1 /*
2 * the plpy module
3 *
4 * src/pl/plpython/plpy_plpymodule.c
5 */
6
7 #include "postgres.h"
8
9 #include "access/xact.h"
10 #include "mb/pg_wchar.h"
11 #include "plpy_cursorobject.h"
12 #include "plpy_elog.h"
13 #include "plpy_main.h"
14 #include "plpy_planobject.h"
15 #include "plpy_plpymodule.h"
16 #include "plpy_resultobject.h"
17 #include "plpy_spi.h"
18 #include "plpy_subxactobject.h"
19 #include "plpython.h"
20 #include "utils/builtins.h"
21 #include "utils/snapmgr.h"
22
23 HTAB *PLy_spi_exceptions = NULL;
24
25
26 static void PLy_add_exceptions(PyObject *plpy);
27 static PyObject *PLy_create_exception(char *name,
28 PyObject *base, PyObject *dict,
29 const char *modname, PyObject *mod);
30 static void PLy_generate_spi_exceptions(PyObject *mod, PyObject *base);
31
32 /* module functions */
33 static PyObject *PLy_debug(PyObject *self, PyObject *args, PyObject *kw);
34 static PyObject *PLy_log(PyObject *self, PyObject *args, PyObject *kw);
35 static PyObject *PLy_info(PyObject *self, PyObject *args, PyObject *kw);
36 static PyObject *PLy_notice(PyObject *self, PyObject *args, PyObject *kw);
37 static PyObject *PLy_warning(PyObject *self, PyObject *args, PyObject *kw);
38 static PyObject *PLy_error(PyObject *self, PyObject *args, PyObject *kw);
39 static PyObject *PLy_fatal(PyObject *self, PyObject *args, PyObject *kw);
40 static PyObject *PLy_quote_literal(PyObject *self, PyObject *args);
41 static PyObject *PLy_quote_nullable(PyObject *self, PyObject *args);
42 static PyObject *PLy_quote_ident(PyObject *self, PyObject *args);
43 static PyObject *PLy_commit(PyObject *self, PyObject *args);
44 static PyObject *PLy_rollback(PyObject *self, PyObject *args);
45
46
47 /* A list of all known exceptions, generated from backend/utils/errcodes.txt */
48 typedef struct ExceptionMap
49 {
50 char *name;
51 char *classname;
52 int sqlstate;
53 } ExceptionMap;
54
55 static const ExceptionMap exception_map[] = {
56 #include "spiexceptions.h"
57 {NULL, NULL, 0}
58 };
59
60 static PyMethodDef PLy_methods[] = {
61 /*
62 * logging methods
63 */
64 {"debug", (PyCFunction) (pg_funcptr_t) PLy_debug, METH_VARARGS | METH_KEYWORDS, NULL},
65 {"log", (PyCFunction) (pg_funcptr_t) PLy_log, METH_VARARGS | METH_KEYWORDS, NULL},
66 {"info", (PyCFunction) (pg_funcptr_t) PLy_info, METH_VARARGS | METH_KEYWORDS, NULL},
67 {"notice", (PyCFunction) (pg_funcptr_t) PLy_notice, METH_VARARGS | METH_KEYWORDS, NULL},
68 {"warning", (PyCFunction) (pg_funcptr_t) PLy_warning, METH_VARARGS | METH_KEYWORDS, NULL},
69 {"error", (PyCFunction) (pg_funcptr_t) PLy_error, METH_VARARGS | METH_KEYWORDS, NULL},
70 {"fatal", (PyCFunction) (pg_funcptr_t) PLy_fatal, METH_VARARGS | METH_KEYWORDS, NULL},
71
72 /*
73 * create a stored plan
74 */
75 {"prepare", PLy_spi_prepare, METH_VARARGS, NULL},
76
77 /*
78 * execute a plan or query
79 */
80 {"execute", PLy_spi_execute, METH_VARARGS, NULL},
81
82 /*
83 * escaping strings
84 */
85 {"quote_literal", PLy_quote_literal, METH_VARARGS, NULL},
86 {"quote_nullable", PLy_quote_nullable, METH_VARARGS, NULL},
87 {"quote_ident", PLy_quote_ident, METH_VARARGS, NULL},
88
89 /*
90 * create the subtransaction context manager
91 */
92 {"subtransaction", PLy_subtransaction_new, METH_NOARGS, NULL},
93
94 /*
95 * create a cursor
96 */
97 {"cursor", PLy_cursor, METH_VARARGS, NULL},
98
99 /*
100 * transaction control
101 */
102 {"commit", PLy_commit, METH_NOARGS, NULL},
103 {"rollback", PLy_rollback, METH_NOARGS, NULL},
104
105 {NULL, NULL, 0, NULL}
106 };
107
108 static PyMethodDef PLy_exc_methods[] = {
109 {NULL, NULL, 0, NULL}
110 };
111
112 #if PY_MAJOR_VERSION >= 3
113 static PyModuleDef PLy_module = {
114 PyModuleDef_HEAD_INIT,
115 .m_name = "plpy",
116 .m_size = -1,
117 .m_methods = PLy_methods,
118 };
119
120 static PyModuleDef PLy_exc_module = {
121 PyModuleDef_HEAD_INIT,
122 .m_name = "spiexceptions",
123 .m_size = -1,
124 .m_methods = PLy_exc_methods,
125 };
126
127 /*
128 * Must have external linkage, because PyMODINIT_FUNC does dllexport on
129 * Windows-like platforms.
