Line data Source code
1 : /*
2 : * executing Python code
3 : *
4 : * src/pl/plpython/plpy_exec.c
5 : */
6 :
7 : #include "postgres.h"
8 :
9 : #include "access/htup_details.h"
10 : #include "access/xact.h"
11 : #include "catalog/pg_type.h"
12 : #include "commands/trigger.h"
13 : #include "executor/spi.h"
14 : #include "funcapi.h"
15 : #include "plpy_elog.h"
16 : #include "plpy_exec.h"
17 : #include "plpy_main.h"
18 : #include "plpy_procedure.h"
19 : #include "plpy_subxactobject.h"
20 : #include "plpython.h"
21 : #include "utils/builtins.h"
22 : #include "utils/lsyscache.h"
23 : #include "utils/rel.h"
24 : #include "utils/typcache.h"
25 :
26 : /* saved state for a set-returning function */
27 : typedef struct PLySRFState
28 : {
29 : PyObject *iter; /* Python iterator producing results */
30 : PLySavedArgs *savedargs; /* function argument values */
31 : MemoryContextCallback callback; /* for releasing refcounts when done */
32 : } PLySRFState;
33 :
34 : static PyObject *PLy_function_build_args(FunctionCallInfo fcinfo, PLyProcedure *proc);
35 : static PLySavedArgs *PLy_function_save_args(PLyProcedure *proc);
36 : static void PLy_function_restore_args(PLyProcedure *proc, PLySavedArgs *savedargs);
37 : static void PLy_function_drop_args(PLySavedArgs *savedargs);
38 : static void PLy_global_args_push(PLyProcedure *proc);
39 : static void PLy_global_args_pop(PLyProcedure *proc);
40 : static void plpython_srf_cleanup_callback(void *arg);
41 : static void plpython_return_error_callback(void *arg);
42 :
43 : static PyObject *PLy_trigger_build_args(FunctionCallInfo fcinfo, PLyProcedure *proc,
44 : HeapTuple *rv);
45 : static HeapTuple PLy_modify_tuple(PLyProcedure *proc, PyObject *pltd,
46 : TriggerData *tdata, HeapTuple otup);
47 : static void plpython_trigger_error_callback(void *arg);
48 :
49 : static PyObject *PLy_procedure_call(PLyProcedure *proc, const char *kargs, PyObject *vargs);
50 : static void PLy_abort_open_subtransactions(int save_subxact_level);
51 :
52 :
53 : /* function subhandler */
54 : Datum
55 1300 : PLy_exec_function(FunctionCallInfo fcinfo, PLyProcedure *proc)
56 : {
57 1300 : bool is_setof = proc->is_setof;
58 : Datum rv;
59 1300 : PyObject *volatile plargs = NULL;
60 1300 : PyObject *volatile plrv = NULL;
61 1300 : FuncCallContext *volatile funcctx = NULL;
62 1300 : PLySRFState *volatile srfstate = NULL;
63 : ErrorContextCallback plerrcontext;
64 :
65 : /*
66 : * If the function is called recursively, we must push outer-level
67 : * arguments into the stack. This must be immediately before the PG_TRY
68 : * to ensure that the corresponding pop happens.
69 : */
70 1300 : PLy_global_args_push(proc);
71 :
72 1300 : PG_TRY();
73 : {
74 1300 : if (is_setof)
75 : {
76 : /* First Call setup */
77 384 : if (SRF_IS_FIRSTCALL())
78 : {
79 98 : funcctx = SRF_FIRSTCALL_INIT();
80 98 : srfstate = (PLySRFState *)
81 98 : MemoryContextAllocZero(funcctx->multi_call_memory_ctx,
82 : sizeof(PLySRFState));
83 : /* Immediately register cleanup callback */
84 98 : srfstate->callback.func = plpython_srf_cleanup_callback;
85 98 : srfstate->callback.arg = (void *) srfstate;
86 98 : MemoryContextRegisterResetCallback(funcctx->multi_call_memory_ctx,
87 98 : &srfstate->callback);
88 98 : funcctx->user_fctx = (void *) srfstate;
89 : }
90 : /* Every call setup */
91 384 : funcctx = SRF_PERCALL_SETUP();
92 : Assert(funcctx != NULL);
93 384 : srfstate = (PLySRFState *) funcctx->user_fctx;
94 : Assert(srfstate != NULL);
95 : }
96 :
97 1300 : if (srfstate == NULL || srfstate->iter == NULL)
98 : {
99 : /*
100 : * Non-SETOF function or first time for SETOF function: build
101 : * args, then actually execute the function.
102 : */
103 1014 : plargs = PLy_function_build_args(fcinfo, proc);
104 1014 : plrv = PLy_procedure_call(proc, "args", plargs);
105 906 : Assert(plrv != NULL);
106 : }
107 : else
108 : {
109 : /*
110 : * Second or later call for a SETOF function: restore arguments in
111 : * globals dict to what they were when we left off. We must do
112 : * this in case multiple evaluations of the same SETOF function
113 : * are interleaved. It's a bit annoying, since the iterator may
114 : * not look at the arguments at all, but we have no way to know
115 : * that. Fortunately this isn't terribly expensive.
116 : */
117 286 : if (srfstate->savedargs)
118 286 : PLy_function_restore_args(proc, srfstate->savedargs);
119 286 : srfstate->savedargs = NULL; /* deleted by restore_args */
120 : }
121 :
122 : /*
123 : * If it returns a set, call the iterator to get the next return item.
124 : * We stay in the SPI context while doing this, because PyIter_Next()
125 : * calls back into Python code which might contain SPI calls.
