Table function support for PL/Python

This allows functions with multiple OUT parameters returning both one
or multiple records (RECORD or SETOF RECORD).

Jan Urbański, reviewed by Hitoshi Harada

doc/src/sgml/plpython.sgml

@@ -390,18 +390,6 @@ $$ LANGUAGE plpythonu;
     return type and the Python data type of the actual return object
     are not flagged; the value will be converted in any case.
    </para>
-
-   <tip>
-    <para>
-     <application>PL/Python</application> functions cannot return
-     either type <type>RECORD</type> or <type>SETOF RECORD</type>.  A
-     workaround is to write a <application>PL/pgSQL</application>
-     function that creates a temporary table, have it call the
-     <application>PL/Python</application> function to fill the table,
-     and then have the <application>PL/pgSQL</application> function
-     return the generic <type>RECORD</type> from the temporary table.
-    </para>
-   </tip>
   </sect2>
 
   <sect2>
@@ -593,6 +581,17 @@ $$ LANGUAGE plpythonu;
     </varlistentry>
    </variablelist>
   </para>
+
+   <para>
+    Functions with <literal>OUT</literal> parameters are also supported.  For example:
+<programlisting>
+CREATE FUNCTION multiout_simple(OUT i integer, OUT j integer) AS $$
+return (1, 2)
+$$ LANGUAGE plpythonu;
+
+SELECT * FROM multiout_simple();
+</programlisting>
+   </para>
   </sect2>
 
   <sect2>
@@ -692,6 +691,19 @@ $$ LANGUAGE plpythonu;
     </varlistentry>
    </variablelist>
   </para>
+
+   <para>
+    Set-returning functions with <literal>OUT</literal> parameters
+    (using <literal>RETURNS SETOF record</literal>) are also
+    supported.  For example:
+<programlisting>
+CREATE FUNCTION multiout_simple_setof(n integer, OUT integer, OUT integer) RETURNS SETOF record AS $$
+return [(1, 2)] * n
+$$ LANGUAGE plpythonu;
+
+SELECT * FROM multiout_simple_setof(3);
+</programlisting>
+   </para>
   </sect2>
  </sect1>
 

src/pl/plpython/Makefile

@@ -80,6 +80,7 @@ REGRESS = \
 	plpython_error \
 	plpython_unicode \
 	plpython_quote \
+	plpython_composite \
 	plpython_drop
 # where to find psql for running the tests
 PSQLDIR = $(bindir)

