greenplumn plpy_exec 源码
greenplumn plpy_exec 代码
文件路径：/src/pl/plpython/plpy_exec.c
/*
* executing Python code
*
* src/pl/plpython/plpy_exec.c
*/
#include "postgres.h"
#include "access/htup_details.h"
#include "access/xact.h"
#include "catalog/pg_type.h"
#include "commands/trigger.h"
#include "executor/spi.h"
#include "funcapi.h"
#include "utils/builtins.h"
#include "utils/lsyscache.h"
#include "utils/rel.h"
#include "utils/typcache.h"
#include "plpython.h"
#include "plpy_exec.h"
#include "plpy_elog.h"
#include "plpy_main.h"
#include "plpy_procedure.h"
#include "plpy_subxactobject.h"
/* saved state for a set-returning function */
typedef struct PLySRFState
{
PyObject *iter; /* Python iterator producing results */
PLySavedArgs *savedargs; /* function argument values */
MemoryContextCallback callback; /* for releasing refcounts when done */
} PLySRFState;
static PyObject *PLy_function_build_args(FunctionCallInfo fcinfo, PLyProcedure *proc);
static PLySavedArgs *PLy_function_save_args(PLyProcedure *proc);
static void PLy_function_restore_args(PLyProcedure *proc, PLySavedArgs *savedargs);
static void PLy_function_drop_args(PLySavedArgs *savedargs);
static void PLy_global_args_push(PLyProcedure *proc);
static void PLy_global_args_pop(PLyProcedure *proc);
static void plpython_srf_cleanup_callback(void *arg);
static void plpython_return_error_callback(void *arg);
static PyObject *PLy_trigger_build_args(FunctionCallInfo fcinfo, PLyProcedure *proc,
HeapTuple *rv);
static HeapTuple PLy_modify_tuple(PLyProcedure *proc, PyObject *pltd,
TriggerData *tdata, HeapTuple otup);
static void plpython_trigger_error_callback(void *arg);
static PyObject *PLy_procedure_call(PLyProcedure *proc, const char *kargs, PyObject *vargs);
static void PLy_abort_open_subtransactions(int save_subxact_level);
/* function subhandler */
Datum
PLy_exec_function(FunctionCallInfo fcinfo, PLyProcedure *proc)
{
bool is_setof = proc->is_setof;
Datum rv;
PyObject *volatile plargs = NULL;
PyObject *volatile plrv = NULL;
FuncCallContext *volatile funcctx = NULL;
PLySRFState *volatile srfstate = NULL;
ErrorContextCallback plerrcontext;
/*
* If the function is called recursively, we must push outer-level
* arguments into the stack. This must be immediately before the PG_TRY
* to ensure that the corresponding pop happens.
*/
PLy_global_args_push(proc);
PG_TRY();
{
if (is_setof)
{
/* First Call setup */
if (SRF_IS_FIRSTCALL())
{
funcctx = SRF_FIRSTCALL_INIT();
srfstate = (PLySRFState *)
MemoryContextAllocZero(funcctx->multi_call_memory_ctx,
sizeof(PLySRFState));
/* Immediately register cleanup callback */
srfstate->callback.func = plpython_srf_cleanup_callback;
srfstate->callback.arg = (void *) srfstate;
MemoryContextRegisterResetCallback(funcctx->multi_call_memory_ctx,
&srfstate->callback);
funcctx->user_fctx = (void *) srfstate;
}
/* Every call setup */
funcctx = SRF_PERCALL_SETUP();
Assert(funcctx != NULL);
srfstate = (PLySRFState *) funcctx->user_fctx;
Assert(srfstate != NULL);
}
if (srfstate == NULL || srfstate->iter == NULL)
{
/*
* Non-SETOF function or first time for SETOF function: build
* args, then actually execute the function.
*/
plargs = PLy_function_build_args(fcinfo, proc);
plrv = PLy_procedure_call(proc, "args", plargs);
Assert(plrv != NULL);
}
else
{
/*
* Second or later call for a SETOF function: restore arguments in
* globals dict to what they were when we left off. We must do
* this in case multiple evaluations of the same SETOF function
* are interleaved. It's a bit annoying, since the iterator may
* not look at the arguments at all, but we have no way to know
* that. Fortunately this isn't terribly expensive.
