From: Peter Eisentraut Date: Thu, 15 Dec 2011 14:52:57 +0000 (+0200) Subject: PL/Python: Refactor subtransaction handling X-Git-Tag: REL9_2_BETA1~697 X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=fc9959701b57d11d08a4a8a0788ccbd887ee2e47;p=postgresql PL/Python: Refactor subtransaction handling Lots of repetitive code was moved into new functions PLy_spi_subtransaction_{begin,commit,abort}. Jan Urbański --- diff --git a/src/pl/plpython/plpython.c b/src/pl/plpython/plpython.c index 29e0ac7c45..dce8ff247b 100644 --- a/src/pl/plpython/plpython.c +++ b/src/pl/plpython/plpython.c @@ -2964,6 +2964,12 @@ static int PLy_result_ass_item(PyObject *, Py_ssize_t, PyObject *); static int PLy_result_ass_slice(PyObject *, Py_ssize_t, Py_ssize_t, PyObject *); +/* handling of SPI operations inside subtransactions */ +static void PLy_spi_subtransaction_begin(MemoryContext oldcontext, ResourceOwner oldowner); +static void PLy_spi_subtransaction_commit(MemoryContext oldcontext, ResourceOwner oldowner); +static void PLy_spi_subtransaction_abort(MemoryContext oldcontext, ResourceOwner oldowner); + +/* SPI operations */ static PyObject *PLy_spi_prepare(PyObject *, PyObject *); static PyObject *PLy_spi_execute(PyObject *, PyObject *); static PyObject *PLy_spi_execute_query(char *query, long limit); @@ -3390,6 +3396,90 @@ PLy_result_ass_slice(PyObject *arg, Py_ssize_t lidx, Py_ssize_t hidx, PyObject * return rv; } +/* + * Utilities for running SPI functions in subtransactions. + * + * Usage: + * + * MemoryContext oldcontext = CurrentMemoryContext; + * ResourceOwner oldowner = CurrentResourceOwner; + * + * PLy_spi_subtransaction_begin(oldcontext, oldowner); + * PG_TRY(); + * { + * + * PLy_spi_subtransaction_commit(oldcontext, oldowner); + * } + * PG_CATCH(); + * { + * + * PLy_spi_subtransaction_abort(oldcontext, oldowner); + * return NULL; + * } + * PG_END_TRY(); + * + * These utilities take care of restoring connection to the SPI manager and + * setting a Python exception in case of an abort. + */ +static void +PLy_spi_subtransaction_begin(MemoryContext oldcontext, ResourceOwner oldowner) +{ + BeginInternalSubTransaction(NULL); + /* Want to run inside function's memory context */ + MemoryContextSwitchTo(oldcontext); +} + +static void +PLy_spi_subtransaction_commit(MemoryContext oldcontext, ResourceOwner oldowner) +{ + /* Commit the inner transaction, return to outer xact context */ + ReleaseCurrentSubTransaction(); + MemoryContextSwitchTo(oldcontext); + CurrentResourceOwner = oldowner; + + /* + * AtEOSubXact_SPI() should not have popped any SPI context, but just + * in case it did, make sure we remain connected. + */ + SPI_restore_connection(); +} + +static void +PLy_spi_subtransaction_abort(MemoryContext oldcontext, ResourceOwner oldowner) +{ + ErrorData *edata; + PLyExceptionEntry *entry; + PyObject *exc; + + /* Save error info */ + MemoryContextSwitchTo(oldcontext); + edata = CopyErrorData(); + FlushErrorState(); + + /* Abort the inner transaction */ + RollbackAndReleaseCurrentSubTransaction(); + MemoryContextSwitchTo(oldcontext); + CurrentResourceOwner = oldowner; + + /* + * If AtEOSubXact_SPI() popped any SPI context of the subxact, it will have + * left us in a disconnected state. We need this hack to return to + * connected state. + */ + SPI_restore_connection(); + + /* Look up the