126 : */
127 1192 : if (is_setof)
128 : {
129 382 : if (srfstate->iter == NULL)
130 : {
131 : /* first time -- do checks and setup */
132 96 : ReturnSetInfo *rsi = (ReturnSetInfo *) fcinfo->resultinfo;
133 :
134 96 : if (!rsi || !IsA(rsi, ReturnSetInfo) ||
135 96 : (rsi->allowedModes & SFRM_ValuePerCall) == 0)
136 : {
137 0 : ereport(ERROR,
138 : (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
139 : errmsg("unsupported set function return mode"),
140 : errdetail("PL/Python set-returning functions only support returning one value per call.")));
141 : }
142 96 : rsi->returnMode = SFRM_ValuePerCall;
143 :
144 : /* Make iterator out of returned object */
145 96 : srfstate->iter = PyObject_GetIter(plrv);
146 :
147 96 : Py_DECREF(plrv);
148 96 : plrv = NULL;
149 :
150 96 : if (srfstate->iter == NULL)
151 2 : ereport(ERROR,
152 : (errcode(ERRCODE_DATATYPE_MISMATCH),
153 : errmsg("returned object cannot be iterated"),
154 : errdetail("PL/Python set-returning functions must return an iterable object.")));
155 : }
156 :
157 : /* Fetch next from iterator */
158 380 : plrv = PyIter_Next(srfstate->iter);
159 380 : if (plrv == NULL)
160 : {
161 : /* Iterator is exhausted or error happened */
162 90 : bool has_error = (PyErr_Occurred() != NULL);
163 :
164 90 : Py_DECREF(srfstate->iter);
165 90 : srfstate->iter = NULL;
166 :
167 90 : if (has_error)
168 2 : PLy_elog(ERROR, "error fetching next item from iterator");
169 :
170 : /* Pass a null through the data-returning steps below */
171 88 : Py_INCREF(Py_None);
172 88 : plrv = Py_None;
173 : }
174 : else
175 : {
176 : /*
177 : * This won't be last call, so save argument values. We do
178 : * this again each time in case the iterator is changing those
179 : * values.
180 : */
181 290 : srfstate->savedargs = PLy_function_save_args(proc);
182 : }
183 : }
184 :
185 : /*
186 : * Disconnect from SPI manager and then create the return values datum
187 : * (if the input function does a palloc for it this must not be
188 : * allocated in the SPI memory context because SPI_finish would free
189 : * it).
190 : */
191 1188 : if (SPI_finish() != SPI_OK_FINISH)
192 0 : elog(ERROR, "SPI_finish failed");
193 :
194 1188 : plerrcontext.callback = plpython_return_error_callback;
195 1188 : plerrcontext.previous = error_context_stack;
196 1188 : error_context_stack = &plerrcontext;
197 :
198 : /*
199 : * For a procedure or function declared to return void, the Python
200 : * return value must be None. For void-returning functions, we also
201 : * treat a None return value as a special "void datum" rather than
202 : * NULL (as is the case for non-void-returning functions).
203 : */
204 1188 : if (proc->result.typoid == VOIDOID)
205 : {
206 58 : if (plrv != Py_None)
207 : {
208 4 : if (proc->is_procedure)
209 2 : ereport(ERROR,
210 : (errcode(ERRCODE_DATATYPE_MISMATCH),
211 : errmsg("PL/Python procedure did not return None")));
212 : else
213 2 : ereport(ERROR,
214 : (errcode(ERRCODE_DATATYPE_MISMATCH),
215 : errmsg("PL/Python function with return type \"void\" did not return None")));
216 : }
217 :
218 54 : fcinfo->isnull = false;
219 54 : rv = (Datum) 0;
220 : }
221 1130 : else if (plrv == Py_None &&
222 100 : srfstate && srfstate->iter == NULL)
223 : {
224 : /*
225 : * In a SETOF function, the iteration-ending null isn't a real
226 : * value; don't pass it through the input function, which might
227 : * complain.
228 : */
229 88 : fcinfo->isnull = true;
230 88 : rv = (Datum) 0;
231 : }
232 : else
233 : {
234 : /* Normal conversion of result */
235 1042 : rv = PLy_output_convert(&proc->result, plrv,
236 : &fcinfo->isnull);
237 : }
238 : }
239 184 : PG_CATCH();
240 : {
241 : /* Pop old arguments from the stack if they were pushed above */
242 184 : PLy_global_args_pop(proc);
243 :
244 184 : Py_XDECREF(plargs);
245 184 : Py_XDECREF(plrv);
246 :
247 : /*
248 : * If there was an error within a SRF, the iterator might not have
249 : * been exhausted yet. Clear it so the next invocation of the
250 : * function will start the iteration again. (This code is probably
251 : * unnecessary now; plpython_srf_cleanup_callback should take care of
252 : * cleanup. But it doesn't hurt anything to do it here.)
253 : */
254 184 : if (srfstate)
255 : {
256 10 : Py_XDECREF(srfstate->iter);
257 10 : srfstate->iter = NULL;
258 : /* And drop any saved args; we won't need them */
259 10 : if (srfstate->savedargs)
260 4 : PLy_function_drop_args(srfstate->savedargs);
261 10 : srfstate->savedargs = NULL;
262 : }
263 :
264 184 : PG_RE_THROW();
265 : }
266 1116 : PG_END_TRY();
267 :
268 1116 : error_context_stack = plerrcontext.previous;
269 :
270 : /* Pop old arguments from the stack if they were pushed above */
271 1116 : PLy_global_args_pop(proc);
272 :
273 1116 : Py_XDECREF(plargs);
274 1116 : Py_DECREF(plrv);
275 :
276 1116 : if (srfstate)
277 : {
278 : /* We're in a SRF, exit appropriately */
279 374 : if (srfstate->iter == NULL)
280 : {
281 : /* Iterator exhausted, so we're done */
282 88 : SRF_RETURN_DONE(funcctx);
283 : }
284 286 : else if (fcinfo->isnull)
285 12 : SRF_RETURN_NEXT_NULL(funcctx);
286 : else
287 274 : SRF_RETURN_NEXT(funcctx, rv);
288 : }
289 :
290 : /* Plain function, just return the Datum value (possibly null) */
291 742 : return rv;
292 : }
293 :
294 : /* trigger subhandler
295 : *
296 : * the python function is expected to return Py_None if the tuple is
297 : * acceptable and unmodified. Otherwise it should return a PyUnicode
298 : * object who's value is SKIP, or MODIFY. SKIP means don't perform
299 : * this action. MODIFY means the tuple has been modified, so update
300 : * tuple and perform action. SKIP and MODIFY assume the trigger fires
301 : * BEFORE the event and is ROW level. postgres expects the function
302 : * to take no arguments and return an argument of type trigger.