*/
if (srfstate->savedargs)
PLy_function_restore_args(proc, srfstate->savedargs);
srfstate->savedargs = NULL; /* deleted by restore_args */
}
/*
* If it returns a set, call the iterator to get the next return item.
* We stay in the SPI context while doing this, because PyIter_Next()
* calls back into Python code which might contain SPI calls.
*/
if (is_setof)
{
if (srfstate->iter == NULL)
{
/* first time -- do checks and setup */
ReturnSetInfo *rsi = (ReturnSetInfo *) fcinfo->resultinfo;
if (!rsi || !IsA(rsi, ReturnSetInfo) ||
(rsi->allowedModes & SFRM_ValuePerCall) == 0)
{
ereport(ERROR,
(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
errmsg("unsupported set function return mode"),
errdetail("PL/Python set-returning functions only support returning one value per call.")));
}
rsi->returnMode = SFRM_ValuePerCall;
/* Make iterator out of returned object */
srfstate->iter = PyObject_GetIter(plrv);
Py_DECREF(plrv);
plrv = NULL;
if (srfstate->iter == NULL)
ereport(ERROR,
(errcode(ERRCODE_DATATYPE_MISMATCH),
errmsg("returned object cannot be iterated"),
errdetail("PL/Python set-returning functions must return an iterable object.")));
}
/* Fetch next from iterator */
plrv = PyIter_Next(srfstate->iter);
if (plrv == NULL)
{
/* Iterator is exhausted or error happened */
bool has_error = (PyErr_Occurred() != NULL);
Py_DECREF(srfstate->iter);
srfstate->iter = NULL;
if (has_error)
PLy_elog(ERROR, "function \"%s\" error fetching next item from iterator", proc->proname);
/* Pass a null through the data-returning steps below */
Py_INCREF(Py_None);
plrv = Py_None;
}
else
{
/*
* This won't be last call, so save argument values. We do
* this again each time in case the iterator is changing those
* values.
*/
srfstate->savedargs = PLy_function_save_args(proc);
}
}
/*
* Disconnect from SPI manager and then create the return values datum
* (if the input function does a palloc for it this must not be
* allocated in the SPI memory context because SPI_finish would free
* it).
*/
if (SPI_finish() != SPI_OK_FINISH)
elog(ERROR, "SPI_finish failed");
plerrcontext.callback = plpython_return_error_callback;
plerrcontext.previous = error_context_stack;
error_context_stack = &plerrcontext;
/*
* For a procedure or function declared to return void, the Python
* return value must be None. For void-returning functions, we also
* treat a None return value as a special "void datum" rather than
* NULL (as is the case for non-void-returning functions).
*/
if (proc->result.typoid == VOIDOID)
{
if (plrv != Py_None)
{
if (proc->is_procedure)
ereport(ERROR,
(errcode(ERRCODE_DATATYPE_MISMATCH),
errmsg("PL/Python procedure did not return None")));
else
ereport(ERROR,
(errcode(ERRCODE_DATATYPE_MISMATCH),
errmsg("PL/Python function with return type \"void\" did not return None")));
}
fcinfo->isnull = false;
rv = (Datum) 0;
}
else if (plrv == Py_None &&
srfstate && srfstate->iter == NULL)
{
/*
* In a SETOF function, the iteration-ending null isn't a real
* value; don't pass it through the input function, which might
* complain.
*/
fcinfo->isnull = true;
rv = (Datum) 0;
}
else
{
/* Normal conversion of result */
rv = PLy_output_convert(&proc->result, plrv,
&fcinfo->isnull);
}
}
PG_CATCH();
{
/* Pop old arguments from the stack if they were pushed above */
PLy_global_args_pop(proc);
Py_XDECREF(plargs);
Py_XDECREF(plrv);
/*
* If there was an error within a SRF, the iterator might not have
* been exhausted yet. Clear it so the next invocation of the
* function will start the iteration again. (This code is probably
* unnecessary now; plpython_srf_cleanup_callback should take care of
* cleanup. But it doesn't hurt anything to do it here.)
