/* prepare(query="select * from foo")
* prepare(query="select * from foo where bar = $1", params=["text"])
* prepare(query="select * from foo where bar = $1", params=["text"], limit=5)
*/
PyObject *
PLy_spi_prepare(PyObject *self, PyObject *args)
{
PLyPlanObject *plan;
PyObject *list = NULL;
PyObject *volatile optr = NULL;
char *query;
volatile MemoryContext oldcontext;
volatile ResourceOwner oldowner;
volatile int nargs;
if (!PyArg_ParseTuple(args, "s|O", &query, &list))
return NULL;
if (list && (!PySequence_Check(list)))
{
PLy_exception_set(PyExc_TypeError,
"second argument of plpy.prepare must be a sequence");
return NULL;
}
if ((plan = (PLyPlanObject *) PLy_plan_new()) == NULL)
return NULL;
nargs = list ? PySequence_Length(list) : 0;
plan->nargs = nargs;
plan->types = nargs ? PLy_malloc(sizeof(Oid) * nargs) : NULL;
plan->values = nargs ? PLy_malloc(sizeof(Datum) * nargs) : NULL;
plan->args = nargs ? PLy_malloc(sizeof(PLyTypeInfo) * nargs) : NULL;
oldcontext = CurrentMemoryContext;
oldowner = CurrentResourceOwner;
PLy_spi_subtransaction_begin(oldcontext, oldowner);
PG_TRY();
{
int i;
/*
* the other loop might throw an exception, if PLyTypeInfo member
* isn't properly initialized the Py_DECREF(plan) will go boom
*/
for (i = 0; i < nargs; i++)
{
PLy_typeinfo_init(&plan->args[i]);
plan->values[i] = PointerGetDatum(NULL);
}
for (i = 0; i < nargs; i++)
{
char *sptr;
HeapTuple typeTup;
Oid typeId;
int32 typmod;
Form_pg_type typeStruct;
optr = PySequence_GetItem(list, i);
if (PyString_Check(optr))
sptr = PyString_AsString(optr);
else if (PyUnicode_Check(optr))
sptr = PLyUnicode_AsString(optr);
else
{
ereport(ERROR,
(errmsg("plpy.prepare: type name at ordinal position %d is not a string", i)));
sptr = NULL; /* keep compiler quiet */
}
/********************************************************
* Resolve argument type names and then look them up by
* oid in the system cache, and remember the required
*information for input conversion.
********************************************************/
parseTypeString(sptr, &typeId, &typmod);
typeTup = SearchSysCache1(TYPEOID,
ObjectIdGetDatum(typeId));
if (!HeapTupleIsValid(typeTup))
elog(ERROR, "cache lookup failed for type %u", typeId);
Py_DECREF(optr);
/*
* set optr to NULL, so we won't try to unref it again in case of
* an error
*/
optr = NULL;
plan->types[i] = typeId;
typeStruct = (Form_pg_type) GETSTRUCT(typeTup);
if (typeStruct->typtype != TYPTYPE_COMPOSITE)
PLy_output_datum_func(&plan->args[i], typeTup);
else
ereport(ERROR,
(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
errmsg("plpy.prepare does not support composite types")));
ReleaseSysCache(typeTup);
}
pg_verifymbstr(query, strlen(query), false);
plan->plan = SPI_prepare(query, plan->nargs, plan->types);
if (plan->plan == NULL)
elog(ERROR, "SPI_prepare failed: %s",
SPI_result_code_string(SPI_result));
/* transfer plan from procCxt to topCxt */
if (SPI_keepplan(plan->plan))
elog(ERROR, "SPI_keepplan failed");
PLy_spi_subtransaction_commit(oldcontext, oldowner);
}
PG_CATCH();
{
Py_DECREF(plan);
Py_XDECREF(optr);
PLy_spi_subtransaction_abort(oldcontext, oldowner);
return NULL;
}
PG_END_TRY();
Assert(plan->plan != NULL);
return (PyObject *) plan;
}
/*
* Create a new PLyProcedure structure
*/
static PLyProcedure *
PLy_procedure_create(HeapTuple procTup, Oid fn_oid, bool is_trigger)
{
char procName[NAMEDATALEN + 256];
Form_pg_proc procStruct;
PLyProcedure *volatile proc;
char *volatile procSource = NULL;
Datum prosrcdatum;
bool isnull;
int i,
rv;
procStruct = (Form_pg_proc) GETSTRUCT(procTup);
rv = snprintf(procName, sizeof(procName),
"__plpython_procedure_%s_%u",
NameStr(procStruct->proname),
fn_oid);
if (rv >= sizeof(procName) || rv < 0)
elog(ERROR, "procedure name would overrun buffer");
proc = PLy_malloc(sizeof(PLyProcedure));
proc->proname = PLy_strdup(NameStr(procStruct->proname));
proc->pyname = PLy_strdup(procName);
proc->fn_xmin = HeapTupleHeaderGetRawXmin(procTup->t_data);
proc->fn_tid = procTup->t_self;
/* Remember if function is STABLE/IMMUTABLE */
proc->fn_readonly =
(procStruct->provolatile != PROVOLATILE_VOLATILE);
PLy_typeinfo_init(&proc->result);
for (i = 0; i < FUNC_MAX_ARGS; i++)
PLy_typeinfo_init(&proc->args[i]);
proc->nargs = 0;
proc->code = proc->statics = NULL;
proc->globals = NULL;
proc->is_setof = procStruct->proretset;
proc->setof = NULL;
proc->src = NULL;
proc->argnames = NULL;
PG_TRY();
{
/*
* get information required for output conversion of the return value,
* but only if this isn't a trigger.