130 */
131 PyMODINIT_FUNC
PyInit_plpy(void)132 PyInit_plpy(void)
133 {
134 PyObject *m;
135
136 m = PyModule_Create(&PLy_module);
137 if (m == NULL)
138 return NULL;
139
140 PLy_add_exceptions(m);
141
142 return m;
143 }
144 #endif /* PY_MAJOR_VERSION >= 3 */
145
146 void
PLy_init_plpy(void)147 PLy_init_plpy(void)
148 {
149 PyObject *main_mod,
150 *main_dict,
151 *plpy_mod;
152
153 #if PY_MAJOR_VERSION < 3
154 PyObject *plpy;
155 #endif
156
157 /*
158 * initialize plpy module
159 */
160 PLy_plan_init_type();
161 PLy_result_init_type();
162 PLy_subtransaction_init_type();
163 PLy_cursor_init_type();
164
165 #if PY_MAJOR_VERSION >= 3
166 PyModule_Create(&PLy_module);
167 /* for Python 3 we initialized the exceptions in PyInit_plpy */
168 #else
169 plpy = Py_InitModule("plpy", PLy_methods);
170 PLy_add_exceptions(plpy);
171 #endif
172
173 /* PyDict_SetItemString(plpy, "PlanType", (PyObject *) &PLy_PlanType); */
174
175 /*
176 * initialize main module, and add plpy
177 */
178 main_mod = PyImport_AddModule("__main__");
179 main_dict = PyModule_GetDict(main_mod);
180 plpy_mod = PyImport_AddModule("plpy");
181 if (plpy_mod == NULL)
182 PLy_elog(ERROR, "could not import \"plpy\" module");
183 PyDict_SetItemString(main_dict, "plpy", plpy_mod);
184 if (PyErr_Occurred())
185 PLy_elog(ERROR, "could not import \"plpy\" module");
186 }
187
188 static void
PLy_add_exceptions(PyObject * plpy)189 PLy_add_exceptions(PyObject *plpy)
190 {
191 PyObject *excmod;
192 HASHCTL hash_ctl;
193
194 #if PY_MAJOR_VERSION < 3
195 excmod = Py_InitModule("spiexceptions", PLy_exc_methods);
196 #else
197 excmod = PyModule_Create(&PLy_exc_module);
198 #endif
199 if (excmod == NULL)
200 PLy_elog(ERROR, "could not create the spiexceptions module");
201
202 /*
203 * PyModule_AddObject does not add a refcount to the object, for some odd
204 * reason; we must do that.
205 */
206 Py_INCREF(excmod);
207 if (PyModule_AddObject(plpy, "spiexceptions", excmod) < 0)
208 PLy_elog(ERROR, "could not add the spiexceptions module");
209
210 PLy_exc_error = PLy_create_exception("plpy.Error", NULL, NULL,
211 "Error", plpy);
212 PLy_exc_fatal = PLy_create_exception("plpy.Fatal", NULL, NULL,
213 "Fatal", plpy);
214 PLy_exc_spi_error = PLy_create_exception("plpy.SPIError", NULL, NULL,
215 "SPIError", plpy);
216
217 hash_ctl.keysize = sizeof(int);
218 hash_ctl.entrysize = sizeof(PLyExceptionEntry);
219 PLy_spi_exceptions = hash_create("PL/Python SPI exceptions", 256,
220 &hash_ctl, HASH_ELEM | HASH_BLOBS);
221
222 PLy_generate_spi_exceptions(excmod, PLy_exc_spi_error);
223 }
224
225 /*
226 * Create an exception object and add it to the module
227 */
228 static PyObject *
PLy_create_exception(char * name,PyObject * base,PyObject * dict,const char * modname,PyObject * mod)229 PLy_create_exception(char *name, PyObject *base, PyObject *dict,
230 const char *modname, PyObject *mod)
231 {
232 PyObject *exc;
233
234 exc = PyErr_NewException(name, base, dict);
235 if (exc == NULL)
236 PLy_elog(ERROR, NULL);
237
238 /*
239 * PyModule_AddObject does not add a refcount to the object, for some odd
240 * reason; we must do that.