src/pl/plpython/expected/plpython_composite.out

@@ -0,0 +1,361 @@
+CREATE FUNCTION multiout_simple(OUT i integer, OUT j integer) AS $$
+return (1, 2)
+$$ LANGUAGE plpythonu;
+SELECT multiout_simple();
+ multiout_simple 
+-----------------
+ (1,2)
+(1 row)
+
+SELECT * FROM multiout_simple();
+ i | j 
+---+---
+ 1 | 2
+(1 row)
+
+SELECT i, j + 2 FROM multiout_simple();
+ i | ?column? 
+---+----------
+ 1 |        4
+(1 row)
+
+SELECT (multiout_simple()).j + 3;
+ ?column? 
+----------
+        5
+(1 row)
+
+CREATE FUNCTION multiout_simple_setof(n integer = 1, OUT integer, OUT integer) RETURNS SETOF record AS $$
+return [(1, 2)] * n
+$$ LANGUAGE plpythonu;
+SELECT multiout_simple_setof();
+ multiout_simple_setof 
+-----------------------
+ (1,2)
+(1 row)
+
+SELECT * FROM multiout_simple_setof();
+ column1 | column2 
+---------+---------
+       1 |       2
+(1 row)
+
+SELECT * FROM multiout_simple_setof(3);
+ column1 | column2 
+---------+---------
+       1 |       2
+       1 |       2
+       1 |       2
+(3 rows)
+
+CREATE FUNCTION multiout_record_as(typ text,
+                                   first text, OUT first text,
+                                   second integer, OUT second integer,
+                                   retnull boolean) RETURNS record AS $$
+if retnull:
+    return None
+if typ == 'dict':
+    return { 'first': first, 'second': second, 'additionalfield': 'must not cause trouble' }
+elif typ == 'tuple':
+    return ( first, second )
+elif typ == 'list':
+    return [ first, second ]
+elif typ == 'obj':
+    class type_record: pass
+    type_record.first = first
+    type_record.second = second
+    return type_record
+$$ LANGUAGE plpythonu;
+SELECT * FROM multiout_record_as('dict', 'foo', 1, 'f');
+ first | second 
+-------+--------
+ foo   |      1
+(1 row)
+
+SELECT multiout_record_as('dict', 'foo', 1, 'f');
+ multiout_record_as 
+--------------------
+ (foo,1)
+(1 row)
+
+SELECT *, s IS NULL AS snull FROM multiout_record_as('tuple', 'xxx', NULL, 'f') AS f(f, s);
+  f  | s | snull 
+-----+---+-------
+ xxx |   | t
+(1 row)
+
+SELECT *, f IS NULL AS fnull, s IS NULL AS snull FROM multiout_record_as('tuple', 'xxx', 1, 't') AS f(f, s);
+ f | s | fnull | snull 
+---+---+-------+-------
+   |   | t     | t
+(1 row)
+
+SELECT * FROM multiout_record_as('obj', NULL, 10, 'f');
+ first | second 
+-------+--------
+       |     10
+(1 row)
+
+CREATE FUNCTION multiout_setof(n integer,
+                               OUT power_of_2 integer,
+                               OUT length integer) RETURNS SETOF record AS $$
+for i in range(n):
+    power = 2 ** i
+    length = plpy.execute("select length('%d')" % power)[0]['length']
+    yield power, length
+$$ LANGUAGE plpythonu;
+SELECT * FROM multiout_setof(3);
+ power_of_2 | length 
+------------+--------
+          1 |      1
+          2 |      1
+          4 |      1
+(3 rows)
+
+SELECT multiout_setof(5);
+ multiout_setof 
+----------------
+ (1,1)
+ (2,1)
+ (4,1)
+ (8,1)
+ (16,2)
+(5 rows)
+
+CREATE FUNCTION multiout_return_table() RETURNS TABLE (x integer, y text) AS $$
+return [{'x': 4, 'y' :'four'},
+        {'x': 7, 'y' :'seven'},
+        {'x': 0, 'y' :'zero'}]
+$$ LANGUAGE plpythonu;
+SELECT * FROM multiout_return_table();
+ x |   y   
+---+-------
+ 4 | four
+ 7 | seven
+ 0 | zero
+(3 rows)
+
+CREATE FUNCTION multiout_array(OUT integer[], OUT text) RETURNS SETOF record AS $$
+yield [[1], 'a']
+yield [[1,2], 'b']
+yield [[1,2,3], None]
+$$ LANGUAGE plpythonu;
+SELECT * FROM multiout_array();
+ column1 | column2 
+---------+---------
+ {1}     | a
+ {1,2}   | b
+ {1,2,3} | 
+(3 rows)
+
+CREATE FUNCTION singleout_composite(OUT type_record) AS $$
+return {'first': 1, 'second': 2}
+$$ LANGUAGE plpythonu;
+CREATE FUNCTION multiout_composite(OUT type_record) RETURNS SETOF type_record AS $$
+return [{'first': 1, 'second': 2},
+       {'first': 3, 'second': 4	}]
+$$ LANGUAGE plpythonu;
+SELECT * FROM singleout_composite();
+ first | second 
+-------+--------
+ 1     |      2
+(1 row)
+
+SELECT * FROM multiout_composite();
+ first | second 
+-------+--------
+ 1     |      2
+ 3     |      4
+(2 rows)
+
+-- composite OUT parameters in functions returning RECORD not supported yet
+CREATE FUNCTION multiout_composite(INOUT n integer, OUT type_record) AS $$
+return (n, (n * 2, n * 3))
+$$ LANGUAGE plpythonu;
+CREATE FUNCTION multiout_table_type_setof(typ text, returnnull boolean, INOUT n integer, OUT table_record) RETURNS SETOF record AS $$
+if returnnull:
+    d = None
+elif typ == 'dict':
+    d = {'first': n * 2, 'second': n * 3, 'extra': 'not important'}
+elif typ == 'tuple':
+    d = (n * 2, n * 3)
+elif typ == 'obj':
+    class d: pass
+    d.first = n * 2
+    d.second = n * 3
+for i in range(n):
+    yield (i, d)
+$$ LANGUAGE plpythonu;
+SELECT * FROM multiout_composite(2);
+ n | column2 
+---+---------
+ 2 | (4,6)
+(1 row)
+
+SELECT * FROM multiout_table_type_setof('dict', 'f', 3);
+ n | column2 
+---+---------
+ 0 | (6,9)
+ 1 | (6,9)
+ 2 | (6,9)
+(3 rows)
+
+SELECT * FROM multiout_table_type_setof('tuple', 'f', 2);
+ n | column2 
+---+---------
+ 0 | (4,6)
+ 1 | (4,6)
+(2 rows)
+
+SELECT * FROM multiout_table_type_setof('obj', 'f', 4);
+ n | column2 
+---+---------
+ 0 | (8,12)
+ 1 | (8,12)
+ 2 | (8,12)
+ 3 | (8,12)
+(4 rows)
+
+SELECT * FROM multiout_table_type_setof('dict', 't', 3);
+ n | column2 
+---+---------
+ 0 | 
+ 1 | 
+ 2 | 
+(3 rows)
+
+-- check what happens if a type changes under us
+CREATE TABLE changing (
+    i integer,
+    j integer
+);
+CREATE FUNCTION changing_test(OUT n integer, OUT changing) RETURNS SETOF record AS $$
+return [(1, {'i': 1, 'j': 2}),
+        (1, (3, 4))]
+$$ LANGUAGE plpythonu;
+SELECT * FROM changing_test();
+ n | column2 
+---+---------
+ 1 | (1,2)
+ 1 | (3,4)
+(2 rows)
+
+ALTER TABLE changing DROP COLUMN j;
+SELECT * FROM changing_test();
+ERROR:  length of returned sequence did not match number of columns in row
+CONTEXT:  while creating return value
+PL/Python function "changing_test"
+SELECT * FROM changing_test();
+ERROR:  length of returned sequence did not match number of columns in row
+CONTEXT:  while creating return value
+PL/Python function "changing_test"
+ALTER TABLE changing ADD COLUMN j integer;
+SELECT * FROM changing_test();
+ n | column2 
+---+---------
+ 1 | (1,2)
+ 1 | (3,4)
+(2 rows)
+
+-- tables of composite types (not yet implemented)
+CREATE FUNCTION composite_types_table(OUT tab table_record[], OUT typ type_record[] ) RETURNS SETOF record AS $$
+yield {'tab': [['first', 1], ['second', 2]],
+      'typ': [{'first': 'third', 'second': 3},
+              {'first': 'fourth', 'second': 4}]}
+yield {'tab': [['first', 1], ['second', 2]],
+      'typ': [{'first': 'third', 'second': 3},
+              {'first': 'fourth', 'second': 4}]}
+yield {'tab': [['first', 1], ['second', 2]],
+      'typ': [{'first': 'third', 'second': 3},
+              {'first': 'fourth', 'second': 4}]}
+$$ LANGUAGE plpythonu;
+SELECT * FROM composite_types_table();
+ERROR:  PL/Python functions cannot return type table_record[]
+DETAIL:  PL/Python does not support conversion to arrays of row types.
+CONTEXT:  PL/Python function "composite_types_table"
+-- check what happens if the output record descriptor changes
+CREATE FUNCTION return_record(t text) RETURNS record AS $$
+return {'t': t, 'val': 10}
+$$ LANGUAGE plpythonu;
+SELECT * FROM return_record('abc') AS r(t text, val integer);
+  t  | val 
+-----+-----
+ abc |  10
+(1 row)
+
+SELECT * FROM return_record('abc') AS r(t text, val bigint);
+  t  | val 
+-----+-----
+ abc |  10
+(1 row)
+
+SELECT * FROM return_record('abc') AS r(t text, val integer);
+  t  | val 
+-----+-----
+ abc |  10
+(1 row)
+
+SELECT * FROM return_record('abc') AS r(t varchar(30), val integer);
+  t  | val 
+-----+-----
+ abc |  10
+(1 row)
+
+SELECT * FROM return_record('abc') AS r(t varchar(100), val integer);
+  t  | val 
+-----+-----
+ abc |  10
+(1 row)
+
+SELECT * FROM return_record('999') AS r(val text, t integer);
+ val |  t  
+-----+-----
+ 10  | 999
+(1 row)
+
+CREATE FUNCTION return_record_2(t text) RETURNS record AS $$
+return {'v1':1,'v2':2,t:3}
+$$ LANGUAGE plpythonu;
+SELECT * FROM return_record_2('v3') AS (v3 int, v2 int, v1 int);
+ v3 | v2 | v1 
+----+----+----
+  3 |  2 |  1
+(1 row)
+
+SELECT * FROM return_record_2('v3') AS (v2 int, v3 int, v1 int);
+ v2 | v3 | v1 
+----+----+----
+  2 |  3 |  1
+(1 row)
+
+SELECT * FROM return_record_2('v4') AS (v1 int, v4 int, v2 int);
+ v1 | v4 | v2 
+----+----+----
+  1 |  3 |  2
+(1 row)
+
+SELECT * FROM return_record_2('v4') AS (v1 int, v4 int, v2 int);
+ v1 | v4 | v2 
+----+----+----
+  1 |  3 |  2
+(1 row)
+
+-- error
+SELECT * FROM return_record_2('v4') AS (v1 int, v3 int, v2 int);
+ERROR:  key "v3" not found in mapping
+HINT:  To return null in a column, add the value None to the mapping with the key named after the column.
+CONTEXT:  while creating return value
+PL/Python function "return_record_2"
+-- works
+SELECT * FROM return_record_2('v3') AS (v1 int, v3 int, v2 int);
+ v1 | v3 | v2 
+----+----+----
+  1 |  3 |  2
+(1 row)
+
+SELECT * FROM return_record_2('v3') AS (v1 int, v2 int, v3 int);
+ v1 | v2 | v3 
+----+----+----
+  1 |  2 |  3
+(1 row)
+

