Line data Source code
1 : /*
2 : * PL/Python main entry points
3 : *
4 : * src/pl/plpython/plpy_main.c
5 : */
6 :
7 : #include "postgres.h"
8 :
9 : #include "access/htup_details.h"
10 : #include "catalog/pg_proc.h"
11 : #include "catalog/pg_type.h"
12 : #include "commands/event_trigger.h"
13 : #include "commands/trigger.h"
14 : #include "executor/spi.h"
15 : #include "miscadmin.h"
16 : #include "plpy_elog.h"
17 : #include "plpy_exec.h"
18 : #include "plpy_main.h"
19 : #include "plpy_plpymodule.h"
20 : #include "plpy_procedure.h"
21 : #include "plpy_subxactobject.h"
22 : #include "plpy_util.h"
23 : #include "utils/guc.h"
24 : #include "utils/memutils.h"
25 : #include "utils/rel.h"
26 : #include "utils/syscache.h"
27 :
28 : /*
29 : * exported functions
30 : */
31 :
32 23 : PG_MODULE_MAGIC_EXT(
33 : .name = "plpython",
34 : .version = PG_VERSION
35 : );
36 :
37 26 : PG_FUNCTION_INFO_V1(plpython3_validator);
38 26 : PG_FUNCTION_INFO_V1(plpython3_call_handler);
39 8 : PG_FUNCTION_INFO_V1(plpython3_inline_handler);
40 :
41 :
42 : static PLyTrigType PLy_procedure_is_trigger(Form_pg_proc procStruct);
43 : static void plpython_error_callback(void *arg);
44 : static void plpython_inline_error_callback(void *arg);
45 :
46 : static PLyExecutionContext *PLy_push_execution_context(bool atomic_context);
47 : static void PLy_pop_execution_context(void);
48 :
49 : /* initialize global variables */
50 : PyObject *PLy_interp_globals = NULL;
51 :
52 : /* this doesn't need to be global; use PLy_current_execution_context() */
53 : static PLyExecutionContext *PLy_execution_contexts = NULL;
54 :
55 :
56 : void
57 23 : _PG_init(void)
58 : {
59 : PyObject *main_mod;
60 : PyObject *main_dict;
61 : PyObject *GD;
62 : PyObject *plpy_mod;
63 :
64 23 : pg_bindtextdomain(TEXTDOMAIN);
65 :
66 : /* Add plpy to table of built-in modules. */
67 23 : PyImport_AppendInittab("plpy", PyInit_plpy);
68 :
69 : /* Initialize Python interpreter. */
70 23 : Py_Initialize();
71 :
72 23 : main_mod = PyImport_AddModule("__main__");
73 23 : if (main_mod == NULL || PyErr_Occurred())
74 0 : PLy_elog(ERROR, "could not import \"%s\" module", "__main__");
75 : Py_INCREF(main_mod);
76 :
77 23 : main_dict = PyModule_GetDict(main_mod);
78 23 : if (main_dict == NULL)
79 0 : PLy_elog(ERROR, NULL);
80 :
81 : /*
82 : * Set up GD.
83 : */
84 23 : GD = PyDict_New();
85 23 : if (GD == NULL)
86 0 : PLy_elog(ERROR, NULL);
87 23 : PyDict_SetItemString(main_dict, "GD", GD);
88 :
89 : /*
90 : * Import plpy.
