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plpy_exec.h File Reference
#include "plpy_procedure.h"
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Functions

Datum PLy_exec_function (FunctionCallInfo fcinfo, PLyProcedure *proc)
 
HeapTuple PLy_exec_trigger (FunctionCallInfo fcinfo, PLyProcedure *proc)
 

Function Documentation

◆ PLy_exec_function()

Datum PLy_exec_function ( FunctionCallInfo  fcinfo,
PLyProcedure proc 
)

Definition at line 53 of file plpy_exec.c.

54 {
55  bool is_setof = proc->is_setof;
56  Datum rv;
57  PyObject *volatile plargs = NULL;
58  PyObject *volatile plrv = NULL;
59  FuncCallContext *volatile funcctx = NULL;
60  PLySRFState *volatile srfstate = NULL;
61  ErrorContextCallback plerrcontext;
62 
63  /*
64  * If the function is called recursively, we must push outer-level
65  * arguments into the stack. This must be immediately before the PG_TRY
66  * to ensure that the corresponding pop happens.
67  */
69 
70  PG_TRY();
71  {
72  if (is_setof)
73  {
74  /* First Call setup */
75  if (SRF_IS_FIRSTCALL())
76  {
77  funcctx = SRF_FIRSTCALL_INIT();
78  srfstate = (PLySRFState *)
80  sizeof(PLySRFState));
81  /* Immediately register cleanup callback */
83  srfstate->callback.arg = srfstate;
85  &srfstate->callback);
86  funcctx->user_fctx = srfstate;
87  }
88  /* Every call setup */
89  funcctx = SRF_PERCALL_SETUP();
90  Assert(funcctx != NULL);
91  srfstate = (PLySRFState *) funcctx->user_fctx;
92  Assert(srfstate != NULL);
93  }
94 
95  if (srfstate == NULL || srfstate->iter == NULL)
96  {
97  /*
98  * Non-SETOF function or first time for SETOF function: build
99  * args, then actually execute the function.
100  */
101  plargs = PLy_function_build_args(fcinfo, proc);
102  plrv = PLy_procedure_call(proc, "args", plargs);
103  Assert(plrv != NULL);
104  }
105  else
106  {
107  /*
108  * Second or later call for a SETOF function: restore arguments in
109  * globals dict to what they were when we left off. We must do
110  * this in case multiple evaluations of the same SETOF function
111  * are interleaved. It's a bit annoying, since the iterator may
112  * not look at the arguments at all, but we have no way to know
113  * that. Fortunately this isn't terribly expensive.
114  */
115  if (srfstate->savedargs)
116  PLy_function_restore_args(proc, srfstate->savedargs);
117  srfstate->savedargs = NULL; /* deleted by restore_args */
118  }
119 
120  /*
121  * If it returns a set, call the iterator to get the next return item.
122  * We stay in the SPI context while doing this, because PyIter_Next()
123  * calls back into Python code which might contain SPI calls.
124  */
125  if (is_setof)
126  {
127  if (srfstate->iter == NULL)
128  {
129  /* first time -- do checks and setup */
130  ReturnSetInfo *rsi = (ReturnSetInfo *) fcinfo->resultinfo;
131 
132  if (!rsi || !IsA(rsi, ReturnSetInfo) ||
133  (rsi->allowedModes & SFRM_ValuePerCall) == 0)
134  {
135  ereport(ERROR,
136  (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
137  errmsg("unsupported set function return mode"),
138  errdetail("PL/Python set-returning functions only support returning one value per call.")));
139  }
141 
142  /* Make iterator out of returned object */
143  srfstate->iter = PyObject_GetIter(plrv);
144 
145  Py_DECREF(plrv);
146  plrv = NULL;
147 
148  if (srfstate->iter == NULL)
149  ereport(ERROR,
150  (errcode(ERRCODE_DATATYPE_MISMATCH),
151  errmsg("returned object cannot be iterated"),
152  errdetail("PL/Python set-returning functions must return an iterable object.")));
153  }
154 
155  /* Fetch next from iterator */
156  plrv = PyIter_Next(srfstate->iter);
157  if (plrv == NULL)
158  {
159  /* Iterator is exhausted or error happened */