*/
if (!is_trigger)
{
HeapTuple rvTypeTup;
Form_pg_type rvTypeStruct;
rvTypeTup = SearchSysCache1(TYPEOID,
ObjectIdGetDatum(procStruct->prorettype));
if (!HeapTupleIsValid(rvTypeTup))
elog(ERROR, "cache lookup failed for type %u",
procStruct->prorettype);
rvTypeStruct = (Form_pg_type) GETSTRUCT(rvTypeTup);
/* Disallow pseudotype result, except for void or record */
if (rvTypeStruct->typtype == TYPTYPE_PSEUDO)
{
if (procStruct->prorettype == TRIGGEROID)
ereport(ERROR,
(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
errmsg("trigger functions can only be called as triggers")));
else if (procStruct->prorettype != VOIDOID &&
procStruct->prorettype != RECORDOID)
ereport(ERROR,
(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
errmsg("PL/Python functions cannot return type %s",
format_type_be(procStruct->prorettype))));
}
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);
}
/*
* Now get information required for input conversion of the
* procedure's arguments. Note that we ignore output arguments here.
* If the function returns record, those I/O functions will be set up
* when the function is first called.
*/
if (procStruct->pronargs)
{
Oid *types;
char **names,
*modes;
int i,
pos,
total;
/* extract argument type info from the pg_proc tuple */
total = get_func_arg_info(procTup, &types, &names, &modes);
/* count number of in+inout args into proc->nargs */
if (modes == NULL)
proc->nargs = total;
else
{
/* proc->nargs was initialized to 0 above */
for (i = 0; i < total; i++)
{
if (modes[i] != PROARGMODE_OUT &&
modes[i] != PROARGMODE_TABLE)
(proc->nargs)++;
}
}
proc->argnames = (char **) PLy_malloc0(sizeof(char *) * proc->nargs);
for (i = pos = 0; i < total; i++)
{
HeapTuple argTypeTup;
Form_pg_type argTypeStruct;
if (modes &&
(modes[i] == PROARGMODE_OUT ||
modes[i] == PROARGMODE_TABLE))
continue; /* skip OUT arguments */
Assert(types[i] == procStruct->proargtypes.values[pos]);
argTypeTup = SearchSysCache1(TYPEOID,
ObjectIdGetDatum(types[i]));
if (!HeapTupleIsValid(argTypeTup))
elog(ERROR, "cache lookup failed for type %u", types[i]);
argTypeStruct = (Form_pg_type) GETSTRUCT(argTypeTup);
/* check argument type is OK, set up I/O function info */
switch (argTypeStruct->typtype)
{
case TYPTYPE_PSEUDO:
/* Disallow pseudotype argument */
ereport(ERROR,
(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
errmsg("PL/Python functions cannot accept type %s",
format_type_be(types[i]))));
break;
case TYPTYPE_COMPOSITE:
/* we'll set IO funcs at first call */
proc->args[pos].is_rowtype = 2;
break;
default:
PLy_input_datum_func(&(proc->args[pos]),
types[i],
argTypeTup);
break;
}
/* get argument name */
proc->argnames[pos] = names ? PLy_strdup(names[i]) : NULL;
ReleaseSysCache(argTypeTup);
pos++;
}
}
/*
* get the text of the function.
*/
prosrcdatum = SysCacheGetAttr(PROCOID, procTup,
Anum_pg_proc_prosrc, &isnull);
if (isnull)
elog(ERROR, "null prosrc");
procSource = TextDatumGetCString(prosrcdatum);
PLy_procedure_compile(proc, procSource);
pfree(procSource);
procSource = NULL;
}
PG_CATCH();
{
PLy_procedure_delete(proc);
if (procSource)
pfree(procSource);
PG_RE_THROW();
}
PG_END_TRY();
return proc;
}