*/
if (srfstate)
{
Py_XDECREF(srfstate->iter);
srfstate->iter = NULL;
/* And drop any saved args; we won't need them */
if (srfstate->savedargs)
PLy_function_drop_args(srfstate->savedargs);
srfstate->savedargs = NULL;
}
PG_RE_THROW();
}
PG_END_TRY();
error_context_stack = plerrcontext.previous;
/* Pop old arguments from the stack if they were pushed above */
PLy_global_args_pop(proc);
Py_XDECREF(plargs);
Py_DECREF(plrv);
if (srfstate)
{
/* We're in a SRF, exit appropriately */
if (srfstate->iter == NULL)
{
/* Iterator exhausted, so we're done */
SRF_RETURN_DONE(funcctx);
}
else if (fcinfo->isnull)
SRF_RETURN_NEXT_NULL(funcctx);
else
SRF_RETURN_NEXT(funcctx, rv);
}
/* Plain function, just return the Datum value (possibly null) */
return rv;
}
/* trigger subhandler
*
* the python function is expected to return Py_None if the tuple is
* acceptable and unmodified. Otherwise it should return a PyString
* object who's value is SKIP, or MODIFY. SKIP means don't perform
* this action. MODIFY means the tuple has been modified, so update
* tuple and perform action. SKIP and MODIFY assume the trigger fires
* BEFORE the event and is ROW level. postgres expects the function
* to take no arguments and return an argument of type trigger.
*/
HeapTuple
PLy_exec_trigger(FunctionCallInfo fcinfo, PLyProcedure *proc)
{
HeapTuple rv = NULL;
PyObject *volatile plargs = NULL;
PyObject *volatile plrv = NULL;
TriggerData *tdata;
TupleDesc rel_descr;
Assert(CALLED_AS_TRIGGER(fcinfo));
tdata = (TriggerData *) fcinfo->context;
/*
* Input/output conversion for trigger tuples. We use the result and
* result_in fields to store the tuple conversion info. We do this over
* again on each call to cover the possibility that the relation's tupdesc
* changed since the trigger was last called. The PLy_xxx_setup_func
* calls should only happen once, but PLy_input_setup_tuple and
* PLy_output_setup_tuple are responsible for not doing repetitive work.
*/
rel_descr = RelationGetDescr(tdata->tg_relation);
if (proc->result.typoid != rel_descr->tdtypeid)
PLy_output_setup_func(&proc->result, proc->mcxt,
rel_descr->tdtypeid,
rel_descr->tdtypmod,
proc);
if (proc->result_in.typoid != rel_descr->tdtypeid)
PLy_input_setup_func(&proc->result_in, proc->mcxt,
rel_descr->tdtypeid,
rel_descr->tdtypmod,
proc);
PLy_output_setup_tuple(&proc->result, rel_descr, proc);
PLy_input_setup_tuple(&proc->result_in, rel_descr, proc);
PG_TRY();
{
int rc PG_USED_FOR_ASSERTS_ONLY;
rc = SPI_register_trigger_data(tdata);
Assert(rc >= 0);
plargs = PLy_trigger_build_args(fcinfo, proc, &rv);
plrv = PLy_procedure_call(proc, "TD", plargs);
Assert(plrv != NULL);
/*
* Disconnect from SPI manager
*/
if (SPI_finish() != SPI_OK_FINISH)
elog(ERROR, "SPI_finish failed");
/*
* return of None means we're happy with the tuple
*/
if (plrv != Py_None)
{
char *srv;
if (PyString_Check(plrv))
srv = PyString_AsString(plrv);
else if (PyUnicode_Check(plrv))
srv = PLyUnicode_AsString(plrv);
else
{
ereport(ERROR,
(errcode(ERRCODE_DATA_EXCEPTION),
errmsg("unexpected return value from trigger procedure"),
errdetail("Expected None or a string.")));
srv = NULL; /* keep compiler quiet */
}
if (pg_strcasecmp(srv, "SKIP") == 0)
rv = NULL;
else if (pg_strcasecmp(srv, "MODIFY") == 0)
{
TriggerData *tdata = (TriggerData *) fcinfo->context;
if (TRIGGER_FIRED_BY_INSERT(tdata->tg_event) ||
TRIGGER_FIRED_BY_UPDATE(tdata->tg_event))
rv = PLy_modify_tuple(proc, plargs, tdata, rv);
else
ereport(WARNING,
