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Allow PL/python to return composite types and result sets

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Sven Suursoho
This commit is contained in:
Bruce Momjian
2006-09-02 12:30:01 +00:00
parent b1620c538d
commit 819f22a302
8 changed files with 1359 additions and 99 deletions
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425
src/pl/plpython/plpython.c
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@ -1,7 +1,7 @@
/**********************************************************************
* plpython.c - python as a procedural language for PostgreSQL
*
* $PostgreSQL: pgsql/src/pl/plpython/plpython.c,v 1.86 2006/08/27 23:47:58 tgl Exp $
* $PostgreSQL: pgsql/src/pl/plpython/plpython.c,v 1.87 2006/09/02 12:30:01 momjian Exp $
*
*********************************************************************
*/
@ -30,6 +30,7 @@
#include "catalog/pg_type.h"
#include "commands/trigger.h"
#include "executor/spi.h"
#include "funcapi.h"
#include "fmgr.h"
#include "nodes/makefuncs.h"
#include "parser/parse_type.h"
@ -121,6 +122,9 @@ typedef struct PLyProcedure
bool fn_readonly;
PLyTypeInfo result; /* also used to store info for trigger tuple
* type */
bool is_setof; /* true, if procedure returns result set */
PyObject *setof; /* contents of result set. */
char **argnames; /* Argument names */
PLyTypeInfo args[FUNC_MAX_ARGS];
int nargs;
PyObject *code; /* compiled procedure code */
@ -196,6 +200,7 @@ static Datum PLy_function_handler(FunctionCallInfo fcinfo, PLyProcedure *);
static HeapTuple PLy_trigger_handler(FunctionCallInfo fcinfo, PLyProcedure *);
static PyObject *PLy_function_build_args(FunctionCallInfo fcinfo, PLyProcedure *);
static void PLy_function_delete_args(PLyProcedure *);
static PyObject *PLy_trigger_build_args(FunctionCallInfo fcinfo, PLyProcedure *,
HeapTuple *);
static HeapTuple PLy_modify_tuple(PLyProcedure *, PyObject *,
@ -231,6 +236,9 @@ static PyObject *PLyInt_FromString(const char *);
static PyObject *PLyLong_FromString(const char *);
static PyObject *PLyString_FromString(const char *);
static HeapTuple PLyMapping_ToTuple(PLyTypeInfo *, PyObject *);
static HeapTuple PLySequence_ToTuple(PLyTypeInfo *, PyObject *);
static HeapTuple PLyObject_ToTuple(PLyTypeInfo *, PyObject *);
/*
* Currently active plpython function
@ -748,11 +756,17 @@ PLy_function_handler(FunctionCallInfo fcinfo, PLyProcedure * proc)
PG_TRY();
{
plargs = PLy_function_build_args(fcinfo, proc);
plrv = PLy_procedure_call(proc, "args", plargs);
Assert(plrv != NULL);
Assert(!PLy_error_in_progress);
if (!proc->is_setof || proc->setof == NULL)
{
/* Simple type returning function or first time for SETOF function */
plargs = PLy_function_build_args(fcinfo, proc);
plrv = PLy_procedure_call(proc, "args", plargs);
if (!proc->is_setof)
/* SETOF function parameters will be deleted when last row is returned */
PLy_function_delete_args(proc);
Assert(plrv != NULL);
Assert(!PLy_error_in_progress);
}
/*
* Disconnect from SPI manager and then create the return values datum
@ -763,6 +777,67 @@ PLy_function_handler(FunctionCallInfo fcinfo, PLyProcedure * proc)
if (SPI_finish() != SPI_OK_FINISH)
elog(ERROR, "SPI_finish failed");
if (proc->is_setof)
{
bool has_error = false;
ReturnSetInfo *rsi = (ReturnSetInfo *)fcinfo->resultinfo;
if (proc->setof == NULL)
{
/* first time -- do checks and setup */
if (!rsi || !IsA(rsi, ReturnSetInfo) ||
(rsi->allowedModes & SFRM_ValuePerCall) == 0)
{
ereport(ERROR,
(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
errmsg("only value per call is allowed")));
}
rsi->returnMode = SFRM_ValuePerCall;
/* Make iterator out of returned object */
