diff --git a/contrib/dblink/dblink.c b/contrib/dblink/dblink.c index 8a0b112a7ff2..1d456ee6391f 100644 --- a/contrib/dblink/dblink.c +++ b/contrib/dblink/dblink.c @@ -101,8 +101,8 @@ static void materializeQueryResult(FunctionCallInfo fcinfo, const char *conname, const char *sql, bool fail); -static PGresult *storeQueryResult(volatile storeInfo *sinfo, PGconn *conn, const char *sql); -static void storeRow(volatile storeInfo *sinfo, PGresult *res, bool first); +static PGresult *storeQueryResult(storeInfo *sinfo, PGconn *conn, const char *sql); +static void storeRow(storeInfo *sinfo, PGresult *res, bool first); static remoteConn *getConnectionByName(const char *name); static HTAB *createConnHash(void); static remoteConn *createNewConnection(const char *name); @@ -169,14 +169,6 @@ typedef struct remoteConnHashEnt /* initial number of connection hashes */ #define NUMCONN 16 -static char * -xpstrdup(const char *in) -{ - if (in == NULL) - return NULL; - return pstrdup(in); -} - pg_noreturn static void dblink_res_internalerror(PGconn *conn, PGresult *res, const char *p2) { @@ -863,131 +855,123 @@ static void materializeResult(FunctionCallInfo fcinfo, PGconn *conn, PGresult *res) { ReturnSetInfo *rsinfo = (ReturnSetInfo *) fcinfo->resultinfo; + TupleDesc tupdesc; + bool is_sql_cmd; + int ntuples; + int nfields; /* prepTuplestoreResult must have been called previously */ Assert(rsinfo->returnMode == SFRM_Materialize); - PG_TRY(); + if (PQresultStatus(res) == PGRES_COMMAND_OK) { - TupleDesc tupdesc; - bool is_sql_cmd; - int ntuples; - int nfields; + is_sql_cmd = true; - if (PQresultStatus(res) == PGRES_COMMAND_OK) - { - is_sql_cmd = true; + /* + * need a tuple descriptor representing one TEXT column to return the + * command status string as our result tuple + */ + tupdesc = CreateTemplateTupleDesc(1); + TupleDescInitEntry(tupdesc, (AttrNumber) 1, "status", + TEXTOID, -1, 0); + ntuples = 1; + nfields = 1; + } + else + { + Assert(PQresultStatus(res) == PGRES_TUPLES_OK); - /* - * need a tuple descriptor representing one TEXT column to return - * the command status string as our result tuple - */ - tupdesc = CreateTemplateTupleDesc(1); - TupleDescInitEntry(tupdesc, (AttrNumber) 1, "status", - TEXTOID, -1, 0); - ntuples = 1; - nfields = 1; - } - else - { - Assert(PQresultStatus(res) == PGRES_TUPLES_OK); + is_sql_cmd = false; - is_sql_cmd = false; + /* get a tuple descriptor for our result type */ + switch (get_call_result_type(fcinfo, NULL, &tupdesc)) + { + case TYPEFUNC_COMPOSITE: + /* success */ + break; + case TYPEFUNC_RECORD: + /* failed to determine actual type of RECORD */ + ereport(ERROR, + (errcode(ERRCODE_FEATURE_NOT_SUPPORTED), + errmsg("function returning record called in context " + "that cannot accept type record"))); + break; + default: + /* result type isn't composite */ + elog(ERROR, "return type must be a row type"); + break; + } - /* get a tuple descriptor for our result type */ - switch (get_call_result_type(fcinfo, NULL, &tupdesc)) - { - case TYPEFUNC_COMPOSITE: - /* success */ - break; - case TYPEFUNC_RECORD: - /* failed to determine actual type of RECORD */ - ereport(ERROR, - (errcode(ERRCODE_FEATURE_NOT_SUPPORTED), - errmsg("function returning record called in context " - "that cannot accept type record"))); - break; - default: - /* result type isn't composite */ - elog(ERROR, "return type must be a row type"); - break; - } + /* make sure we have a persistent copy of the tupdesc */ + tupdesc = CreateTupleDescCopy(tupdesc); + ntuples = PQntuples(res); + nfields = PQnfields(res); + } - /* make sure we have a persistent copy of the tupdesc */ - tupdesc = CreateTupleDescCopy(tupdesc); - ntuples = PQntuples(res); - nfields = PQnfields(res); - } + /* + * check result and tuple descriptor have the same number of columns + */ + if (nfields != tupdesc->natts) + ereport(ERROR, + (errcode(ERRCODE_DATATYPE_MISMATCH), + errmsg("remote query result rowtype does not match " + "the specified FROM clause rowtype"))); - /* - * check result and tuple descriptor have the same number of columns - */ - if (nfields != tupdesc->natts) - ereport(ERROR, - (errcode(ERRCODE_DATATYPE_MISMATCH), - errmsg("remote query result rowtype does not match " - "the specified FROM clause rowtype"))); + if (ntuples > 0) + { + AttInMetadata *attinmeta; + int nestlevel = -1; + Tuplestorestate *tupstore; + MemoryContext oldcontext; + int row; + char **values; - if (ntuples > 0) - { - AttInMetadata *attinmeta; - int nestlevel = -1; - Tuplestorestate *tupstore; - MemoryContext oldcontext; - int row; - char **values; + attinmeta = TupleDescGetAttInMetadata(tupdesc); - attinmeta = TupleDescGetAttInMetadata(tupdesc); + /* Set GUCs to ensure we read GUC-sensitive data types correctly */ + if (!is_sql_cmd) + nestlevel = applyRemoteGucs(conn); - /* Set GUCs to ensure we read GUC-sensitive data types correctly */ - if (!is_sql_cmd) - nestlevel = applyRemoteGucs(conn); + oldcontext = MemoryContextSwitchTo(rsinfo->econtext->ecxt_per_query_memory); + tupstore = tuplestore_begin_heap(true, false, work_mem); + rsinfo->setResult = tupstore; + rsinfo->setDesc = tupdesc; + MemoryContextSwitchTo(oldcontext); - oldcontext = MemoryContextSwitchTo(rsinfo->econtext->ecxt_per_query_memory); - tupstore = tuplestore_begin_heap(true, false, work_mem); - rsinfo->setResult = tupstore; - rsinfo->setDesc = tupdesc; - MemoryContextSwitchTo(oldcontext); + values = palloc_array(char *, nfields); - values = palloc_array(char *, nfields); + /* put all tuples into the tuplestore */ + for (row = 0; row < ntuples; row++) + { + HeapTuple tuple; - /* put all tuples into the tuplestore */ - for (row = 0; row < ntuples; row++) + if (!is_sql_cmd) { - HeapTuple tuple; + int i; - if (!is_sql_cmd) - { - int i; - - for (i = 0; i < nfields; i++) - { - if (PQgetisnull(res, row, i)) - values[i] = NULL; - else - values[i] = PQgetvalue(res, row, i); - } - } - else + for (i = 0; i < nfields; i++) { - values[0] = PQcmdStatus(res); + if (PQgetisnull(res, row, i)) + values[i] = NULL; + else + values[i] = PQgetvalue(res, row, i); } - - /* build the tuple and put it into the tuplestore. */ - tuple = BuildTupleFromCStrings(attinmeta, values); - tuplestore_puttuple(tupstore, tuple); + } + else + { + values[0] = PQcmdStatus(res); } - /* clean up GUC settings, if we changed any */ - restoreLocalGucs(nestlevel); + /* build the tuple and put it into the tuplestore. */ + tuple = BuildTupleFromCStrings(attinmeta, values); + tuplestore_puttuple(tupstore, tuple); } + + /* clean up GUC settings, if we changed any */ + restoreLocalGucs(nestlevel); } - PG_FINALLY(); - { - /* be sure to release the libpq result */ - PQclear(res); - } - PG_END_TRY(); + + PQclear(res); } /* @@ -1006,16 +990,17 @@ materializeQueryResult(FunctionCallInfo fcinfo, bool fail) { ReturnSetInfo *rsinfo = (ReturnSetInfo *) fcinfo->resultinfo; - PGresult *volatile res = NULL; - volatile storeInfo sinfo = {0}; /* prepTuplestoreResult must have been called previously */ Assert(rsinfo->returnMode == SFRM_Materialize); - sinfo.fcinfo = fcinfo; - + /* Use a PG_TRY block to ensure we pump libpq dry of results */ PG_TRY(); { + storeInfo sinfo = {0}; + PGresult *res; + + sinfo.fcinfo = fcinfo; /* Create short-lived memory context for data conversions */ sinfo.tmpcontext = AllocSetContextCreate(CurrentMemoryContext, "dblink temporary context", @@ -1028,14 +1013,7 @@ materializeQueryResult(FunctionCallInfo fcinfo, (PQresultStatus(res) != PGRES_COMMAND_OK && PQresultStatus(res) != PGRES_TUPLES_OK)) { - /* - * dblink_res_error will clear the passed PGresult, so we need - * this ugly dance to avoid doing so twice during error exit - */ - PGresult *res1 = res; - - res = NULL; - dblink_res_error(conn, conname, res1, fail, + dblink_res_error(conn, conname, res, fail, "while executing query"); /* if fail isn't set, we'll return an empty query result */ } @@ -1074,7 +1052,6 @@ materializeQueryResult(FunctionCallInfo fcinfo, tuplestore_puttuple(tupstore, tuple); PQclear(res); - res = NULL; } else { @@ -1083,26 +1060,20 @@ materializeQueryResult(FunctionCallInfo fcinfo, Assert(rsinfo->setResult != NULL); PQclear(res); - res = NULL; } /* clean up data conversion short-lived memory context */ if (sinfo.tmpcontext != NULL) MemoryContextDelete(sinfo.tmpcontext); - sinfo.tmpcontext = NULL; PQclear(sinfo.last_res); - sinfo.last_res = NULL; PQclear(sinfo.cur_res); - sinfo.cur_res = NULL; } PG_CATCH(); { - /* be sure to release any libpq result we collected */ - PQclear(res); - PQclear(sinfo.last_res); - PQclear(sinfo.cur_res); - /* and clear out any pending data in libpq */ + PGresult *res; + + /* be sure to clear out any pending data in libpq */ while ((res = libpqsrv_get_result(conn, dblink_we_get_result)) != NULL) PQclear(res); @@ -1115,7 +1086,7 @@ materializeQueryResult(FunctionCallInfo fcinfo, * Execute query, and send any result rows to sinfo->tuplestore. */ static PGresult * -storeQueryResult(volatile storeInfo *sinfo, PGconn *conn, const char *sql) +storeQueryResult(storeInfo *sinfo, PGconn *conn, const char *sql) { bool first = true; int nestlevel = -1; @@ -1183,7 +1154,7 @@ storeQueryResult(volatile storeInfo *sinfo, PGconn *conn, const char *sql) * (in this case the PGresult might contain either zero or one row). */ static void -storeRow(volatile storeInfo *sinfo, PGresult *res, bool first) +storeRow(storeInfo *sinfo, PGresult *res, bool first) { int nfields = PQnfields(res); HeapTuple tuple; @@ -2788,10 +2759,13 @@ dblink_connstr_check(const char *connstr) /* * Report an error received from the