src/pl/plpython/expected/plpython_record.out

@@ -42,12 +42,10 @@ $$ LANGUAGE plpythonu;
 CREATE FUNCTION test_in_out_params(first in text, second out text) AS $$
 return first + '_in_to_out';
 $$ LANGUAGE plpythonu;
--- this doesn't work yet :-(
 CREATE FUNCTION test_in_out_params_multi(first in text,
                                          second out text, third out text) AS $$
-return first + '_record_in_to_out';
+return (first + '_record_in_to_out_1', first + '_record_in_to_out_2');
 $$ LANGUAGE plpythonu;
-ERROR:  PL/Python functions cannot return type record
 CREATE FUNCTION test_inout_params(first inout text) AS $$
 return first + '_inout';
 $$ LANGUAGE plpythonu;
@@ -298,12 +296,12 @@ SELECT * FROM test_in_out_params('test_in');
  test_in_in_to_out
 (1 row)
 
--- this doesn't work yet :-(
 SELECT * FROM test_in_out_params_multi('test_in');
-ERROR:  function test_in_out_params_multi(unknown) does not exist
+           second           |           third            
-LINE 1: SELECT * FROM test_in_out_params_multi('test_in');
+----------------------------+----------------------------
-                      ^
+ test_in_record_in_to_out_1 | test_in_record_in_to_out_2
-HINT:  No function matches the given name and argument types. You might need to add explicit type casts.
+(1 row)
+
 SELECT * FROM test_inout_params('test_in');
      first     
 ---------------

src/pl/plpython/expected/plpython_trigger.out

@@ -549,3 +549,21 @@ SELECT * FROM pb;
  b | 2010-10-13 21:57:29
 (1 row)
 