proc->setof = PyObject_GetIter(plrv);
Py_DECREF(plrv);
plrv = NULL;
if (proc->setof == NULL)
ereport(ERROR,
(errcode(ERRCODE_DATATYPE_MISMATCH),
errmsg("returned object can not be iterated"),
errdetail("SETOF must be returned as iterable object")));
}
/* Fetch next from iterator */
plrv = PyIter_Next(proc->setof);
if (plrv)
rsi->isDone = ExprMultipleResult;
else
{
rsi->isDone = ExprEndResult;
has_error = PyErr_Occurred() != NULL;
}
if (rsi->isDone == ExprEndResult)
{
/* Iterator is exhausted or error happened */
Py_DECREF(proc->setof);
proc->setof = NULL;
Py_XDECREF(plargs);
Py_XDECREF(plrv);
Py_XDECREF(plrv_so);
PLy_function_delete_args(proc);
if (has_error)
ereport(ERROR,
(errcode(ERRCODE_DATA_EXCEPTION),
errmsg("error fetching next item from iterator")));
fcinfo->isnull = true;
return (Datum)NULL;
}
}
/*
* If the function is declared to return void, the Python
* return value must be None. For void-returning functions, we
@ -784,10 +859,39 @@ PLy_function_handler(FunctionCallInfo fcinfo, PLyProcedure * proc)
else if (plrv == Py_None)
{
fcinfo->isnull = true;
rv = InputFunctionCall(&proc->result.out.d.typfunc,
NULL,
proc->result.out.d.typioparam,
-1);
if (proc->result.is_rowtype < 1)
rv = InputFunctionCall(&proc->result.out.d.typfunc,
NULL,
proc->result.out.d.typioparam,
-1);
else
/* Tuple as None */
rv = (Datum) NULL;
}
else if (proc->result.is_rowtype >= 1)
{
HeapTuple tuple = NULL;
if (PySequence_Check(plrv))
/* composite type as sequence (tuple, list etc) */
tuple = PLySequence_ToTuple(&proc->result, plrv);
else if (PyMapping_Check(plrv))
/* composite type as mapping (currently only dict) */
tuple = PLyMapping_ToTuple(&proc->result, plrv);
else
/* returned as smth, must provide method __getattr__(name) */
tuple = PLyObject_ToTuple(&proc->result, plrv);
if (tuple != NULL)
{
fcinfo->isnull = false;
rv = HeapTupleGetDatum(tuple);
}
else
{
fcinfo->isnull = true;
rv = (Datum) NULL;
}
}
else
{
@ -912,10 +1016,10 @@ PLy_function_build_args(FunctionCallInfo fcinfo, PLyProcedure * proc)
arg = Py_None;
}
/*
* FIXME -- error check this
*/
PyList_SetItem(args, i, arg);
if (PyList_SetItem(args, i, arg) == -1 ||
(proc->argnames &&
PyDict_SetItemString(proc->globals, proc->argnames[i], arg) == -1))
PLy_elog(ERROR, "problem setting up arguments for \"%s\"", proc->proname);
arg = NULL;
}
}
@ -932,6 +1036,19 @@ PLy_function_build_args(FunctionCallInfo fcinfo, PLyProcedure * proc)
}
static void
PLy_function_delete_args(PLyProcedure *proc)
{
int i;
if (!proc->argnames)
return;
for (i = 0; i < proc->nargs; i++)
PyDict_DelItemString(proc->globals, proc->argnames[i]);
}
/*
* PLyProcedure functions
*/
@ -1002,6 +1119,9 @@ PLy_procedure_create(FunctionCallInfo fcinfo, Oid tgreloid,
bool isnull;
int i,
rv;
Datum argnames;
Datum *elems;
int nelems;
procStruct = (Form_pg_proc) GETSTRUCT(procTup);
@ -1033,6 +1153,9 @@ PLy_procedure_create(FunctionCallInfo fcinfo, Oid tgreloid,
proc->nargs = 0;
proc->code = proc->statics = NULL;
proc->globals = proc->me = NULL;
proc->is_setof = procStruct->proretset;
proc->setof = NULL;
proc->argnames = NULL;
PG_TRY();
{
@ -1069,9 +1192,11 @@ PLy_procedure_create(FunctionCallInfo fcinfo, Oid tgreloid,
}
if (rvTypeStruct->typtype == 'c')
ereport(ERROR,
(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
errmsg("plpython functions cannot return tuples yet")));
{
/* Tuple: set up later, during first call to PLy_function_handler */
proc->result.out.d.typoid = procStruct->prorettype;
proc->result.is_rowtype = 2;
}
else
PLy_output_datum_func(&proc->result, rvTypeTup);
@ -1094,6 +1219,20 @@ PLy_procedure_create(FunctionCallInfo fcinfo, Oid tgreloid,
* arguments.
