diff --git a/doc/src/sgml/plpython.sgml b/doc/src/sgml/plpython.sgml index cb065bf5f88..27c4467ba7d 100644 --- a/doc/src/sgml/plpython.sgml +++ b/doc/src/sgml/plpython.sgml @@ -662,6 +662,14 @@ $$ LANGUAGE plpython3u; in PL/Python + + PL/Python can be used to define trigger + functions. + PostgreSQL requires that a function that is to + be called as a trigger must be declared as a function with no arguments and + a return type of trigger. + + When a function is used as a trigger, the dictionary TD contains trigger-related values: @@ -769,6 +777,74 @@ $$ LANGUAGE plpython3u; + + Event Trigger Functions + + + event trigger + in PL/Python + + + + PL/Python can be used to define event triggers + (see also ). + PostgreSQL requires that a function that is to + be called as an event trigger must be declared as a function with no + arguments and a return type of event_trigger. + + + + When a function is used as an event trigger, the dictionary + TD contains trigger-related values: + + + + TD["event"] + + + The event the trigger was fired for, as a string, for example + ddl_command_start. + + + + + + TD["tag"] + + + The command tag for which the trigger was fired, as a string, for + example DROP TABLE. + + + + + + + + shows an example of an + event trigger function in PL/Python. + + + + A <application>PL/Python</application> Event Trigger Function + + + This example trigger simply raises a NOTICE message + each time a supported command is executed. + + + +CREATE OR REPLACE FUNCTION pysnitch() RETURNS event_trigger +LANGUAGE plpython3u +AS $$ + plpy.notice("TD[event] => " + TD["event"] + " ; TD[tag] => " + TD["tag"]); +$$; + +CREATE EVENT TRIGGER pysnitch ON ddl_command_start EXECUTE FUNCTION pysnitch(); + + + + Database Access diff --git a/src/pl/plpython/expected/plpython_trigger.out b/src/pl/plpython/expected/plpython_trigger.out index 64eab2fa3f4..bd35b220c5e 100644 --- a/src/pl/plpython/expected/plpython_trigger.out +++ b/src/pl/plpython/expected/plpython_trigger.out @@ -646,3 +646,30 @@ SELECT * FROM recursive_trigger_test; 1 | 2 (2 rows) +-- event triggers +CREATE OR REPLACE FUNCTION pysnitch() RETURNS event_trigger +LANGUAGE plpython3u +AS $$ + plpy.notice("TD[event] => " + TD["event"] + " ; TD[tag] => " + TD["tag"]); +$$; +CREATE EVENT TRIGGER python_a_snitch ON ddl_command_start + EXECUTE PROCEDURE pysnitch(); +CREATE EVENT TRIGGER python_b_snitch ON ddl_command_end + EXECUTE PROCEDURE pysnitch(); +CREATE OR REPLACE FUNCTION foobar() RETURNS int LANGUAGE sql AS $$SELECT 1;$$; +NOTICE: TD[event] => ddl_command_start ; TD[tag] => CREATE FUNCTION +NOTICE: TD[event] => ddl_command_end ; TD[tag] => CREATE FUNCTION +ALTER FUNCTION foobar() COST 77; +NOTICE: TD[event] => ddl_command_start ; TD[tag] => ALTER FUNCTION +NOTICE: TD[event] => ddl_command_end ; TD[tag] => ALTER FUNCTION +DROP FUNCTION foobar(); +NOTICE: TD[event] => ddl_command_start ; TD[tag] => DROP FUNCTION +NOTICE: TD[event] => ddl_command_end ; TD[tag] => DROP FUNCTION +CREATE TABLE foo(); +NOTICE: TD[event] => ddl_command_start ; TD[tag] => CREATE TABLE +NOTICE: TD[event] => ddl_command_end ; TD[tag] => CREATE TABLE +DROP TABLE foo; +NOTICE: TD[event] => ddl_command_start ; TD[tag] => DROP TABLE +NOTICE: TD[event] => ddl_command_end ; TD[tag] => DROP TABLE +DROP EVENT TRIGGER python_a_snitch; +DROP EVENT TRIGGER python_b_snitch; diff --git a/src/pl/plpython/plpy_exec.c b/src/pl/plpython/plpy_exec.c index 22835174b69..fd06b9e0e4e 100644 --- a/src/pl/plpython/plpy_exec.c +++ b/src/pl/plpython/plpy_exec.c @@ -9,6 +9,7 @@ #include "access/htup_details.h" #include "access/xact.h" #include "catalog/pg_type.h" +#include "commands/event_trigger.h" #include "commands/trigger.h" #include "executor/spi.h" #include "funcapi.h" @@ -427,6 +428,47 @@ PLy_exec_trigger(FunctionCallInfo fcinfo, PLyProcedure *proc) return