160  bool has_error = (PyErr_Occurred() != NULL);
161 
162  Py_DECREF(srfstate->iter);
163  srfstate->iter = NULL;
164 
165  if (has_error)
166  PLy_elog(ERROR, "error fetching next item from iterator");
167 
168  /* Pass a null through the data-returning steps below */
169  Py_INCREF(Py_None);
170  plrv = Py_None;
171  }
172  else
173  {
174  /*
175  * This won't be last call, so save argument values. We do
176  * this again each time in case the iterator is changing those
177  * values.
178  */
179  srfstate->savedargs = PLy_function_save_args(proc);
180  }
181  }
182 
183  /*
184  * Disconnect from SPI manager and then create the return values datum
185  * (if the input function does a palloc for it this must not be
186  * allocated in the SPI memory context because SPI_finish would free
187  * it).
188  */
189  if (SPI_finish() != SPI_OK_FINISH)
190  elog(ERROR, "SPI_finish failed");
191 
193  plerrcontext.previous = error_context_stack;
194  error_context_stack = &plerrcontext;
195 
196  /*
197  * For a procedure or function declared to return void, the Python
198  * return value must be None. For void-returning functions, we also
199  * treat a None return value as a special "void datum" rather than
200  * NULL (as is the case for non-void-returning functions).
201  */
202  if (proc->result.typoid == VOIDOID)
203  {
204  if (plrv != Py_None)
205  {
206  if (proc->is_procedure)
207  ereport(ERROR,
208  (errcode(ERRCODE_DATATYPE_MISMATCH),
209  errmsg("PL/Python procedure did not return None")));
210  else
211  ereport(ERROR,
212  (errcode(ERRCODE_DATATYPE_MISMATCH),
213  errmsg("PL/Python function with return type \"void\" did not return None")));
214  }
215 
216  fcinfo->isnull = false;
217  rv = (Datum) 0;
218  }
219  else if (plrv == Py_None &&
220  srfstate && srfstate->iter == NULL)
221  {
222  /*
223  * In a SETOF function, the iteration-ending null isn't a real
224  * value; don't pass it through the input function, which might
225  * complain.
226  */
227  fcinfo->isnull = true;
228  rv = (Datum) 0;
229  }
230  else
231  {
232  /*
233  * Normal conversion of result. However, if the result is of type
234  * RECORD, we have to set up for that each time through, since it
235  * might be different from last time.
236  */
237  if (proc->result.typoid == RECORDOID)
238  {
239  TupleDesc desc;
240 
241  if (get_call_result_type(fcinfo, NULL, &desc) != TYPEFUNC_COMPOSITE)
242  ereport(ERROR,
243  (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
244  errmsg("function returning record called in context "
245  "that cannot accept type record")));
246  PLy_output_setup_record(&proc->result, desc, proc);
247  }
248 
249  rv = PLy_output_convert(&proc->result, plrv,
250  &fcinfo->isnull);
251  }
252  }
253  PG_CATCH();
254  {
255  /* Pop old arguments from the stack if they were pushed above */
256  PLy_global_args_pop(proc);
257 
258  Py_XDECREF(plargs);
259  Py_XDECREF(plrv);
260 
261  /*
262  * If there was an error within a SRF, the iterator might not have
263  * been exhausted yet. Clear it so the next invocation of the
264  * function will start the iteration again. (This code is probably
265  * unnecessary now; plpython_srf_cleanup_callback should take care of
266  * cleanup. But it doesn't hurt anything to do it here.)
267  */
268  if (srfstate)
269  {
270  Py_XDECREF(srfstate->iter);
271  srfstate->iter = NULL;
272  /* And drop any saved args; we won't need them */
273  if (srfstate->savedargs)
275  srfstate->savedargs = NULL;
276  }
277 
278  PG_RE_THROW();
279  }
280  PG_END_TRY();
281 
282  error_context_stack = plerrcontext.previous;
283 
284  /* Pop old arguments from the stack if they were pushed above */
285  PLy_global_args_pop(proc);
286 
287  Py_XDECREF(plargs);