91 : */
92 23 : plpy_mod = PyImport_ImportModule("plpy");
93 23 : if (plpy_mod == NULL)
94 0 : PLy_elog(ERROR, "could not import \"%s\" module", "plpy");
95 23 : if (PyDict_SetItemString(main_dict, "plpy", plpy_mod) == -1)
96 0 : PLy_elog(ERROR, NULL);
97 :
98 23 : if (PyErr_Occurred())
99 0 : PLy_elog(FATAL, "untrapped error in initialization");
100 :
101 : Py_INCREF(main_dict);
102 23 : PLy_interp_globals = main_dict;
103 :
104 : Py_DECREF(main_mod);
105 :
106 23 : init_procedure_caches();
107 :
108 23 : explicit_subtransactions = NIL;
109 :
110 23 : PLy_execution_contexts = NULL;
111 23 : }
112 :
113 : Datum
114 251 : plpython3_validator(PG_FUNCTION_ARGS)
115 : {
116 251 : Oid funcoid = PG_GETARG_OID(0);
117 : HeapTuple tuple;
118 : Form_pg_proc procStruct;
119 : PLyTrigType is_trigger;
120 :
121 251 : if (!CheckFunctionValidatorAccess(fcinfo->flinfo->fn_oid, funcoid))
122 0 : PG_RETURN_VOID();
123 :
124 251 : if (!check_function_bodies)
125 1 : PG_RETURN_VOID();
126 :
127 : /* Get the new function's pg_proc entry */
128 250 : tuple = SearchSysCache1(PROCOID, ObjectIdGetDatum(funcoid));
129 250 : if (!HeapTupleIsValid(tuple))
130 0 : elog(ERROR, "cache lookup failed for function %u", funcoid);
131 250 : procStruct = (Form_pg_proc) GETSTRUCT(tuple);
132 :
133 250 : is_trigger = PLy_procedure_is_trigger(procStruct);
134 :
135 250 : ReleaseSysCache(tuple);
136 :
137 : /* We can't validate triggers against any particular table ... */
138 250 : (void) PLy_procedure_get(funcoid, InvalidOid, is_trigger);
139 :
140 249 : PG_RETURN_VOID();
141 : }
142 :
143 : Datum
144 701 : plpython3_call_handler(PG_FUNCTION_ARGS)
145 : {
146 : bool nonatomic;
147 : Datum retval;
148 : PLyExecutionContext *exec_ctx;
149 : ErrorContextCallback plerrcontext;
150 :
151 1469 : nonatomic = fcinfo->context &&
152 709 : IsA(fcinfo->context, CallContext) &&
153 8 : !castNode(CallContext, fcinfo->context)->atomic;
154 :
155 : /* Note: SPI_finish() happens in plpy_exec.c, which is dubious design */
156 701 : SPI_connect_ext(nonatomic ? SPI_OPT_NONATOMIC : 0);
157 :
158 : /*
159 : * Push execution context onto stack. It is important that this get
160 : * popped again, so avoid putting anything that could throw error between
161 : * here and the PG_TRY.
162 : */
163 701 : exec_ctx = PLy_push_execution_context(!nonatomic);
164 :
165 701 : PG_TRY();
166 : {
167 701 : Oid funcoid = fcinfo->flinfo->fn_oid;
168 : PLyProcedure *proc;
169 :
170 : /*
171 : * Setup error traceback support for ereport(). Note that the PG_TRY
172 : * structure pops this for us again at exit, so we needn't do that
173 : * explicitly, nor do we risk the callback getting called after we've
174 : * destroyed the exec_ctx.