(errmsg("PL/Python trigger function returned \"MODIFY\" in a DELETE trigger -- ignored")));
}
else if (pg_strcasecmp(srv, "OK") != 0)
{
/*
* accept "OK" as an alternative to None; otherwise, raise an
* error
*/
ereport(ERROR,
(errcode(ERRCODE_DATA_EXCEPTION),
errmsg("unexpected return value from trigger procedure"),
errdetail("Expected None, \"OK\", \"SKIP\", or \"MODIFY\".")));
}
}
}
PG_CATCH();
{
Py_XDECREF(plargs);
Py_XDECREF(plrv);
PG_RE_THROW();
}
PG_END_TRY();
Py_DECREF(plargs);
Py_DECREF(plrv);
return rv;
}
/* helper functions for Python code execution */
static PyObject *
PLy_function_build_args(FunctionCallInfo fcinfo, PLyProcedure *proc)
{
PyObject *volatile arg = NULL;
PyObject *volatile args = NULL;
int i;
PG_TRY();
{
args = PyList_New(proc->nargs);
if (!args)
return NULL;
for (i = 0; i < proc->nargs; i++)
{
PLyDatumToOb *arginfo = &proc->args[i];
if (fcinfo->args[i].isnull)
arg = NULL;
else
arg = PLy_input_convert(arginfo, fcinfo->args[i].value);
if (arg == NULL)
{
Py_INCREF(Py_None);
arg = Py_None;
}
if (PyList_SetItem(args, i, arg) == -1)
PLy_elog(ERROR, "PyList_SetItem() failed, while setting up arguments");
if (proc->argnames && proc->argnames[i] &&
PyDict_SetItemString(proc->globals, proc->argnames[i], arg) == -1)
PLy_elog(ERROR, "PyDict_SetItemString() failed, while setting up arguments");
arg = NULL;
}
/* Set up output conversion for functions returning RECORD */
if (proc->result.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_setup_record(&proc->result, desc, proc);
}
}
PG_CATCH();
{
Py_XDECREF(arg);
Py_XDECREF(args);
PG_RE_THROW();
}
PG_END_TRY();
return args;
}
/*
* Construct a PLySavedArgs struct representing the current values of the
* procedure's arguments in its globals dict. This can be used to restore
* those values when exiting a recursive call level or returning control to a
* set-returning function.
*
* This would not be necessary except for an ancient decision to make args
* available via the proc's globals :-( ... but we're stuck with that now.
*/
static PLySavedArgs *
PLy_function_save_args(PLyProcedure *proc)
{
PLySavedArgs *result;
/* saved args are always allocated in procedure's context */
result = (PLySavedArgs *)
MemoryContextAllocZero(proc->mcxt,
offsetof(PLySavedArgs, namedargs) +
proc->nargs * sizeof(PyObject *));
result->nargs = proc->nargs;
/* Fetch the "args" list */
result->args = PyDict_GetItemString(proc->globals, "args");
Py_XINCREF(result->args);
/* Fetch all the named arguments */
if (proc->argnames)
{
int i;
for (i = 0; i < result->nargs; i++)
{
if (proc->argnames[i])
{
result->namedargs[i] = PyDict_GetItemString(proc->globals,
proc->argnames[i]);
Py_XINCREF(result->namedargs[i]);
}
}
}
return result;
}
/*
* Restore procedure's arguments from a PLySavedArgs struct,
* then free the struct.
*/
static void
PLy_function_restore_args(PLyProcedure *proc, PLySavedArgs *savedargs)
{
/* Restore named arguments into their slots in the globals dict */
if (proc->argnames)
{
int i;
for (i = 0; i < savedargs->nargs; i++)
{
if (proc->argnames[i] && savedargs->namedargs[i])
{
PyDict_SetItemString(proc->globals, proc->argnames[i],
savedargs->namedargs[i]);
Py_DECREF(savedargs->namedargs[i]);
}
}
}
/* Restore the "args" object, too */
if (savedargs->args)
{
PyDict_SetItemString(proc->globals, "args", savedargs->args);
Py_DECREF(savedargs->args);
}
/* And free the PLySavedArgs struct */
pfree(savedargs);
}
/*
* Free a PLySavedArgs struct without restoring the values.