303 : */
304 : HeapTuple
305 98 : PLy_exec_trigger(FunctionCallInfo fcinfo, PLyProcedure *proc)
306 : {
307 98 : HeapTuple rv = NULL;
308 98 : PyObject *volatile plargs = NULL;
309 98 : PyObject *volatile plrv = NULL;
310 : TriggerData *tdata;
311 : TupleDesc rel_descr;
312 :
313 : Assert(CALLED_AS_TRIGGER(fcinfo));
314 98 : tdata = (TriggerData *) fcinfo->context;
315 :
316 : /*
317 : * Input/output conversion for trigger tuples. We use the result and
318 : * result_in fields to store the tuple conversion info. We do this over
319 : * again on each call to cover the possibility that the relation's tupdesc
320 : * changed since the trigger was last called. The PLy_xxx_setup_func
321 : * calls should only happen once, but PLy_input_setup_tuple and
322 : * PLy_output_setup_tuple are responsible for not doing repetitive work.
323 : */
324 98 : rel_descr = RelationGetDescr(tdata->tg_relation);
325 98 : if (proc->result.typoid != rel_descr->tdtypeid)
326 52 : PLy_output_setup_func(&proc->result, proc->mcxt,
327 : rel_descr->tdtypeid,
328 : rel_descr->tdtypmod,
329 : proc);
330 98 : if (proc->result_in.typoid != rel_descr->tdtypeid)
331 52 : PLy_input_setup_func(&proc->result_in, proc->mcxt,
332 : rel_descr->tdtypeid,
333 : rel_descr->tdtypmod,
334 : proc);
335 98 : PLy_output_setup_tuple(&proc->result, rel_descr, proc);
336 98 : PLy_input_setup_tuple(&proc->result_in, rel_descr, proc);
337 :
338 : /*
339 : * If the trigger is called recursively, we must push outer-level
340 : * arguments into the stack. This must be immediately before the PG_TRY
341 : * to ensure that the corresponding pop happens.
342 : */
343 98 : PLy_global_args_push(proc);
344 :
345 98 : PG_TRY();
346 : {
347 : int rc PG_USED_FOR_ASSERTS_ONLY;
348 :
349 98 : rc = SPI_register_trigger_data(tdata);
350 : Assert(rc >= 0);
351 :
352 98 : plargs = PLy_trigger_build_args(fcinfo, proc, &rv);
353 98 : plrv = PLy_procedure_call(proc, "TD", plargs);
354 :
355 : Assert(plrv != NULL);
356 :
357 : /*
358 : * Disconnect from SPI manager
359 : */
360 98 : if (SPI_finish() != SPI_OK_FINISH)
361 0 : elog(ERROR, "SPI_finish failed");
362 :
363 : /*
364 : * return of None means we're happy with the tuple
365 : */
366 98 : if (plrv != Py_None)
367 : {
368 : char *srv;
369 :
370 50 : if (PyUnicode_Check(plrv))
371 48 : srv = PLyUnicode_AsString(plrv);
372 : else
373 : {
374 2 : ereport(ERROR,
375 : (errcode(ERRCODE_DATA_EXCEPTION),
376 : errmsg("unexpected return value from trigger procedure"),
377 : errdetail("Expected None or a string.")));
378 : srv = NULL; /* keep compiler quiet */
379 : }
380 :
381 48 : if (pg_strcasecmp(srv, "SKIP") == 0)
382 2 : rv = NULL;
383 46 : else if (pg_strcasecmp(srv, "MODIFY") == 0)
384 : {
385 42 : if (TRIGGER_FIRED_BY_INSERT(tdata->tg_event) ||
386 18 : TRIGGER_FIRED_BY_UPDATE(tdata->tg_event))
387 40 : rv = PLy_modify_tuple(proc, plargs, tdata, rv);
388 : else
389 2 : ereport(WARNING,
390 : (errmsg("PL/Python trigger function returned \"MODIFY\" in a DELETE trigger -- ignored")));
391 : }
392 4 : else if (pg_strcasecmp(srv, "OK") != 0)
393 : {
394 : /*
395 : * accept "OK" as an alternative to None; otherwise, raise an
396 : * error
397 : */
398 4 : ereport(ERROR,
399 : (errcode(ERRCODE_DATA_EXCEPTION),
400 : errmsg("unexpected return value from trigger procedure"),
401 : errdetail("Expected None, \"OK\", \"SKIP\", or \"MODIFY\".")));
402 : }
403 : }
404 : }
405 18 : PG_FINALLY();
406 : {
407 98 : PLy_global_args_pop(proc);
408 98 : Py_XDECREF(plargs);
409 98 : Py_XDECREF(plrv);
410 : }
411 98 : PG_END_TRY();
412 :
413 80 : return rv;
414 : }
415 :
416 : /* helper functions for Python code execution */
417 :
418 : static PyObject *
419 1014 : PLy_function_build_args(FunctionCallInfo fcinfo, PLyProcedure *proc)
420 : {
421 1014 : PyObject *volatile arg = NULL;
422 : PyObject *args;
423 : int i;
424 :
425 : /*
426 : * Make any Py*_New() calls before the PG_TRY block so that we can quickly
427 : * return NULL on failure. We can't return within the PG_TRY block, else
428 : * we'd miss unwinding the exception stack.