241 */
242 Py_INCREF(exc);
243 PyModule_AddObject(mod, modname, exc);
244
245 /*
246 * The caller will also store a pointer to the exception object in some
247 * permanent variable, so add another ref to account for that. This is
248 * probably excessively paranoid, but let's be sure.
249 */
250 Py_INCREF(exc);
251 return exc;
252 }
253
254 /*
255 * Add all the autogenerated exceptions as subclasses of SPIError
256 */
257 static void
PLy_generate_spi_exceptions(PyObject * mod,PyObject * base)258 PLy_generate_spi_exceptions(PyObject *mod, PyObject *base)
259 {
260 int i;
261
262 for (i = 0; exception_map[i].name != NULL; i++)
263 {
264 bool found;
265 PyObject *exc;
266 PLyExceptionEntry *entry;
267 PyObject *sqlstate;
268 PyObject *dict = PyDict_New();
269
270 if (dict == NULL)
271 PLy_elog(ERROR, NULL);
272
273 sqlstate = PyString_FromString(unpack_sql_state(exception_map[i].sqlstate));
274 if (sqlstate == NULL)
275 PLy_elog(ERROR, "could not generate SPI exceptions");
276
277 PyDict_SetItemString(dict, "sqlstate", sqlstate);
278 Py_DECREF(sqlstate);
279
280 exc = PLy_create_exception(exception_map[i].name, base, dict,
281 exception_map[i].classname, mod);
282
283 entry = hash_search(PLy_spi_exceptions, &exception_map[i].sqlstate,
284 HASH_ENTER, &found);
285 Assert(!found);
286 entry->exc = exc;
287 }
288 }
289
290
291 /*
292 * the python interface to the elog function
293 * don't confuse these with PLy_elog
294 */
295 static PyObject *PLy_output(volatile int level, PyObject *self,
296 PyObject *args, PyObject *kw);
297
298 static PyObject *
PLy_debug(PyObject * self,PyObject * args,PyObject * kw)299 PLy_debug(PyObject *self, PyObject *args, PyObject *kw)
300 {
301 return PLy_output(DEBUG2, self, args, kw);
302 }
303
304 static PyObject *
PLy_log(PyObject * self,PyObject * args,PyObject * kw)305 PLy_log(PyObject *self, PyObject *args, PyObject *kw)
306 {
307 return PLy_output(LOG, self, args, kw);
308 }
309
310 static PyObject *
PLy_info(PyObject * self,PyObject * args,PyObject * kw)311 PLy_info(PyObject *self, PyObject *args, PyObject *kw)
312 {
313 return PLy_output(INFO, self, args, kw);
314 }
315
316 static PyObject *
PLy_notice(PyObject * self,PyObject * args,PyObject * kw)317 PLy_notice(PyObject *self, PyObject *args, PyObject *kw)
318 {
319 return PLy_output(NOTICE, self, args, kw);
320 }
321
322 static PyObject *
PLy_warning(PyObject * self,PyObject * args,PyObject * kw)323 PLy_warning(PyObject *self, PyObject *args, PyObject *kw)
324 {
325 return PLy_output(WARNING, self, args, kw);
326 }
327
328 static PyObject *
PLy_error(PyObject * self,PyObject * args,PyObject * kw)329 PLy_error(PyObject *self, PyObject *args, PyObject *kw)
330 {
331 return PLy_output(ERROR, self, args, kw);
332 }
333
334 static PyObject *
PLy_fatal(PyObject * self,PyObject * args,PyObject * kw)335 PLy_fatal(PyObject *self, PyObject *args, PyObject *kw)
336 {
337 return PLy_output(FATAL, self, args, kw);
338 }
339
340 static PyObject *
PLy_quote_literal(PyObject * self,PyObject * args)341 PLy_quote_literal(PyObject *self, PyObject *args)
342 {
343 const char *str;
344 char *quoted;
345 PyObject *ret;
346
347 if (!PyArg_ParseTuple(args, "s:quote_literal", &str))
348 return NULL;
349
350 quoted = quote_literal_cstr(str);
351 ret = PyString_FromString(quoted);
352 pfree(quoted);
353
354 return ret;
355 }
356
357 static PyObject *