+-- triggers for tables with composite types
+CREATE TABLE comp1 (i integer, j boolean);
+CREATE TYPE comp2 AS (k integer, l boolean);
+CREATE TABLE composite_trigger_test (f1 comp1, f2 comp2);
+CREATE FUNCTION composite_trigger_f() RETURNS trigger AS $$
+    TD['new']['f1'] = (3, False)
+    TD['new']['f2'] = {'k': 7, 'l': 'yes', 'ignored': 10}
+    return 'MODIFY'
+$$ LANGUAGE plpythonu;
+CREATE TRIGGER composite_trigger BEFORE INSERT ON composite_trigger_test
+  FOR EACH ROW EXECUTE PROCEDURE composite_trigger_f();
+INSERT INTO composite_trigger_test VALUES (NULL, NULL);
+SELECT * FROM composite_trigger_test;
+  f1   |  f2   
+-------+-------
+ (3,f) | (7,t)
+(1 row)
+

src/pl/plpython/plpython.c

@@ -132,6 +132,7 @@ typedef struct PLyDatumToOb
 	PLyDatumToObFunc func;
 	FmgrInfo	typfunc;		/* The type's output function */
 	Oid			typoid;			/* The OID of the type */
+	int32		typmod;			/* The typmod of the type */
 	Oid			typioparam;
 	bool		typbyval;
 	int16		typlen;
@@ -164,6 +165,7 @@ typedef struct PLyObToDatum
 	PLyObToDatumFunc func;
 	FmgrInfo	typfunc;		/* The type's input function */
 	Oid			typoid;			/* The OID of the type */
+	int32		typmod;			/* The typmod of the type */
 	Oid			typioparam;
 	bool		typbyval;
 	int16		typlen;
@@ -348,6 +350,7 @@ static void PLy_input_datum_func(PLyTypeInfo *, Oid, HeapTuple);
 static void PLy_input_datum_func2(PLyDatumToOb *, Oid, HeapTuple);
 static void PLy_output_tuple_funcs(PLyTypeInfo *, TupleDesc);
 static void PLy_input_tuple_funcs(PLyTypeInfo *, TupleDesc);
+static void PLy_output_record_funcs(PLyTypeInfo *, TupleDesc);
 
 /* conversion functions */
 static PyObject *PLyBool_FromBool(PLyDatumToOb *arg, Datum d);
@@ -365,12 +368,14 @@ static PyObject *PLyDict_FromTuple(PLyTypeInfo *, HeapTuple, TupleDesc);
 
 static Datum PLyObject_ToBool(PLyObToDatum *, int32, PyObject *);
 static Datum PLyObject_ToBytea(PLyObToDatum *, int32, PyObject *);
+static Datum PLyObject_ToComposite(PLyObToDatum *, int32, PyObject *);
 static Datum PLyObject_ToDatum(PLyObToDatum *, int32, PyObject *);
 static Datum PLySequence_ToArray(PLyObToDatum *, int32, PyObject *);
 
-static HeapTuple PLyMapping_ToTuple(PLyTypeInfo *, PyObject *);
+static HeapTuple PLyObject_ToTuple(PLyTypeInfo *, TupleDesc, PyObject *);
-static HeapTuple PLySequence_ToTuple(PLyTypeInfo *, PyObject *);
+static HeapTuple PLyMapping_ToTuple(PLyTypeInfo *, TupleDesc, PyObject *);
-static HeapTuple PLyObject_ToTuple(PLyTypeInfo *, PyObject *);
+static HeapTuple PLySequence_ToTuple(PLyTypeInfo *, TupleDesc, PyObject *);
+static HeapTuple PLyGenericObject_ToTuple(PLyTypeInfo *, TupleDesc, PyObject *);
 
 /*
  * Currently active plpython function
@@ -1165,17 +1170,19 @@ PLy_function_handler(FunctionCallInfo fcinfo, PLyProcedure *proc)
 		}
 		else if (proc->result.is_rowtype >= 1)
 		{
+			TupleDesc	desc;
 			HeapTuple	tuple = NULL;
 
-			if (PySequence_Check(plrv))
+			/* make sure it's not an unnamed record */
-				/* composite type as sequence (tuple, list etc) */
+			Assert((proc->result.out.d.typoid == RECORDOID &&
-				tuple = PLySequence_ToTuple(&proc->result, plrv);
+					proc->result.out.d.typmod != -1) ||
-			else if (PyMapping_Check(plrv))
+				   (proc->result.out.d.typoid != RECORDOID &&
-				/* composite type as mapping (currently only dict) */
+					proc->result.out.d.typmod == -1));
-				tuple = PLyMapping_ToTuple(&proc->result, plrv);
+
-			else
+			desc = lookup_rowtype_tupdesc(proc->result.out.d.typoid,
-				/* returned as smth, must provide method __getattr__(name) */
+										  proc->result.out.d.typmod);
-				tuple = PLyObject_ToTuple(&proc->result, plrv);
+
+			tuple = PLyObject_ToTuple(&proc->result, desc, plrv);
 
