Here is a patch to support arrays in PL/Python as parameters and return
values. It converts an array parameter to a Python "list", and converts
a Python "sequence" return value back to an array.
I have settled on two implementation restrictions for the moment:
- Only supports one-dimensional arrays. (Python has no multidimensional
lists, so the semantics of this would be dubious.)
- Does not support returning arrays of composite types. (Basically too
complicated to implement right now and seemingly of limited practical
value.)
diff --git a/src/pl/plpython/expected/plpython_types.out b/src/pl/plpython/expected/plpython_types.out
index 2dd498c..cbc93a2 100644
--- a/src/pl/plpython/expected/plpython_types.out
+++ b/src/pl/plpython/expected/plpython_types.out
@@ -477,3 +477,106 @@ CONTEXT: PL/Python function "test_type_conversion_bytea10"
ERROR: value for domain bytea10 violates check constraint "bytea10_check"
CONTEXT: while creating return value
PL/Python function "test_type_conversion_bytea10"
+--
+-- Arrays
+--
+CREATE FUNCTION test_type_conversion_array_int4(x int4[]) RETURNS int4[] AS $$
+plpy.info(x, type(x))
+return x
+$$ LANGUAGE plpythonu;
+SELECT * FROM test_type_conversion_array_int4(ARRAY[0, 100]);
+INFO: ([0, 100], <type 'list'>)
+CONTEXT: PL/Python function "test_type_conversion_array_int4"
+ test_type_conversion_array_int4
+---------------------------------
+ {0,100}
+(1 row)
+
+SELECT * FROM test_type_conversion_array_int4(ARRAY[0,-100,55]);
+INFO: ([0, -100, 55], <type 'list'>)
+CONTEXT: PL/Python function "test_type_conversion_array_int4"
+ test_type_conversion_array_int4
+---------------------------------
+ {0,-100,55}
+(1 row)
+
+SELECT * FROM test_type_conversion_array_int4(ARRAY[NULL,1]);
+INFO: ([None, 1], <type 'list'>)
+CONTEXT: PL/Python function "test_type_conversion_array_int4"
+ test_type_conversion_array_int4
+---------------------------------
+ {NULL,1}
+(1 row)
+
+SELECT * FROM test_type_conversion_array_int4(ARRAY[]::integer[]);
+INFO: ([], <type 'list'>)
+CONTEXT: PL/Python function "test_type_conversion_array_int4"
+ test_type_conversion_array_int4
+---------------------------------
+ {}
+(1 row)
+
+SELECT * FROM test_type_conversion_array_int4(NULL);
+INFO: (None, <type 'NoneType'>)
+CONTEXT: PL/Python function "test_type_conversion_array_int4"
+ test_type_conversion_array_int4
+---------------------------------
+
+(1 row)
+
+SELECT * FROM test_type_conversion_array_int4(ARRAY[[1,2,3],[4,5,6]]);
+ERROR: cannot convert multidimensional array to Python list
+DETAIL: PL/Python only supports one-dimensional arrays.
+CONTEXT: PL/Python function "test_type_conversion_array_int4"
+CREATE FUNCTION test_type_conversion_array_bytea(x bytea[]) RETURNS bytea[] AS $$
+plpy.info(x, type(x))
+return x
+$$ LANGUAGE plpythonu;
+SELECT * FROM test_type_conversion_array_bytea(ARRAY[E'\\xdeadbeef'::bytea, NULL]);
+INFO: (['\xde\xad\xbe\xef', None], <type 'list'>)
+CONTEXT: PL/Python function "test_type_conversion_array_bytea"
+ test_type_conversion_array_bytea
+----------------------------------
+ {"\\xdeadbeef",NULL}
+(1 row)
+
+CREATE FUNCTION test_type_conversion_array_mixed1() RETURNS text[] AS $$
+return [123, 'abc']
+$$ LANGUAGE plpythonu;
+SELECT * FROM test_type_conversion_array_mixed1();
+ test_type_conversion_array_mixed1
+-----------------------------------
+ {123,abc}
+(1 row)
+
+CREATE FUNCTION test_type_conversion_array_mixed2() RETURNS int[] AS $$
+return [123, 'abc']
+$$ LANGUAGE plpythonu;
+SELECT * FROM test_type_conversion_array_mixed2();
+ERROR: invalid input syntax for integer: "abc"
+CONTEXT: while creating return value
+PL/Python function "test_type_conversion_array_mixed2"
+CREATE FUNCTION test_type_conversion_array_record() RETURNS type_record[] AS $$
+return [None]
+$$ LANGUAGE plpythonu;
+SELECT * FROM test_type_conversion_array_record();
+ERROR: PL/Python functions cannot return type type_record[]
+DETAIL: PL/Python does not support conversion to arrays of row types.