PLy_quote_nullable(PyObject * self,PyObject * args)358 PLy_quote_nullable(PyObject *self, PyObject *args)
359 {
360 const char *str;
361 char *quoted;
362 PyObject *ret;
363
364 if (!PyArg_ParseTuple(args, "z:quote_nullable", &str))
365 return NULL;
366
367 if (str == NULL)
368 return PyString_FromString("NULL");
369
370 quoted = quote_literal_cstr(str);
371 ret = PyString_FromString(quoted);
372 pfree(quoted);
373
374 return ret;
375 }
376
377 static PyObject *
PLy_quote_ident(PyObject * self,PyObject * args)378 PLy_quote_ident(PyObject *self, PyObject *args)
379 {
380 const char *str;
381 const char *quoted;
382 PyObject *ret;
383
384 if (!PyArg_ParseTuple(args, "s:quote_ident", &str))
385 return NULL;
386
387 quoted = quote_identifier(str);
388 ret = PyString_FromString(quoted);
389
390 return ret;
391 }
392
393 /* enforce cast of object to string */
394 static char *
object_to_string(PyObject * obj)395 object_to_string(PyObject *obj)
396 {
397 if (obj)
398 {
399 PyObject *so = PyObject_Str(obj);
400
401 if (so != NULL)
402 {
403 char *str;
404
405 str = pstrdup(PyString_AsString(so));
406 Py_DECREF(so);
407
408 return str;
409 }
410 }
411
412 return NULL;
413 }
414
415 static PyObject *
PLy_output(volatile int level,PyObject * self,PyObject * args,PyObject * kw)416 PLy_output(volatile int level, PyObject *self, PyObject *args, PyObject *kw)
417 {
418 int sqlstate = 0;
419 char *volatile sqlstatestr = NULL;
420 char *volatile message = NULL;
421 char *volatile detail = NULL;
422 char *volatile hint = NULL;
423 char *volatile column_name = NULL;
424 char *volatile constraint_name = NULL;
425 char *volatile datatype_name = NULL;
426 char *volatile table_name = NULL;
427 char *volatile schema_name = NULL;
428 volatile MemoryContext oldcontext;
429 PyObject *key,
430 *value;
431 PyObject *volatile so;
432 Py_ssize_t pos = 0;
433
434 if (PyTuple_Size(args) == 1)
435 {
436 /*
437 * Treat single argument specially to avoid undesirable ('tuple',)
438 * decoration.
439 */
440 PyObject *o;
441
442 if (!PyArg_UnpackTuple(args, "plpy.elog", 1, 1, &o))
443 PLy_elog(ERROR, "could not unpack arguments in plpy.elog");
444 so = PyObject_Str(o);
445 }
446 else
447 so = PyObject_Str(args);
448
449 if (so == NULL || ((message = PyString_AsString(so)) == NULL))
450 {
451 level = ERROR;
452 message = dgettext(TEXTDOMAIN, "could not parse error message in plpy.elog");
453 }
454 message = pstrdup(message);
455
456 Py_XDECREF(so);
457
458 if (kw != NULL)
459 {
460 while (PyDict_Next(kw, &pos, &key, &value))
461 {
462 char *keyword = PyString_AsString(key);
463
464 if (strcmp(keyword, "message") == 0)
465 {
466 /* the message should not be overwritten */
467 if (PyTuple_Size(args) != 0)
468 {
469 PLy_exception_set(PyExc_TypeError, "argument 'message' given by name and position");
470 return NULL;
471 }
472
473 if (message)
474 pfree(message);
475 message = object_to_string(value);
476 }
477 else if (strcmp(keyword, "detail") == 0)
478 detail = object_to_string(value);
479 else if (strcmp(keyword, "hint") == 0)
480 hint = object_to_string(value);
481 else if (strcmp(keyword, "sqlstate") == 0)
482 sqlstatestr = object_to_string(value);
483 else if (strcmp(keyword, "schema_name") == 0)
484 schema_name = object_to_string(value);
485 else if (strcmp(keyword, "table_name") == 0)
486 table_name = object_to_string(value);
487 else if (strcmp(keyword, "column_name") == 0)
488 column_name = object_to_string(value);
489 else if (strcmp(keyword, "datatype_name") == 0)