*/
proc->nargs = fcinfo->nargs;
if (proc->nargs)
{
argnames = SysCacheGetAttr(PROCOID, procTup, Anum_pg_proc_proargnames, &isnull);
if (!isnull)
{
deconstruct_array(DatumGetArrayTypeP(argnames), TEXTOID, -1, false, 'i',
&elems, NULL, &nelems);
if (nelems != proc->nargs)
elog(ERROR,
"proargnames must have the same number of elements "
"as the function has arguments");
proc->argnames = (char **) PLy_malloc(sizeof(char *)*proc->nargs);
}
}
for (i = 0; i < fcinfo->nargs; i++)
{
HeapTuple argTypeTup;
@ -1122,8 +1261,11 @@ PLy_procedure_create(FunctionCallInfo fcinfo, Oid tgreloid,
proc->args[i].is_rowtype = 2; /* still need to set I/O funcs */
ReleaseSysCache(argTypeTup);
}
/* Fetch argument name */
if (proc->argnames)
proc->argnames[i] = PLy_strdup(DatumGetCString(DirectFunctionCall1(textout, elems[i])));
}
/*
* get the text of the function.
@ -1259,6 +1401,7 @@ PLy_procedure_delete(PLyProcedure * proc)
if (proc->pyname)
PLy_free(proc->pyname);
for (i = 0; i < proc->nargs; i++)
{
if (proc->args[i].is_rowtype == 1)
{
if (proc->args[i].in.r.atts)
@ -1266,6 +1409,11 @@ PLy_procedure_delete(PLyProcedure * proc)
if (proc->args[i].out.r.atts)
PLy_free(proc->args[i].out.r.atts);
}
if (proc->argnames && proc->argnames[i])
PLy_free(proc->argnames[i]);
}
if (proc->argnames)
PLy_free(proc->argnames);
}
/* conversion functions. remember output from python is
@ -1524,6 +1672,247 @@ PLyDict_FromTuple(PLyTypeInfo * info, HeapTuple tuple, TupleDesc desc)
return dict;
}
static HeapTuple
PLyMapping_ToTuple(PLyTypeInfo *info, PyObject *mapping)
{
TupleDesc desc;
HeapTuple tuple;
Datum *values;
char *nulls;
int i;
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);
/* Build tuple */
values = palloc(sizeof(Datum)*desc->natts);
nulls = palloc(sizeof(char)*desc->natts);
for (i = 0; i < desc->natts; ++i)
{
char *key;
PyObject *value,
*so;
key = NameStr(desc->attrs[i]->attname);
value = so = NULL;
PG_TRY();
{
value = PyMapping_GetItemString(mapping, key);
if (value == Py_None)
{
values[i] = (Datum) NULL;
nulls[i] = 'n';
}
else if (value)
{
char *valuestr;
so = PyObject_Str(value);
if (so == NULL)
PLy_elog(ERROR, "can't convert mapping type");
valuestr = PyString_AsString(so);
values[i] = InputFunctionCall(&info->out.r.atts[i].typfunc
, valuestr
, info->out.r.atts[i].typioparam
, -1);
Py_DECREF(so);
so = NULL;
nulls[i] = ' ';
}
else
ereport(ERROR,
(errcode(ERRCODE_UNDEFINED_COLUMN),
errmsg("no mapping found with key \"%s\"", key),
errhint("to return null in specific column, "
"add value None to map with key named after column")));
Py_XDECREF(value);
value = NULL;
}
PG_CATCH();
{
Py_XDECREF(so);
Py_XDECREF(value);
PG_RE_THROW();
}
PG_END_TRY();
}
tuple = heap_formtuple(desc, values, nulls);
ReleaseTupleDesc(desc);
pfree(values);
pfree(nulls);
return tuple;
}
static HeapTuple