*/
static void
PLy_function_drop_args(PLySavedArgs *savedargs)
{
int i;
/* Drop references for named args */
for (i = 0; i < savedargs->nargs; i++)
{
Py_XDECREF(savedargs->namedargs[i]);
}
/* Drop ref to the "args" object, too */
Py_XDECREF(savedargs->args);
/* And free the PLySavedArgs struct */
pfree(savedargs);
}
/*
* Save away any existing arguments for the given procedure, so that we can
* install new values for a recursive call. This should be invoked before
* doing PLy_function_build_args().
*
* NB: caller must ensure that PLy_global_args_pop gets invoked once, and
* only once, per successful completion of PLy_global_args_push. Otherwise
* we'll end up out-of-sync between the actual call stack and the contents
* of proc->argstack.
*/
static void
PLy_global_args_push(PLyProcedure *proc)
{
/* We only need to push if we are already inside some active call */
if (proc->calldepth > 0)
{
PLySavedArgs *node;
/* Build a struct containing current argument values */
node = PLy_function_save_args(proc);
/*
* Push the saved argument values into the procedure's stack. Once we
* modify either proc->argstack or proc->calldepth, we had better
* return without the possibility of error.
*/
node->next = proc->argstack;
proc->argstack = node;
}
proc->calldepth++;
}
/*
* Pop old arguments when exiting a recursive call.
*
* Note: the idea here is to adjust the proc's callstack state before doing
* anything that could possibly fail. In event of any error, we want the
* callstack to look like we've done the pop. Leaking a bit of memory is
* tolerable.
*/
static void
PLy_global_args_pop(PLyProcedure *proc)
{
Assert(proc->calldepth > 0);
/* We only need to pop if we were already inside some active call */
if (proc->calldepth > 1)
{
PLySavedArgs *ptr = proc->argstack;
/* Pop the callstack */
Assert(ptr != NULL);
proc->argstack = ptr->next;
proc->calldepth--;
/* Restore argument values, then free ptr */
PLy_function_restore_args(proc, ptr);
}
else
{
/* Exiting call depth 1 */
Assert(proc->argstack == NULL);
proc->calldepth--;
/*
* We used to delete the named arguments (but not "args") from the
* proc's globals dict when exiting the outermost call level for a
* function. This seems rather pointless though: nothing can see the
* dict until the function is called again, at which time we'll
* overwrite those dict entries. So don't bother with that.
*/
}
}
/*
* Memory context deletion callback for cleaning up a PLySRFState.
* We need this in case execution of the SRF is terminated early,
* due to error or the caller simply not running it to completion.
*/
static void
plpython_srf_cleanup_callback(void *arg)
{
PLySRFState *srfstate = (PLySRFState *) arg;
/* Release refcount on the iter, if we still have one */
Py_XDECREF(srfstate->iter);
srfstate->iter = NULL;
/* And drop any saved args; we won't need them */
if (srfstate->savedargs)
PLy_function_drop_args(srfstate->savedargs);
srfstate->savedargs = NULL;
}
static void
plpython_return_error_callback(void *arg)
{
PLyExecutionContext *exec_ctx = PLy_current_execution_context();
if (exec_ctx->curr_proc &&
!exec_ctx->curr_proc->is_procedure)
errcontext("while creating return value");
}
static PyObject *
PLy_trigger_build_args(FunctionCallInfo fcinfo, PLyProcedure *proc, HeapTuple *rv)
{
TriggerData *tdata = (TriggerData *) fcinfo->context;
TupleDesc rel_descr = RelationGetDescr(tdata->tg_relation);
PyObject *pltname,
*pltevent,
*pltwhen,
*pltlevel,
*pltrelid,
*plttablename,
*plttableschema;
PyObject *pltargs,
*pytnew,
*pytold;
PyObject *volatile pltdata = NULL;
char *stroid;
PG_TRY();
{
pltdata = PyDict_New();
if (!pltdata)
return NULL;
pltname = PyString_FromString(tdata->tg_trigger->tgname);
