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plpy_main.c File Reference
#include "postgres.h"
#include "access/htup_details.h"
#include "catalog/pg_proc.h"
#include "catalog/pg_type.h"
#include "commands/trigger.h"
#include "executor/spi.h"
#include "miscadmin.h"
#include "plpy_elog.h"
#include "plpy_exec.h"
#include "plpy_main.h"
#include "plpy_plpymodule.h"
#include "plpy_procedure.h"
#include "plpy_subxactobject.h"
#include "plpy_util.h"
#include "utils/guc.h"
#include "utils/memutils.h"
#include "utils/rel.h"
#include "utils/syscache.h"
Include dependency graph for plpy_main.c:

Go to the source code of this file.

Functions

 PG_MODULE_MAGIC_EXT (.name="plpython",.version=PG_VERSION)
 
 PG_FUNCTION_INFO_V1 (plpython3_validator)
 
 PG_FUNCTION_INFO_V1 (plpython3_call_handler)
 
 PG_FUNCTION_INFO_V1 (plpython3_inline_handler)
 
static bool PLy_procedure_is_trigger (Form_pg_proc procStruct)
 
static void plpython_error_callback (void *arg)
 
static void plpython_inline_error_callback (void *arg)
 
static void PLy_init_interp (void)
 
static PLyExecutionContextPLy_push_execution_context (bool atomic_context)
 
static void PLy_pop_execution_context (void)
 
void _PG_init (void)
 
static void PLy_initialize (void)
 
Datum plpython3_validator (PG_FUNCTION_ARGS)
 
Datum plpython3_call_handler (PG_FUNCTION_ARGS)
 
Datum plpython3_inline_handler (PG_FUNCTION_ARGS)
 
PLyExecutionContextPLy_current_execution_context (void)
 
MemoryContext PLy_get_scratch_context (PLyExecutionContext *context)
 

Variables

static int * plpython_version_bitmask_ptr = NULL
 
static int plpython_version_bitmask = 0
 
PyObject * PLy_interp_globals = NULL
 
static PLyExecutionContextPLy_execution_contexts = NULL
 

Function Documentation

◆ _PG_init()

void _PG_init ( void  )

Definition at line 61 of file plpy_main.c.

62{
63 int **bitmask_ptr;
64
65 /*
66 * Set up a shared bitmask variable telling which Python version(s) are
67 * loaded into this process's address space. If there's more than one, we
68 * cannot call into libpython for fear of causing crashes. But postpone
69 * the actual failure for later, so that operations like pg_restore can
70 * load more than one plpython library so long as they don't try to do
71 * anything much with the language.
72 *
73 * While we only support Python 3 these days, somebody might create an
74 * out-of-tree version adding back support for Python 2. Conflicts with
75 * such an extension should be detected.
76 */
77 bitmask_ptr = (int **) find_rendezvous_variable("plpython_version_bitmask");
78 if (!(*bitmask_ptr)) /* am I the first? */
79 *bitmask_ptr = &plpython_version_bitmask;
80 /* Retain pointer to the agreed-on shared variable ... */
81 plpython_version_bitmask_ptr = *bitmask_ptr;
82 /* ... and announce my presence */
83 *plpython_version_bitmask_ptr |= (1 << PY_MAJOR_VERSION);
84
85 /*
86 * This should be safe even in the presence of conflicting plpythons, and
87 * it's necessary to do it before possibly throwing a conflict error, or
88 * the error message won't get localized.
89 */
91}
void ** find_rendezvous_variable(const char *varName)
Definition: dfmgr.c:657
#define TEXTDOMAIN
Definition: elog.h:152
void pg_bindtextdomain(const char *domain)
Definition: miscinit.c:1939
static int plpython_version_bitmask
Definition: plpy_main.c:51
static int * plpython_version_bitmask_ptr
Definition: plpy_main.c:50

References find_rendezvous_variable(), pg_bindtextdomain(), plpython_version_bitmask, plpython_version_bitmask_ptr, and TEXTDOMAIN.