remote server * - * res: the received error result (will be freed) + * res: the received error result * fail: true for ERROR ereport, false for NOTICE * fmt and following args: sprintf-style format and values for errcontext; * the resulting string should be worded like "while " + * + * If "res" is not NULL, it'll be PQclear'ed here (unless we throw error, + * in which case memory context cleanup will clear it eventually). */ static void dblink_res_error(PGconn *conn, const char *conname, PGresult *res, @@ -2799,15 +2773,11 @@ dblink_res_error(PGconn *conn, const char *conname, PGresult *res, { int level; char *pg_diag_sqlstate = PQresultErrorField(res, PG_DIAG_SQLSTATE); - char *pg_diag_message_primary = PQresultErrorField(res, PG_DIAG_MESSAGE_PRIMARY); - char *pg_diag_message_detail = PQresultErrorField(res, PG_DIAG_MESSAGE_DETAIL); - char *pg_diag_message_hint = PQresultErrorField(res, PG_DIAG_MESSAGE_HINT); - char *pg_diag_context = PQresultErrorField(res, PG_DIAG_CONTEXT); + char *message_primary = PQresultErrorField(res, PG_DIAG_MESSAGE_PRIMARY); + char *message_detail = PQresultErrorField(res, PG_DIAG_MESSAGE_DETAIL); + char *message_hint = PQresultErrorField(res, PG_DIAG_MESSAGE_HINT); + char *message_context = PQresultErrorField(res, PG_DIAG_CONTEXT); int sqlstate; - char *message_primary; - char *message_detail; - char *message_hint; - char *message_context; va_list ap; char dblink_context_msg[512]; @@ -2825,11 +2795,6 @@ dblink_res_error(PGconn *conn, const char *conname, PGresult *res, else sqlstate = ERRCODE_CONNECTION_FAILURE; - message_primary = xpstrdup(pg_diag_message_primary); - message_detail = xpstrdup(pg_diag_message_detail); - message_hint = xpstrdup(pg_diag_message_hint); - message_context = xpstrdup(pg_diag_context); - /* * If we don't get a message from the PGresult, try the PGconn. This is * needed because for connection-level failures, PQgetResult may just @@ -2838,14 +2803,6 @@ dblink_res_error(PGconn *conn, const char *conname, PGresult *res, if (message_primary == NULL) message_primary = pchomp(PQerrorMessage(conn)); - /* - * Now that we've copied all the data we need out of the PGresult, it's - * safe to free it. We must do this to avoid PGresult leakage. We're - * leaking all the strings too, but those are in palloc'd memory that will - * get cleaned up eventually. - */ - PQclear(res); - /* * Format the basic errcontext string. Below, we'll add on something * about the connection name. That's a violation of the translatability @@ -2870,6 +2827,7 @@ dblink_res_error(PGconn *conn, const char *conname, PGresult *res, dblink_context_msg, conname)) : (errcontext("%s on unnamed dblink connection", dblink_context_msg)))); + PQclear(res); } /* diff --git a/contrib/postgres_fdw/connection.c b/contrib/postgres_fdw/connection.c index caf144626963..fc8c004e89f9 100644 --- a/contrib/postgres_fdw/connection.c +++ b/contrib/postgres_fdw/connection.c @@ -820,7 +820,7 @@ static void do_sql_command_begin(PGconn *conn, const char *sql) { if (!PQsendQuery(conn, sql)) - pgfdw_report_error(ERROR, NULL, conn, false, sql); + pgfdw_report_error(ERROR, NULL, conn, sql); } static void @@ -835,10 +835,10 @@ do_sql_command_end(PGconn *conn, const char *sql, bool consume_input) * would be large compared to the overhead of PQconsumeInput.) */ if (consume_input && !PQconsumeInput(conn)) - pgfdw_report_error(ERROR, NULL, conn, false, sql); + pgfdw_report_error(ERROR, NULL, conn, sql); res = pgfdw_get_result(conn); if (PQresultStatus(res) != PGRES_COMMAND_OK) - pgfdw_report_error(ERROR, res, conn, true, sql); + pgfdw_report_error(ERROR, res, conn, sql); PQclear(res); } @@ -1033,62 +1033,55 @@ pgfdw_get_result(PGconn *conn) * Report an error we got from the remote server. * * elevel: error level to use (typically ERROR, but might be less) - * res: PGresult containing the error + * res: PGresult containing the error (might be NULL) * conn: connection we did the query on - * clear: if true, PQclear the result (otherwise caller will handle it) * sql: NULL, or text of remote command we tried to execute * + * If "res" is not NULL, it'll be PQclear'ed here (unless we throw error, + * in which case memory context cleanup will clear it eventually). + * * Note: callers that choose not to throw ERROR for a remote error are * responsible for making sure that the associated ConnCacheEntry gets * marked with have_error = true. */ void pgfdw_report_error(int elevel, PGresult *res, PGconn *conn, - bool clear, const char *sql) + const char *sql) { - /* If requested, PGresult must be released before leaving this function. */ - PG_TRY(); - { - char *diag_sqlstate = PQresultErrorField(res, PG_DIAG_SQLSTATE); - char *message_primary = PQresultErrorField(res, PG_DIAG_MESSAGE_PRIMARY); - char *message_detail = PQresultErrorField(res, PG_DIAG_MESSAGE_DETAIL); - char *message_hint = PQresultErrorField(res, PG_DIAG_MESSAGE_HINT); - char *message_context = PQresultErrorField(res, PG_DIAG_CONTEXT); - int sqlstate; - - if (diag_sqlstate) - sqlstate = MAKE_SQLSTATE(diag_sqlstate[0], - diag_sqlstate[1], - diag_sqlstate[2], - diag_sqlstate[3], - diag_sqlstate[4]); - else - sqlstate = ERRCODE_CONNECTION_FAILURE; + char *diag_sqlstate = PQresultErrorField(res, PG_DIAG_SQLSTATE); + char *message_primary = PQresultErrorField(res, PG_DIAG_MESSAGE_PRIMARY); + char *message_detail = PQresultErrorField(res, PG_DIAG_MESSAGE_DETAIL); + char *message_hint = PQresultErrorField(res, PG_DIAG_MESSAGE_HINT); + char *message_context = PQresultErrorField(res, PG_DIAG_CONTEXT); + int sqlstate; + + if (diag_sqlstate) + sqlstate = MAKE_SQLSTATE(diag_sqlstate[0], + diag_sqlstate[1], + diag_sqlstate[2], + diag_sqlstate[3], + diag_sqlstate[4]); + else + sqlstate = ERRCODE_CONNECTION_FAILURE; - /* - * If we don't get a message from the PGresult, try the PGconn. This - * is needed because for connection-level failures, PQgetResult may - * just return NULL, not a PGresult at all. - */ - if (message_primary == NULL) - message_primary = pchomp(PQerrorMessage(conn)); - - ereport(elevel, - (errcode(sqlstate), - (message_primary != NULL && message_primary[0] != '\0') ? - errmsg_internal("%s", message_primary) : - errmsg("could not obtain message string for remote error"), - message_detail ? errdetail_internal("%s", message_detail) : 0, - message_hint ? errhint("%s", message_hint) : 0, - message_context ? errcontext("%s", message_context) : 0, - sql ? errcontext("remote SQL command: %s", sql) : 0)); - } - PG_FINALLY(); - { - if (clear) - PQclear(res); - } - PG_END_TRY(); + /* + * If we don't get a message from the PGresult, try the PGconn. This is + * needed because for connection-level failures, PQgetResult may just + * return NULL, not a PGresult at all. + */ + if (message_primary == NULL) + message_primary = pchomp(PQerrorMessage(conn)); + + ereport(elevel, + (errcode(sqlstate), + (message_primary != NULL && message_primary[0] != '\0') ? + errmsg_internal("%s", message_primary) : + errmsg("could not obtain message string for remote error"), + message_detail ? errdetail_internal("%s", message_detail) : 0, + message_hint ? errhint("%s", message_hint) : 0, + message_context ? errcontext("%s", message_context) : 0, + sql ? errcontext("remote SQL command: %s", sql) : 0)); + PQclear(res); } /* @@ -1625,7 +1618,7 @@ pgfdw_exec_cleanup_query_begin(PGconn *conn, const char *query) */ if (!PQsendQuery(conn, query)) { - pgfdw_report_error(WARNING, NULL, conn, false, query); + pgfdw_report_error(WARNING, NULL, conn, query); return false; } @@ -1650,7 +1643,7 @@ pgfdw_exec_cleanup_query_end(PGconn *conn, const char *query, */ if (consume_input && !PQconsumeInput(conn)) { - pgfdw_report_error(WARNING, NULL, conn, false, query); + pgfdw_report_error(WARNING, NULL, conn, query); return false; } @@ -1662,7 +1655,7 @@ pgfdw_exec_cleanup_query_end(PGconn *conn, const char *query, (errmsg("could not get query result due to timeout"), errcontext("remote SQL command: %s", query))); else - pgfdw_report_error(WARNING, NULL, conn, false, query); + pgfdw_report_error(WARNING, NULL, conn, query); return false; } @@ -1670,7 +1663,7 @@ pgfdw_exec_cleanup_query_end(PGconn *conn, const char *query, /* Issue a warning if not successful. */ if (PQresultStatus(result) != PGRES_COMMAND_OK) { - pgfdw_report_error(WARNING, result, conn, true, query); + pgfdw_report_error(WARNING, result, conn, query); return ignore_errors; } PQclear(result); @@ -1698,103 +1691,90 @@ pgfdw_get_cleanup_result(PGconn *conn, TimestampTz endtime, PGresult **result, bool *timed_out) { - volatile bool failed = false; - PGresult *volatile last_res = NULL; + bool failed = false; + PGresult *last_res = NULL; + int canceldelta = RETRY_CANCEL_TIMEOUT * 2; *result = NULL; *timed_out = false; - - /* In what follows, do not leak any PGresults on an error. */ - PG_TRY(); + for (;;) { - int canceldelta = RETRY_CANCEL_TIMEOUT * 2; + PGresult *res; - for (;;) + while (PQisBusy(conn)) { - PGresult *res; + int wc; + TimestampTz now = GetCurrentTimestamp(); + long cur_timeout; - while (PQisBusy(conn)) + /* If timeout has expired, give up. */ + if (now >= endtime) { - int wc; - TimestampTz now = GetCurrentTimestamp(); - long cur_timeout; - - /* If timeout has expired, give up. */ - if (now >= endtime) - { - *timed_out = true; - failed = true; - goto exit; - } + *timed_out = true; + failed = true; + goto exit; + } - /* If we need to re-issue the cancel request, do that. */ - if (now >= retrycanceltime) - { - /* We ignore failure to issue the repeated request. */ - (void) libpqsrv_cancel(conn, endtime); + /* If