429 : */
430 1014 : args = PyList_New(proc->nargs);
431 1014 : if (!args)
432 0 : return NULL;
433 :
434 1014 : PG_TRY();
435 : {
436 2424 : for (i = 0; i < proc->nargs; i++)
437 : {
438 1410 : PLyDatumToOb *arginfo = &proc->args[i];
439 :
440 1410 : if (fcinfo->args[i].isnull)
441 240 : arg = NULL;
442 : else
443 1170 : arg = PLy_input_convert(arginfo, fcinfo->args[i].value);
444 :
445 1410 : if (arg == NULL)
446 : {
447 240 : Py_INCREF(Py_None);
448 240 : arg = Py_None;
449 : }
450 :
451 1410 : if (PyList_SetItem(args, i, arg) == -1)
452 0 : PLy_elog(ERROR, "PyList_SetItem() failed, while setting up arguments");
453 :
454 1410 : if (proc->argnames && proc->argnames[i] &&
455 1404 : PyDict_SetItemString(proc->globals, proc->argnames[i], arg) == -1)
456 0 : PLy_elog(ERROR, "PyDict_SetItemString() failed, while setting up arguments");
457 1410 : arg = NULL;
458 : }
459 :
460 : /* Set up output conversion for functions returning RECORD */
461 1014 : if (proc->result.typoid == RECORDOID)
462 : {
463 : TupleDesc desc;
464 :
465 148 : if (get_call_result_type(fcinfo, NULL, &desc) != TYPEFUNC_COMPOSITE)
466 0 : ereport(ERROR,
467 : (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
468 : errmsg("function returning record called in context "
469 : "that cannot accept type record")));
470 :
471 : /* cache the output conversion functions */
472 148 : PLy_output_setup_record(&proc->result, desc, proc);
473 : }
474 : }
475 0 : PG_CATCH();
476 : {
477 0 : Py_XDECREF(arg);
478 0 : Py_XDECREF(args);
479 :
480 0 : PG_RE_THROW();
481 : }
482 1014 : PG_END_TRY();
483 :
484 1014 : return args;
485 : }
486 :
487 : /*
488 : * Construct a PLySavedArgs struct representing the current values of the
489 : * procedure's arguments in its globals dict. This can be used to restore
490 : * those values when exiting a recursive call level or returning control to a
491 : * set-returning function.
492 : *
493 : * This would not be necessary except for an ancient decision to make args
494 : * available via the proc's globals :-( ... but we're stuck with that now.
495 : */
496 : static PLySavedArgs *
497 310 : PLy_function_save_args(PLyProcedure *proc)
498 : {
499 : PLySavedArgs *result;
500 :
501 : /* saved args are always allocated in procedure's context */
502 : result = (PLySavedArgs *)
503 310 : MemoryContextAllocZero(proc->mcxt,
504 310 : offsetof(PLySavedArgs, namedargs) +
505 310 : proc->nargs * sizeof(PyObject *));
506 310 : result->nargs = proc->nargs;
507 :
508 : /* Fetch the "args" list */
509 310 : result->args = PyDict_GetItemString(proc->globals, "args");
510 310 : Py_XINCREF(result->args);
511 :
512 : /* If it's a trigger, also save "TD" */
513 310 : if (proc->is_trigger)
514 : {
515 2 : result->td = PyDict_GetItemString(proc->globals, "TD");
516 2 : Py_XINCREF(result->td);
517 : }
518 :
519 : /* Fetch all the named arguments */
520 310 : if (proc->argnames)
521 : {
522 : int i;
523 :
524 598 : for (i = 0; i < result->nargs; i++)
525 : {
526 414 : if (proc->argnames[i])
527 : {
528 828 : result->namedargs[i] = PyDict_GetItemString(proc->globals,
529 414 : proc->argnames[i]);
530 414 : Py_XINCREF(result->namedargs[i]);
531 : }
532 : }
533 : }
534 :
535 310 : return result;
536 : }
537 :
538 : /*
539 : * Restore procedure's arguments from a PLySavedArgs struct,
540 : * then free the struct.
541 : */
542 : static void
543 306 : PLy_function_restore_args(PLyProcedure *proc, PLySavedArgs *savedargs)
544 : {
545 : /* Restore named arguments into their slots in the globals dict */
546 306 : if (proc->argnames)
547 : {
548 : int i;
549 :
550 598 : for (i = 0; i < savedargs->nargs; i++)
551 : {
552 414 : if (proc->argnames[i] && savedargs->namedargs[i])
553 : {
554 414 : PyDict_SetItemString(proc->globals, proc->argnames[i],
555 : savedargs->namedargs[i]);
556 414 : Py_DECREF(savedargs->namedargs[i]);
557 : }
558 : }
559 : }
560 :
561 : /* Restore the "args" object, too */
562 306 : if (savedargs->args)
563 : {
564 304 : PyDict_SetItemString(proc->globals, "args", savedargs->args);
565 304 : Py_DECREF(savedargs->args);
566 : }
567 :
568 : /* Restore the "TD" object, too */
569 306 : if (savedargs->td)
570 : {
571 2 : PyDict_SetItemString(proc->globals, "TD", savedargs->td);
572 2 : Py_DECREF(savedargs->td);
573 : }
574 :
575 : /* And free the PLySavedArgs struct */
576 306 : pfree(savedargs);
577 306 : }
578 :
579 : /*
580 : * Free a PLySavedArgs struct without restoring the values.
