete on when_test
+for each row execute procedure pgq.logutriga('que3', 'when=dat1=''foo''');
+insert into when_test values ('foo', '2');
+NOTICE:  insert_event(que3, I:dat1, dat1=foo&dat2=2&dat3, public.when_test)
+CONTEXT:  SQL statement "select pgq.insert_event($1, $2, $3, $4, $5, $6, $7)"
+insert into when_test values ('bar', '2');
+select * from when_test;
+ dat1 | dat2 | dat3 
+------+------+------
+ foo  |    2 | 
+ bar  |    2 | 
+(2 rows)
+
+update when_test set dat3 = 'bat';
+NOTICE:  insert_event(que3, U:dat1, dat1=foo&dat2=2&dat3=bat, public.when_test)
+CONTEXT:  SQL statement "select pgq.insert_event($1, $2, $3, $4, $5, $6, $7)"
+delete from when_test;
+NOTICE:  insert_event(que3, D:dat1, dat1=foo&dat2=2&dat3=bat, public.when_test)
+CONTEXT:  SQL statement "select pgq.insert_event($1, $2, $3, $4, $5, $6, $7)"
+drop trigger when_triga on when_test;
+create trigger when_triga after insert or update or delete on when_test
+for each row execute procedure pgq.logutriga('que3', 'when=current_user=''random''');
+insert into when_test values ('foo', '2');
+select * from when_test;
+ dat1 | dat2 | dat3 
+------+------+------
+ foo  |    2 | 
+(1 row)
+
diff --git a/sql/pgq/sql/logutriga.sql b/sql/pgq/sql/logutriga.sql
index 11b24427..647d6b80 100644
--- a/sql/pgq/sql/logutriga.sql
+++ b/sql/pgq/sql/logutriga.sql
@@ -87,4 +87,26 @@ insert into custom_expr2 values ('foo', '2');
 update custom_expr2 set dat3 = 'bat';
 delete from custom_expr2;
 
+-- test when=
+create table when_test (
+    dat1 text not null primary key,
+    dat2 int2 not null,
+    dat3 text
+);
+create trigger when_triga after insert or update or delete on when_test
+for each row execute procedure pgq.logutriga('que3', 'when=dat1=''foo''');
+
+insert into when_test values ('foo', '2');
+insert into when_test values ('bar', '2');
+select * from when_test;
+update when_test set dat3 = 'bat';
+delete from when_test;
+
+drop trigger when_triga on when_test;
+create trigger when_triga after insert or update or delete on when_test
+for each row execute procedure pgq.logutriga('que3', 'when=current_user=''random''');
+
+insert into when_test values ('foo', '2');
+select * from when_test;
+
 
diff --git a/sql/pgq/triggers/common.c b/sql/pgq/triggers/common.c
index 123706dc..0a1d6c81 100644
--- a/sql/pgq/triggers/common.c
+++ b/sql/pgq/triggers/common.c
@@ -157,6 +157,9 @@ void pgq_insert_tg_event(PgqTriggerEvent *ev)
 
 	override_fields(ev);
 
+	if (ev->skip_event)
+		return;
+
 	pgq_simple_insert(ev->queue_name,
 			  pgq_finish_varbuf(ev->field[EV_TYPE]),
 			  pgq_finish_varbuf(ev->field[EV_DATA]),
@@ -416,6 +419,8 @@ static void parse_newstyle_args(PgqTriggerEvent *ev, TriggerData *tg)
 			make_query(ev, EV_DATA, arg + 8);
 		else if (strncmp(arg, "ev_type=", 8) == 0)
 			make_query(ev, EV_TYPE, arg + 8);
+		else if (strncmp(arg, "when=", 5) == 0)
+			make_query(ev, EV_WHEN, arg + 5);
 		else
 			elog(ERROR, "bad param to pgq trigger");
 	}
@@ -707,6 +712,23 @@ static void override_fields(struct PgqTriggerEvent *ev)
 			elog(ERROR, "Override query failed");
 		if (SPI_processed != 1)
 			elog(ERROR, "Expect 1 row from override query, got %d", SPI_processed);
+
+		/* special handling for EV_WHEN */
+		if (i == EV_WHEN) {
+			bool isnull;
+			Oid oid = SPI_gettypeid(SPI_tuptable->tupdesc, 1);
+			Datum res;
+			if (oid != BOOLOID)
+				elog(ERROR, "when= query result must be boolean, got=%u", oid);
+			res = SPI_getbinval(SPI_tuptable->vals[0], SPI_tuptable->tupdesc, 1, &isnull);
+			if (isnull)
+				elog(ERROR, "when= should not be NULL");
+			if (DatumGetBool(res) == 0)
+				ev->skip_event = true;
+			continue;
+		}
+
+		/* normal field */
 		val = SPI_getvalue(SPI_tuptable->vals[0], SPI_tuptable->tupdesc, 1);
 		if (ev->field[i]) {
 			pfree(ev->field[i]->data);
diff --git a/sql/pgq/triggers/common.h b/sql/pgq/triggers/common.h
index 89d12187..64ee4d11 100644
--- a/sql/pgq/triggers/common.h
+++ b/sql/pgq/triggers/common.h
@@ -5,6 +5,7 @@ enum PgqFields {
 	EV_EXTRA2,
 	EV_EXTRA3,
 	EV_EXTRA4,
+	EV_WHEN,
 	EV_NFIELDS
 };
 
@@ -35,6 +36,9 @@ struct PgqTriggerEvent {
 
 	/* result fields */
 	StringInfo field[EV_NFIELDS];
+
+	/* if 'when=' query fails */
+	bool skip_event;
 };
 typedef struct PgqTriggerEvent PgqTriggerEvent;
 
diff --git a/sql/pgq/triggers/pgq_triggers.sql.in b/sql/pgq/triggers/pgq_triggers.sql.in
index 22509202..6f1f71c8 100644
--- a/sql/pgq/triggers/pgq_triggers.sql.in
+++ b/sql/pgq/triggers/pgq_triggers.sql.in
@@ -18,6 +18,7 @@
 --      backup              - Put urlencoded contents of old row to ev_extra2
 --      colname=EXPR        - Override field value with SQL expression.  Can reference table
 --                            columns.  colname can be: ev_type, ev_data, ev_extra1 .. ev_extra4
+--      when=EXPR           - If EXPR returns false, don't insert event.
 --
 -- Queue event fields:
 --    ev_type     - I/U/D
@@ -50,6 +51,7 @@ AS 'MODULE_PATHNAME', 'pgq_sqltriga' LANGUAGE C;
 --      backup              - Put urlencoded contents of old row to ev_extra2
 --      colname=EXPR        - Override field value with SQL expression.  Can reference table
 --                            columns.  colname can be: ev_type, ev_data, ev_extra1 .. ev_extra4
+--      when=EXPR           - If EXPR returns false, don't insert event.
 --
 -- Queue event fields:
 --      ev_type      - I/U/D ':' pkey_column_list