 			if (tuple != NULL)
 			{
@@ -1307,6 +1314,21 @@ PLy_function_build_args(FunctionCallInfo fcinfo, PLyProcedure *proc)
 				PLy_elog(ERROR, "PyDict_SetItemString() failed, while setting up arguments");
 			arg = NULL;
 		}
+
+		/* Set up output conversion for functions returning RECORD */
+		if (proc->result.out.d.typoid == RECORDOID)
+		{
+			TupleDesc	desc;
+
+			if (get_call_result_type(fcinfo, NULL, &desc) != TYPEFUNC_COMPOSITE)
+				ereport(ERROR,
+						(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+						 errmsg("function returning record called in context "
+								"that cannot accept type record")));
+
+			/* cache the output conversion functions */
+			PLy_output_record_funcs(&(proc->result), desc);
+		}
 	}
 	PG_CATCH();
 	{
@@ -1508,32 +1530,37 @@ PLy_procedure_create(HeapTuple procTup, Oid fn_oid, bool is_trigger)
 					 procStruct->prorettype);
 			rvTypeStruct = (Form_pg_type) GETSTRUCT(rvTypeTup);
 
-			/* Disallow pseudotype result, except for void */
+			/* Disallow pseudotype result, except for void or record */
-			if (rvTypeStruct->typtype == TYPTYPE_PSEUDO &&
+			if (rvTypeStruct->typtype == TYPTYPE_PSEUDO)
-				procStruct->prorettype != VOIDOID)
 			{
 				if (procStruct->prorettype == TRIGGEROID)
 					ereport(ERROR,
 							(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
 							 errmsg("trigger functions can only be called as triggers")));
-				else
+				else if (procStruct->prorettype != VOIDOID &&
+						 procStruct->prorettype != RECORDOID)
 					ereport(ERROR,
 							(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
-						  errmsg("PL/Python functions cannot return type %s",
+							 errmsg("PL/Python functions cannot return type %s",
-								 format_type_be(procStruct->prorettype))));
+									format_type_be(procStruct->prorettype))));
 			}
 
-			if (rvTypeStruct->typtype == TYPTYPE_COMPOSITE)
+			if (rvTypeStruct->typtype == TYPTYPE_COMPOSITE ||
+				procStruct->prorettype == RECORDOID)
 			{
 				/*
 				 * Tuple: set up later, during first call to
 				 * PLy_function_handler
 				 */
 				proc->result.out.d.typoid = procStruct->prorettype;
+				proc->result.out.d.typmod = -1;
 				proc->result.is_rowtype = 2;
 			}
 			else
+			{
+				/* do the real work */
 				PLy_output_datum_func(&proc->result, rvTypeTup);
+			}
 
 			ReleaseSysCache(rvTypeTup);
 		}
@@ -1842,6 +1869,29 @@ PLy_input_tuple_funcs(PLyTypeInfo *arg, TupleDesc desc)
 	}
 }
 
+static void
+PLy_output_record_funcs(PLyTypeInfo *arg, TupleDesc desc)
+{
+	/*
+	 * If the output record functions are already set, we just have to check
+	 * if the record descriptor has not changed
+	 */
+	if ((arg->is_rowtype == 1) &&
+		(arg->out.d.typmod != -1) &&
+		(arg->out.d.typmod == desc->tdtypmod))
+		return;
+
+	/* bless the record to make it known to the typcache lookup code */
+	BlessTupleDesc(desc);
+	/* save the freshly generated typmod */
+	arg->out.d.typmod = desc->tdtypmod;
+	/* proceed with normal I/O function caching */
+	PLy_output_tuple_funcs(arg, desc);
+	/* it should change is_rowtype to 1, so we won't go through this again
+	 * unless the the output record description changes */
+	Assert(arg->is_rowtype == 1);
+}
+
 static void
 PLy_output_tuple_funcs(PLyTypeInfo *arg, TupleDesc desc)
 {
@@ -1898,6 +1948,7 @@ PLy_output_datum_func2(PLyObToDatum *arg, HeapTuple typeTup)
 
 	perm_fmgr_info(typeStruct->typinput, &arg->typfunc);
 	arg->typoid = HeapTupleGetOid(typeTup);
+	arg->typmod = -1;
 	arg->typioparam = getTypeIOParam(typeTup);
 	arg->typbyval = typeStruct->typbyval;
 
@@ -1920,6 +1971,12 @@ PLy_output_datum_func2(PLyObToDatum *arg, HeapTuple typeTup)
 			break;
 	}
 
+	/* Composite types need their own input routine, though */
+	if (typeStruct->typtype == TYPTYPE_COMPOSITE)
+	{
+		arg->func = PLyObject_ToComposite;
+	}
+
 	if (element_type)
 	{
 		char		dummy_delim;
@@ -1937,6 +1994,7 @@ PLy_output_datum_func2(PLyObToDatum *arg, HeapTuple typeTup)
 		arg->func = PLySequence_ToArray;
 