◆ PG_FUNCTION_INFO_V1() [1/3]

PG_FUNCTION_INFO_V1 ( plpython3_call_handler  )

◆ PG_FUNCTION_INFO_V1() [2/3]

PG_FUNCTION_INFO_V1 ( plpython3_inline_handler  )

◆ PG_FUNCTION_INFO_V1() [3/3]

PG_FUNCTION_INFO_V1 ( plpython3_validator  )

◆ PG_MODULE_MAGIC_EXT()

PG_MODULE_MAGIC_EXT ( name = "plpython",
version = PG_VERSION 
)

◆ plpython3_call_handler()

Datum plpython3_call_handler ( PG_FUNCTION_ARGS  )

Definition at line 194 of file plpy_main.c.

195{
196 bool nonatomic;
197 Datum retval;
198 PLyExecutionContext *exec_ctx;
199 ErrorContextCallback plerrcontext;
200
202
203 nonatomic = fcinfo->context &&
204 IsA(fcinfo->context, CallContext) &&
205 !castNode(CallContext, fcinfo->context)->atomic;
206
207 /* Note: SPI_finish() happens in plpy_exec.c, which is dubious design */
208 SPI_connect_ext(nonatomic ? SPI_OPT_NONATOMIC : 0);
209
210 /*
211 * Push execution context onto stack. It is important that this get
212 * popped again, so avoid putting anything that could throw error between
213 * here and the PG_TRY.
214 */
215 exec_ctx = PLy_push_execution_context(!nonatomic);
216
217 PG_TRY();
218 {
219 Oid funcoid = fcinfo->flinfo->fn_oid;
220 PLyProcedure *proc;
221
222 /*
223 * Setup error traceback support for ereport(). Note that the PG_TRY
224 * structure pops this for us again at exit, so we needn't do that
225 * explicitly, nor do we risk the callback getting called after we've
226 * destroyed the exec_ctx.
227 */
228 plerrcontext.callback = plpython_error_callback;
229 plerrcontext.arg = exec_ctx;
230 plerrcontext.previous = error_context_stack;
231 error_context_stack = &plerrcontext;
232
233 if (CALLED_AS_TRIGGER(fcinfo))
234 {
235 Relation tgrel = ((TriggerData *) fcinfo->context)->tg_relation;
236 HeapTuple trv;
237
238 proc = PLy_procedure_get(funcoid, RelationGetRelid(tgrel), true);
239 exec_ctx->curr_proc = proc;
240 trv = PLy_exec_trigger(fcinfo, proc);
241 retval = PointerGetDatum(trv);
242 }
243 else
244 {
245 proc = PLy_procedure_get(funcoid, InvalidOid, false);
246 exec_ctx->curr_proc = proc;
247 retval = PLy_exec_function(fcinfo, proc);
248 }
249 }
250 PG_CATCH();
251 {
253 PyErr_Clear();
254 PG_RE_THROW();
255 }
256 PG_END_TRY();
257
258 /* Destroy the execution context */
260
261 return retval;
262}
ErrorContextCallback * error_context_stack
Definition: elog.c:95
#define PG_RE_THROW()
Definition: elog.h:404
#define PG_TRY(...)
Definition: elog.h:371
#define PG_END_TRY(...)
Definition: elog.h:396
#define PG_CATCH(...)
Definition: elog.h:381
#define IsA(nodeptr, _type_)
Definition: nodes.h:164
#define castNode(_type_, nodeptr)
Definition: nodes.h:182
Datum PLy_exec_function(FunctionCallInfo fcinfo, PLyProcedure *proc)
Definition: plpy_exec.c:53
HeapTuple PLy_exec_trigger(FunctionCallInfo fcinfo, PLyProcedure *proc)
Definition: plpy_exec.c:319
static void PLy_initialize(void)
Definition: plpy_main.c:98
static void plpython_error_callback(void *arg)
Definition: plpy_main.c:346
static PLyExecutionContext * PLy_push_execution_context(bool atomic_context)
Definition: plpy_main.c:392
static void PLy_pop_execution_context(void)
Definition: plpy_main.c:408
PLyProcedure * PLy_procedure_get(Oid fn_oid, Oid fn_rel, bool is_trigger)
static Datum PointerGetDatum(const void *X)
Definition: postgres.h:327
uintptr_t Datum
Definition: postgres.h:69
#define InvalidOid
Definition: postgres_ext.h:35
unsigned int Oid
Definition: postgres_ext.h:30
#define RelationGetRelid(relation)
Definition: rel.h:516
int SPI_connect_ext(int options)
Definition: spi.c:100
#define SPI_OPT_NONATOMIC
Definition: spi.h:102
struct ErrorContextCallback * previous
Definition: elog.h:296
void(* callback)(void *arg)
Definition: elog.h:297
PLyProcedure * curr_proc
Definition: plpy_main.h:20
#define CALLED_AS_TRIGGER(fcinfo)
Definition: trigger.h:26