581 : */
582 : static void
583 4 : PLy_function_drop_args(PLySavedArgs *savedargs)
584 : {
585 : int i;
586 :
587 : /* Drop references for named args */
588 4 : for (i = 0; i < savedargs->nargs; i++)
589 : {
590 0 : Py_XDECREF(savedargs->namedargs[i]);
591 : }
592 :
593 : /* Drop refs to the "args" and "TD" objects, too */
594 4 : Py_XDECREF(savedargs->args);
595 4 : Py_XDECREF(savedargs->td);
596 :
597 : /* And free the PLySavedArgs struct */
598 4 : pfree(savedargs);
599 4 : }
600 :
601 : /*
602 : * Save away any existing arguments for the given procedure, so that we can
603 : * install new values for a recursive call. This should be invoked before
604 : * doing PLy_function_build_args() or PLy_trigger_build_args().
605 : *
606 : * NB: callers must ensure that PLy_global_args_pop gets invoked once, and
607 : * only once, per successful completion of PLy_global_args_push. Otherwise
608 : * we'll end up out-of-sync between the actual call stack and the contents
609 : * of proc->argstack.
610 : */
611 : static void
612 1398 : PLy_global_args_push(PLyProcedure *proc)
613 : {
614 : /* We only need to push if we are already inside some active call */
615 1398 : if (proc->calldepth > 0)
616 : {
617 : PLySavedArgs *node;
618 :
619 : /* Build a struct containing current argument values */
620 20 : node = PLy_function_save_args(proc);
621 :
622 : /*
623 : * Push the saved argument values into the procedure's stack. Once we
624 : * modify either proc->argstack or proc->calldepth, we had better
625 : * return without the possibility of error.
626 : */
627 20 : node->next = proc->argstack;
628 20 : proc->argstack = node;
629 : }
630 1398 : proc->calldepth++;
631 1398 : }
632 :
633 : /*
634 : * Pop old arguments when exiting a recursive call.
635 : *
636 : * Note: the idea here is to adjust the proc's callstack state before doing
637 : * anything that could possibly fail. In event of any error, we want the
638 : * callstack to look like we've done the pop. Leaking a bit of memory is
639 : * tolerable.
640 : */
641 : static void
642 1398 : PLy_global_args_pop(PLyProcedure *proc)
643 : {
644 : Assert(proc->calldepth > 0);
645 : /* We only need to pop if we were already inside some active call */
646 1398 : if (proc->calldepth > 1)
647 : {
648 20 : PLySavedArgs *ptr = proc->argstack;
649 :
650 : /* Pop the callstack */
651 : Assert(ptr != NULL);
652 20 : proc->argstack = ptr->next;
653 20 : proc->calldepth--;
654 :
655 : /* Restore argument values, then free ptr */
656 20 : PLy_function_restore_args(proc, ptr);
657 : }
658 : else
659 : {
660 : /* Exiting call depth 1 */
661 : Assert(proc->argstack == NULL);
662 1378 : proc->calldepth--;
663 :
664 : /*
665 : * We used to delete the named arguments (but not "args") from the
666 : * proc's globals dict when exiting the outermost call level for a
667 : * function. This seems rather pointless though: nothing can see the
668 : * dict until the function is called again, at which time we'll
669 : * overwrite those dict entries. So don't bother with that.
670 : */
671 : }
672 1398 : }
673 :
674 : /*
675 : * Memory context deletion callback for cleaning up a PLySRFState.
676 : * We need this in case execution of the SRF is terminated early,
677 : * due to error or the caller simply not running it to completion.
678 : */
679 : static void
680 98 : plpython_srf_cleanup_callback(void *arg)
681 : {
682 98 : PLySRFState *srfstate = (PLySRFState *) arg;
683 :
684 : /* Release refcount on the iter, if we still have one */
685 98 : Py_XDECREF(srfstate->iter);
686 98 : srfstate->iter = NULL;
687 : /* And drop any saved args; we won't need them */
688 98 : if (srfstate->savedargs)
689 0 : PLy_function_drop_args(srfstate->savedargs);
690 98 : srfstate->savedargs = NULL;
691 98 : }
692 :
693 : static void
694 74 : plpython_return_error_callback(void *arg)
695 : {
696 74 : PLyExecutionContext *exec_ctx = PLy_current_execution_context();
697 :
698 74 : if (exec_ctx->curr_proc &&
699 74 : !exec_ctx->curr_proc->is_procedure)
700 72 : errcontext("while creating return value");
701 74 : }
702 :
703 : static PyObject *
704 98 : PLy_trigger_build_args(FunctionCallInfo fcinfo, PLyProcedure *proc, HeapTuple *rv)
705 : {
706 98 : TriggerData *tdata = (TriggerData *) fcinfo->context;
707 98 : TupleDesc rel_descr = RelationGetDescr(tdata->tg_relation);
708 : PyObject *pltname,
709 : *pltevent,
710 : *pltwhen,
711 : *pltlevel,
712 : *pltrelid,
713 : *plttablename,
714 : *plttableschema,
715 : *pltargs,
716 : *pytnew,
717 : *pytold,
718 : *pltdata;
719 : char *stroid;
720 :
721 : /*
722 : * Make any Py*_New() calls before the PG_TRY block so that we can quickly
723 : * return NULL on failure. We can't return within the PG_TRY block, else
724 : * we'd miss unwinding the exception stack.