288  Py_DECREF(plrv);
289 
290  if (srfstate)
291  {
292  /* We're in a SRF, exit appropriately */
293  if (srfstate->iter == NULL)
294  {
295  /* Iterator exhausted, so we're done */
296  SRF_RETURN_DONE(funcctx);
297  }
298  else if (fcinfo->isnull)
299  SRF_RETURN_NEXT_NULL(funcctx);
300  else
301  SRF_RETURN_NEXT(funcctx, rv);
302  }
303 
304  /* Plain function, just return the Datum value (possibly null) */
305  return rv;
306 }
#define Assert(condition)
Definition: c.h:837
int errdetail(const char *fmt,...)
Definition: elog.c:1203
ErrorContextCallback * error_context_stack
Definition: elog.c:94
int errcode(int sqlerrcode)
Definition: elog.c:853
int errmsg(const char *fmt,...)
Definition: elog.c:1070
#define PG_RE_THROW()
Definition: elog.h:412
#define PG_TRY(...)
Definition: elog.h:371
#define PG_END_TRY(...)
Definition: elog.h:396
#define ERROR
Definition: elog.h:39
#define PG_CATCH(...)
Definition: elog.h:381
#define elog(elevel,...)
Definition: elog.h:225
#define ereport(elevel,...)
Definition: elog.h:149
@ SFRM_ValuePerCall
Definition: execnodes.h:319
TypeFuncClass get_call_result_type(FunctionCallInfo fcinfo, Oid *resultTypeId, TupleDesc *resultTupleDesc)
Definition: funcapi.c:276
#define SRF_IS_FIRSTCALL()
Definition: funcapi.h:304
#define SRF_RETURN_NEXT_NULL(_funcctx)
Definition: funcapi.h:319
#define SRF_PERCALL_SETUP()
Definition: funcapi.h:308
@ TYPEFUNC_COMPOSITE
Definition: funcapi.h:149
#define SRF_RETURN_NEXT(_funcctx, _result)
Definition: funcapi.h:310
#define SRF_FIRSTCALL_INIT()
Definition: funcapi.h:306
#define SRF_RETURN_DONE(_funcctx)
Definition: funcapi.h:328
if(TABLE==NULL||TABLE_index==NULL)
Definition: isn.c:76
#define PLy_elog
void MemoryContextRegisterResetCallback(MemoryContext context, MemoryContextCallback *cb)
Definition: mcxt.c:568
void * MemoryContextAllocZero(MemoryContext context, Size size)
Definition: mcxt.c:1215
#define IsA(nodeptr, _type_)
Definition: nodes.h:158
static void PLy_function_drop_args(PLySavedArgs *savedargs)
Definition: plpy_exec.c:582
static void PLy_global_args_push(PLyProcedure *proc)
Definition: plpy_exec.c:611
static PyObject * PLy_function_build_args(FunctionCallInfo fcinfo, PLyProcedure *proc)
Definition: plpy_exec.c:433
static void PLy_function_restore_args(PLyProcedure *proc, PLySavedArgs *savedargs)
Definition: plpy_exec.c:542
static PyObject * PLy_procedure_call(PLyProcedure *proc, const char *kargs, PyObject *vargs)
Definition: plpy_exec.c:1060
static void PLy_global_args_pop(PLyProcedure *proc)
Definition: plpy_exec.c:641
static void plpython_srf_cleanup_callback(void *arg)
Definition: plpy_exec.c:679
static PLySavedArgs * PLy_function_save_args(PLyProcedure *proc)
Definition: plpy_exec.c:496
static void plpython_return_error_callback(void *arg)
Definition: plpy_exec.c:693
void PLy_output_setup_record(PLyObToDatum *arg, TupleDesc desc, PLyProcedure *proc)
Definition: plpy_typeio.c:261
Datum PLy_output_convert(PLyObToDatum *arg, PyObject *val, bool *isnull)
Definition: plpy_typeio.c:120
uintptr_t Datum
Definition: postgres.h:64
int SPI_finish(void)
Definition: spi.c:182
#define SPI_OK_FINISH
Definition: spi.h:83
struct ErrorContextCallback * previous
Definition: elog.h:296
void(* callback)(void *arg)
Definition: elog.h:297
void * user_fctx
Definition: funcapi.h:82
MemoryContext multi_call_memory_ctx
Definition: funcapi.h:101
fmNodePtr resultinfo
Definition: fmgr.h:89
MemoryContextCallbackFunction func
Definition: palloc.h:49
PLyObToDatum result
MemoryContextCallback callback
Definition: plpy_exec.c:29
PLySavedArgs * savedargs
Definition: plpy_exec.c:28
PyObject * iter
Definition: plpy_exec.c:27
SetFunctionReturnMode returnMode
Definition: execnodes.h:339
int allowedModes
Definition: execnodes.h:337