correct exception */ + entry = hash_search(PLy_spi_exceptions, &(edata->sqlerrcode), + HASH_FIND, NULL); + /* We really should find it, but just in case have a fallback */ + Assert(entry != NULL); + exc = entry ? entry->exc : PLy_exc_spi_error; + /* Make Python raise the exception */ + PLy_spi_exception_set(exc, edata); + FreeErrorData(edata); +} + + /* SPI interface */ static PyObject * PLy_spi_prepare(PyObject *self, PyObject *args) @@ -3425,8 +3515,7 @@ PLy_spi_prepare(PyObject *self, PyObject *args) oldcontext = CurrentMemoryContext; oldowner = CurrentResourceOwner; - BeginInternalSubTransaction(NULL); - MemoryContextSwitchTo(oldcontext); + PLy_spi_subtransaction_begin(oldcontext, oldowner); PG_TRY(); { @@ -3504,50 +3593,14 @@ PLy_spi_prepare(PyObject *self, PyObject *args) if (SPI_keepplan(plan->plan)) elog(ERROR, "SPI_keepplan failed"); - /* Commit the inner transaction, return to outer xact context */ - ReleaseCurrentSubTransaction(); - MemoryContextSwitchTo(oldcontext); - CurrentResourceOwner = oldowner; - - /* - * AtEOSubXact_SPI() should not have popped any SPI context, but just - * in case it did, make sure we remain connected. - */ - SPI_restore_connection(); + PLy_spi_subtransaction_commit(oldcontext, oldowner); } PG_CATCH(); { - ErrorData *edata; - PLyExceptionEntry *entry; - PyObject *exc; - - /* Save error info */ - MemoryContextSwitchTo(oldcontext); - edata = CopyErrorData(); - FlushErrorState(); Py_DECREF(plan); Py_XDECREF(optr); - /* Abort the inner transaction */ - RollbackAndReleaseCurrentSubTransaction(); - MemoryContextSwitchTo(oldcontext); - CurrentResourceOwner = oldowner; - - /* - * If AtEOSubXact_SPI() popped any SPI context of the subxact, it will - * have left us in a disconnected state. We need this hack to return - * to connected state. - */ - SPI_restore_connection(); - - /* Look up the correct exception */ - entry = hash_search(PLy_spi_exceptions, &(edata->sqlerrcode), - HASH_FIND, NULL); - /* We really should find it, but just in case have a fallback */ - Assert(entry != NULL); - exc = entry ? entry->exc : PLy_exc_spi_error; - /* Make Python raise the exception */ - PLy_spi_exception_set(exc, edata); + PLy_spi_subtransaction_abort(oldcontext, oldowner); return NULL; } PG_END_TRY(); @@ -3626,9 +3679,7 @@ PLy_spi_execute_plan(PyObject *ob, PyObject *list, long limit) oldcontext = CurrentMemoryContext; oldowner = CurrentResourceOwner; - BeginInternalSubTransaction(NULL); - /* Want to run inside function's memory context */ - MemoryContextSwitchTo(oldcontext); + PLy_spi_subtransaction_begin(oldcontext, oldowner); PG_TRY(); { @@ -3683,28 +3734,11 @@ PLy_spi_execute_plan(PyObject *ob, PyObject *list, long limit) if (nargs > 0) pfree(nulls); - /* Commit the inner transaction, return to outer xact context */ - ReleaseCurrentSubTransaction(); - MemoryContextSwitchTo(oldcontext); - CurrentResourceOwner = oldowner; - - /* - * AtEOSubXact_SPI() should not have popped any SPI context, but just - * in case it did, make sure we remain connected. - */ - SPI_restore_connection(); + PLy_spi_subtransaction_commit(oldcontext, oldowner); } PG_CATCH(); { int k; - ErrorData *edata; - PLyExceptionEntry *entry; - PyObject *exc; - - /* Save error info */ - MemoryContextSwitchTo(oldcontext); - edata = CopyErrorData(); - FlushErrorState(); /* * cleanup plan->values