725 : */
726 98 : pltdata = PyDict_New();
727 98 : if (!pltdata)
728 0 : return NULL;
729 :
730 98 : if (tdata->tg_trigger->tgnargs)
731 : {
732 32 : pltargs = PyList_New(tdata->tg_trigger->tgnargs);
733 32 : if (!pltargs)
734 : {
735 0 : Py_DECREF(pltdata);
736 0 : return NULL;
737 : }
738 : }
739 : else
740 : {
741 66 : Py_INCREF(Py_None);
742 66 : pltargs = Py_None;
743 : }
744 :
745 98 : PG_TRY();
746 : {
747 98 : pltname = PLyUnicode_FromString(tdata->tg_trigger->tgname);
748 98 : PyDict_SetItemString(pltdata, "name", pltname);
749 98 : Py_DECREF(pltname);
750 :
751 98 : stroid = DatumGetCString(DirectFunctionCall1(oidout,
752 : ObjectIdGetDatum(tdata->tg_relation->rd_id)));
753 98 : pltrelid = PLyUnicode_FromString(stroid);
754 98 : PyDict_SetItemString(pltdata, "relid", pltrelid);
755 98 : Py_DECREF(pltrelid);
756 98 : pfree(stroid);
757 :
758 98 : stroid = SPI_getrelname(tdata->tg_relation);
759 98 : plttablename = PLyUnicode_FromString(stroid);
760 98 : PyDict_SetItemString(pltdata, "table_name", plttablename);
761 98 : Py_DECREF(plttablename);
762 98 : pfree(stroid);
763 :
764 98 : stroid = SPI_getnspname(tdata->tg_relation);
765 98 : plttableschema = PLyUnicode_FromString(stroid);
766 98 : PyDict_SetItemString(pltdata, "table_schema", plttableschema);
767 98 : Py_DECREF(plttableschema);
768 98 : pfree(stroid);
769 :
770 98 : if (TRIGGER_FIRED_BEFORE(tdata->tg_event))
771 72 : pltwhen = PLyUnicode_FromString("BEFORE");
772 26 : else if (TRIGGER_FIRED_AFTER(tdata->tg_event))
773 20 : pltwhen = PLyUnicode_FromString("AFTER");
774 6 : else if (TRIGGER_FIRED_INSTEAD(tdata->tg_event))
775 6 : pltwhen = PLyUnicode_FromString("INSTEAD OF");
776 : else
777 : {
778 0 : elog(ERROR, "unrecognized WHEN tg_event: %u", tdata->tg_event);
779 : pltwhen = NULL; /* keep compiler quiet */
780 : }
781 98 : PyDict_SetItemString(pltdata, "when", pltwhen);
782 98 : Py_DECREF(pltwhen);
783 :
784 98 : if (TRIGGER_FIRED_FOR_ROW(tdata->tg_event))
785 : {
786 88 : pltlevel = PLyUnicode_FromString("ROW");
787 88 : PyDict_SetItemString(pltdata, "level", pltlevel);
788 88 : Py_DECREF(pltlevel);
789 :
790 : /*
791 : * Note: In BEFORE trigger, stored generated columns are not
792 : * computed yet, so don't make them accessible in NEW row.
793 : */
794 :
795 88 : if (TRIGGER_FIRED_BY_INSERT(tdata->tg_event))
796 : {
797 42 : pltevent = PLyUnicode_FromString("INSERT");
798 :
799 42 : PyDict_SetItemString(pltdata, "old", Py_None);
800 84 : pytnew = PLy_input_from_tuple(&proc->result_in,
801 : tdata->tg_trigtuple,
802 : rel_descr,
803 42 : !TRIGGER_FIRED_BEFORE(tdata->tg_event));
804 42 : PyDict_SetItemString(pltdata, "new", pytnew);
805 42 : Py_DECREF(pytnew);
806 42 : *rv = tdata->tg_trigtuple;
807 : }
808 46 : else if (TRIGGER_FIRED_BY_DELETE(tdata->tg_event))
809 : {
810 12 : pltevent = PLyUnicode_FromString("DELETE");
811 :
812 12 : PyDict_SetItemString(pltdata, "new", Py_None);
813 12 : pytold = PLy_input_from_tuple(&proc->result_in,
814 : tdata->tg_trigtuple,
815 : rel_descr,
816 : true);
817 12 : PyDict_SetItemString(pltdata, "old", pytold);
818 12 : Py_DECREF(pytold);
819 12 : *rv = tdata->tg_trigtuple;
820 : }
821 34 : else if (TRIGGER_FIRED_BY_UPDATE(tdata->tg_event))
822 : {
823 34 : pltevent = PLyUnicode_FromString("UPDATE");
824 :
825 68 : pytnew = PLy_input_from_tuple(&proc->result_in,
826 : tdata->tg_newtuple,
827 : rel_descr,
828 34 : !TRIGGER_FIRED_BEFORE(tdata->tg_event));
829 34 : PyDict_SetItemString(pltdata, "new", pytnew);
830 34 : Py_DECREF(pytnew);
831 34 : pytold = PLy_input_from_tuple(&proc->result_in,
832 : tdata->tg_trigtuple,
833 : rel_descr,
834 : true);
835 34 : PyDict_SetItemString(pltdata, "old", pytold);
836 34 : Py_DECREF(pytold);
837 34 : *rv = tdata->tg_newtuple;
838 : }
839 : else
840 : {
841 0 : elog(ERROR, "unrecognized OP tg_event: %u", tdata->tg_event);
842 : pltevent = NULL; /* keep compiler quiet */
843 : }
844 :
845 88 : PyDict_SetItemString(pltdata, "event", pltevent);
846 88 : Py_DECREF(pltevent);
847 : }
848 10 : else if (TRIGGER_FIRED_FOR_STATEMENT(tdata->tg_event))
849 : {
850 10 : pltlevel = PLyUnicode_FromString("STATEMENT");
851 10 : PyDict_SetItemString(pltdata, "level", pltlevel);
852 10 : Py_DECREF(pltlevel);
853 :
854 10 : PyDict_SetItemString(pltdata, "old", Py_None);
855 10 : PyDict_SetItemString(pltdata, "new", Py_None);
856 10 : *rv = NULL;
857 :
858 10 : if (TRIGGER_FIRED_BY_INSERT(tdata->tg_event))
859 2 : pltevent = PLyUnicode_FromString("INSERT");
860 8 : else if (TRIGGER_FIRED_BY_DELETE(tdata->tg_event))
861 2 : pltevent = PLyUnicode_FromString("DELETE");
862 6 : else if (TRIGGER_FIRED_BY_UPDATE(tdata->tg_event))
863 4 : pltevent = PLyUnicode_FromString("UPDATE");
864 2 : else if (TRIGGER_FIRED_BY_TRUNCATE(tdata->tg_event))
865 2 : pltevent = PLyUnicode_FromString("TRUNCATE");
866 : else
867 : {
868 0 : elog(ERROR, "unrecognized OP tg_event: %u", tdata->tg_event);
869 : pltevent = NULL; /* keep compiler quiet */
870 : }
871 :
872 10 : PyDict_SetItemString(pltdata, "event", pltevent);
873 10 : Py_DECREF(pltevent);
874 : }
875 : else
876 0 : elog(ERROR, "unrecognized LEVEL tg_event: %u", tdata->tg_event);
877 :
878 98 : if (tdata->tg_trigger->tgnargs)
879 : {
880 : /*
881 : * all strings...