+CREATE FUNCTION test_type_conversion_array_string() RETURNS text[] AS $$
+return 'abc'
+$$ LANGUAGE plpythonu;
+SELECT * FROM test_type_conversion_array_string();
+ test_type_conversion_array_string
+-----------------------------------
+ {a,b,c}
+(1 row)
+
+CREATE FUNCTION test_type_conversion_array_tuple() RETURNS text[] AS $$
+return ('abc', 'def')
+$$ LANGUAGE plpythonu;
+SELECT * FROM test_type_conversion_array_tuple();
+ test_type_conversion_array_tuple
+----------------------------------
+ {abc,def}
+(1 row)
+
diff --git a/src/pl/plpython/plpython.c b/src/pl/plpython/plpython.c
index 6fd4aca..8640496 100644
--- a/src/pl/plpython/plpython.c
+++ b/src/pl/plpython/plpython.c
@@ -89,6 +89,9 @@ typedef struct PLyDatumToOb
Oid typoid; /* The OID of the type */
Oid typioparam;
bool typbyval;
+ int16 typlen;
+ char typalign;
+ struct PLyDatumToOb *elm;
} PLyDatumToOb;
typedef struct PLyTupleToOb
@@ -120,6 +123,9 @@ typedef struct PLyObToDatum
Oid typoid; /* The OID of the type */
Oid typioparam;
bool typbyval;
+ int16 typlen;
+ char typalign;
+ struct PLyObToDatum *elm;
} PLyObToDatum;
typedef struct PLyObToTuple
@@ -284,6 +290,7 @@ static PyObject *PLyInt_FromInt32(PLyDatumToOb *arg, Datum d);
static PyObject *PLyLong_FromInt64(PLyDatumToOb *arg, Datum d);
static PyObject *PLyString_FromBytea(PLyDatumToOb *arg, Datum d);
static PyObject *PLyString_FromDatum(PLyDatumToOb *arg, Datum d);
+static PyObject *PLyList_FromArray(PLyDatumToOb *arg, Datum d);
static PyObject *PLyDict_FromTuple(PLyTypeInfo *, HeapTuple, TupleDesc);
@@ -293,6 +300,8 @@ static Datum PLyObject_ToBytea(PLyTypeInfo *, PLyObToDatum *,
PyObject *);
static Datum PLyObject_ToDatum(PLyTypeInfo *, PLyObToDatum *,
PyObject *);
+static Datum PLySequence_ToArray(PLyTypeInfo *, PLyObToDatum *,
+ PyObject *);
static HeapTuple PLyMapping_ToTuple(PLyTypeInfo *, PyObject *);
static HeapTuple PLySequence_ToTuple(PLyTypeInfo *, PyObject *);
@@ -1653,18 +1662,21 @@ static void
PLy_output_datum_func2(PLyObToDatum *arg, HeapTuple typeTup)
{
Form_pg_type typeStruct = (Form_pg_type) GETSTRUCT(typeTup);
+ Oid element_type;
perm_fmgr_info(typeStruct->typinput, &arg->typfunc);
arg->typoid = HeapTupleGetOid(typeTup);
arg->typioparam = getTypeIOParam(typeTup);
arg->typbyval = typeStruct->typbyval;
+ element_type = get_element_type(arg->typoid);
+
/*
* Select a conversion function to convert Python objects to
* PostgreSQL datums. Most data types can go through the generic
* function.