we need to re-issue the cancel request, do that. */ + if (now >= retrycanceltime) + { + /* We ignore failure to issue the repeated request. */ + (void) libpqsrv_cancel(conn, endtime); - /* Recompute "now" in case that took measurable time. */ - now = GetCurrentTimestamp(); + /* Recompute "now" in case that took measurable time. */ + now = GetCurrentTimestamp(); - /* Adjust re-cancel timeout in increasing steps. */ - retrycanceltime = TimestampTzPlusMilliseconds(now, - canceldelta); - canceldelta += canceldelta; - } + /* Adjust re-cancel timeout in increasing steps. */ + retrycanceltime = TimestampTzPlusMilliseconds(now, + canceldelta); + canceldelta += canceldelta; + } - /* If timeout has expired, give up, else get sleep time. */ - cur_timeout = TimestampDifferenceMilliseconds(now, - Min(endtime, - retrycanceltime)); - if (cur_timeout <= 0) - { - *timed_out = true; - failed = true; - goto exit; - } + /* If timeout has expired, give up, else get sleep time. */ + cur_timeout = TimestampDifferenceMilliseconds(now, + Min(endtime, + retrycanceltime)); + if (cur_timeout <= 0) + { + *timed_out = true; + failed = true; + goto exit; + } - /* first time, allocate or get the custom wait event */ - if (pgfdw_we_cleanup_result == 0) - pgfdw_we_cleanup_result = WaitEventExtensionNew("PostgresFdwCleanupResult"); + /* first time, allocate or get the custom wait event */ + if (pgfdw_we_cleanup_result == 0) + pgfdw_we_cleanup_result = WaitEventExtensionNew("PostgresFdwCleanupResult"); - /* Sleep until there's something to do */ - wc = WaitLatchOrSocket(MyLatch, - WL_LATCH_SET | WL_SOCKET_READABLE | - WL_TIMEOUT | WL_EXIT_ON_PM_DEATH, - PQsocket(conn), - cur_timeout, pgfdw_we_cleanup_result); - ResetLatch(MyLatch); + /* Sleep until there's something to do */ + wc = WaitLatchOrSocket(MyLatch, + WL_LATCH_SET | WL_SOCKET_READABLE | + WL_TIMEOUT | WL_EXIT_ON_PM_DEATH, + PQsocket(conn), + cur_timeout, pgfdw_we_cleanup_result); + ResetLatch(MyLatch); - CHECK_FOR_INTERRUPTS(); + CHECK_FOR_INTERRUPTS(); - /* Data available in socket? */ - if (wc & WL_SOCKET_READABLE) + /* Data available in socket? */ + if (wc & WL_SOCKET_READABLE) + { + if (!PQconsumeInput(conn)) { - if (!PQconsumeInput(conn)) - { - /* connection trouble */ - failed = true; - goto exit; - } + /* connection trouble */ + failed = true; + goto exit; } } + } - res = PQgetResult(conn); - if (res == NULL) - break; /* query is complete */ + res = PQgetResult(conn); + if (res == NULL) + break; /* query is complete */ - PQclear(last_res); - last_res = res; - } -exit: ; - } - PG_CATCH(); - { PQclear(last_res); - PG_RE_THROW(); + last_res = res; } - PG_END_TRY(); - +exit: if (failed) PQclear(last_res); else diff --git a/contrib/postgres_fdw/option.c b/contrib/postgres_fdw/option.c index c2f936640bca..d6fa89bad939 100644 --- a/contrib/postgres_fdw/option.c +++ b/contrib/postgres_fdw/option.c @@ -21,6 +21,7 @@ #include "libpq/libpq-be.h" #include "postgres_fdw.h" #include "utils/guc.h" +#include "utils/memutils.h" #include "utils/varlena.h" /* @@ -39,12 +40,6 @@ typedef struct PgFdwOption */ static PgFdwOption *postgres_fdw_options; -/* - * Valid options for libpq. - * Allocated and filled in InitPgFdwOptions. - */ -static PQconninfoOption *libpq_options; - /* * GUC parameters */ @@ -239,6 +234,7 @@ static void InitPgFdwOptions(void) { int num_libpq_opts; + PQconninfoOption *libpq_options; PQconninfoOption *lopt; PgFdwOption *popt; @@ -307,8 +303,8 @@ InitPgFdwOptions(void) * Get list of valid libpq options. * * To avoid unnecessary work, we get the list once and use it throughout - * the lifetime of this backend process. We don't need to care about - * memory context issues, because PQconndefaults allocates with malloc. + * the lifetime of this backend process. Hence, we'll allocate it in + * TopMemoryContext. */ libpq_options = PQconndefaults(); if (!libpq_options) /* assume reason for failure is OOM */ @@ -325,19 +321,11 @@ InitPgFdwOptions(void) /* * Construct an array which consists of all valid options for * postgres_fdw, by appending FDW-specific options to libpq options. - * - * We use plain malloc here to allocate postgres_fdw_options because it - * lives as long as the backend process does. Besides, keeping - * libpq_options in memory allows us to avoid copying every keyword - * string. */ postgres_fdw_options = (PgFdwOption *) - malloc(sizeof(PgFdwOption) * num_libpq_opts + - sizeof(non_libpq_options)); - if (postgres_fdw_options == NULL) - ereport(ERROR, - (errcode(ERRCODE_FDW_OUT_OF_MEMORY), - errmsg("out of memory"))); + MemoryContextAlloc(TopMemoryContext, + sizeof(PgFdwOption) * num_libpq_opts + + sizeof(non_libpq_options)); popt = postgres_fdw_options; for (lopt = libpq_options; lopt->keyword; lopt++) @@ -355,8 +343,8 @@ InitPgFdwOptions(void) if (strncmp(lopt->keyword, "oauth_", strlen("oauth_")) == 0) continue; - /* We don't have to copy keyword string, as described above. */ - popt->keyword = lopt->keyword; + popt->keyword = MemoryContextStrdup(TopMemoryContext, + lopt->keyword); /* * "user" and any secret options are allowed only on user mappings. @@ -371,6 +359,9 @@ InitPgFdwOptions(void) popt++; } + /* Done with libpq's output structure. */ + PQconninfoFree(libpq_options); + /* Append FDW-specific options and dummy terminator. */ memcpy(popt, non_libpq_options, sizeof(non_libpq_options)); } diff --git a/contrib/postgres_fdw/postgres_fdw.c b/contrib/postgres_fdw/postgres_fdw.c index 4283ce9f9625..3d12aeafa688 100644 --- a/contrib/postgres_fdw/postgres_fdw.c +++ b/contrib/postgres_fdw/postgres_fdw.c @@ -240,7 +240,6 @@ typedef struct PgFdwDirectModifyState PGresult *result; /* result for query */ int num_tuples; /* # of result tuples */ int next_tuple; /* index of next one to return */ - MemoryContextCallback result_cb; /* ensures result will get freed */ Relation resultRel; /* relcache entry for the target relation */ AttrNumber *attnoMap; /* array of attnums of input user columns */ AttrNumber ctidAttno; /* attnum of input ctid column */ @@ -1703,13 +1702,9 @@ postgresReScanForeignScan(ForeignScanState *node) return; } - /* - * We don't use a PG_TRY block here, so be careful not to throw error - * without releasing the PGresult. - */ res = pgfdw_exec_query(fsstate->conn, sql, fsstate->conn_state); if (PQresultStatus(res) != PGRES_COMMAND_OK) - pgfdw_report_error(ERROR, res, fsstate->conn, true, sql); + pgfdw_report_error(ERROR, res, fsstate->conn, sql); PQclear(res); /* Now force a fresh FETCH. */ @@ -2671,17 +2666,6 @@ postgresBeginDirectModify(ForeignScanState *node, int eflags) dmstate = (PgFdwDirectModifyState *) palloc0(sizeof(PgFdwDirectModifyState)); node->fdw_state = dmstate; - /* - * We use a memory context callback to ensure that the dmstate's PGresult - * (if any) will be released, even if the query fails somewhere that's - * outside our control. The callback is always armed for the duration of - * the query; this relies on PQclear(NULL) being a no-op. - */ - dmstate->result_cb.func = (MemoryContextCallbackFunction) PQclear; - dmstate->result_cb.arg = NULL; - MemoryContextRegisterResetCallback(CurrentMemoryContext, - &dmstate->result_cb); - /* * Identify which user to do the remote access as. This should match what * ExecCheckPermissions() does. @@ -2829,13 +2813,7 @@ postgresEndDirectModify(ForeignScanState *node) return; /* Release PGresult */ - if (dmstate->result) - { - PQclear(dmstate->result); - dmstate->result = NULL; - /* ... and don't forget to disable the callback */ - dmstate->result_cb.arg = NULL; - } + PQclear(dmstate->result); /* Release remote connection */ ReleaseConnection(dmstate->conn); @@ -3619,41 +3597,32 @@ get_remote_estimate(const char *sql, PGconn *conn, double *rows, int *width, Cost *startup_cost, Cost *total_cost) { - PGresult *volatile res = NULL; - - /* PGresult must be released before leaving this function. */ - PG_TRY(); - { - char *line; - char *p; - int n; + PGresult *res; + char *line; + char *p; + int n; - /* - * Execute EXPLAIN remotely. - */ - res = pgfdw_exec_query(conn, sql, NULL); - if (PQresultStatus(res) != PGRES_TUPLES_OK) - pgfdw_report_error(ERROR, res, conn, false, sql); + /* + * Execute EXPLAIN remotely. + */ + res = pgfdw_exec_query(conn, sql, NULL); + if (PQresultStatus(res) != PGRES_TUPLES_OK) + pgfdw_report_error(ERROR, res, conn, sql); - /* - * Extract cost numbers for topmost plan node. Note we search for a - * left paren from the end of the line to avoid being confused by - * other uses of parentheses. - */ - line = PQgetvalue(res, 0, 0); - p = strrchr(line, '('); - if (p == NULL) - elog(ERROR, "could not interpret EXPLAIN output: \"%s\"", line); - n = sscanf(p, "(cost=%lf..%lf rows=%lf width=%d)", - startup_cost, total_cost, rows, width); - if (n != 4) - elog(ERROR, "could not interpret EXPLAIN output: \"%s\"", line); - } - PG_FINALLY(); - { - PQclear(res); - } - PG_END_TRY(); + /* + * Extract cost numbers for topmost plan node. Note we search for a left + * paren from the end of the line to avoid being confused by other uses of + * parentheses. + */ + line = PQgetvalue(res, 0, 0); + p = strrchr(line, '('); + if (p == NULL) + elog(ERROR, "could not interpret EXPLAIN output: \"%s\"", line); + n = sscanf(p, "(cost=%lf..