175 : */
176 701 : plerrcontext.callback = plpython_error_callback;
177 701 : plerrcontext.arg = exec_ctx;
178 701 : plerrcontext.previous = error_context_stack;
179 701 : error_context_stack = &plerrcontext;
180 :
181 701 : if (CALLED_AS_TRIGGER(fcinfo))
182 40 : {
183 49 : Relation tgrel = ((TriggerData *) fcinfo->context)->tg_relation;
184 : HeapTuple trv;
185 :
186 49 : proc = PLy_procedure_get(funcoid, RelationGetRelid(tgrel), PLPY_TRIGGER);
187 49 : exec_ctx->curr_proc = proc;
188 49 : trv = PLy_exec_trigger(fcinfo, proc);
189 40 : retval = PointerGetDatum(trv);
190 : }
191 652 : else if (CALLED_AS_EVENT_TRIGGER(fcinfo))
192 : {
193 10 : proc = PLy_procedure_get(funcoid, InvalidOid, PLPY_EVENT_TRIGGER);
194 10 : exec_ctx->curr_proc = proc;
195 10 : PLy_exec_event_trigger(fcinfo, proc);
196 10 : retval = (Datum) 0;
197 : }
198 : else
199 : {
200 642 : proc = PLy_procedure_get(funcoid, InvalidOid, PLPY_NOT_TRIGGER);
201 639 : exec_ctx->curr_proc = proc;
202 639 : retval = PLy_exec_function(fcinfo, proc);
203 : }
204 : }
205 93 : PG_CATCH();
206 : {
207 93 : PLy_pop_execution_context();
208 93 : PyErr_Clear();
209 93 : PG_RE_THROW();
210 : }
211 608 : PG_END_TRY();
212 :
213 : /* Destroy the execution context */
214 608 : PLy_pop_execution_context();
215 :
216 608 : return retval;
217 : }
218 :
219 : Datum
220 21 : plpython3_inline_handler(PG_FUNCTION_ARGS)
221 : {
222 21 : LOCAL_FCINFO(fake_fcinfo, 0);
223 21 : InlineCodeBlock *codeblock = (InlineCodeBlock *) DatumGetPointer(PG_GETARG_DATUM(0));
224 : FmgrInfo flinfo;
225 : PLyProcedure proc;
226 : PLyExecutionContext *exec_ctx;
227 : ErrorContextCallback plerrcontext;
228 :
229 : /* Note: SPI_finish() happens in plpy_exec.c, which is dubious design */
230 21 : SPI_connect_ext(codeblock->atomic ? 0 : SPI_OPT_NONATOMIC);
231 :
232 105 : MemSet(fcinfo, 0, SizeForFunctionCallInfo(0));
233 147 : MemSet(&flinfo, 0, sizeof(flinfo));
234 21 : fake_fcinfo->flinfo = &flinfo;
235 21 : flinfo.fn_oid = InvalidOid;
236 21 : flinfo.fn_mcxt = CurrentMemoryContext;
237 :
238 882 : MemSet(&proc, 0, sizeof(PLyProcedure));
239 21 : proc.mcxt = AllocSetContextCreate(TopMemoryContext,
240 : "__plpython_inline_block",
241 : ALLOCSET_DEFAULT_SIZES);
242 21 : proc.pyname = MemoryContextStrdup(proc.mcxt, "__plpython_inline_block");
243 21 : proc.langid = codeblock->langOid;
244 :
245 : /*
246 : * This is currently sufficient to get PLy_exec_function to work, but
247 : * someday we might need to be honest and use PLy_output_setup_func.
248 : */
249 21 : proc.result.typoid = VOIDOID;
250 :
251 : /*
252 : * Push execution context onto stack. It is important that this get
253 : * popped again, so avoid putting anything that could throw error between
254 : * here and the PG_TRY.
255 : */
256 21 : exec_ctx = PLy_push_execution_context(codeblock->atomic);
257 :
258 21 : PG_TRY();
259 : {
260 : /*
261 : * Setup error traceback support for ereport().
262 : * plpython_inline_error_callback doesn't currently need exec_ctx, but
263 : * for consistency with plpython3_call_handler we do it the same way.