 		arg->elm->typoid = element_type;
+		arg->elm->typmod = -1;
 		get_type_io_data(element_type, IOFunc_input,
 						 &arg->elm->typlen, &arg->elm->typbyval, &arg->elm->typalign, &dummy_delim,
 						 &arg->elm->typioparam, &funcid);
@@ -1962,6 +2020,7 @@ PLy_input_datum_func2(PLyDatumToOb *arg, Oid typeOid, HeapTuple typeTup)
 	/* Get the type's conversion information */
 	perm_fmgr_info(typeStruct->typoutput, &arg->typfunc);
 	arg->typoid = HeapTupleGetOid(typeTup);
+	arg->typmod = -1;
 	arg->typioparam = getTypeIOParam(typeTup);
 	arg->typbyval = typeStruct->typbyval;
 	arg->typlen = typeStruct->typlen;
@@ -2008,6 +2067,7 @@ PLy_input_datum_func2(PLyDatumToOb *arg, Oid typeOid, HeapTuple typeTup)
 		arg->elm->func = arg->func;
 		arg->func = PLyList_FromArray;
 		arg->elm->typoid = element_type;
+		arg->elm->typmod = -1;
 		get_type_io_data(element_type, IOFunc_output,
 						 &arg->elm->typlen, &arg->elm->typbyval, &arg->elm->typalign, &dummy_delim,
 						 &arg->elm->typioparam, &funcid);
@@ -2213,6 +2273,29 @@ PLyDict_FromTuple(PLyTypeInfo *info, HeapTuple tuple, TupleDesc desc)
 	return dict;
 }
 
+/*
+ *  Convert a Python object to a PostgreSQL tuple, using all supported
+ *  conversion methods: tuple as a sequence, as a mapping or as an object that
+ *  has __getattr__ support.
+ */
+static HeapTuple
+PLyObject_ToTuple(PLyTypeInfo *info, TupleDesc desc, PyObject *plrv)
+{
+	HeapTuple	tuple;
+
+	if (PySequence_Check(plrv))
+		/* composite type as sequence (tuple, list etc) */
+		tuple = PLySequence_ToTuple(info, desc, plrv);
+	else if (PyMapping_Check(plrv))
+		/* composite type as mapping (currently only dict) */
+		tuple = PLyMapping_ToTuple(info, desc, plrv);
+	else
+		/* returned as smth, must provide method __getattr__(name) */
+		tuple = PLyGenericObject_ToTuple(info, desc, plrv);
+
+	return tuple;
+}
+
 /*
  * Convert a Python object to a PostgreSQL bool datum.	This can't go
  * through the generic conversion function, because Python attaches a
@@ -2276,6 +2359,50 @@ PLyObject_ToBytea(PLyObToDatum *arg, int32 typmod, PyObject *plrv)
 	return rv;
 }
 
+
+/*
+ * Convert a Python object to a composite type. First look up the type's
+ * description, then route the Python object through the conversion function
+ * for obtaining PostgreSQL tuples.
+ */
+static Datum
+PLyObject_ToComposite(PLyObToDatum *arg, int32 typmod, PyObject *plrv)
+{
+	HeapTuple	tuple = NULL;
+	Datum		rv;
+	PLyTypeInfo	info;
+	TupleDesc	desc;
+
+	if (typmod != -1)
+		elog(ERROR, "received unnamed record type as input");
+
+	/* Create a dummy PLyTypeInfo */
+	MemSet(&info, 0, sizeof(PLyTypeInfo));
+	PLy_typeinfo_init(&info);
+	/* Mark it as needing output routines lookup */
+	info.is_rowtype = 2;
+
+	desc = lookup_rowtype_tupdesc(arg->typoid, arg->typmod);
+
+	/*
+	 * This will set up the dummy PLyTypeInfo's output conversion routines,
+	 * since we left is_rowtype as 2. A future optimisation could be caching
+	 * that info instead of looking it up every time a tuple is returned from
+	 * the function.
+	 */
+	tuple = PLyObject_ToTuple(&info, desc, plrv);
+
+	PLy_typeinfo_dealloc(&info);
+
+	if (tuple != NULL)
+		rv = HeapTupleGetDatum(tuple);
+	else
+		rv = (Datum) NULL;
+
+	return rv;
+}
+
+
 /*
  * Generic conversion function: Convert PyObject to cstring and
  * cstring into PostgreSQL type.
@@ -2379,9 +2506,8 @@ PLySequence_ToArray(PLyObToDatum *arg, int32 typmod, PyObject *plrv)
 }
 
 static HeapTuple
-PLyMapping_ToTuple(PLyTypeInfo *info, PyObject *mapping)
+PLyMapping_ToTuple(PLyTypeInfo *info, TupleDesc desc, PyObject *mapping)
 {
-	TupleDesc	desc;
 	HeapTuple	tuple;
 	Datum	   *values;
 	bool	   *nulls;
@@ -2389,7 +2515,6 @@ PLyMapping_ToTuple(PLyTypeInfo *info, PyObject *mapping)
 
 	Assert(PyMapping_Check(mapping));
 
-	desc = lookup_rowtype_tupdesc(info->out.d.typoid, -1);
 	if (info->is_rowtype == 2)
 		PLy_output_tuple_funcs(info, desc);
 	Assert(info->is_rowtype == 1);
@@ -2450,9 +2575,8 @@ PLyMapping_ToTuple(PLyTypeInfo *info, PyObject *mapping)
 
 
 static HeapTuple
-PLySequence_ToTuple(PLyTypeInfo *info, PyObject *sequence)
+PLySequence_ToTuple(PLyTypeInfo *info, TupleDesc desc, PyObject *sequence)
 {
-	TupleDesc	desc;
 	HeapTuple	tuple;
 	Datum	   *values;
 	bool	   *nulls;
@@ -2466,7 +2590,6 @@ PLySequence_ToTuple(PLyTypeInfo *info, PyObject *sequence)
 	 * can ignore exceeding items or assume missing ones as null but to avoid
 	 * plpython developer's errors we are strict here
 	 */
-	desc = lookup_rowtype_tupdesc(info->out.d.typoid, -1);
 	idx = 0;
 	for (i = 0; i < desc->natts; i++)
 	{
@@ -2534,15 +2657,13 @@ PLySequence_ToTuple(PLyTypeInfo *info, PyObject *sequence)
 
 
 static HeapTuple
-PLyObject_ToTuple(PLyTypeInfo *info, PyObject *object)
+PLyGenericObject_ToTuple(PLyTypeInfo *info, TupleDesc desc, PyObject *object)
 {
-	TupleDesc	desc;
 	HeapTuple	tuple;
 	Datum	   *values;
 	bool	   *nulls;
 	volatile int i;
 