PyDict_SetItemString(pltdata, "name", pltname);
Py_DECREF(pltname);
stroid = DatumGetCString(DirectFunctionCall1(oidout,
ObjectIdGetDatum(tdata->tg_relation->rd_id)));
pltrelid = PyString_FromString(stroid);
PyDict_SetItemString(pltdata, "relid", pltrelid);
Py_DECREF(pltrelid);
pfree(stroid);
stroid = SPI_getrelname(tdata->tg_relation);
plttablename = PyString_FromString(stroid);
PyDict_SetItemString(pltdata, "table_name", plttablename);
Py_DECREF(plttablename);
pfree(stroid);
stroid = SPI_getnspname(tdata->tg_relation);
plttableschema = PyString_FromString(stroid);
PyDict_SetItemString(pltdata, "table_schema", plttableschema);
Py_DECREF(plttableschema);
pfree(stroid);
if (TRIGGER_FIRED_BEFORE(tdata->tg_event))
pltwhen = PyString_FromString("BEFORE");
else if (TRIGGER_FIRED_AFTER(tdata->tg_event))
pltwhen = PyString_FromString("AFTER");
else if (TRIGGER_FIRED_INSTEAD(tdata->tg_event))
pltwhen = PyString_FromString("INSTEAD OF");
else
{
elog(ERROR, "unrecognized WHEN tg_event: %u", tdata->tg_event);
pltwhen = NULL; /* keep compiler quiet */
}
PyDict_SetItemString(pltdata, "when", pltwhen);
Py_DECREF(pltwhen);
if (TRIGGER_FIRED_FOR_ROW(tdata->tg_event))
{
pltlevel = PyString_FromString("ROW");
PyDict_SetItemString(pltdata, "level", pltlevel);
Py_DECREF(pltlevel);
/*
* Note: In BEFORE trigger, stored generated columns are not
* computed yet, so don't make them accessible in NEW row.
*/
if (TRIGGER_FIRED_BY_INSERT(tdata->tg_event))
{
pltevent = PyString_FromString("INSERT");
PyDict_SetItemString(pltdata, "old", Py_None);
pytnew = PLy_input_from_tuple(&proc->result_in,
tdata->tg_trigtuple,
rel_descr,
!TRIGGER_FIRED_BEFORE(tdata->tg_event));
PyDict_SetItemString(pltdata, "new", pytnew);
Py_DECREF(pytnew);
*rv = tdata->tg_trigtuple;
}
else if (TRIGGER_FIRED_BY_DELETE(tdata->tg_event))
{
pltevent = PyString_FromString("DELETE");
PyDict_SetItemString(pltdata, "new", Py_None);
pytold = PLy_input_from_tuple(&proc->result_in,
tdata->tg_trigtuple,
rel_descr,
true);
PyDict_SetItemString(pltdata, "old", pytold);
Py_DECREF(pytold);
*rv = tdata->tg_trigtuple;
}
else if (TRIGGER_FIRED_BY_UPDATE(tdata->tg_event))
{
pltevent = PyString_FromString("UPDATE");
pytnew = PLy_input_from_tuple(&proc->result_in,
tdata->tg_newtuple,
rel_descr,
!TRIGGER_FIRED_BEFORE(tdata->tg_event));
PyDict_SetItemString(pltdata, "new", pytnew);
Py_DECREF(pytnew);
pytold = PLy_input_from_tuple(&proc->result_in,
tdata->tg_trigtuple,
rel_descr,
true);
PyDict_SetItemString(pltdata, "old", pytold);
Py_DECREF(pytold);
*rv = tdata->tg_newtuple;
}
else
{
elog(ERROR, "unrecognized OP tg_event: %u", tdata->tg_event);
pltevent = NULL; /* keep compiler quiet */
}
PyDict_SetItemString(pltdata, "event", pltevent);
Py_DECREF(pltevent);
}
else if (TRIGGER_FIRED_FOR_STATEMENT(tdata->tg_event))
{
pltlevel = PyString_FromString("STATEMENT");
PyDict_SetItemString(pltdata, "level", pltlevel);
Py_DECREF(pltlevel);
PyDict_SetItemString(pltdata, "old", Py_None);
PyDict_SetItemString(pltdata, "new", Py_None);
*rv = NULL;
if (TRIGGER_FIRED_BY_INSERT(tdata->tg_event))
pltevent = PyString_FromString("INSERT");
else if (TRIGGER_FIRED_BY_DELETE(tdata->tg_event))
pltevent = PyString_FromString("DELETE");
else if (TRIGGER_FIRED_BY_UPDATE(tdata->tg_event))
pltevent = PyString_FromString("UPDATE");
else if (TRIGGER_FIRED_BY_TRUNCATE(tdata->tg_event))
pltevent = PyString_FromString("TRUNCATE");
else
{
elog(ERROR, "unrecognized OP tg_event: %u", tdata->tg_event);
pltevent = NULL; /* keep compiler quiet */
}
PyDict_SetItemString(pltdata, "event", pltevent);
Py_DECREF(pltevent);
}
else
elog(ERROR, "unrecognized LEVEL tg_event: %u", tdata->tg_event);
if (tdata->tg_trigger->tgnargs)
{
/*
* all strings...