264 : */
265 21 : plerrcontext.callback = plpython_inline_error_callback;
266 21 : plerrcontext.arg = exec_ctx;
267 21 : plerrcontext.previous = error_context_stack;
268 21 : error_context_stack = &plerrcontext;
269 :
270 21 : PLy_procedure_compile(&proc, codeblock->source_text);
271 21 : exec_ctx->curr_proc = &proc;
272 21 : PLy_exec_function(fake_fcinfo, &proc);
273 : }
274 11 : PG_CATCH();
275 : {
276 11 : PLy_pop_execution_context();
277 11 : PLy_procedure_delete(&proc);
278 11 : PyErr_Clear();
279 11 : PG_RE_THROW();
280 : }
281 10 : PG_END_TRY();
282 :
283 : /* Destroy the execution context */
284 10 : PLy_pop_execution_context();
285 :
286 : /* Now clean up the transient procedure we made */
287 10 : PLy_procedure_delete(&proc);
288 :
289 10 : PG_RETURN_VOID();
290 : }
291 :
292 : static PLyTrigType
293 250 : PLy_procedure_is_trigger(Form_pg_proc procStruct)
294 : {
295 : PLyTrigType ret;
296 :
297 250 : switch (procStruct->prorettype)
298 : {
299 24 : case TRIGGEROID:
300 24 : ret = PLPY_TRIGGER;
301 24 : break;
302 1 : case EVENT_TRIGGEROID:
303 1 : ret = PLPY_EVENT_TRIGGER;
304 1 : break;
305 225 : default:
306 225 : ret = PLPY_NOT_TRIGGER;
307 225 : break;
308 : }
309 :
310 250 : return ret;
311 : }
312 :
313 : static void
314 466 : plpython_error_callback(void *arg)
315 : {
316 466 : PLyExecutionContext *exec_ctx = (PLyExecutionContext *) arg;
317 :
318 466 : if (exec_ctx->curr_proc)
319 : {
320 463 : if (exec_ctx->curr_proc->is_procedure)
321 4 : errcontext("PL/Python procedure \"%s\"",
322 : PLy_procedure_name(exec_ctx->curr_proc));
323 : else
324 459 : errcontext("PL/Python function \"%s\"",
325 : PLy_procedure_name(exec_ctx->curr_proc));
326 : }
327 466 : }
328 :
329 : static void
330 28 : plpython_inline_error_callback(void *arg)
331 : {
332 28 : errcontext("PL/Python anonymous code block");
333 28 : }
334 :
335 : PLyExecutionContext *
336 1428 : PLy_current_execution_context(void)
337 : {
338 1428 : if (PLy_execution_contexts == NULL)
339 0 : elog(ERROR, "no Python function is currently executing");
340 :
341 1428 : return PLy_execution_contexts;
342 : }
343 :
344 : MemoryContext
345 793 : PLy_get_scratch_context(PLyExecutionContext *context)
346 : {
347 : /*
348 : * A scratch context might never be needed in a given plpython procedure,
349 : * so allocate it on first request.
350 : */
351 793 : if (context->scratch_ctx == NULL)
352 442 : context->scratch_ctx =
353 442 : AllocSetContextCreate(TopTransactionContext,
354 : "PL/Python scratch context",
355 : ALLOCSET_DEFAULT_SIZES);
356 793 : return context->scratch_ctx;
357 : }
358 :
359 : static PLyExecutionContext *
360 722 : PLy_push_execution_context(bool atomic_context)
361 : {
362 : PLyExecutionContext *context;
363 :
364 : /* Pick a memory context similar to what SPI uses. */
365 : context = (PLyExecutionContext *)
366 722 : MemoryContextAlloc(atomic_context ? TopTransactionContext : PortalContext,
367 : sizeof(PLyExecutionContext));
368 722 : context->curr_proc = NULL;
369 722 : context->scratch_ctx = NULL;
370 722 : context->next = PLy_execution_contexts;
371 722 : PLy_execution_contexts = context;
372 722 : return context;
373 : }
374 :
375 : static void
376 722 : PLy_pop_execution_context(void)
377 : {
378 722 : PLyExecutionContext *context = PLy_execution_contexts;
379 :
380 722 : if (context == NULL)
381 0 : elog(ERROR, "no Python function is currently executing");
382 :
383 722 : PLy_execution_contexts = context->next;
384 :
385 722 : if (context->scratch_ctx)
386 425 : MemoryContextDelete(context->scratch_ctx);
387 722 : pfree(context);
388 722 : }
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