References ErrorContextCallback::arg, ErrorContextCallback::callback, CALLED_AS_TRIGGER, castNode, PLyExecutionContext::curr_proc, error_context_stack, InvalidOid, IsA, PG_CATCH, PG_END_TRY, PG_RE_THROW, PG_TRY, plpython_error_callback(), PLy_exec_function(), PLy_exec_trigger(), PLy_initialize(), PLy_pop_execution_context(), PLy_procedure_get(), PLy_push_execution_context(), PointerGetDatum(), ErrorContextCallback::previous, RelationGetRelid, SPI_connect_ext(), and SPI_OPT_NONATOMIC.

◆ plpython3_inline_handler()

Datum plpython3_inline_handler ( PG_FUNCTION_ARGS  )

Definition at line 265 of file plpy_main.c.

266{
267 LOCAL_FCINFO(fake_fcinfo, 0);
269 FmgrInfo flinfo;
270 PLyProcedure proc;
271 PLyExecutionContext *exec_ctx;
272 ErrorContextCallback plerrcontext;
273
275
276 /* Note: SPI_finish() happens in plpy_exec.c, which is dubious design */
277 SPI_connect_ext(codeblock->atomic ? 0 : SPI_OPT_NONATOMIC);
278
279 MemSet(fcinfo, 0, SizeForFunctionCallInfo(0));
280 MemSet(&flinfo, 0, sizeof(flinfo));
281 fake_fcinfo->flinfo = &flinfo;
282 flinfo.fn_oid = InvalidOid;
284
285 MemSet(&proc, 0, sizeof(PLyProcedure));
287 "__plpython_inline_block",
289 proc.pyname = MemoryContextStrdup(proc.mcxt, "__plpython_inline_block");
290 proc.langid = codeblock->langOid;
291
292 /*
293 * This is currently sufficient to get PLy_exec_function to work, but
294 * someday we might need to be honest and use PLy_output_setup_func.
295 */
296 proc.result.typoid = VOIDOID;
297
298 /*
299 * Push execution context onto stack. It is important that this get
300 * popped again, so avoid putting anything that could throw error between
301 * here and the PG_TRY.
302 */
303 exec_ctx = PLy_push_execution_context(codeblock->atomic);
304
305 PG_TRY();
306 {
307 /*
308 * Setup error traceback support for ereport().
309 * plpython_inline_error_callback doesn't currently need exec_ctx, but
310 * for consistency with plpython3_call_handler we do it the same way.
311 */
313 plerrcontext.arg = exec_ctx;
314 plerrcontext.previous = error_context_stack;
315 error_context_stack = &plerrcontext;
316
317 PLy_procedure_compile(&proc, codeblock->source_text);
318 exec_ctx->curr_proc = &proc;
319 PLy_exec_function(fake_fcinfo, &proc);
320 }
321 PG_CATCH();
322 {
325 PyErr_Clear();
326 PG_RE_THROW();
327 }
328 PG_END_TRY();
329
330 /* Destroy the execution context */
332
333 /* Now clean up the transient procedure we made */
335
337}
#define MemSet(start, val, len)
Definition: c.h:991
#define PG_RETURN_VOID()
Definition: fmgr.h:349
#define SizeForFunctionCallInfo(nargs)
Definition: fmgr.h:102
#define PG_GETARG_DATUM(n)
Definition: fmgr.h:268
#define LOCAL_FCINFO(name, nargs)
Definition: fmgr.h:110
char * MemoryContextStrdup(MemoryContext context, const char *string)
Definition: mcxt.c:1690
MemoryContext TopMemoryContext
Definition: mcxt.c:149
MemoryContext CurrentMemoryContext
Definition: mcxt.c:143
#define AllocSetContextCreate
Definition: memutils.h:129
#define ALLOCSET_DEFAULT_SIZES
Definition: memutils.h:160
static void plpython_inline_error_callback(void *arg)
Definition: plpy_main.c:362
void PLy_procedure_compile(PLyProcedure *proc, const char *src)
void PLy_procedure_delete(PLyProcedure *proc)
static Pointer DatumGetPointer(Datum X)
Definition: postgres.h:317
Definition: fmgr.h:57
MemoryContext fn_mcxt
Definition: fmgr.h:65
Oid fn_oid
Definition: fmgr.h:59
char * source_text
Definition: parsenodes.h:3581
PLyObToDatum result
MemoryContext mcxt