%lf rows=%lf width=%d)", + startup_cost, total_cost, rows, width); + if (n != 4) + elog(ERROR, "could not interpret EXPLAIN output: \"%s\"", line); + PQclear(res); } /* @@ -3793,17 +3762,14 @@ create_cursor(ForeignScanState *node) */ if (!PQsendQueryParams(conn, buf.data, numParams, NULL, values, NULL, NULL, 0)) - pgfdw_report_error(ERROR, NULL, conn, false, buf.data); + pgfdw_report_error(ERROR, NULL, conn, buf.data); /* * Get the result, and check for success. - * - * We don't use a PG_TRY block here, so be careful not to throw error - * without releasing the PGresult. */ res = pgfdw_get_result(conn); if (PQresultStatus(res) != PGRES_COMMAND_OK) - pgfdw_report_error(ERROR, res, conn, true, fsstate->query); + pgfdw_report_error(ERROR, res, conn, fsstate->query); PQclear(res); /* Mark the cursor as created, and show no tuples have been retrieved */ @@ -3825,7 +3791,10 @@ static void fetch_more_data(ForeignScanState *node) { PgFdwScanState *fsstate = (PgFdwScanState *) node->fdw_state; - PGresult *volatile res = NULL; + PGconn *conn = fsstate->conn; + PGresult *res; + int numrows; + int i; MemoryContext oldcontext; /* @@ -3836,74 +3805,63 @@ fetch_more_data(ForeignScanState *node) MemoryContextReset(fsstate->batch_cxt); oldcontext = MemoryContextSwitchTo(fsstate->batch_cxt); - /* PGresult must be released before leaving this function. */ - PG_TRY(); + if (fsstate->async_capable) { - PGconn *conn = fsstate->conn; - int numrows; - int i; + Assert(fsstate->conn_state->pendingAreq); - if (fsstate->async_capable) - { - Assert(fsstate->conn_state->pendingAreq); + /* + * The query was already sent by an earlier call to + * fetch_more_data_begin. So now we just fetch the result. + */ + res = pgfdw_get_result(conn); + /* On error, report the original query, not the FETCH. */ + if (PQresultStatus(res) != PGRES_TUPLES_OK) + pgfdw_report_error(ERROR, res, conn, fsstate->query); - /* - * The query was already sent by an earlier call to - * fetch_more_data_begin. So now we just fetch the result. - */ - res = pgfdw_get_result(conn); - /* On error, report the original query, not the FETCH. */ - if (PQresultStatus(res) != PGRES_TUPLES_OK) - pgfdw_report_error(ERROR, res, conn, false, fsstate->query); + /* Reset per-connection state */ + fsstate->conn_state->pendingAreq = NULL; + } + else + { + char sql[64]; - /* Reset per-connection state */ - fsstate->conn_state->pendingAreq = NULL; - } - else - { - char sql[64]; + /* This is a regular synchronous fetch. */ + snprintf(sql, sizeof(sql), "FETCH %d FROM c%u", + fsstate->fetch_size, fsstate->cursor_number); - /* This is a regular synchronous fetch. */ - snprintf(sql, sizeof(sql), "FETCH %d FROM c%u", - fsstate->fetch_size, fsstate->cursor_number); + res = pgfdw_exec_query(conn, sql, fsstate->conn_state); + /* On error, report the original query, not the FETCH. */ + if (PQresultStatus(res) != PGRES_TUPLES_OK) + pgfdw_report_error(ERROR, res, conn, fsstate->query); + } - res = pgfdw_exec_query(conn, sql, fsstate->conn_state); - /* On error, report the original query, not the FETCH. */ - if (PQresultStatus(res) != PGRES_TUPLES_OK) - pgfdw_report_error(ERROR, res, conn, false, fsstate->query); - } + /* Convert the data into HeapTuples */ + numrows = PQntuples(res); + fsstate->tuples = (HeapTuple *) palloc0(numrows * sizeof(HeapTuple)); + fsstate->num_tuples = numrows; + fsstate->next_tuple = 0; - /* Convert the data into HeapTuples */ - numrows = PQntuples(res); - fsstate->tuples = (HeapTuple *) palloc0(numrows * sizeof(HeapTuple)); - fsstate->num_tuples = numrows; - fsstate->next_tuple = 0; + for (i = 0; i < numrows; i++) + { + Assert(IsA(node->ss.ps.plan, ForeignScan)); - for (i = 0; i < numrows; i++) - { - Assert(IsA(node->ss.ps.plan, ForeignScan)); - - fsstate->tuples[i] = - make_tuple_from_result_row(res, i, - fsstate->rel, - fsstate->attinmeta, - fsstate->retrieved_attrs, - node, - fsstate->temp_cxt); - } + fsstate->tuples[i] = + make_tuple_from_result_row(res, i, + fsstate->rel, + fsstate->attinmeta, + fsstate->retrieved_attrs, + node, + fsstate->temp_cxt); + } - /* Update fetch_ct_2 */ - if (fsstate->fetch_ct_2 < 2) - fsstate->fetch_ct_2++; + /* Update fetch_ct_2 */ + if (fsstate->fetch_ct_2 < 2) + fsstate->fetch_ct_2++; - /* Must be EOF if we didn't get as many tuples as we asked for. */ - fsstate->eof_reached = (numrows < fsstate->fetch_size); - } - PG_FINALLY(); - { - PQclear(res); - } - PG_END_TRY(); + /* Must be EOF if we didn't get as many tuples as we asked for. */ + fsstate->eof_reached = (numrows < fsstate->fetch_size); + + PQclear(res); MemoryContextSwitchTo(oldcontext); } @@ -3977,14 +3935,9 @@ close_cursor(PGconn *conn, unsigned int cursor_number, PGresult *res; snprintf(sql, sizeof(sql), "CLOSE c%u", cursor_number); - - /* - * We don't use a PG_TRY block here, so be careful not to throw error - * without releasing the PGresult. - */ res = pgfdw_exec_query(conn, sql, conn_state); if (PQresultStatus(res) != PGRES_COMMAND_OK) - pgfdw_report_error(ERROR, res, conn, true, sql); + pgfdw_report_error(ERROR, res, conn, sql); PQclear(res); } @@ -4192,18 +4145,15 @@ execute_foreign_modify(EState *estate, NULL, NULL, 0)) - pgfdw_report_error(ERROR, NULL, fmstate->conn, false, fmstate->query); + pgfdw_report_error(ERROR, NULL, fmstate->conn, fmstate->query); /* * Get the result, and check for success. - * - * We don't use a PG_TRY block here, so be careful not to throw error - * without releasing the PGresult. */ res = pgfdw_get_result(fmstate->conn); if (PQresultStatus(res) != (fmstate->has_returning ? PGRES_TUPLES_OK : PGRES_COMMAND_OK)) - pgfdw_report_error(ERROR, res, fmstate->conn, true, fmstate->query); + pgfdw_report_error(ERROR, res, fmstate->conn, fmstate->query); /* Check number of rows affected, and fetch RETURNING tuple if any */ if (fmstate->has_returning) @@ -4262,17 +4212,14 @@ prepare_foreign_modify(PgFdwModifyState *fmstate) fmstate->query, 0, NULL)) - pgfdw_report_error(ERROR, NULL, fmstate->conn, false, fmstate->query); + pgfdw_report_error(ERROR, NULL, fmstate->conn, fmstate->query); /* * Get the result, and check for success. - * - * We don't use a PG_TRY block here, so be careful not to throw error - * without releasing the PGresult. */ res = pgfdw_get_result(fmstate->conn); if (PQresultStatus(res) != PGRES_COMMAND_OK) - pgfdw_report_error(ERROR, res, fmstate->conn, true, fmstate->query); + pgfdw_report_error(ERROR, res, fmstate->conn, fmstate->query); PQclear(res); /* This action shows that the prepare has been done. */ @@ -4363,37 +4310,25 @@ convert_prep_stmt_params(PgFdwModifyState *fmstate, /* * store_returning_result * Store the result of a RETURNING clause - * - * On error, be sure to release the PGresult on the way out. Callers do not - * have PG_TRY blocks to ensure this happens. */ static void store_returning_result(PgFdwModifyState *fmstate, TupleTableSlot *slot, PGresult *res) { - PG_TRY(); - { - HeapTuple newtup; + HeapTuple newtup; - newtup = make_tuple_from_result_row(res, 0, - fmstate->rel, - fmstate->attinmeta, - fmstate->retrieved_attrs, - NULL, - fmstate->temp_cxt); + newtup = make_tuple_from_result_row(res, 0, + fmstate->rel, + fmstate->attinmeta, + fmstate->retrieved_attrs, + NULL, + fmstate->temp_cxt); - /* - * The returning slot will not necessarily be suitable to store - * heaptuples directly, so allow for conversion. - */ - ExecForceStoreHeapTuple(newtup, slot, true); - } - PG_CATCH(); - { - PQclear(res); - PG_RE_THROW(); - } - PG_END_TRY(); + /* + * The returning slot will not necessarily be suitable to store heaptuples + * directly, so allow for conversion. + */ + ExecForceStoreHeapTuple(newtup, slot, true); } /* @@ -4429,14 +4364,9 @@ deallocate_query(PgFdwModifyState *fmstate) return; snprintf(sql, sizeof(sql), "DEALLOCATE %s", fmstate->p_name); - - /* - * We don't use a PG_TRY block here, so be careful not to throw error - * without releasing the PGresult. - */ res = pgfdw_exec_query(fmstate->conn, sql, fmstate->conn_state); if (PQresultStatus(res) != PGRES_COMMAND_OK) - pgfdw_report_error(ERROR, res, fmstate->conn, true, sql); + pgfdw_report_error(ERROR, res, fmstate->conn, sql); PQclear(res); pfree(fmstate->p_name); fmstate->p_name = NULL; @@ -4604,24 +4534,24 @@ execute_dml_stmt(ForeignScanState *node) */ if (!PQsendQueryParams(dmstate->conn, dmstate->query, numParams, NULL, values, NULL, NULL, 0)) - pgfdw_report_error(ERROR, NULL, dmstate->conn, false, dmstate->query); + pgfdw_report_error(ERROR, NULL, dmstate->conn, dmstate->query); /* * Get the result, and check for success. - * - * We use a memory context callback to ensure that the PGresult will be - * released, even if the query fails somewhere that's outside our control. - * The callback is already registered, just need to fill in its arg. */ - Assert(dmstate->result == NULL); dmstate->result = pgfdw_get_result(dmstate->conn); - dmstate->result_cb.arg = dmstate->result; - if (PQresultStatus(dmstate->result) != (dmstate->has_returning ? PGRES_TUPLES_OK : PGRES_COMMAND_OK)) - pgfdw_report_error(ERROR, dmstate->result, dmstate->conn, false, + pgfdw_report_error(ERROR, dmstate->result, dmstate->conn, dmstate->query); + /* + * The result potentially needs to survive across multiple executor row + * cycles, so move it to the context where the dmstate is. + */ + dmstate->result = libpqsrv_PGresultSetParent(dmstate->result, + GetMemoryChunkContext(dmstate)); + /* Get the number of rows affected. */ if (dmstate->has_returning) dmstate->num_tuples = PQntuples(dmstate->result); @@ -4958,7 +4888,7 @@ postgresAnalyzeForeignTable(Relation relation, UserMapping *user; PGconn *conn; StringInfoData sql; - PGresult *volatile res = NULL; + PGresult *res; /* Return the row-analysis function pointer */ *func = postgresAcquireSampleRowsFunc; @@ -4984,22 +4914,14 @@ postgresAnalyzeForeignTable(Relation