*/
- switch (getBaseType(arg->typoid))
+ switch (getBaseType(element_type ? element_type : arg->typoid))
{
case BOOLOID:
arg->func = PLyObject_ToBool;
@@ -1676,6 +1688,29 @@ PLy_output_datum_func2(PLyObToDatum *arg, HeapTuple typeTup)
arg->func = PLyObject_ToDatum;
break;
}
+
+ if (element_type)
+ {
+ char dummy_delim;
+ Oid funcid;
+
+ if (type_is_rowtype(element_type))
+ ereport(ERROR,
+ (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+ errmsg("PL/Python functions cannot return type %s",
+ format_type_be(arg->typoid)),
+ errdetail("PL/Python does not support conversion to arrays of row types.")));
+
+ arg->elm = PLy_malloc0(sizeof(*arg->elm));
+ arg->elm->func = arg->func;
+ arg->func = PLySequence_ToArray;
+
+ arg->elm->typoid = element_type;
+ get_type_io_data(element_type, IOFunc_input,
+ &arg->elm->typlen, &arg->elm->typbyval, &arg->elm->typalign, &dummy_delim,
+ &arg->elm->typioparam, &funcid);
+ perm_fmgr_info(funcid, &arg->elm->typfunc);
+ }
}
static void
@@ -1691,15 +1726,17 @@ static void
PLy_input_datum_func2(PLyDatumToOb *arg, Oid typeOid, HeapTuple typeTup)
{
Form_pg_type typeStruct = (Form_pg_type) GETSTRUCT(typeTup);
+ Oid element_type = get_element_type(typeOid);
/* Get the type's conversion information */
perm_fmgr_info(typeStruct->typoutput, &arg->typfunc);
arg->typoid = HeapTupleGetOid(typeTup);
arg->typioparam = getTypeIOParam(typeTup);
arg->typbyval = typeStruct->typbyval;
+ arg->typlen = typeStruct->typlen;
/* Determine which kind of Python object we will convert to */
- switch (getBaseType(typeOid))
+ switch (getBaseType(element_type ? element_type : typeOid))
{
case BOOLOID:
arg->func = PLyBool_FromBool;
@@ -1729,6 +1766,14 @@ PLy_input_datum_func2(PLyDatumToOb *arg, Oid typeOid, HeapTuple typeTup)
arg->func = PLyString_FromDatum;
break;
}
+
+ if (element_type)
+ {
+ arg->elm = PLy_malloc0(sizeof(*arg->elm));
+ arg->elm->func = arg->func;
+ arg->func = PLyList_FromArray;
+ get_typlenbyvalalign(element_type, &arg->elm->typlen, &arg->elm->typbyval, &arg->elm->typalign);
+ }
}
static void
@@ -1833,6 +1878,45 @@ PLyString_FromDatum(PLyDatumToOb *arg, Datum d)
}
static PyObject *
+PLyList_FromArray(PLyDatumToOb *arg, Datum d)
+{
+ ArrayType *array = DatumGetArrayTypeP(d);
+ PyObject *list;
+ int length;
+ int lbound;
+ int i;
+
+ if (ARR_NDIM(array) == 0)
+ return PyList_New(0);
+
+ if (ARR_NDIM(array) != 1)
+ ereport(ERROR,
+ (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+ errmsg("cannot convert multidimensional array to Python list"),
+ errdetail("PL/Python only supports one-dimensional arrays.")));
+
+ length = ARR_DIMS(array)[0];
+ lbound = ARR_LBOUND(array)[0];
+ list = PyList_New(length);
+
+ for (i = 0; i < length; i++)
+ {
+ Datum elem;
+ bool isnull;
+ int offset;
+
+ offset = lbound + i;
+ elem = array_ref(array, 1, &offset, arg->typlen, arg->elm->typlen, arg->elm->typbyval, arg->elm->typalign, &isnull);
+ if (isnull)
+ PyList_SET_ITEM(list, i, Py_None);
+ else
+ PyList_SET_ITEM(list, i, arg->elm->func(arg, elem));
+ }
+
+ return list;
+}
+
+static PyObject *
PLyDict_FromTuple(PLyTypeInfo *info, HeapTuple tuple, TupleDesc desc)
{
PyObject *volatile dict;