-	desc = lookup_rowtype_tupdesc(info->out.d.typoid, -1);
 	if (info->is_rowtype == 2)
 		PLy_output_tuple_funcs(info, desc);
 	Assert(info->is_rowtype == 1);

src/pl/plpython/sql/plpython_composite.sql

@@ -0,0 +1,168 @@
+CREATE FUNCTION multiout_simple(OUT i integer, OUT j integer) AS $$
+return (1, 2)
+$$ LANGUAGE plpythonu;
+
+SELECT multiout_simple();
+SELECT * FROM multiout_simple();
+SELECT i, j + 2 FROM multiout_simple();
+SELECT (multiout_simple()).j + 3;
+
+CREATE FUNCTION multiout_simple_setof(n integer = 1, OUT integer, OUT integer) RETURNS SETOF record AS $$
+return [(1, 2)] * n
+$$ LANGUAGE plpythonu;
+
+SELECT multiout_simple_setof();
+SELECT * FROM multiout_simple_setof();
+SELECT * FROM multiout_simple_setof(3);
+
+CREATE FUNCTION multiout_record_as(typ text,
+                                   first text, OUT first text,
+                                   second integer, OUT second integer,
+                                   retnull boolean) RETURNS record AS $$
+if retnull:
+    return None
+if typ == 'dict':
+    return { 'first': first, 'second': second, 'additionalfield': 'must not cause trouble' }
+elif typ == 'tuple':
+    return ( first, second )
+elif typ == 'list':
+    return [ first, second ]
+elif typ == 'obj':
+    class type_record: pass
+    type_record.first = first
+    type_record.second = second
+    return type_record
+$$ LANGUAGE plpythonu;
+
+SELECT * FROM multiout_record_as('dict', 'foo', 1, 'f');
+SELECT multiout_record_as('dict', 'foo', 1, 'f');
+SELECT *, s IS NULL AS snull FROM multiout_record_as('tuple', 'xxx', NULL, 'f') AS f(f, s);
+SELECT *, f IS NULL AS fnull, s IS NULL AS snull FROM multiout_record_as('tuple', 'xxx', 1, 't') AS f(f, s);
+SELECT * FROM multiout_record_as('obj', NULL, 10, 'f');
+
+CREATE FUNCTION multiout_setof(n integer,
+                               OUT power_of_2 integer,
+                               OUT length integer) RETURNS SETOF record AS $$
+for i in range(n):
+    power = 2 ** i
+    length = plpy.execute("select length('%d')" % power)[0]['length']
+    yield power, length
+$$ LANGUAGE plpythonu;
+
+SELECT * FROM multiout_setof(3);
+SELECT multiout_setof(5);
+
+CREATE FUNCTION multiout_return_table() RETURNS TABLE (x integer, y text) AS $$
+return [{'x': 4, 'y' :'four'},
+        {'x': 7, 'y' :'seven'},
+        {'x': 0, 'y' :'zero'}]
+$$ LANGUAGE plpythonu;
+
+SELECT * FROM multiout_return_table();
+
+CREATE FUNCTION multiout_array(OUT integer[], OUT text) RETURNS SETOF record AS $$
+yield [[1], 'a']
+yield [[1,2], 'b']
+yield [[1,2,3], None]
+$$ LANGUAGE plpythonu;
+
+SELECT * FROM multiout_array();
+
+CREATE FUNCTION singleout_composite(OUT type_record) AS $$
+return {'first': 1, 'second': 2}
+$$ LANGUAGE plpythonu;
+
+CREATE FUNCTION multiout_composite(OUT type_record) RETURNS SETOF type_record AS $$
+return [{'first': 1, 'second': 2},
+       {'first': 3, 'second': 4	}]
+$$ LANGUAGE plpythonu;
+
+SELECT * FROM singleout_composite();
+SELECT * FROM multiout_composite();
+
+-- composite OUT parameters in functions returning RECORD not supported yet
+CREATE FUNCTION multiout_composite(INOUT n integer, OUT type_record) AS $$
+return (n, (n * 2, n * 3))
+$$ LANGUAGE plpythonu;
+
+CREATE FUNCTION multiout_table_type_setof(typ text, returnnull boolean, INOUT n integer, OUT table_record) RETURNS SETOF record AS $$
+if returnnull:
+    d = None
+elif typ == 'dict':
+    d = {'first': n * 2, 'second': n * 3, 'extra': 'not important'}
+elif typ == 'tuple':
+    d = (n * 2, n * 3)
+elif typ == 'obj':
+    class d: pass
+    d.first = n * 2
+    d.second = n * 3
+for i in range(n):
+    yield (i, d)
+$$ LANGUAGE plpythonu;
+
+SELECT * FROM multiout_composite(2);
+SELECT * FROM multiout_table_type_setof('dict', 'f', 3);
+SELECT * FROM multiout_table_type_setof('tuple', 'f', 2);
+SELECT * FROM multiout_table_type_setof('obj', 'f', 4);
+SELECT * FROM multiout_table_type_setof('dict', 't', 3);
+
+-- check what happens if a type changes under us
+
+CREATE TABLE changing (
+    i integer,
+    j integer
+);
+
+CREATE FUNCTION changing_test(OUT n integer, OUT changing) RETURNS SETOF record AS $$
+return [(1, {'i': 1, 'j': 2}),
+        (1, (3, 4))]
+$$ LANGUAGE plpythonu;
+
+SELECT * FROM changing_test();
+ALTER TABLE changing DROP COLUMN j;
+SELECT * FROM changing_test();
+SELECT * FROM changing_test();
+ALTER TABLE changing ADD COLUMN j integer;
+SELECT * FROM changing_test();
+
+-- tables of composite types (not yet implemented)
+
+CREATE FUNCTION composite_types_table(OUT tab table_record[], OUT typ type_record[] ) RETURNS SETOF record AS $$
+yield {'tab': [['first', 1], ['second', 2]],
+      'typ': [{'first': 'third', 'second': 3},
+              {'first': 'fourth', 'second': 4}]}
+yield {'tab': [['first', 1], ['second', 2]],
+      'typ': [{'first': 'third', 'second': 3},
+              {'first': 'fourth', 'second': 4}]}
+yield {'tab': [['first', 1], ['second', 2]],
+      'typ': [{'first': 'third', 'second': 3},
+              {'first': 'fourth', 'second': 4}]}
+$$ LANGUAGE plpythonu;
+
+SELECT * FROM composite_types_table();
+
+-- check what happens if the output record descriptor changes
+CREATE FUNCTION return_record(t text) RETURNS record AS $$
+return {'t': t, 'val': 10}
+$$ LANGUAGE plpythonu;
+
+SELECT * FROM return_record('abc') AS r(t text, val integer);
+SELECT * FROM return_record('abc') AS r(t text, val bigint);
+SELECT * FROM return_record('abc') AS r(t text, val integer);
+SELECT * FROM return_record('abc') AS r(t varchar(30), val integer);
+SELECT * FROM return_record('abc') AS r(t varchar(100), val integer);
+SELECT * FROM return_record('999') AS r(val text, t integer);
+
+CREATE FUNCTION return_record_2(t text) RETURNS record AS $$
+return {'v1':1,'v2':2,t:3}
+$$ LANGUAGE plpythonu;
+
+SELECT * FROM return_record_2('v3') AS (v3 int, v2 int, v1 int);
+SELECT * FROM return_record_2('v3') AS (v2 int, v3 int, v1 int);
+SELECT * FROM return_record_2('v4') AS (v1 int, v4 int, v2 int);
+SELECT * FROM return_record_2('v4') AS (v1 int, v4 int, v2 int);
+-- error
+SELECT * FROM return_record_2('v4') AS (v1 int, v3 int, v2 int);
+-- works
+SELECT * FROM return_record_2('v3') AS (v1 int, v3 int, v2 int);
+SELECT * FROM return_record_2('v3') AS (v1 int, v2 int, v3 int);