References ReturnSetInfo::allowedModes, MemoryContextCallback::arg, Assert, ErrorContextCallback::callback, PLySRFState::callback, elog, ereport, errcode(), errdetail(), errmsg(), ERROR, error_context_stack, MemoryContextCallback::func, get_call_result_type(), if(), PLyProcedure::is_procedure, PLyProcedure::is_setof, IsA, FunctionCallInfoBaseData::isnull, PLySRFState::iter, MemoryContextAllocZero(), MemoryContextRegisterResetCallback(), FuncCallContext::multi_call_memory_ctx, PG_CATCH, PG_END_TRY, PG_RE_THROW, PG_TRY, plpython_return_error_callback(), plpython_srf_cleanup_callback(), PLy_elog, PLy_function_build_args(), PLy_function_drop_args(), PLy_function_restore_args(), PLy_function_save_args(), PLy_global_args_pop(), PLy_global_args_push(), PLy_output_convert(), PLy_output_setup_record(), PLy_procedure_call(), ErrorContextCallback::previous, PLyProcedure::result, FunctionCallInfoBaseData::resultinfo, ReturnSetInfo::returnMode, PLySRFState::savedargs, SFRM_ValuePerCall, SPI_finish(), SPI_OK_FINISH, SRF_FIRSTCALL_INIT, SRF_IS_FIRSTCALL, SRF_PERCALL_SETUP, SRF_RETURN_DONE, SRF_RETURN_NEXT, SRF_RETURN_NEXT_NULL, TYPEFUNC_COMPOSITE, PLyObToDatum::typoid, and FuncCallContext::user_fctx.