*/
int i;
PyObject *pltarg;
pltargs = PyList_New(tdata->tg_trigger->tgnargs);
if (!pltargs)
{
Py_DECREF(pltdata);
return NULL;
}
for (i = 0; i < tdata->tg_trigger->tgnargs; i++)
{
pltarg = PyString_FromString(tdata->tg_trigger->tgargs[i]);
/*
* stolen, don't Py_DECREF
*/
PyList_SetItem(pltargs, i, pltarg);
}
}
else
{
Py_INCREF(Py_None);
pltargs = Py_None;
}
PyDict_SetItemString(pltdata, "args", pltargs);
Py_DECREF(pltargs);
}
PG_CATCH();
{
Py_XDECREF(pltdata);
PG_RE_THROW();
}
PG_END_TRY();
return pltdata;
}
/*
* Apply changes requested by a MODIFY return from a trigger function.
*/
static HeapTuple
PLy_modify_tuple(PLyProcedure *proc, PyObject *pltd, TriggerData *tdata,
HeapTuple otup)
{
HeapTuple rtup;
PyObject *volatile plntup;
PyObject *volatile plkeys;
PyObject *volatile plval;
Datum *volatile modvalues;
bool *volatile modnulls;
bool *volatile modrepls;
ErrorContextCallback plerrcontext;
plerrcontext.callback = plpython_trigger_error_callback;
plerrcontext.previous = error_context_stack;
error_context_stack = &plerrcontext;
plntup = plkeys = plval = NULL;
modvalues = NULL;
modnulls = NULL;
modrepls = NULL;
PG_TRY();
{
TupleDesc tupdesc;
int nkeys,
i;
if ((plntup = PyDict_GetItemString(pltd, "new")) == NULL)
ereport(ERROR,
(errcode(ERRCODE_UNDEFINED_OBJECT),
errmsg("TD[\"new\"] deleted, cannot modify row")));
Py_INCREF(plntup);
if (!PyDict_Check(plntup))
ereport(ERROR,
(errcode(ERRCODE_DATATYPE_MISMATCH),
errmsg("TD[\"new\"] is not a dictionary")));
plkeys = PyDict_Keys(plntup);
nkeys = PyList_Size(plkeys);
tupdesc = RelationGetDescr(tdata->tg_relation);
modvalues = (Datum *) palloc0(tupdesc->natts * sizeof(Datum));
modnulls = (bool *) palloc0(tupdesc->natts * sizeof(bool));
modrepls = (bool *) palloc0(tupdesc->natts * sizeof(bool));
for (i = 0; i < nkeys; i++)
{
PyObject *platt;
char *plattstr;
int attn;
PLyObToDatum *att;
platt = PyList_GetItem(plkeys, i);
if (PyString_Check(platt))
plattstr = PyString_AsString(platt);
else if (PyUnicode_Check(platt))
plattstr = PLyUnicode_AsString(platt);
else
{
ereport(ERROR,
(errcode(ERRCODE_DATATYPE_MISMATCH),
errmsg("TD[\"new\"] dictionary key at ordinal position %d is not a string", i)));
plattstr = NULL; /* keep compiler quiet */
}
attn = SPI_fnumber(tupdesc, plattstr);
if (attn == SPI_ERROR_NOATTRIBUTE)
ereport(ERROR,
(errcode(ERRCODE_UNDEFINED_COLUMN),
errmsg("key \"%s\" found in TD[\"new\"] does not exist as a column in the triggering row",
plattstr)));
if (attn <= 0)
ereport(ERROR,
(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
errmsg("cannot set system attribute \"%s\"",
plattstr)));
if (TupleDescAttr(tupdesc, attn - 1)->attgenerated)
ereport(ERROR,
(errcode(ERRCODE_E_R_I_E_TRIGGER_PROTOCOL_VIOLATED),
errmsg("cannot set generated column \"%s\"",
plattstr)));
plval = PyDict_GetItem(plntup, platt);
if (plval == NULL)
elog(FATAL, "Python interpreter is probably corrupted");
Py_INCREF(plval);