src/pl/plpython/sql/plpython_record.sql

@@ -49,10 +49,9 @@ CREATE FUNCTION test_in_out_params(first in text, second out text) AS $$
 return first + '_in_to_out';
 $$ LANGUAGE plpythonu;
 
--- this doesn't work yet :-(
 CREATE FUNCTION test_in_out_params_multi(first in text,
                                          second out text, third out text) AS $$
-return first + '_record_in_to_out';
+return (first + '_record_in_to_out_1', first + '_record_in_to_out_2');
 $$ LANGUAGE plpythonu;
 
 CREATE FUNCTION test_inout_params(first inout text) AS $$
@@ -110,7 +109,6 @@ SELECT * FROM test_type_record_as('obj', 'three', 3, false);
 SELECT * FROM test_type_record_as('obj', null, null, true);
 
 SELECT * FROM test_in_out_params('test_in');
--- this doesn't work yet :-(
 SELECT * FROM test_in_out_params_multi('test_in');
 SELECT * FROM test_inout_params('test_in');
 

src/pl/plpython/sql/plpython_trigger.sql

@@ -326,3 +326,23 @@ INSERT INTO pb VALUES ('a', '2010-10-09 21:57:33.930486');
 SELECT * FROM pb;
 UPDATE pb SET a = 'b';
 SELECT * FROM pb;
+
+
+-- triggers for tables with composite types
+
+CREATE TABLE comp1 (i integer, j boolean);
+CREATE TYPE comp2 AS (k integer, l boolean);
+
+CREATE TABLE composite_trigger_test (f1 comp1, f2 comp2);
+
+CREATE FUNCTION composite_trigger_f() RETURNS trigger AS $$
+    TD['new']['f1'] = (3, False)
+    TD['new']['f2'] = {'k': 7, 'l': 'yes', 'ignored': 10}
+    return 'MODIFY'
+$$ LANGUAGE plpythonu;
+
+CREATE TRIGGER composite_trigger BEFORE INSERT ON composite_trigger_test
+  FOR EACH ROW EXECUTE PROCEDURE composite_trigger_f();
+
+INSERT INTO composite_trigger_test VALUES (NULL, NULL);
+SELECT * FROM composite_trigger_test;