882 : */
883 : int i;
884 : PyObject *pltarg;
885 :
886 : /* pltargs should have been allocated before the PG_TRY block. */
887 : Assert(pltargs && pltargs != Py_None);
888 :
889 90 : for (i = 0; i < tdata->tg_trigger->tgnargs; i++)
890 : {
891 58 : pltarg = PLyUnicode_FromString(tdata->tg_trigger->tgargs[i]);
892 :
893 : /*
894 : * stolen, don't Py_DECREF
895 : */
896 58 : PyList_SetItem(pltargs, i, pltarg);
897 : }
898 : }
899 : else
900 : {
901 : Assert(pltargs == Py_None);
902 : }
903 98 : PyDict_SetItemString(pltdata, "args", pltargs);
904 98 : Py_DECREF(pltargs);
905 : }
906 0 : PG_CATCH();
907 : {
908 0 : Py_XDECREF(pltargs);
909 0 : Py_XDECREF(pltdata);
910 0 : PG_RE_THROW();
911 : }
912 98 : PG_END_TRY();
913 :
914 98 : return pltdata;
915 : }
916 :
917 : /*
918 : * Apply changes requested by a MODIFY return from a trigger function.
919 : */
920 : static HeapTuple
921 40 : PLy_modify_tuple(PLyProcedure *proc, PyObject *pltd, TriggerData *tdata,
922 : HeapTuple otup)
923 : {
924 : HeapTuple rtup;
925 : PyObject *volatile plntup;
926 : PyObject *volatile plkeys;
927 : PyObject *volatile plval;
928 : Datum *volatile modvalues;
929 : bool *volatile modnulls;
930 : bool *volatile modrepls;
931 : ErrorContextCallback plerrcontext;
932 :
933 40 : plerrcontext.callback = plpython_trigger_error_callback;
934 40 : plerrcontext.previous = error_context_stack;
935 40 : error_context_stack = &plerrcontext;
936 :
937 40 : plntup = plkeys = plval = NULL;
938 40 : modvalues = NULL;
939 40 : modnulls = NULL;
940 40 : modrepls = NULL;
941 :
942 40 : PG_TRY();
943 : {
944 : TupleDesc tupdesc;
945 : int nkeys,
946 : i;
947 :
948 40 : if ((plntup = PyDict_GetItemString(pltd, "new")) == NULL)
949 2 : ereport(ERROR,
950 : (errcode(ERRCODE_UNDEFINED_OBJECT),
951 : errmsg("TD[\"new\"] deleted, cannot modify row")));
952 38 : Py_INCREF(plntup);
953 38 : if (!PyDict_Check(plntup))
954 2 : ereport(ERROR,
955 : (errcode(ERRCODE_DATATYPE_MISMATCH),
956 : errmsg("TD[\"new\"] is not a dictionary")));
957 :
958 36 : plkeys = PyDict_Keys(plntup);
959 36 : nkeys = PyList_Size(plkeys);
960 :
961 36 : tupdesc = RelationGetDescr(tdata->tg_relation);
962 :
963 36 : modvalues = (Datum *) palloc0(tupdesc->natts * sizeof(Datum));
964 36 : modnulls = (bool *) palloc0(tupdesc->natts * sizeof(bool));
965 36 : modrepls = (bool *) palloc0(tupdesc->natts * sizeof(bool));
966 :
967 90 : for (i = 0; i < nkeys; i++)
968 : {
969 : PyObject *platt;
970 : char *plattstr;
971 : int attn;
972 : PLyObToDatum *att;
973 :
974 62 : platt = PyList_GetItem(plkeys, i);
975 62 : if (PyUnicode_Check(platt))
976 60 : plattstr = PLyUnicode_AsString(platt);
977 : else
978 : {
979 2 : ereport(ERROR,
980 : (errcode(ERRCODE_DATATYPE_MISMATCH),
981 : errmsg("TD[\"new\"] dictionary key at ordinal position %d is not a string", i)));
982 : plattstr = NULL; /* keep compiler quiet */
983 : }
984 60 : attn = SPI_fnumber(tupdesc, plattstr);
985 60 : if (attn == SPI_ERROR_NOATTRIBUTE)
986 4 : ereport(ERROR,
987 : (errcode(ERRCODE_UNDEFINED_COLUMN),
988 : errmsg("key \"%s\" found in TD[\"new\"] does not exist as a column in the triggering row",
989 : plattstr)));
990 56 : if (attn <= 0)
991 0 : ereport(ERROR,
992 : (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
993 : errmsg("cannot set system attribute \"%s\"",
994 : plattstr)));
995 56 : if (TupleDescAttr(tupdesc, attn - 1)->attgenerated)
996 2 : ereport(ERROR,
997 : (errcode(ERRCODE_E_R_I_E_TRIGGER_PROTOCOL_VIOLATED),
998 : errmsg("cannot set generated column \"%s\"",
999 : plattstr)));
1000 :
1001 54 : plval = PyDict_GetItem(plntup, platt);
1002 54 : if (plval == NULL)
1003 0 : elog(FATAL, "Python interpreter is probably corrupted");
1004 :