/* We assume proc->result is set up to convert tuples properly */
att = &proc->result.u.tuple.atts[attn - 1];
modvalues[attn - 1] = PLy_output_convert(att,
plval,
&modnulls[attn - 1]);
modrepls[attn - 1] = true;
Py_DECREF(plval);
plval = NULL;
}
rtup = heap_modify_tuple(otup, tupdesc, modvalues, modnulls, modrepls);
}
PG_CATCH();
{
Py_XDECREF(plntup);
Py_XDECREF(plkeys);
Py_XDECREF(plval);
if (modvalues)
pfree(modvalues);
if (modnulls)
pfree(modnulls);
if (modrepls)
pfree(modrepls);
PG_RE_THROW();
}
PG_END_TRY();
Py_DECREF(plntup);
Py_DECREF(plkeys);
pfree(modvalues);
pfree(modnulls);
pfree(modrepls);
error_context_stack = plerrcontext.previous;
return rtup;
}
static void
plpython_trigger_error_callback(void *arg)
{
PLyExecutionContext *exec_ctx = PLy_current_execution_context();
if (exec_ctx->curr_proc)
errcontext("while modifying trigger row");
}
/* execute Python code, propagate Python errors to the backend */
static PyObject *
PLy_procedure_call(PLyProcedure *proc, const char *kargs, PyObject *vargs)
{
PyObject *rv;
int volatile save_subxact_level = list_length(explicit_subtransactions);
PyDict_SetItemString(proc->globals, kargs, vargs);
PG_TRY();
{
PLy_enter_python_intepreter = true;
#if PY_VERSION_HEX >= 0x03020000
rv = PyEval_EvalCode(proc->code,
proc->globals, proc->globals);
#else
rv = PyEval_EvalCode((PyCodeObject *) proc->code,
proc->globals, proc->globals);
#endif
PLy_enter_python_intepreter = false;
/*
* Since plpy will only let you close subtransactions that you
* started, you cannot *unnest* subtransactions, only *nest* them
* without closing.
*/
Assert(list_length(explicit_subtransactions) >= save_subxact_level);
}
PG_CATCH();
{
PLy_enter_python_intepreter = false;
PLy_abort_open_subtransactions(save_subxact_level);
PG_RE_THROW();
}
PG_END_TRY();
PLy_abort_open_subtransactions(save_subxact_level);
/* If the Python code returned an error, propagate it */
if (rv == NULL)
PLy_elog(ERROR, NULL);
return rv;
}
/*
* Abort lingering subtransactions that have been explicitly started
* by plpy.subtransaction().start() and not properly closed.
*/
static void
PLy_abort_open_subtransactions(int save_subxact_level)
{
Assert(save_subxact_level >= 0);
while (list_length(explicit_subtransactions) > save_subxact_level)
{
PLySubtransactionData *subtransactiondata;
Assert(explicit_subtransactions != NIL);
ereport(WARNING,
(errmsg("forcibly aborting a subtransaction that has not been exited")));
RollbackAndReleaseCurrentSubTransaction();
subtransactiondata = (PLySubtransactionData *) linitial(explicit_subtransactions);
explicit_subtransactions = list_delete_first(explicit_subtransactions);
MemoryContextSwitchTo(subtransactiondata->oldcontext);
CurrentResourceOwner = subtransactiondata->oldowner;
pfree(subtransactiondata);
}
}
相关信息
相关文章
greenplumn plpy_cursorobject 源码
0
赞
热门推荐
-
2、 - 优质文章
-
3、 gate.io
-
7、 golang
-
9、 openharmony
-
10、 Vue中input框自动聚焦