PLySequence_ToTuple(PLyTypeInfo *info, PyObject *sequence)
{
TupleDesc desc;
HeapTuple tuple;
Datum *values;
char *nulls;
int i;
Assert(PySequence_Check(sequence));
/*
* Check that sequence length is exactly same as PG tuple's. We actually
* 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);
if (PySequence_Length(sequence) != desc->natts)
ereport(ERROR,
(errcode(ERRCODE_DATATYPE_MISMATCH),
errmsg("returned sequence's length must be same as tuple's length")));
if (info->is_rowtype == 2)
PLy_output_tuple_funcs(info, desc);
Assert(info->is_rowtype == 1);
/* Build tuple */
values = palloc(sizeof(Datum)*desc->natts);
nulls = palloc(sizeof(char)*desc->natts);
for (i = 0; i < desc->natts; ++i)
{
PyObject *value,
*so;
value = so = NULL;
PG_TRY();
{
value = PySequence_GetItem(sequence, i);
Assert(value);
if (value == Py_None)
{
values[i] = (Datum) NULL;
nulls[i] = 'n';
}
else if (value)
{
char *valuestr;
so = PyObject_Str(value);
if (so == NULL)
PLy_elog(ERROR, "can't convert sequence type");
valuestr = PyString_AsString(so);
values[i] = InputFunctionCall(&info->out.r.atts[i].typfunc
, valuestr
, info->out.r.atts[i].typioparam
, -1);
Py_DECREF(so);
so = NULL;
nulls[i] = ' ';
}
Py_XDECREF(value);
value = NULL;
}
PG_CATCH();
{
Py_XDECREF(so);
Py_XDECREF(value);
PG_RE_THROW();
}
PG_END_TRY();
}
tuple = heap_formtuple(desc, values, nulls);
ReleaseTupleDesc(desc);
pfree(values);
pfree(nulls);
return tuple;
}
static HeapTuple
PLyObject_ToTuple(PLyTypeInfo *info, PyObject *object)
{
TupleDesc desc;
HeapTuple tuple;
Datum *values;
char *nulls;
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);
/* Build tuple */
values = palloc(sizeof(Datum)*desc->natts);
nulls = palloc(sizeof(char)*desc->natts);
for (i = 0; i < desc->natts; ++i)
{
char *key;
PyObject *value,
*so;
key = NameStr(desc->attrs[i]->attname);
value = so = NULL;
PG_TRY();
{
value = PyObject_GetAttrString(object, key);
if (value == Py_None)
{
values[i] = (Datum) NULL;
nulls[i] = 'n';
}
else if (value)
{
char *valuestr;
so = PyObject_Str(value);
if (so == NULL)
PLy_elog(ERROR, "can't convert object type");
valuestr = PyString_AsString(so);
values[i] = InputFunctionCall(&info->out.r.atts[i].typfunc
, valuestr
, info->out.r.atts[i].typioparam
, -1);
Py_DECREF(so);
so = NULL;
nulls[i] = ' ';
}
else
ereport(ERROR,
(errcode(ERRCODE_UNDEFINED_COLUMN),
errmsg("no attribute named \"%s\"", key),
errhint("to return null in specific column, "
"let returned object to have attribute named "
"after column with value None")));
Py_XDECREF(value);
value = NULL;
}
PG_CATCH();
{
Py_XDECREF(so);
Py_XDECREF(value);
PG_RE_THROW();
}
PG_END_TRY();
}
tuple = heap_formtuple(desc, values, nulls);
ReleaseTupleDesc(desc);
pfree(values);
pfree(nulls);
return tuple;
}
/* initialization, some python variables function declared here */
/* interface to postgresql elog */