1005 54 : Py_INCREF(plval);
1006 :
1007 : /* We assume proc->result is set up to convert tuples properly */
1008 54 : att = &proc->result.u.tuple.atts[attn - 1];
1009 :
1010 108 : modvalues[attn - 1] = PLy_output_convert(att,
1011 : plval,
1012 54 : &modnulls[attn - 1]);
1013 54 : modrepls[attn - 1] = true;
1014 :
1015 54 : Py_DECREF(plval);
1016 54 : plval = NULL;
1017 : }
1018 :
1019 28 : rtup = heap_modify_tuple(otup, tupdesc, modvalues, modnulls, modrepls);
1020 : }
1021 12 : PG_CATCH();
1022 : {
1023 12 : Py_XDECREF(plntup);
1024 12 : Py_XDECREF(plkeys);
1025 12 : Py_XDECREF(plval);
1026 :
1027 12 : if (modvalues)
1028 8 : pfree(modvalues);
1029 12 : if (modnulls)
1030 8 : pfree(modnulls);
1031 12 : if (modrepls)
1032 8 : pfree(modrepls);
1033 :
1034 12 : PG_RE_THROW();
1035 : }
1036 28 : PG_END_TRY();
1037 :
1038 28 : Py_DECREF(plntup);
1039 28 : Py_DECREF(plkeys);
1040 :
1041 28 : pfree(modvalues);
1042 28 : pfree(modnulls);
1043 28 : pfree(modrepls);
1044 :
1045 28 : error_context_stack = plerrcontext.previous;
1046 :
1047 28 : return rtup;
1048 : }
1049 :
1050 : static void
1051 12 : plpython_trigger_error_callback(void *arg)
1052 : {
1053 12 : PLyExecutionContext *exec_ctx = PLy_current_execution_context();
1054 :
1055 12 : if (exec_ctx->curr_proc)
1056 12 : errcontext("while modifying trigger row");
1057 12 : }
1058 :
1059 : /* execute Python code, propagate Python errors to the backend */
1060 : static PyObject *
1061 1112 : PLy_procedure_call(PLyProcedure *proc, const char *kargs, PyObject *vargs)
1062 : {
1063 1112 : PyObject *rv = NULL;
1064 1112 : int volatile save_subxact_level = list_length(explicit_subtransactions);
1065 :
1066 1112 : PyDict_SetItemString(proc->globals, kargs, vargs);
1067 :
1068 1112 : PG_TRY();
1069 : {
1070 : #if PY_VERSION_HEX >= 0x03020000
1071 1112 : rv = PyEval_EvalCode(proc->code,
1072 : proc->globals, proc->globals);
1073 : #else
1074 : rv = PyEval_EvalCode((PyCodeObject *) proc->code,
1075 : proc->globals, proc->globals);
1076 : #endif
1077 :
1078 : /*
1079 : * Since plpy will only let you close subtransactions that you
1080 : * started, you cannot *unnest* subtransactions, only *nest* them
1081 : * without closing.
1082 : */
1083 : Assert(list_length(explicit_subtransactions) >= save_subxact_level);
1084 : }
1085 0 : PG_FINALLY();
1086 : {
1087 1112 : PLy_abort_open_subtransactions(save_subxact_level);
1088 : }
1089 1112 : PG_END_TRY();
1090 :
1091 : /* If the Python code returned an error, propagate it */
1092 1112 : if (rv == NULL)
1093 108 : PLy_elog(ERROR, NULL);
1094 :
1095 1004 : return rv;
1096 : }
1097 :
1098 : /*
1099 : * Abort lingering subtransactions that have been explicitly started
1100 : * by plpy.subtransaction().start() and not properly closed.
1101 : */
1102 : static void
1103 1112 : PLy_abort_open_subtransactions(int save_subxact_level)
1104 : {
1105 : Assert(save_subxact_level >= 0);
1106 :
1107 1124 : while (list_length(explicit_subtransactions) > save_subxact_level)
1108 : {
1109 : PLySubtransactionData *subtransactiondata;
1110 :
1111 : Assert(explicit_subtransactions != NIL);
1112 :
1113 12 : ereport(WARNING,
1114 : (errmsg("forcibly aborting a subtransaction that has not been exited")));
1115 :
1116 12 : RollbackAndReleaseCurrentSubTransaction();
1117 :
1118 12 : subtransactiondata = (PLySubtransactionData *) linitial(explicit_subtransactions);
1119 12 : explicit_subtransactions = list_delete_first(explicit_subtransactions);
1120 :
1121 12 : MemoryContextSwitchTo(subtransactiondata->oldcontext);
1122 12 : CurrentResourceOwner = subtransactiondata->oldowner;
1123 12 : pfree(subtransactiondata);
1124 : }
1125 1112 : }
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