@@ -1994,6 +2078,45 @@ PLyObject_ToDatum(PLyTypeInfo *info,
return rv;
}
+static Datum
+PLySequence_ToArray(PLyTypeInfo *info,
+ PLyObToDatum *arg,
+ PyObject *plrv)
+{
+ ArrayType *array;
+ int i;
+ Datum *elems;
+ bool *nulls;
+ int len;
+ int lbs;
+
+ Assert(plrv != Py_None);
+
+ len = PySequence_Length(plrv);
+ elems = palloc(sizeof(*elems) * len);
+ nulls = palloc(sizeof(*nulls) * len);
+
+ for (i = 0; i < len; i++)
+ {
+ PyObject *obj = PySequence_GetItem(plrv, i);
+
+ if (obj == Py_None)
+ nulls[i] = true;
+ else
+ {
+ nulls[i] = false;
+ /* We don't support arrays of row types yet, so the first
+ * argument can be NULL. */
+ elems[i] = arg->elm->func(NULL, arg->elm, obj);
+ }
+ }
+
+ lbs = 1;
+ array = construct_md_array(elems, nulls, 1, &len, &lbs,
+ get_element_type(arg->typoid), arg->elm->typlen, arg->elm->typbyval, arg->elm->typalign);
+ return PointerGetDatum(array);
+}
+
static HeapTuple
PLyMapping_ToTuple(PLyTypeInfo *info, PyObject *mapping)
{
diff --git a/src/pl/plpython/sql/plpython_types.sql b/src/pl/plpython/sql/plpython_types.sql
index becf5cf..6bc2e57 100644
--- a/src/pl/plpython/sql/plpython_types.sql
+++ b/src/pl/plpython/sql/plpython_types.sql
@@ -204,3 +204,62 @@ SELECT * FROM test_type_conversion_bytea10('hello world', 'hello wold');
SELECT * FROM test_type_conversion_bytea10('hello word', 'hello world');
SELECT * FROM test_type_conversion_bytea10(null, 'hello word');
SELECT * FROM test_type_conversion_bytea10('hello word', null);
+
+
+--
+-- Arrays
+--
+
+CREATE FUNCTION test_type_conversion_array_int4(x int4[]) RETURNS int4[] AS $$
+plpy.info(x, type(x))
+return x
+$$ LANGUAGE plpythonu;
+
+SELECT * FROM test_type_conversion_array_int4(ARRAY[0, 100]);
+SELECT * FROM test_type_conversion_array_int4(ARRAY[0,-100,55]);
+SELECT * FROM test_type_conversion_array_int4(ARRAY[NULL,1]);
+SELECT * FROM test_type_conversion_array_int4(ARRAY[]::integer[]);
+SELECT * FROM test_type_conversion_array_int4(NULL);
+SELECT * FROM test_type_conversion_array_int4(ARRAY[[1,2,3],[4,5,6]]);
+
+
+CREATE FUNCTION test_type_conversion_array_bytea(x bytea[]) RETURNS bytea[] AS $$
+plpy.info(x, type(x))
+return x
+$$ LANGUAGE plpythonu;
+
+SELECT * FROM test_type_conversion_array_bytea(ARRAY[E'\\xdeadbeef'::bytea, NULL]);
+
+
+CREATE FUNCTION test_type_conversion_array_mixed1() RETURNS text[] AS $$
+return [123, 'abc']
+$$ LANGUAGE plpythonu;
+
+SELECT * FROM test_type_conversion_array_mixed1();
+
+
+CREATE FUNCTION test_type_conversion_array_mixed2() RETURNS int[] AS $$
+return [123, 'abc']
+$$ LANGUAGE plpythonu;
+
+SELECT * FROM test_type_conversion_array_mixed2();
+
+
+CREATE FUNCTION test_type_conversion_array_record() RETURNS type_record[] AS $$
+return [None]
+$$ LANGUAGE plpythonu;
+
+SELECT * FROM test_type_conversion_array_record();
+
+
+CREATE FUNCTION test_type_conversion_array_string() RETURNS text[] AS $$
+return 'abc'
+$$ LANGUAGE plpythonu;
+
+SELECT * FROM test_type_conversion_array_string();
+
+CREATE FUNCTION test_type_conversion_array_tuple() RETURNS text[] AS $$
+return ('abc', 'def')
+$$ LANGUAGE plpythonu;
+
+SELECT * FROM test_type_conversion_array_tuple();
--
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