References ALLOCSET_DEFAULT_SIZES, AllocSetContextCreate, ErrorContextCallback::arg, InlineCodeBlock::atomic, ErrorContextCallback::callback, PLyExecutionContext::curr_proc, CurrentMemoryContext, DatumGetPointer(), error_context_stack, FmgrInfo::fn_mcxt, FmgrInfo::fn_oid, InvalidOid, PLyProcedure::langid, InlineCodeBlock::langOid, LOCAL_FCINFO, PLyProcedure::mcxt, MemoryContextStrdup(), MemSet, PG_CATCH, PG_END_TRY, PG_GETARG_DATUM, PG_RE_THROW, PG_RETURN_VOID, PG_TRY, plpython_inline_error_callback(), PLy_exec_function(), PLy_initialize(), PLy_pop_execution_context(), PLy_procedure_compile(), PLy_procedure_delete(), PLy_push_execution_context(), ErrorContextCallback::previous, PLyProcedure::pyname, PLyProcedure::result, SizeForFunctionCallInfo, InlineCodeBlock::source_text, SPI_connect_ext(), SPI_OPT_NONATOMIC, TopMemoryContext, and PLyObToDatum::typoid.

◆ plpython3_validator()

Datum plpython3_validator ( PG_FUNCTION_ARGS  )

Definition at line 161 of file plpy_main.c.

162{
163 Oid funcoid = PG_GETARG_OID(0);
164 HeapTuple tuple;
165 Form_pg_proc procStruct;
166 bool is_trigger;
167
168 if (!CheckFunctionValidatorAccess(fcinfo->flinfo->fn_oid, funcoid))
170
173
174 /* Do this only after making sure we need to do something */
176
177 /* Get the new function's pg_proc entry */
178 tuple = SearchSysCache1(PROCOID, ObjectIdGetDatum(funcoid));
179 if (!HeapTupleIsValid(tuple))
180 elog(ERROR, "cache lookup failed for function %u", funcoid);
181 procStruct = (Form_pg_proc) GETSTRUCT(tuple);
182
183 is_trigger = PLy_procedure_is_trigger(procStruct);
184
185 ReleaseSysCache(tuple);
186
187 /* We can't validate triggers against any particular table ... */
188 PLy_procedure_get(funcoid, InvalidOid, is_trigger);
189
191}
#define ERROR
Definition: elog.h:39
#define elog(elevel,...)
Definition: elog.h:225
bool CheckFunctionValidatorAccess(Oid validatorOid, Oid functionOid)
Definition: fmgr.c:2145
#define PG_GETARG_OID(n)
Definition: fmgr.h:275
bool check_function_bodies
Definition: guc_tables.c:528
#define HeapTupleIsValid(tuple)
Definition: htup.h:78
static void * GETSTRUCT(const HeapTupleData *tuple)
Definition: htup_details.h:728
FormData_pg_proc * Form_pg_proc
Definition: pg_proc.h:136
static bool PLy_procedure_is_trigger(Form_pg_proc procStruct)
Definition: plpy_main.c:340
static Datum ObjectIdGetDatum(Oid X)
Definition: postgres.h:257
void ReleaseSysCache(HeapTuple tuple)
Definition: syscache.c:269
HeapTuple SearchSysCache1(int cacheId, Datum key1)
Definition: syscache.c:221

References check_function_bodies, CheckFunctionValidatorAccess(), elog, ERROR, GETSTRUCT(), HeapTupleIsValid, InvalidOid, ObjectIdGetDatum(), PG_GETARG_OID, PG_RETURN_VOID, PLy_initialize(), PLy_procedure_get(), PLy_procedure_is_trigger(), ReleaseSysCache(), and SearchSysCache1().