Referenced by plpython3_call_handler(), and plpython3_inline_handler().

◆ PLy_exec_trigger()

HeapTuple PLy_exec_trigger ( FunctionCallInfo  fcinfo,
PLyProcedure proc 
)

Definition at line 319 of file plpy_exec.c.

320 {
321  HeapTuple rv = NULL;
322  PyObject *volatile plargs = NULL;
323  PyObject *volatile plrv = NULL;
324  TriggerData *tdata;
325  TupleDesc rel_descr;
326 
327  Assert(CALLED_AS_TRIGGER(fcinfo));
328  tdata = (TriggerData *) fcinfo->context;
329 
330  /*
331  * Input/output conversion for trigger tuples. We use the result and
332  * result_in fields to store the tuple conversion info. We do this over
333  * again on each call to cover the possibility that the relation's tupdesc
334  * changed since the trigger was last called. The PLy_xxx_setup_func
335  * calls should only happen once, but PLy_input_setup_tuple and
336  * PLy_output_setup_tuple are responsible for not doing repetitive work.
337  */
338  rel_descr = RelationGetDescr(tdata->tg_relation);
339  if (proc->result.typoid != rel_descr->tdtypeid)
340  PLy_output_setup_func(&proc->result, proc->mcxt,
341  rel_descr->tdtypeid,
342  rel_descr->tdtypmod,
343  proc);
344  if (proc->result_in.typoid != rel_descr->tdtypeid)
345  PLy_input_setup_func(&proc->result_in, proc->mcxt,
346  rel_descr->tdtypeid,
347  rel_descr->tdtypmod,
348  proc);
349  PLy_output_setup_tuple(&proc->result, rel_descr, proc);
350  PLy_input_setup_tuple(&proc->result_in, rel_descr, proc);
351 
352  /*
353  * If the trigger is called recursively, we must push outer-level
354  * arguments into the stack. This must be immediately before the PG_TRY
355  * to ensure that the corresponding pop happens.
356  */
357  PLy_global_args_push(proc);
358 
359  PG_TRY();
360  {
362 
363  rc = SPI_register_trigger_data(tdata);
364  Assert(rc >= 0);
365 
366  plargs = PLy_trigger_build_args(fcinfo, proc, &rv);
367  plrv = PLy_procedure_call(proc, "TD", plargs);
368 
369  Assert(plrv != NULL);
370 
371  /*
372  * Disconnect from SPI manager
373  */
374  if (SPI_finish() != SPI_OK_FINISH)
375  elog(ERROR, "SPI_finish failed");
376 
377  /*
378  * return of None means we're happy with the tuple
379  */
380  if (plrv != Py_None)
381  {
382  char *srv;
383 
384  if (PyUnicode_Check(plrv))
385  srv = PLyUnicode_AsString(plrv);
386  else
387  {
388  ereport(ERROR,
389  (errcode(ERRCODE_DATA_EXCEPTION),
390  errmsg("unexpected return value from trigger procedure"),
391  errdetail("Expected None or a string.")));
392  srv = NULL; /* keep compiler quiet */
393  }
394 
395  if (pg_strcasecmp(srv, "SKIP") == 0)
396  rv = NULL;
397  else if (pg_strcasecmp(srv, "MODIFY") == 0)
398  {
399  if (TRIGGER_FIRED_BY_INSERT(tdata->tg_event) ||
401  rv = PLy_modify_tuple(proc, plargs, tdata, rv);
402  else
404  (errmsg("PL/Python trigger function returned \"MODIFY\" in a DELETE trigger -- ignored")));
405  }
406  else if (pg_strcasecmp(srv, "OK") != 0)
407  {
408  /*
409  * accept "OK" as an alternative to None; otherwise, raise an
410  * error
411  */
412  ereport(ERROR,
413  (errcode(ERRCODE_DATA_EXCEPTION),
414  errmsg("unexpected return value from trigger procedure"),
415  errdetail("Expected None, \"OK\", \"SKIP\", or \"MODIFY\".")));
416  }
417  }
418  }
419  PG_FINALLY();
420  {
421  PLy_global_args_pop(proc);
422  Py_XDECREF(plargs);
423  Py_XDECREF(plrv);
424  }
425  PG_END_TRY();
426 
427  return rv;
428 }
#define PG_USED_FOR_ASSERTS_ONLY
Definition: c.h:197
#define WARNING
Definition: elog.h:36
#define PG_FINALLY(...)
Definition: elog.h:388
static PyObject * PLy_trigger_build_args(FunctionCallInfo fcinfo, PLyProcedure *proc, HeapTuple *rv)
Definition: plpy_exec.c:703
static HeapTuple PLy_modify_tuple(PLyProcedure *proc, PyObject *pltd, TriggerData *tdata, HeapTuple otup)
Definition: plpy_exec.c:920
void PLy_output_setup_func(PLyObToDatum *arg, MemoryContext arg_mcxt, Oid typeOid, int32 typmod, PLyProcedure *proc)
Definition: plpy_typeio.c:296
void PLy_input_setup_func(PLyDatumToOb *arg, MemoryContext arg_mcxt, Oid typeOid, int32 typmod, PLyProcedure *proc)
Definition: plpy_typeio.c:418
void PLy_input_setup_tuple(PLyDatumToOb *arg, TupleDesc desc, PLyProcedure *proc)
Definition: plpy_typeio.c:165
void PLy_output_setup_tuple(PLyObToDatum *arg, TupleDesc desc, PLyProcedure *proc)
Definition: plpy_typeio.c:215
char * PLyUnicode_AsString(PyObject *unicode)
Definition: plpy_util.c:82
int pg_strcasecmp(const char *s1, const char *s2)
Definition: pgstrcasecmp.c:36
#define RelationGetDescr(relation)
Definition: rel.h:531
int SPI_register_trigger_data(TriggerData *tdata)
Definition: spi.c:3364
fmNodePtr context
Definition: fmgr.h:88
PLyDatumToOb result_in
MemoryContext mcxt
Relation tg_relation
Definition: trigger.h:35
TriggerEvent tg_event
Definition: trigger.h:34
int32 tdtypmod
Definition: tupdesc.h:83
Oid tdtypeid
Definition: tupdesc.h:82
#define CALLED_AS_TRIGGER(fcinfo)
Definition: trigger.h:26
#define TRIGGER_FIRED_BY_INSERT(event)
Definition: trigger.h:110
#define TRIGGER_FIRED_BY_UPDATE(event)
Definition: trigger.h:116

References Assert, CALLED_AS_TRIGGER, FunctionCallInfoBaseData::context, elog, ereport, errcode(), errdetail(), errmsg(), ERROR, PLyProcedure::mcxt, PG_END_TRY, PG_FINALLY, pg_strcasecmp(), PG_TRY, PG_USED_FOR_ASSERTS_ONLY, PLy_global_args_pop(), PLy_global_args_push(), PLy_input_setup_func(), PLy_input_setup_tuple(), PLy_modify_tuple(), PLy_output_setup_func(), PLy_output_setup_tuple(), PLy_procedure_call(), PLy_trigger_build_args(), PLyUnicode_AsString(), RelationGetDescr, PLyProcedure::result, PLyProcedure::result_in, SPI_finish(), SPI_OK_FINISH, SPI_register_trigger_data(), TupleDescData::tdtypeid, TupleDescData::tdtypmod, TriggerData::tg_event, TriggerData::tg_relation, TRIGGER_FIRED_BY_INSERT, TRIGGER_FIRED_BY_UPDATE, PLyDatumToOb::typoid, PLyObToDatum::typoid, and WARNING.

Referenced by plpython3_call_handler().