array @@ -3719,26 +3753,7 @@ PLy_spi_execute_plan(PyObject *ob, PyObject *list, long limit) } } - /* Abort the inner transaction */ - RollbackAndReleaseCurrentSubTransaction(); - MemoryContextSwitchTo(oldcontext); - CurrentResourceOwner = oldowner; - - /* - * If AtEOSubXact_SPI() popped any SPI context of the subxact, it will - * have left us in a disconnected state. We need this hack to return - * to connected state. - */ - SPI_restore_connection(); - - /* Look up the correct exception */ - entry = hash_search(PLy_spi_exceptions, &(edata->sqlerrcode), - HASH_FIND, NULL); - /* We really should find it, but just in case have a fallback */ - Assert(entry != NULL); - exc = entry ? entry->exc : PLy_exc_spi_error; - /* Make Python raise the exception */ - PLy_spi_exception_set(exc, edata); + PLy_spi_subtransaction_abort(oldcontext, oldowner); return NULL; } PG_END_TRY(); @@ -3775,9 +3790,7 @@ PLy_spi_execute_query(char *query, long limit) oldcontext = CurrentMemoryContext; oldowner = CurrentResourceOwner; - BeginInternalSubTransaction(NULL); - /* Want to run inside function's memory context */ - MemoryContextSwitchTo(oldcontext); + PLy_spi_subtransaction_begin(oldcontext, oldowner); PG_TRY(); { @@ -3785,48 +3798,11 @@ PLy_spi_execute_query(char *query, long limit) rv = SPI_execute(query, PLy_curr_procedure->fn_readonly, limit); ret = PLy_spi_execute_fetch_result(SPI_tuptable, SPI_processed, rv); - /* Commit the inner transaction, return to outer xact context */ - ReleaseCurrentSubTransaction(); - MemoryContextSwitchTo(oldcontext); - CurrentResourceOwner = oldowner; - - /* - * AtEOSubXact_SPI() should not have popped any SPI context, but just - * in case it did, make sure we remain connected. - */ - SPI_restore_connection(); + PLy_spi_subtransaction_commit(oldcontext, oldowner); } PG_CATCH(); { - ErrorData *edata; - PLyExceptionEntry *entry; - PyObject *exc; - - /* Save error info */ - MemoryContextSwitchTo(oldcontext); - edata = CopyErrorData(); - FlushErrorState(); - - /* Abort the inner transaction */ - RollbackAndReleaseCurrentSubTransaction(); - MemoryContextSwitchTo(oldcontext); - CurrentResourceOwner = oldowner; - - /* - * If AtEOSubXact_SPI() popped any SPI context of the subxact, it will - * have left us in a disconnected state. We need this hack to return - * to connected state. - */ - SPI_restore_connection(); - - /* Look up the correct exception */ - entry = hash_search(PLy_spi_exceptions, &edata->sqlerrcode, - HASH_FIND, NULL); - /* We really should find it, but just in case have a fallback */ - Assert(entry != NULL); - exc = entry ? entry->exc : PLy_exc_spi_error; - /* Make Python raise the exception */ - PLy_spi_exception_set(exc, edata); + PLy_spi_subtransaction_abort(oldcontext, oldowner); return NULL; } PG_END_TRY(); @@ -3944,8 +3920,7 @@ PLy_cursor_query(const char *query) oldcontext = CurrentMemoryContext; oldowner = CurrentResourceOwner; - BeginInternalSubTransaction(NULL); - MemoryContextSwitchTo(oldcontext); + PLy_spi_subtransaction_begin(oldcontext, oldowner); PG_TRY(); { @@ -3969,50 +3944,11 @@ PLy_cursor_query(const char *query) cursor->portalname = PLy_strdup(portal->name); - /* Commit the inner transaction, return to outer xact context */ - ReleaseCurrentSubTransaction(); - MemoryContextSwitchTo(oldcontext); - CurrentResourceOwner = oldowner; - - /* - * AtEOSubXact_SPI() should not have popped any SPI context, but just - * in case it did, make sure we remain connected. - */ - SPI_restore_connection(); + PLy_spi_subtransaction_commit(oldcontext, oldowner); } PG_CATCH(); { - ErrorData *edata; - PLyExceptionEntry *entry; - PyObject *exc; - - /* Save error info */ - MemoryContextSwitchTo(oldcontext); - edata = CopyErrorData(); - FlushErrorState(); - - /* Abort the inner transaction */ - RollbackAndReleaseCurrentSubTransaction(); - MemoryContextSwitchTo(oldcontext); - CurrentResourceOwner = oldowner; - - Py_DECREF(cursor); - - /* - * If AtEOSubXact_SPI() popped any SPI context of the subxact, it will - * have left us in a disconnected state. We need this hack to return - * to connected state. - */ - SPI_restore_connection(); - - /* Look up the correct exception */ - entry = hash_search(PLy_spi_exceptions, &(edata->sqlerrcode), - HASH_FIND, NULL); - /* We really should find it, but just in case have a fallback */ - Assert(entry != NULL); - exc = entry ? entry->exc : PLy_exc_spi_error; - /* Make Python raise the exception */ - PLy_spi_exception_set(exc, edata); + PLy_spi_subtransaction_abort(oldcontext, oldowner); return NULL; } PG_END_TRY(); @@ -4072,8 +4008,7 @@ PLy_cursor_plan(PyObject *ob, PyObject *args) oldcontext = CurrentMemoryContext; oldowner = CurrentResourceOwner; - BeginInternalSubTransaction(NULL); - MemoryContextSwitchTo(oldcontext); + PLy_spi_subtransaction_begin(oldcontext, oldowner); PG_TRY(); { @@ -4130,28 +4065,11 @@ PLy_cursor_plan(PyObject *ob, PyObject *args) cursor->portalname = PLy_strdup(portal->name); - /* Commit the inner transaction, return to outer xact context */ - ReleaseCurrentSubTransaction(); - MemoryContextSwitchTo(oldcontext); - CurrentResourceOwner = oldowner; - - /* - * AtEOSubXact_SPI() should not have popped any SPI context, but just - * in case it did, make sure we remain connected. - */ - SPI_restore_connection(); + PLy_spi_subtransaction_commit(oldcontext, oldowner); } PG_CATCH(); { int k; - ErrorData *edata; - PLyExceptionEntry *entry; - PyObject *exc; - - /* Save error info */ - MemoryContextSwitchTo(oldcontext); - edata = CopyErrorData(); - FlushErrorState(); /* cleanup plan->values array */ for (k = 0; k < nargs; k++) @@ -4164,28 +4082,9 @@ PLy_cursor_plan(PyObject *ob, PyObject *args) } } - /* Abort the inner transaction */ - RollbackAndReleaseCurrentSubTransaction(); - MemoryContextSwitchTo(oldcontext); - CurrentResourceOwner = oldowner; - Py_DECREF(cursor); - /* - * If AtEOSubXact_SPI() popped any SPI context of the subxact, it will - * have left us in a disconnected state. We need this hack to return - * to connected state. - */ - SPI_restore_connection(); - - /* Look up the correct exception */ - entry = hash_search(PLy_spi_exceptions, &(edata->sqlerrcode), - HASH_FIND, NULL); - /* We really should find it, but just in case have a fallback */ - Assert(entry != NULL); - exc = entry ? entry->exc : PLy_exc_spi_error; - /* Make Python raise the exception */ - PLy_spi_exception_set(exc, edata); + PLy_spi_subtransaction_abort(oldcontext, oldowner); return NULL; } PG_END_TRY(); @@ -4255,8 +4154,7 @@ PLy_cursor_iternext(PyObject *self) oldcontext = CurrentMemoryContext; oldowner = CurrentResourceOwner; - BeginInternalSubTransaction(NULL); - MemoryContextSwitchTo(oldcontext); + PLy_spi_subtransaction_begin(oldcontext, oldowner); PG_TRY(); { @@ -4277,50 +4175,13 @@ PLy_cursor_iternext(PyObject *self) SPI_freetuptable(SPI_tuptable); - /* Commit the inner transaction, return to outer xact context */ - ReleaseCurrentSubTransaction(); - MemoryContextSwitchTo(oldcontext); - CurrentResourceOwner = oldowner; - - /* - * AtEOSubXact_SPI() should not have popped any SPI context, but just - * in case it did, make sure we remain connected. - */ - SPI_restore_connection(); + PLy_spi_subtransaction_commit(oldcontext, oldowner); } PG_CATCH(); { - ErrorData *edata; - PLyExceptionEntry *entry; - PyObject *exc; - - /* Save error info */ - MemoryContextSwitchTo(oldcontext); - edata = CopyErrorData(); - FlushErrorState(); - - /* Abort the inner transaction */ - RollbackAndReleaseCurrentSubTransaction(); - MemoryContextSwitchTo(oldcontext); - CurrentResourceOwner = oldowner; - SPI_freetuptable(SPI_tuptable); - /* - * If AtEOSubXact_SPI() popped any SPI context of the subxact, it will - * have left us in a disconnected state. We need this hack to return - * to connected state. - */ - SPI_restore_connection(); - - /* Look up the correct exception */ - entry = hash_search(PLy_spi_exceptions, &edata->sqlerrcode, - HASH_FIND, NULL); - /* We really should find it, but just in case have a fallback */ - Assert(entry != NULL); - exc = entry ? entry->exc : PLy_exc_spi_error; - /* Make Python raise the exception */ - PLy_spi_exception_set(exc, edata); + PLy_spi_subtransaction_abort(oldcontext, oldowner); return NULL; } PG_END_TRY(); @@ -4364,8 +4225,7 @@ PLy_cursor_fetch(PyObject *self, PyObject *args) oldcontext = CurrentMemoryContext; oldowner = CurrentResourceOwner; - BeginInternalSubTransaction(NULL); - MemoryContextSwitchTo(oldcontext); + PLy_spi_subtransaction_begin(oldcontext, oldowner); PG_TRY(); { @@ -4398,50 +4258,13 @@ PLy_cursor_fetch(PyObject *self, PyObject *args) SPI_freetuptable(SPI_tuptable); - /* Commit the inner transaction, return to outer xact context */ - ReleaseCurrentSubTransaction(); - MemoryContextSwitchTo(oldcontext); - CurrentResourceOwner = oldowner; - - /* - * AtEOSubXact_SPI() should not have popped any SPI context, but just - * in case it did, make sure we remain connected. - */ - SPI_restore_connection(); + PLy_spi_subtransaction_commit(oldcontext, oldowner); } PG_CATCH(); { - ErrorData *edata; - PLyExceptionEntry *entry; - PyObject *exc; - - /* Save error info */ - MemoryContextSwitchTo(oldcontext); - edata = CopyErrorData(); - FlushErrorState(); - - /* Abort the inner transaction */ - RollbackAndReleaseCurrentSubTransaction(); - MemoryContextSwitchTo(oldcontext); - CurrentResourceOwner = oldowner; - SPI_freetuptable(SPI_tuptable); - /* - * If AtEOSubXact_SPI() popped any SPI context of the subxact, it will - * have left us in a disconnected state. We need this hack to return - * to connected state. - */ - SPI_restore_connection(); - - /* Look up the correct exception */ - entry = hash_search(PLy_spi_exceptions, &edata->sqlerrcode, - HASH_FIND, NULL); - /* We really should find it, but just in case have a fallback */ - Assert(entry != NULL); - exc = entry ? entry->exc : PLy_exc_spi_error; - /* Make Python raise the exception */ - PLy_spi_exception_set(exc, edata); + PLy_spi_subtransaction_abort(oldcontext, oldowner); return NULL; } PG_END_TRY();