◆ plpython_error_callback()

static void plpython_error_callback ( void *  arg)
static

Definition at line 346 of file plpy_main.c.

347{
349
350 if (exec_ctx->curr_proc)
351 {
352 if (exec_ctx->curr_proc->is_procedure)
353 errcontext("PL/Python procedure \"%s\"",
354 PLy_procedure_name(exec_ctx->curr_proc));
355 else
356 errcontext("PL/Python function \"%s\"",
357 PLy_procedure_name(exec_ctx->curr_proc));
358 }
359}
#define errcontext
Definition: elog.h:197
void * arg
char * PLy_procedure_name(PLyProcedure *proc)

References arg, PLyExecutionContext::curr_proc, errcontext, PLyProcedure::is_procedure, and PLy_procedure_name().

Referenced by plpython3_call_handler().

◆ plpython_inline_error_callback()

static void plpython_inline_error_callback ( void *  arg)
static

Definition at line 362 of file plpy_main.c.

363{
364 errcontext("PL/Python anonymous code block");
365}

References errcontext.

Referenced by plpython3_inline_handler().

◆ PLy_current_execution_context()

◆ PLy_get_scratch_context()

MemoryContext PLy_get_scratch_context ( PLyExecutionContext context)

Definition at line 377 of file plpy_main.c.

378{
379 /*
380 * A scratch context might never be needed in a given plpython procedure,
381 * so allocate it on first request.
382 */
383 if (context->scratch_ctx == NULL)
384 context->scratch_ctx =
386 "PL/Python scratch context",
388 return context->scratch_ctx;
389}
MemoryContext TopTransactionContext
Definition: mcxt.c:154
MemoryContext scratch_ctx
Definition: plpy_main.h:21

References ALLOCSET_DEFAULT_SIZES, AllocSetContextCreate, PLyExecutionContext::scratch_ctx, and TopTransactionContext.

Referenced by PLy_input_convert(), and PLy_input_from_tuple().

◆ PLy_init_interp()

static void PLy_init_interp ( void  )
static

Definition at line 141 of file plpy_main.c.

142{
143 static PyObject *PLy_interp_safe_globals = NULL;
144 PyObject *mainmod;
145
146 mainmod = PyImport_AddModule("__main__");
147 if (mainmod == NULL || PyErr_Occurred())
148 PLy_elog(ERROR, "could not import \"__main__\" module");
149 Py_INCREF(mainmod);
150 PLy_interp_globals = PyModule_GetDict(mainmod);
151 PLy_interp_safe_globals = PyDict_New();
152 if (PLy_interp_safe_globals == NULL)
153 PLy_elog(ERROR, NULL);
154 PyDict_SetItemString(PLy_interp_globals, "GD", PLy_interp_safe_globals);
155 Py_DECREF(mainmod);
156 if (PLy_interp_globals == NULL || PyErr_Occurred())
157 PLy_elog(ERROR, "could not initialize globals");
158}
#define PLy_elog
PyObject * PLy_interp_globals
Definition: plpy_main.c:54

References ERROR, PLy_elog, and PLy_interp_globals.

Referenced by PLy_initialize().

◆ PLy_initialize()

static void PLy_initialize ( void  )
static

Definition at line 98 of file plpy_main.c.