relation, initStringInfo(&sql); deparseAnalyzeSizeSql(&sql, relation); - /* In what follows, do not risk leaking any PGresults. */ - PG_TRY(); - { - res = pgfdw_exec_query(conn, sql.data, NULL); - if (PQresultStatus(res) != PGRES_TUPLES_OK) - pgfdw_report_error(ERROR, res, conn, false, sql.data); + res = pgfdw_exec_query(conn, sql.data, NULL); + if (PQresultStatus(res) != PGRES_TUPLES_OK) + pgfdw_report_error(ERROR, res, conn, sql.data); - if (PQntuples(res) != 1 || PQnfields(res) != 1) - elog(ERROR, "unexpected result from deparseAnalyzeSizeSql query"); - *totalpages = strtoul(PQgetvalue(res, 0, 0), NULL, 10); - } - PG_FINALLY(); - { - PQclear(res); - } - PG_END_TRY(); + if (PQntuples(res) != 1 || PQnfields(res) != 1) + elog(ERROR, "unexpected result from deparseAnalyzeSizeSql query"); + *totalpages = strtoul(PQgetvalue(res, 0, 0), NULL, 10); + PQclear(res); ReleaseConnection(conn); @@ -5020,9 +4942,9 @@ postgresGetAnalyzeInfoForForeignTable(Relation relation, bool *can_tablesample) UserMapping *user; PGconn *conn; StringInfoData sql; - PGresult *volatile res = NULL; - volatile double reltuples = -1; - volatile char relkind = 0; + PGresult *res; + double reltuples; + char relkind; /* assume the remote relation does not support TABLESAMPLE */ *can_tablesample = false; @@ -5041,24 +4963,15 @@ postgresGetAnalyzeInfoForForeignTable(Relation relation, bool *can_tablesample) initStringInfo(&sql); deparseAnalyzeInfoSql(&sql, relation); - /* In what follows, do not risk leaking any PGresults. */ - PG_TRY(); - { - res = pgfdw_exec_query(conn, sql.data, NULL); - if (PQresultStatus(res) != PGRES_TUPLES_OK) - pgfdw_report_error(ERROR, res, conn, false, sql.data); + res = pgfdw_exec_query(conn, sql.data, NULL); + if (PQresultStatus(res) != PGRES_TUPLES_OK) + pgfdw_report_error(ERROR, res, conn, sql.data); - if (PQntuples(res) != 1 || PQnfields(res) != 2) - elog(ERROR, "unexpected result from deparseAnalyzeInfoSql query"); - reltuples = strtod(PQgetvalue(res, 0, 0), NULL); - relkind = *(PQgetvalue(res, 0, 1)); - } - PG_FINALLY(); - { - if (res) - PQclear(res); - } - PG_END_TRY(); + if (PQntuples(res) != 1 || PQnfields(res) != 2) + elog(ERROR, "unexpected result from deparseAnalyzeInfoSql query"); + reltuples = strtod(PQgetvalue(res, 0, 0), NULL); + relkind = *(PQgetvalue(res, 0, 1)); + PQclear(res); ReleaseConnection(conn); @@ -5101,7 +5014,9 @@ postgresAcquireSampleRowsFunc(Relation relation, int elevel, double reltuples; unsigned int cursor_number; StringInfoData sql; - PGresult *volatile res = NULL; + PGresult *res; + char fetch_sql[64]; + int fetch_size; ListCell *lc; /* Initialize workspace state */ @@ -5278,91 +5193,76 @@ postgresAcquireSampleRowsFunc(Relation relation, int elevel, deparseAnalyzeSql(&sql, relation, method, sample_frac, &astate.retrieved_attrs); - /* In what follows, do not risk leaking any PGresults. */ - PG_TRY(); - { - char fetch_sql[64]; - int fetch_size; - - res = pgfdw_exec_query(conn, sql.data, NULL); - if (PQresultStatus(res) != PGRES_COMMAND_OK) - pgfdw_report_error(ERROR, res, conn, false, sql.data); - PQclear(res); - res = NULL; + res = pgfdw_exec_query(conn, sql.data, NULL); + if (PQresultStatus(res) != PGRES_COMMAND_OK) + pgfdw_report_error(ERROR, res, conn, sql.data); + PQclear(res); - /* - * Determine the fetch size. The default is arbitrary, but shouldn't - * be enormous. - */ - fetch_size = 100; - foreach(lc, server->options) - { - DefElem *def = (DefElem *) lfirst(lc); + /* + * Determine the fetch size. The default is arbitrary, but shouldn't be + * enormous. + */ + fetch_size = 100; + foreach(lc, server->options) + { + DefElem *def = (DefElem *) lfirst(lc); - if (strcmp(def->defname, "fetch_size") == 0) - { - (void) parse_int(defGetString(def), &fetch_size, 0, NULL); - break; - } - } - foreach(lc, table->options) + if (strcmp(def->defname, "fetch_size") == 0) { - DefElem *def = (DefElem *) lfirst(lc); - - if (strcmp(def->defname, "fetch_size") == 0) - { - (void) parse_int(defGetString(def), &fetch_size, 0, NULL); - break; - } + (void) parse_int(defGetString(def), &fetch_size, 0, NULL); + break; } + } + foreach(lc, table->options) + { + DefElem *def = (DefElem *) lfirst(lc); - /* Construct command to fetch rows from remote. */ - snprintf(fetch_sql, sizeof(fetch_sql), "FETCH %d FROM c%u", - fetch_size, cursor_number); - - /* Retrieve and process rows a batch at a time. */ - for (;;) + if (strcmp(def->defname, "fetch_size") == 0) { - int numrows; - int i; + (void) parse_int(defGetString(def), &fetch_size, 0, NULL); + break; + } + } - /* Allow users to cancel long query */ - CHECK_FOR_INTERRUPTS(); + /* Construct command to fetch rows from remote. */ + snprintf(fetch_sql, sizeof(fetch_sql), "FETCH %d FROM c%u", + fetch_size, cursor_number); - /* - * XXX possible future improvement: if rowstoskip is large, we - * could issue a MOVE rather than physically fetching the rows, - * then just adjust rowstoskip and samplerows appropriately. - */ + /* Retrieve and process rows a batch at a time. */ + for (;;) + { + int numrows; + int i; - /* Fetch some rows */ - res = pgfdw_exec_query(conn, fetch_sql, NULL); - /* On error, report the original query, not the FETCH. */ - if (PQresultStatus(res) != PGRES_TUPLES_OK) - pgfdw_report_error(ERROR, res, conn, false, sql.data); + /* Allow users to cancel long query */ + CHECK_FOR_INTERRUPTS(); - /* Process whatever we got. */ - numrows = PQntuples(res); - for (i = 0; i < numrows; i++) - analyze_row_processor(res, i, &astate); + /* + * XXX possible future improvement: if rowstoskip is large, we could + * issue a MOVE rather than physically fetching the rows, then just + * adjust rowstoskip and samplerows appropriately. + */ - PQclear(res); - res = NULL; + /* Fetch some rows */ + res = pgfdw_exec_query(conn, fetch_sql, NULL); + /* On error, report the original query, not the FETCH. */ + if (PQresultStatus(res) != PGRES_TUPLES_OK) + pgfdw_report_error(ERROR, res, conn, sql.data); - /* Must be EOF if we didn't get all the rows requested. */ - if (numrows < fetch_size) - break; - } + /* Process whatever we got. */ + numrows = PQntuples(res); + for (i = 0; i < numrows; i++) + analyze_row_processor(res, i, &astate); - /* Close the cursor, just to be tidy. */ - close_cursor(conn, cursor_number, NULL); - } - PG_CATCH(); - { PQclear(res); - PG_RE_THROW(); + + /* Must be EOF if we didn't get all the rows requested. */ + if (numrows < fetch_size) + break; } - PG_END_TRY(); + + /* Close the cursor, just to be tidy. */ + close_cursor(conn, cursor_number, NULL); ReleaseConnection(conn); @@ -5474,7 +5374,7 @@ postgresImportForeignSchema(ImportForeignSchemaStmt *stmt, Oid serverOid) UserMapping *mapping; PGconn *conn; StringInfoData buf; - PGresult *volatile res = NULL; + PGresult *res; int numrows, i; ListCell *lc; @@ -5513,243 +5413,231 @@ postgresImportForeignSchema(ImportForeignSchemaStmt *stmt, Oid serverOid) /* Create workspace for strings */ initStringInfo(&buf); - /* In what follows, do not risk leaking any PGresults. */ - PG_TRY(); - { - /* Check that the schema really exists */ - appendStringInfoString(&buf, "SELECT 1 FROM pg_catalog.pg_namespace WHERE nspname = "); - deparseStringLiteral(&buf, stmt->remote_schema); + /* Check that the schema really exists */ + appendStringInfoString(&buf, "SELECT 1 FROM pg_catalog.pg_namespace WHERE nspname = "); + deparseStringLiteral(&buf, stmt->remote_schema); - res = pgfdw_exec_query(conn, buf.data, NULL); - if (PQresultStatus(res) != PGRES_TUPLES_OK) - pgfdw_report_error(ERROR, res, conn, false, buf.data); + res = pgfdw_exec_query(conn, buf.data, NULL); + if (PQresultStatus(res) != PGRES_TUPLES_OK) + pgfdw_report_error(ERROR, res, conn, buf.data); - if (PQntuples(res) != 1) - ereport(ERROR, - (errcode(ERRCODE_FDW_SCHEMA_NOT_FOUND), - errmsg("schema \"%s\" is not present on foreign server \"%s\"", - stmt->remote_schema, server->servername))); + if (PQntuples(res) != 1) + ereport(ERROR, + (errcode(ERRCODE_FDW_SCHEMA_NOT_FOUND), + errmsg("schema \"%s\" is not present on foreign server \"%s\"", + stmt->remote_schema, server->servername))); - PQclear(res); - res = NULL; - resetStringInfo(&buf); + PQclear(res); + resetStringInfo(&buf); - /* - * Fetch all table data from this schema, possibly restricted by - * EXCEPT or LIMIT TO. (We don't actually need to pay any attention - * to EXCEPT/LIMIT TO here, because the core code will filter the - * statements we return according to those lists anyway. But it - * should save a few cycles to not process excluded tables in the - * first place.) - * - * Import table data for partitions only when they are explicitly - * specified in LIMIT TO clause. Otherwise ignore them and only - * include the definitions of the root partitioned tables to allow - * access to the complete remote data set locally in the schema - * imported. - * - * Note: because we run the connection with search_path restricted to - * pg_catalog, the format_type() and pg_get_expr() outputs will always - * include a schema name for types/functions in other schemas, which - * is what we want. - */ + /* + * Fetch all table data from this schema, possibly restricted by EXCEPT or + * LIMIT TO. (We don't actually need to pay any attention to EXCEPT/LIMIT + * TO here, because the core code will filter the statements we return + * according to those lists anyway. But it should save a few cycles to + * not process excluded tables in the first place.) + * + * Import table data for partitions only when they are explicitly + * specified in LIMIT TO clause. Otherwise ignore them and only include + * the definitions of the root partitioned tables to allow access to the + * complete remote data set locally in the schema imported. + * + * Note: because we run the connection with search_path restricted to + * pg_catalog, the format_type() and pg_get_expr() outputs will always + * include a schema name for types/functions in other schemas, which is + * what we want. + */ + appendStringInfoString(&buf, + "SELECT relname, " + " attname, " + " format_type(atttypid, atttypmod), " + " attnotnull, " + " pg_get_expr(adbin, adrelid), "); + + /* Generated columns are supported since Postgres 12 */ + if (PQserverVersion(conn) >= 120000) appendStringInfoString(&buf, - "SELECT relname, " - " attname, " - " format_type(atttypid, atttypmod), " - " attnotnull, " - " pg_get_expr(adbin, adrelid), "); - - /* Generated columns are supported since Postgres 12 */ - if (PQserverVersion(conn) >= 120000) - appendStringInfoString(&buf, - " attgenerated, "); - else - appendStringInfoString(&buf, - " NULL, "); - - if (import_collate) - appendStringInfoString(&buf, - " collname, " - " collnsp.nspname "); - else - appendStringInfoString(&buf, - " NULL, NULL "); - + " attgenerated, "); + else appendStringInfoString(&buf, - "FROM pg_class c " - " JOIN pg_namespace n ON " - " relnamespace = n.oid " - " LEFT JOIN pg_attribute a ON " - " attrelid = c.oid AND attnum > 0 " - " AND NOT attisdropped " - " LEFT JOIN pg_attrdef ad ON " - " adrelid = c.oid AND adnum = attnum "); - - if (import_collate) - appendStringInfoString(&buf, - " LEFT JOIN pg_collation coll ON " - " coll.oid = attcollation " - " LEFT JOIN pg_namespace collnsp ON " - " collnsp.oid = collnamespace "); + " NULL, "); + if (import_collate) appendStringInfoString(&buf, - "WHERE c.relkind IN (" - CppAsString2(RELKIND_RELATION) "," - CppAsString2(RELKIND_VIEW) "," - CppAsString2(RELKIND_FOREIGN_TABLE) "," - CppAsString2(RELKIND_MATVIEW) "," - CppAsString2(RELKIND_PARTITIONED_TABLE) ") " - " AND n.nspname = "); - deparseStringLiteral(&buf, stmt->remote_schema); - - /* Partitions are supported since Postgres 10 */ - if (PQserverVersion(conn) >= 100000 && - stmt->list_type != FDW_IMPORT_SCHEMA_LIMIT_TO) - appendStringInfoString(&buf, " AND NOT c.relispartition "); - - /* Apply restrictions for LIMIT TO and EXCEPT */ - if (stmt->list_type == FDW_IMPORT_SCHEMA_LIMIT_TO || - stmt->list_type == FDW_IMPORT_SCHEMA_EXCEPT) + " collname, " + " collnsp.nspname "); + else + appendStringInfoString(&buf, + " NULL, NULL "); + + appendStringInfoString(&buf, + "FROM pg_class c " + " JOIN pg_namespace n ON " + " relnamespace = n.oid " + " LEFT JOIN pg_attribute a ON " + " attrelid = c.oid AND attnum > 0 " + " AND NOT attisdropped " + " LEFT JOIN pg_attrdef ad ON " + " adrelid = c.oid AND adnum = attnum "); + + if (import_collate) + appendStringInfoString(&buf, + " LEFT JOIN pg_collation coll ON " + " coll.oid = attcollation " + " LEFT JOIN pg_namespace collnsp ON " + " collnsp.oid = collnamespace "); + + appendStringInfoString(&buf, + "WHERE c.relkind IN (" + CppAsString2(RELKIND_RELATION) "," + CppAsString2(RELKIND_VIEW) "," + CppAsString2(RELKIND_FOREIGN_TABLE) "," + CppAsString2(RELKIND_MATVIEW) "," + CppAsString2(RELKIND_PARTITIONED_TABLE) ") " + " AND n.nspname = "); + deparseStringLiteral(&buf, stmt->remote_schema); + + /* Partitions are supported since Postgres 10 */ + if (PQserverVersion(conn) >= 100000 && + stmt->list_type != FDW_IMPORT_SCHEMA_LIMIT_TO) + appendStringInfoString(&buf, " AND NOT c.relispartition "); + + /* Apply restrictions for LIMIT TO and EXCEPT */ + if (stmt->list_type == FDW_IMPORT_SCHEMA_LIMIT_TO || + stmt->list_type == FDW_IMPORT_SCHEMA_EXCEPT) + { + bool first_item = true; + + appendStringInfoString(&buf, " AND c.relname "); + if (stmt->list_type == FDW_IMPORT_SCHEMA_EXCEPT) + appendStringInfoString(&buf, "NOT "); + appendStringInfoString(&buf, "IN ("); + + /* Append list of table names within IN clause */ + foreach(lc, stmt->table_list) { - bool first_item = true; + RangeVar *rv = (RangeVar *) lfirst(lc); - appendStringInfoString(&buf, " AND c.relname "); - if (stmt->list_type == FDW_IMPORT_SCHEMA_EXCEPT) - appendStringInfoString(&buf, "NOT "); - appendStringInfoString(&buf, "IN ("); + if (first_item) + first_item = false; + else + appendStringInfoString(&buf, ", "); + deparseStringLiteral(&buf, rv->relname); + } + appendStringInfoChar(&buf, ')'); + } - /* Append list of table names within IN clause */ - foreach(lc, stmt->table_list) - { - RangeVar *rv = (RangeVar *) lfirst(lc); + /* Append ORDER BY at the end of query to ensure output ordering */ + appendStringInfoString(&buf, " ORDER BY c.relname, a.attnum"); - if (first_item) - first_item = false; - else - appendStringInfoString(&buf, ", "); - deparseStringLiteral(&buf, rv->relname); - } - appendStringInfoChar(&buf, ')'); - } + /* Fetch the data */ + res = pgfdw_exec_query(conn, buf.data, NULL); + if (PQresultStatus(res) != PGRES_TUPLES_OK) + pgfdw_report_error(ERROR, res, conn, buf.data); - /* Append ORDER BY at the end of query to ensure output ordering */ - appendStringInfoString(&buf, " ORDER BY c.relname, a.attnum"); + /* Process results */ + numrows = PQntuples(res); + /* note: incrementation of i happens in inner loop's while() test */ + for (i = 0; i < numrows;) + { + char *tablename = PQgetvalue(res, i, 0); + bool first_item = true; - /* Fetch the data */ - res = pgfdw_exec_query(conn, buf.data, NULL); - if (PQresultStatus(res) != PGRES_TUPLES_OK) - pgfdw_report_error(ERROR, res, conn, false, buf.data); + resetStringInfo(&buf); + appendStringInfo(&buf, "CREATE FOREIGN TABLE %s (\n", + quote_identifier(tablename)); - /* Process results */ - numrows = PQntuples(res); - /* note: incrementation of i happens in inner loop's while() test */ - for (i = 0; i < numrows;) + /* Scan all rows for this table */ + do { - char *tablename = PQgetvalue(res, i, 0); - bool first_item = true; + char *attname; + char *typename; + char *attnotnull; + char *attgenerated; + char *attdefault; + char *collname; + char *collnamespace; + + /* If table has no columns, we'll see nulls here */ + if (PQgetisnull(res, i, 1)) + continue; - resetStringInfo(&buf); - appendStringInfo(&buf, "CREATE FOREIGN TABLE %s (\n", - quote_identifier(tablename)); + attname = PQgetvalue(res, i, 1); + typename = PQgetvalue(res, i, 2); + attnotnull = PQgetvalue(res, i, 3); + attdefault = PQgetisnull(res, i, 4) ? NULL : + PQgetvalue(res, i, 4); + attgenerated = PQgetisnull(res, i, 5) ? NULL : + PQgetvalue(res, i, 5); + collname = PQgetisnull(res, i, 6) ? NULL : + PQgetvalue(res, i, 6); + collnamespace = PQgetisnull(res, i, 7) ? NULL : + PQgetvalue(res, i, 7); + + if (first_item) + first_item = false; + else + appendStringInfoString(&buf, ",\n"); - /* Scan all rows for this table */ - do - { - char *attname; - char *typename; - char *attnotnull; - char *attgenerated; - char *attdefault; - char *collname; - char *collnamespace; - - /* If table has no columns, we'll see nulls here */ - if (PQgetisnull(res, i, 1)) - continue; + /* Print column name and type */ + appendStringInfo(&buf, " %s %s", + quote_identifier(attname), + typename); - attname = PQgetvalue(res, i, 1); - typename = PQgetvalue(res, i, 2); - attnotnull = PQgetvalue(res, i, 3); - attdefault = PQgetisnull(res, i, 4) ? NULL : - PQgetvalue(res, i, 4); - attgenerated = PQgetisnull(res, i, 5) ? NULL : - PQgetvalue(res, i, 5); - collname = PQgetisnull(res, i, 6) ? NULL : - PQgetvalue(res, i, 6); - collnamespace = PQgetisnull(res, i, 7) ? NULL : - PQgetvalue(res, i, 7); - - if (first_item) - first_item = false; - else - appendStringInfoString(&buf, ",\n"); + /* + * Add column_name option so that renaming the foreign table's + * column doesn't break the association to the underlying column. + */ + appendStringInfoString(&buf, " OPTIONS (column_name "); + deparseStringLiteral(&buf, attname); + appendStringInfoChar(&buf, ')'); - /* Print column name and type */ - appendStringInfo(&buf, " %s %s", - quote_identifier(attname), - typename); + /* Add COLLATE if needed */ + if (import_collate && collname != NULL && collnamespace != NULL) + appendStringInfo(&buf, " COLLATE %s.%s", + quote_identifier(collnamespace), + quote_identifier(collname)); - /* - * Add column_name option so that renaming the foreign table's - * column doesn't break the association to the underlying - * column. - */ - appendStringInfoString(&buf, " OPTIONS (column_name "); - deparseStringLiteral(&buf, attname); - appendStringInfoChar(&buf, ')'); - - /* Add COLLATE if needed */ - if (import_collate && collname != NULL && collnamespace != NULL) - appendStringInfo(&buf, " COLLATE %s.