490 datatype_name = object_to_string(value);
491 else if (strcmp(keyword, "constraint_name") == 0)
492 constraint_name = object_to_string(value);
493 else
494 {
495 PLy_exception_set(PyExc_TypeError,
496 "'%s' is an invalid keyword argument for this function",
497 keyword);
498 return NULL;
499 }
500 }
501 }
502
503 if (sqlstatestr != NULL)
504 {
505 if (strlen(sqlstatestr) != 5)
506 {
507 PLy_exception_set(PyExc_ValueError, "invalid SQLSTATE code");
508 return NULL;
509 }
510
511 if (strspn(sqlstatestr, "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ") != 5)
512 {
513 PLy_exception_set(PyExc_ValueError, "invalid SQLSTATE code");
514 return NULL;
515 }
516
517 sqlstate = MAKE_SQLSTATE(sqlstatestr[0],
518 sqlstatestr[1],
519 sqlstatestr[2],
520 sqlstatestr[3],
521 sqlstatestr[4]);
522 }
523
524 oldcontext = CurrentMemoryContext;
525 PG_TRY();
526 {
527 if (message != NULL)
528 pg_verifymbstr(message, strlen(message), false);
529 if (detail != NULL)
530 pg_verifymbstr(detail, strlen(detail), false);
531 if (hint != NULL)
532 pg_verifymbstr(hint, strlen(hint), false);
533 if (schema_name != NULL)
534 pg_verifymbstr(schema_name, strlen(schema_name), false);
535 if (table_name != NULL)
536 pg_verifymbstr(table_name, strlen(table_name), false);
537 if (column_name != NULL)
538 pg_verifymbstr(column_name, strlen(column_name), false);
539 if (datatype_name != NULL)
540 pg_verifymbstr(datatype_name, strlen(datatype_name), false);
541 if (constraint_name != NULL)
542 pg_verifymbstr(constraint_name, strlen(constraint_name), false);
543
544 ereport(level,
545 ((sqlstate != 0) ? errcode(sqlstate) : 0,
546 (message != NULL) ? errmsg_internal("%s", message) : 0,
547 (detail != NULL) ? errdetail_internal("%s", detail) : 0,
548 (hint != NULL) ? errhint("%s", hint) : 0,
549 (column_name != NULL) ?
550 err_generic_string(PG_DIAG_COLUMN_NAME, column_name) : 0,
551 (constraint_name != NULL) ?
552 err_generic_string(PG_DIAG_CONSTRAINT_NAME, constraint_name) : 0,
553 (datatype_name != NULL) ?
554 err_generic_string(PG_DIAG_DATATYPE_NAME, datatype_name) : 0,
555 (table_name != NULL) ?
556 err_generic_string(PG_DIAG_TABLE_NAME, table_name) : 0,
557 (schema_name != NULL) ?
558 err_generic_string(PG_DIAG_SCHEMA_NAME, schema_name) : 0));
559 }
560 PG_CATCH();
561 {
562 ErrorData *edata;
563
564 MemoryContextSwitchTo(oldcontext);
565 edata = CopyErrorData();
566 FlushErrorState();
567
568 PLy_exception_set_with_details(PLy_exc_error, edata);
569 FreeErrorData(edata);
570
571 return NULL;
572 }
573 PG_END_TRY();
574
575 /*
576 * return a legal object so the interpreter will continue on its merry way
577 */
578 Py_RETURN_NONE;
579 }
580
581 static PyObject *
PLy_commit(PyObject * self,PyObject * args)582 PLy_commit(PyObject *self, PyObject *args)
583 {
584 PLyExecutionContext *exec_ctx = PLy_current_execution_context();
585
586 SPI_commit();
587 SPI_start_transaction();
588
589 /* was cleared at transaction end, reset pointer */
590 exec_ctx->scratch_ctx = NULL;
591
592 Py_RETURN_NONE;
593 }
594
595 static PyObject *
PLy_rollback(PyObject * self,PyObject * args)596 PLy_rollback(PyObject *self, PyObject *args)
597 {
598 PLyExecutionContext *exec_ctx = PLy_current_execution_context();
599
600 SPI_rollback();
601 SPI_start_transaction();
602
603 /* was cleared at transaction end, reset pointer */
604 exec_ctx->scratch_ctx = NULL;
605
606 Py_RETURN_NONE;
607 }
608