99{
100 static bool inited = false;
101
102 /*
103 * Check for multiple Python libraries before actively doing anything with
104 * libpython. This must be repeated on each entry to PL/Python, in case a
105 * conflicting library got loaded since we last looked.
106 *
107 * It is attractive to weaken this error from FATAL to ERROR, but there
108 * would be corner cases, so it seems best to be conservative.
109 */
110 if (*plpython_version_bitmask_ptr != (1 << PY_MAJOR_VERSION))
112 (errmsg("multiple Python libraries are present in session"),
113 errdetail("Only one Python major version can be used in one session.")));
114
115 /* The rest should only be done once per session */
116 if (inited)
117 return;
118
119 PyImport_AppendInittab("plpy", PyInit_plpy);
120 Py_Initialize();
121 PyImport_ImportModule("plpy");
124 if (PyErr_Occurred())
125 PLy_elog(FATAL, "untrapped error in initialization");
126
128
130
132
133 inited = true;
134}
int errdetail(const char *fmt,...)
Definition: elog.c:1204
int errmsg(const char *fmt,...)
Definition: elog.c:1071
#define FATAL
Definition: elog.h:41
#define ereport(elevel,...)
Definition: elog.h:149
#define NIL
Definition: pg_list.h:68
static void PLy_init_interp(void)
Definition: plpy_main.c:141
PyMODINIT_FUNC PyInit_plpy(void)
void PLy_init_plpy(void)
void init_procedure_caches(void)
List * explicit_subtransactions

References ereport, errdetail(), errmsg(), explicit_subtransactions, FATAL, init_procedure_caches(), NIL, plpython_version_bitmask_ptr, PLy_elog, PLy_execution_contexts, PLy_init_interp(), PLy_init_plpy(), and PyInit_plpy().

Referenced by plpython3_call_handler(), plpython3_inline_handler(), and plpython3_validator().

◆ PLy_pop_execution_context()

static void PLy_pop_execution_context ( void  )
static

Definition at line 408 of file plpy_main.c.

409{
411
412 if (context == NULL)
413 elog(ERROR, "no Python function is currently executing");
414
415 PLy_execution_contexts = context->next;
416
417 if (context->scratch_ctx)
419 pfree(context);
420}
void pfree(void *pointer)
Definition: mcxt.c:1528
void MemoryContextDelete(MemoryContext context)
Definition: mcxt.c:454
struct PLyExecutionContext * next
Definition: plpy_main.h:22

References elog, ERROR, MemoryContextDelete(), PLyExecutionContext::next, pfree(), PLy_execution_contexts, and PLyExecutionContext::scratch_ctx.

Referenced by plpython3_call_handler(), and plpython3_inline_handler().

◆ PLy_procedure_is_trigger()

static bool PLy_procedure_is_trigger ( Form_pg_proc  procStruct)
static

Definition at line 340 of file plpy_main.c.

341{
342 return (procStruct->prorettype == TRIGGEROID);
343}

Referenced by plpython3_validator().

◆ PLy_push_execution_context()

static PLyExecutionContext * PLy_push_execution_context ( bool  atomic_context)
static

Definition at line 392 of file plpy_main.c.

393{
394 PLyExecutionContext *context;
395
396 /* Pick a memory context similar to what SPI uses. */
397 context = (PLyExecutionContext *)
399 sizeof(PLyExecutionContext));
400 context->curr_proc = NULL;
401 context->scratch_ctx = NULL;
402 context->next = PLy_execution_contexts;
403 PLy_execution_contexts = context;
404 return context;
405}
void * MemoryContextAlloc(MemoryContext context, Size size)
Definition: mcxt.c:1185
MemoryContext PortalContext
Definition: mcxt.c:158

References PLyExecutionContext::curr_proc, MemoryContextAlloc(), PLyExecutionContext::next, PLy_execution_contexts, PortalContext, PLyExecutionContext::scratch_ctx, and TopTransactionContext.

Referenced by plpython3_call_handler(), and plpython3_inline_handler().

Variable Documentation

◆ plpython_version_bitmask

int plpython_version_bitmask = 0
static

Definition at line 51 of file plpy_main.c.

Referenced by _PG_init().

◆ plpython_version_bitmask_ptr

int* plpython_version_bitmask_ptr = NULL
static

Definition at line 50 of file plpy_main.c.

Referenced by _PG_init(), and PLy_initialize().

◆ PLy_execution_contexts

PLyExecutionContext* PLy_execution_contexts = NULL
static

◆ PLy_interp_globals

PyObject* PLy_interp_globals = NULL

Definition at line 54 of file plpy_main.c.

Referenced by PLy_init_interp(), and PLy_procedure_compile().