%s", - quote_identifier(collnamespace), - quote_identifier(collname)); - - /* Add DEFAULT if needed */ - if (import_default && attdefault != NULL && - (!attgenerated || !attgenerated[0])) - appendStringInfo(&buf, " DEFAULT %s", attdefault); - - /* Add GENERATED if needed */ - if (import_generated && attgenerated != NULL && - attgenerated[0] == ATTRIBUTE_GENERATED_STORED) - { - Assert(attdefault != NULL); - appendStringInfo(&buf, - " GENERATED ALWAYS AS (%s) STORED", - attdefault); - } + /* Add DEFAULT if needed */ + if (import_default && attdefault != NULL && + (!attgenerated || !attgenerated[0])) + appendStringInfo(&buf, " DEFAULT %s", attdefault); - /* Add NOT NULL if needed */ - if (import_not_null && attnotnull[0] == 't') - appendStringInfoString(&buf, " NOT NULL"); + /* Add GENERATED if needed */ + if (import_generated && attgenerated != NULL && + attgenerated[0] == ATTRIBUTE_GENERATED_STORED) + { + Assert(attdefault != NULL); + appendStringInfo(&buf, + " GENERATED ALWAYS AS (%s) STORED", + attdefault); } - while (++i < numrows && - strcmp(PQgetvalue(res, i, 0), tablename) == 0); - /* - * Add server name and table-level options. We specify remote - * schema and table name as options (the latter to ensure that - * renaming the foreign table doesn't break the association). - */ - appendStringInfo(&buf, "\n) SERVER %s\nOPTIONS (", - quote_identifier(server->servername)); + /* Add NOT NULL if needed */ + if (import_not_null && attnotnull[0] == 't') + appendStringInfoString(&buf, " NOT NULL"); + } + while (++i < numrows && + strcmp(PQgetvalue(res, i, 0), tablename) == 0); - appendStringInfoString(&buf, "schema_name "); - deparseStringLiteral(&buf, stmt->remote_schema); - appendStringInfoString(&buf, ", table_name "); - deparseStringLiteral(&buf, tablename); + /* + * Add server name and table-level options. We specify remote schema + * and table name as options (the latter to ensure that renaming the + * foreign table doesn't break the association). + */ + appendStringInfo(&buf, "\n) SERVER %s\nOPTIONS (", + quote_identifier(server->servername)); - appendStringInfoString(&buf, ");"); + appendStringInfoString(&buf, "schema_name "); + deparseStringLiteral(&buf, stmt->remote_schema); + appendStringInfoString(&buf, ", table_name "); + deparseStringLiteral(&buf, tablename); - commands = lappend(commands, pstrdup(buf.data)); - } - } - PG_FINALLY(); - { - PQclear(res); + appendStringInfoString(&buf, ");"); + + commands = lappend(commands, pstrdup(buf.data)); } - PG_END_TRY(); + PQclear(res); ReleaseConnection(conn); @@ -7417,7 +7305,7 @@ postgresForeignAsyncNotify(AsyncRequest *areq) /* On error, report the original query, not the FETCH. */ if (!PQconsumeInput(fsstate->conn)) - pgfdw_report_error(ERROR, NULL, fsstate->conn, false, fsstate->query); + pgfdw_report_error(ERROR, NULL, fsstate->conn, fsstate->query); fetch_more_data(node); @@ -7516,7 +7404,7 @@ fetch_more_data_begin(AsyncRequest *areq) fsstate->fetch_size, fsstate->cursor_number); if (!PQsendQuery(fsstate->conn, sql)) - pgfdw_report_error(ERROR, NULL, fsstate->conn, false, fsstate->query); + pgfdw_report_error(ERROR, NULL, fsstate->conn, fsstate->query); /* Remember that the request is in process */ fsstate->conn_state->pendingAreq = areq; diff --git a/contrib/postgres_fdw/postgres_fdw.h b/contrib/postgres_fdw/postgres_fdw.h index 81358f3bde7d..38e1a8859413 100644 --- a/contrib/postgres_fdw/postgres_fdw.h +++ b/contrib/postgres_fdw/postgres_fdw.h @@ -15,7 +15,7 @@ #include "foreign/foreign.h" #include "lib/stringinfo.h" -#include "libpq-fe.h" +#include "libpq/libpq-be-fe.h" #include "nodes/execnodes.h" #include "nodes/pathnodes.h" #include "utils/relcache.h" @@ -167,7 +167,7 @@ extern PGresult *pgfdw_get_result(PGconn *conn); extern PGresult *pgfdw_exec_query(PGconn *conn, const char *query, PgFdwConnState *state); extern void pgfdw_report_error(int elevel, PGresult *res, PGconn *conn, - bool clear, const char *sql); + const char *sql); /* in option.c */ extern int ExtractConnectionOptions(List *defelems, diff --git a/src/backend/replication/libpqwalreceiver/libpqwalreceiver.c b/src/backend/replication/libpqwalreceiver/libpqwalreceiver.c index 7b4ddf7a8f52..d615f340ac74 100644 --- a/src/backend/replication/libpqwalreceiver/libpqwalreceiver.c +++ b/src/backend/replication/libpqwalreceiver/libpqwalreceiver.c @@ -418,31 +418,22 @@ libpqrcv_identify_system(WalReceiverConn *conn, TimeLineID *primary_tli) "IDENTIFY_SYSTEM", WAIT_EVENT_LIBPQWALRECEIVER_RECEIVE); if (PQresultStatus(res) != PGRES_TUPLES_OK) - { - PQclear(res); ereport(ERROR, (errcode(ERRCODE_PROTOCOL_VIOLATION), errmsg("could not receive database system identifier and timeline ID from " "the primary server: %s", pchomp(PQerrorMessage(conn->streamConn))))); - } /* * IDENTIFY_SYSTEM returns 3 columns in 9.3 and earlier, and 4 columns in * 9.4 and onwards. */ if (PQnfields(res) < 3 || PQntuples(res) != 1) - { - int ntuples = PQntuples(res); - int nfields = PQnfields(res); - - PQclear(res); ereport(ERROR, (errcode(ERRCODE_PROTOCOL_VIOLATION), errmsg("invalid response from primary server"), errdetail("Could not identify system: got %d rows and %d fields, expected %d rows and %d or more fields.", - ntuples, nfields, 1, 3))); - } + PQntuples(res), PQnfields(res), 1, 3))); primary_sysid = pstrdup(PQgetvalue(res, 0, 0)); *primary_tli = pg_strtoint32(PQgetvalue(res, 0, 1)); PQclear(res); @@ -604,13 +595,10 @@ libpqrcv_startstreaming(WalReceiverConn *conn, return false; } else if (PQresultStatus(res) != PGRES_COPY_BOTH) - { - PQclear(res); ereport(ERROR, (errcode(ERRCODE_PROTOCOL_VIOLATION), errmsg("could not start WAL streaming: %s", pchomp(PQerrorMessage(conn->streamConn))))); - } PQclear(res); return true; } @@ -718,26 +706,17 @@ libpqrcv_readtimelinehistoryfile(WalReceiverConn *conn, cmd, WAIT_EVENT_LIBPQWALRECEIVER_RECEIVE); if (PQresultStatus(res) != PGRES_TUPLES_OK) - { - PQclear(res); ereport(ERROR, (errcode(ERRCODE_PROTOCOL_VIOLATION), errmsg("could not receive timeline history file from " "the primary server: %s", pchomp(PQerrorMessage(conn->streamConn))))); - } if (PQnfields(res) != 2 || PQntuples(res) != 1) - { - int ntuples = PQntuples(res); - int nfields = PQnfields(res); - - PQclear(res); ereport(ERROR, (errcode(ERRCODE_PROTOCOL_VIOLATION), errmsg("invalid response from primary server"), errdetail("Expected 1 tuple with 2 fields, got %d tuples with %d fields.", - ntuples, nfields))); - } + PQntuples(res), PQnfields(res)))); *filename = pstrdup(PQgetvalue(res, 0, 0)); *len = PQgetlength(res, 0, 1); @@ -841,13 +820,10 @@ libpqrcv_receive(WalReceiverConn *conn, char **buffer, return -1; } else - { - PQclear(res); ereport(ERROR, (errcode(ERRCODE_PROTOCOL_VIOLATION), errmsg("could not receive data from WAL stream: %s", pchomp(PQerrorMessage(conn->streamConn))))); - } } if (rawlen < -1) ereport(ERROR, @@ -971,13 +947,10 @@ libpqrcv_create_slot(WalReceiverConn *conn, const char *slotname, pfree(cmd.data); if (PQresultStatus(res) != PGRES_TUPLES_OK) - { - PQclear(res); ereport(ERROR, (errcode(ERRCODE_PROTOCOL_VIOLATION), errmsg("could not create replication slot \"%s\": %s", slotname, pchomp(PQerrorMessage(conn->streamConn))))); - } if (lsn) *lsn = DatumGetLSN(DirectFunctionCall1Coll(pg_lsn_in, InvalidOid, diff --git a/src/backend/utils/mmgr/mcxt.c b/src/backend/utils/mmgr/mcxt.c index 15fa4d0a55ee..ce01dce9861d 100644 --- a/src/backend/utils/mmgr/mcxt.c +++ b/src/backend/utils/mmgr/mcxt.c @@ -560,9 +560,7 @@ MemoryContextDeleteChildren(MemoryContext context) * the specified context, since that means it will automatically be freed * when no longer needed. * - * There is no API for deregistering a callback once registered. If you - * want it to not do anything anymore, adjust the state pointed to by its - * "arg" to indicate that. + * Note that callers can assume this cannot fail. */ void MemoryContextRegisterResetCallback(MemoryContext context, @@ -577,6 +575,41 @@ MemoryContextRegisterResetCallback(MemoryContext context, context->isReset = false; } +/* + * MemoryContextUnregisterResetCallback + * Undo the effects of MemoryContextRegisterResetCallback. + * + * This can be used if a callback's effects are no longer required + * at some point before the context has been reset/deleted. It is the + * caller's responsibility to pfree the callback struct (if needed). + * + * An assertion failure occurs if the callback was not registered. + * We could alternatively define that case as a no-op, but that seems too + * likely to mask programming errors such as passing the wrong context. + */ +void +MemoryContextUnregisterResetCallback(MemoryContext context, + MemoryContextCallback *cb) +{ + MemoryContextCallback *prev, + *cur; + + Assert(MemoryContextIsValid(context)); + + for (prev = NULL, cur = context->reset_cbs; cur != NULL; + prev = cur, cur = cur->next) + { + if (cur != cb) + continue; + if (prev) + prev->next = cur->next; + else + context->reset_cbs = cur->next; + return; + } + Assert(false); +} + /* * MemoryContextCallResetCallbacks * Internal function to call all registered callbacks for context. diff --git a/src/include/libpq/libpq-be-fe-helpers.h b/src/include/libpq/libpq-be-fe-helpers.h index 16205b824fa5..6f4e2bd7ef90 100644 --- a/src/include/libpq/libpq-be-fe-helpers.h +++ b/src/include/libpq/libpq-be-fe-helpers.h @@ -30,17 +30,7 @@ #ifndef LIBPQ_BE_FE_HELPERS_H #define LIBPQ_BE_FE_HELPERS_H -/* - * Despite the name, BUILDING_DLL is set only when building code directly part - * of the backend. Which also is where libpq isn't allowed to be - * used. Obviously this doesn't protect against libpq-fe.h getting included - * otherwise, but perhaps still protects against a few mistakes... - */ -#ifdef BUILDING_DLL -#error "libpq may not be used code directly built into the backend" -#endif - -#include "libpq-fe.h" +#include "libpq/libpq-be-fe.h" #include "miscadmin.h" #include "storage/fd.h" #include "storage/latch.h" @@ -289,41 +279,30 @@ libpqsrv_exec_params(PGconn *conn, static inline PGresult * libpqsrv_get_result_last(PGconn *conn, uint32 wait_event_info) { - PGresult *volatile lastResult = NULL; + PGresult *lastResult = NULL; - /* In what follows, do not leak any PGresults on an error. */ - PG_TRY(); + for (;;) { - for (;;) - { - /* Wait for, and collect, the next PGresult. */ - PGresult *result; + /* Wait for, and collect, the next PGresult. */ + PGresult *result; - result = libpqsrv_get_result(conn, wait_event_info); - if (result == NULL) - break; /* query is complete, or failure */ + result = libpqsrv_get_result(conn, wait_event_info); + if (result == NULL) + break; /* query is complete, or failure */ - /* - * Emulate PQexec()'s behavior of returning the last result when - * there are many. - */ - PQclear(lastResult); - lastResult = result; - - if (PQresultStatus(lastResult) == PGRES_COPY_IN || - PQresultStatus(lastResult) == PGRES_COPY_OUT || - PQresultStatus(lastResult) == PGRES_COPY_BOTH || - PQstatus(conn) == CONNECTION_BAD) - break; - } - } - PG_CATCH(); - { + /* + * Emulate PQexec()'s behavior of returning the last result when there + * are many. + */ PQclear(lastResult); - PG_RE_THROW(); - } - PG_END_TRY(); + lastResult = result; + if (PQresultStatus(lastResult) == PGRES_COPY_IN || + PQresultStatus(lastResult) == PGRES_COPY_OUT || + PQresultStatus(lastResult) == PGRES_COPY_BOTH || + PQstatus(conn) == CONNECTION_BAD) + break; + } return lastResult; } diff --git a/src/include/libpq/libpq-be-fe.h b/src/include/libpq/libpq-be-fe.h new file mode 100644 index 000000000000..e3f796b02309 --- /dev/null +++ b/src/include/libpq/libpq-be-fe.h @@ -0,0 +1,259 @@ +/*------------------------------------------------------------------------- + * + * libpq-be-fe.h + * Wrapper functions for using libpq in extensions + * + * Code built directly into the backend is not allowed to link to libpq + * directly. Extension code is allowed to use libpq however. One of the + * main risks in doing so is leaking the malloc-allocated structures + * returned by libpq, causing a process-lifespan memory leak. + * + * This file provides wrapper objects to help in building memory-safe code. + * A PGresult object wrapped this way acts much as if it were palloc'd: + * it will go away when the specified context is reset or deleted. + * We might later extend the concept to other objects such as PGconns. + * + * See also the libpq-be-fe-helpers.h file, which provides additional + * facilities built on top of this one. + * + * Portions Copyright (c) 1996-2025, PostgreSQL Global Development Group + * Portions Copyright (c) 1994, Regents of the University of California + * + * src/include/libpq/libpq-be-fe.h + * + *------------------------------------------------------------------------- + */ +#ifndef LIBPQ_BE_FE_H +#define LIBPQ_BE_FE_H + +/* + * Despite the name, BUILDING_DLL is set only when building code directly part + * of the backend. Which also is where libpq isn't allowed to be + * used. Obviously this doesn't protect against libpq-fe.h getting included + * otherwise, but perhaps still protects against a few mistakes... + */ +#ifdef BUILDING_DLL +#error "libpq may not be used in code directly built into the backend" +#endif + +#include "libpq-fe.h" + +/* + * Memory-context-safe wrapper object for a PGresult. + */ +typedef struct libpqsrv_PGresult +{ + PGresult *res; /* the wrapped PGresult */ + MemoryContext ctx; /* the MemoryContext it's attached to */ + MemoryContextCallback cb; /* the callback that implements freeing */ +} libpqsrv_PGresult; + + +/* + * Wrap the given PGresult in a libpqsrv_PGresult object, so that it will + * go away automatically if the current memory context is reset or deleted. + * + * To avoid potential memory leaks, backend code must always apply this + * immediately to the output of any PGresult-yielding libpq function. + */ +static inline libpqsrv_PGresult * +libpqsrv_PQwrap(PGresult *res) +{ + libpqsrv_PGresult *bres; + MemoryContext ctx = CurrentMemoryContext; + + /* We pass through a NULL result as-is, since there's nothing to free */ + if (res == NULL) + return NULL; + /* Attempt to allocate the wrapper ... this had better not throw error */ + bres = (libpqsrv_PGresult *) + MemoryContextAllocExtended(ctx, + sizeof(libpqsrv_PGresult), + MCXT_ALLOC_NO_OOM); + /* If we failed to allocate a wrapper, free the PGresult before failing */ + if (bres == NULL) + { + PQclear(res); + ereport(ERROR, + (errcode(ERRCODE_OUT_OF_MEMORY), + errmsg("out of memory"))); + } + /* Okay, set up the wrapper */ + bres->res = res; + bres->ctx = ctx; + bres->cb.func = (MemoryContextCallbackFunction) PQclear; + bres->cb.arg = res; + MemoryContextRegisterResetCallback(ctx, &bres->cb); + return bres; +} + +/* + * Free a wrapped PGresult, after detaching it from the memory context. + * Like PQclear(), allow the argument to be NULL. + */ +static inline void +libpqsrv_PQclear(libpqsrv_PGresult *bres) +{ + if (bres) + { + MemoryContextUnregisterResetCallback(bres->ctx, &bres->cb); + PQclear(bres->res); + pfree(bres); + } +} + +/* + * Move a wrapped PGresult to have a different parent context. + */ +static inline libpqsrv_PGresult * +libpqsrv_PGresultSetParent(libpqsrv_PGresult *bres, MemoryContext ctx) +{ + libpqsrv_PGresult *newres; + + /* We pass through a NULL result as-is */ + if (bres == NULL) + return NULL; + /* Make a new wrapper in the target context, raising error on OOM */ + newres = (libpqsrv_PGresult *) + MemoryContextAlloc(ctx, sizeof(libpqsrv_PGresult)); + /* Okay, set up the new wrapper */ + newres->res = bres->res; + newres->ctx = ctx; + newres->cb.func = (MemoryContextCallbackFunction) PQclear; + newres->cb.arg = bres->res; + MemoryContextRegisterResetCallback(ctx, &newres->cb); + /* Disarm and delete the old wrapper */ + MemoryContextUnregisterResetCallback(bres->ctx, &bres->cb); + pfree(bres); + return newres; +} + +/* + * Convenience wrapper for PQgetResult. + * + * We could supply wrappers for other PGresult-returning functions too, + * but at present there's no need. + */ +static inline libpqsrv_PGresult * +libpqsrv_PQgetResult(PGconn *conn) +{ + return libpqsrv_PQwrap(PQgetResult(conn)); +} + +/* + * Accessor functions for libpqsrv_PGresult. While it's not necessary to use + * these, they emulate the behavior of the underlying libpq functions when + * passed a NULL pointer. This is particularly important for PQresultStatus, + * which is often the first check on a result. + */ + +static inline ExecStatusType +libpqsrv_PQresultStatus(const libpqsrv_PGresult *res) +{ + if (!res) + return PGRES_FATAL_ERROR; + return PQresultStatus(res->res); +} + +static inline const char * +libpqsrv_PQresultErrorMessage(const libpqsrv_PGresult *res) +{ + if (!res) + return ""; + return PQresultErrorMessage(res->res); +} + +static inline char * +libpqsrv_PQresultErrorField(const libpqsrv_PGresult *res, int fieldcode) +{ + if (!res) + return NULL; + return PQresultErrorField(res->res, fieldcode); +} + +static inline char * +libpqsrv_PQcmdStatus(const libpqsrv_PGresult *res) +{ + if (!res) + return NULL; + return PQcmdStatus(res->res); +} + +static inline int +libpqsrv_PQntuples(const libpqsrv_PGresult *res) +{ + if (!res) + return 0; + return PQntuples(res->res); +} + +static inline int +libpqsrv_PQnfields(const libpqsrv_PGresult *res) +{ + if (!res) + return 0; + return PQnfields(res->res); +} + +static inline char * +libpqsrv_PQgetvalue(const libpqsrv_PGresult *res, int tup_num, int field_num) +{ + if (!res) + return NULL; + return PQgetvalue(res->res, tup_num, field_num); +} + +static inline int +libpqsrv_PQgetlength(const libpqsrv_PGresult *res, int tup_num, int field_num) +{ + if (!res) + return 0; + return PQgetlength(res->res, tup_num, field_num); +} + +static inline int +libpqsrv_PQgetisnull(const libpqsrv_PGresult *res, int tup_num, int field_num) +{ + if (!res) + return 1; /* pretend it is null */ + return PQgetisnull(res->res, tup_num, field_num); +} + +static inline char * +libpqsrv_PQfname(const libpqsrv_PGresult *res, int field_num) +{ + if (!res) + return NULL; + return PQfname(res->res, field_num); +} + +static inline const char * +libpqsrv_PQcmdTuples(const libpqsrv_PGresult *res) +{ + if (!res) + return ""; + return PQcmdTuples(res->res); +} + +/* + * Redefine these libpq entry point names concerned with PGresults so that + * they will operate on libpqsrv_PGresults instead. This avoids needing to + * convert a lot of pre-existing code, and reduces the notational differences + * between frontend and backend libpq-using code. + */ +#define PGresult libpqsrv_PGresult +#define PQclear libpqsrv_PQclear +#define PQgetResult libpqsrv_PQgetResult +#define PQresultStatus libpqsrv_PQresultStatus +#define PQresultErrorMessage libpqsrv_PQresultErrorMessage +#define PQresultErrorField libpqsrv_PQresultErrorField +#define PQcmdStatus libpqsrv_PQcmdStatus +#define PQntuples libpqsrv_PQntuples +#define PQnfields libpqsrv_PQnfields +#define PQgetvalue libpqsrv_PQgetvalue +#define PQgetlength libpqsrv_PQgetlength +#define PQgetisnull libpqsrv_PQgetisnull +#define PQfname libpqsrv_PQfname +#define PQcmdTuples libpqsrv_PQcmdTuples + +#endif /* LIBPQ_BE_FE_H */ diff --git a/src/include/utils/palloc.h b/src/include/utils/palloc.h index e1b42267b22a..039b9cba61a3 100644 --- a/src/include/utils/palloc.h +++ b/src/include/utils/palloc.h @@ -133,6 +133,8 @@ MemoryContextSwitchTo(MemoryContext context) /* Registration of memory context reset/delete callbacks */ extern void MemoryContextRegisterResetCallback(MemoryContext context, MemoryContextCallback *cb); +extern void MemoryContextUnregisterResetCallback(MemoryContext context, + MemoryContextCallback *cb); /* * These are like standard strdup() except the copied string is diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list index a8346cda633a..0b1a8f71af63 100644 --- a/src/tools/pgindent/typedefs.list +++ b/src/tools/pgindent/typedefs.list @@ -3714,6 +3714,7 @@ lclTocEntry leafSegmentInfo leaf_item libpq_source +libpqsrv_PGresult line_t lineno_t list_sort_comparator