rv; } +/* + * event trigger subhandler + */ +void +PLy_exec_event_trigger(FunctionCallInfo fcinfo, PLyProcedure *proc) +{ + EventTriggerData *tdata; + PyObject *volatile pltdata = NULL; + + Assert(CALLED_AS_EVENT_TRIGGER(fcinfo)); + tdata = (EventTriggerData *) fcinfo->context; + + PG_TRY(); + { + PyObject *pltevent, + *plttag; + + pltdata = PyDict_New(); + if (!pltdata) + PLy_elog(ERROR, NULL); + + pltevent = PLyUnicode_FromString(tdata->event); + PyDict_SetItemString(pltdata, "event", pltevent); + Py_DECREF(pltevent); + + plttag = PLyUnicode_FromString(GetCommandTagName(tdata->tag)); + PyDict_SetItemString(pltdata, "tag", plttag); + Py_DECREF(plttag); + + PLy_procedure_call(proc, "TD", pltdata); + + if (SPI_finish() != SPI_OK_FINISH) + elog(ERROR, "SPI_finish() failed"); + } + PG_FINALLY(); + { + Py_XDECREF(pltdata); + } + PG_END_TRY(); +} + /* helper functions for Python code execution */ static PyObject * diff --git a/src/pl/plpython/plpy_exec.h b/src/pl/plpython/plpy_exec.h index 68da1ffcb2e..f35eabbd8ee 100644 --- a/src/pl/plpython/plpy_exec.h +++ b/src/pl/plpython/plpy_exec.h @@ -9,5 +9,6 @@ extern Datum PLy_exec_function(FunctionCallInfo fcinfo, PLyProcedure *proc); extern HeapTuple PLy_exec_trigger(FunctionCallInfo fcinfo, PLyProcedure *proc); +extern void PLy_exec_event_trigger(FunctionCallInfo fcinfo, PLyProcedure *proc); #endif /* PLPY_EXEC_H */ diff --git a/src/pl/plpython/plpy_main.c b/src/pl/plpython/plpy_main.c index 900c65e8da0..70fc2c9257a 100644 --- a/src/pl/plpython/plpy_main.c +++ b/src/pl/plpython/plpy_main.c @@ -9,6 +9,7 @@ #include "access/htup_details.h" #include "catalog/pg_proc.h" #include "catalog/pg_type.h" +#include "commands/event_trigger.h" #include "commands/trigger.h" #include "executor/spi.h" #include "miscadmin.h" @@ -240,6 +241,13 @@ plpython3_call_handler(PG_FUNCTION_ARGS) trv = PLy_exec_trigger(fcinfo, proc); retval = PointerGetDatum(trv); } + else if (CALLED_AS_EVENT_TRIGGER(fcinfo)) + { + proc = PLy_procedure_get(funcoid, InvalidOid, PLPY_EVENT_TRIGGER); + exec_ctx->curr_proc = proc; + PLy_exec_event_trigger(fcinfo, proc); + retval = (Datum) 0; + } else { proc = PLy_procedure_get(funcoid, InvalidOid, PLPY_NOT_TRIGGER); @@ -346,6 +354,9 @@ PLy_procedure_is_trigger(Form_pg_proc procStruct) case TRIGGEROID: ret = PLPY_TRIGGER; break; + case EVENT_TRIGGEROID: + ret = PLPY_EVENT_TRIGGER; + break; default: ret = PLPY_NOT_TRIGGER; break; diff --git a/src/pl/plpython/plpy_procedure.h b/src/pl/plpython/plpy_procedure.h index 601b91d5d94..3ef22844a9b 100644 --- a/src/pl/plpython/plpy_procedure.h +++ b/src/pl/plpython/plpy_procedure.h @@ -17,6 +17,7 @@ extern void init_procedure_caches(void); typedef enum PLyTrigType { PLPY_TRIGGER, + PLPY_EVENT_TRIGGER, PLPY_NOT_TRIGGER, } PLyTrigType; diff --git a/src/pl/plpython/sql/plpython_trigger.sql b/src/pl/plpython/sql/plpython_trigger.sql index 440549c0785..e1a552e079f 100644 --- a/src/pl/plpython/sql/plpython_trigger.sql +++ b/src/pl/plpython/sql/plpython_trigger.sql @@ -492,3 +492,27 @@ CREATE TRIGGER recursive_trigger_trig INSERT INTO recursive_trigger_test VALUES (0, 0); UPDATE recursive_trigger_test SET a = 11 WHERE b = 0; SELECT * FROM recursive_trigger_test; + + +-- event triggers + +CREATE OR REPLACE FUNCTION pysnitch() RETURNS event_trigger +LANGUAGE plpython3u +AS $$ + plpy.notice("TD[event] => " + TD["event"] + " ; TD[tag] => " + TD["tag"]); +$$; + +CREATE EVENT TRIGGER python_a_snitch ON ddl_command_start + EXECUTE PROCEDURE pysnitch(); +CREATE EVENT TRIGGER python_b_snitch ON ddl_command_end + EXECUTE PROCEDURE pysnitch(); + +CREATE OR REPLACE FUNCTION foobar() RETURNS int LANGUAGE sql AS $$SELECT 1;$$; +ALTER FUNCTION foobar() COST 77; +DROP FUNCTION foobar(); + +CREATE TABLE foo(); +DROP TABLE foo; + +DROP EVENT TRIGGER python_a_snitch; +DROP EVENT TRIGGER python_b_snitch;