From a709ddb30b2b747beb214f0b13cd1e1816094e6b Mon Sep 17 00:00:00 2001 From: Melanie Plageman Date: Thu, 30 Sep 2021 16:16:22 -0400 Subject: [PATCH v13 2/4] Add utility to make tuplestores for pg stat views Most of the steps to make a tuplestore for those pg_stat views requiring one are the same. Consolidate them into a single helper function for clarity and to avoid bugs. --- src/backend/utils/adt/pgstatfuncs.c | 129 ++++++++++------------------ 1 file changed, 44 insertions(+), 85 deletions(-) diff --git a/src/backend/utils/adt/pgstatfuncs.c b/src/backend/utils/adt/pgstatfuncs.c index ff5aedc99c..513f5aecf6 100644 --- a/src/backend/utils/adt/pgstatfuncs.c +++ b/src/backend/utils/adt/pgstatfuncs.c @@ -36,6 +36,42 @@ #define HAS_PGSTAT_PERMISSIONS(role) (is_member_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS) || has_privs_of_role(GetUserId(), role)) +/* + * Helper function for views with multiple rows constructed from a tuplestore + */ +static Tuplestorestate * +pg_stat_make_tuplestore(FunctionCallInfo fcinfo, TupleDesc *tupdesc) +{ + Tuplestorestate *tupstore; + ReturnSetInfo *rsinfo = (ReturnSetInfo *) fcinfo->resultinfo; + MemoryContext per_query_ctx; + MemoryContext oldcontext; + + /* check to see if caller supports us returning a tuplestore */ + if (rsinfo == NULL || !IsA(rsinfo, ReturnSetInfo)) + ereport(ERROR, + (errcode(ERRCODE_FEATURE_NOT_SUPPORTED), + errmsg("set-valued function called in context that cannot accept a set"))); + if (!(rsinfo->allowedModes & SFRM_Materialize)) + ereport(ERROR, + (errcode(ERRCODE_FEATURE_NOT_SUPPORTED), + errmsg("materialize mode required, but it is not allowed in this context"))); + + /* Build a tuple descriptor for our result type */ + if (get_call_result_type(fcinfo, NULL, tupdesc) != TYPEFUNC_COMPOSITE) + elog(ERROR, "return type must be a row type"); + + per_query_ctx = rsinfo->econtext->ecxt_per_query_memory; + oldcontext = MemoryContextSwitchTo(per_query_ctx); + + tupstore = tuplestore_begin_heap(true, false, work_mem); + rsinfo->returnMode = SFRM_Materialize; + rsinfo->setResult = tupstore; + rsinfo->setDesc = *tupdesc; + MemoryContextSwitchTo(oldcontext); + return tupstore; +} + Datum pg_stat_get_numscans(PG_FUNCTION_ARGS) { @@ -457,29 +493,13 @@ Datum pg_stat_get_progress_info(PG_FUNCTION_ARGS) { #define PG_STAT_GET_PROGRESS_COLS PGSTAT_NUM_PROGRESS_PARAM + 3 - int num_backends = pgstat_fetch_stat_numbackends(); int curr_backend; - char *cmd = text_to_cstring(PG_GETARG_TEXT_PP(0)); ProgressCommandType cmdtype; TupleDesc tupdesc; - Tuplestorestate *tupstore; - ReturnSetInfo *rsinfo = (ReturnSetInfo *) fcinfo->resultinfo; - MemoryContext per_query_ctx; - MemoryContext oldcontext; - - /* check to see if caller supports us returning a tuplestore */ - if (rsinfo == NULL || !IsA(rsinfo, ReturnSetInfo)) - ereport(ERROR, - (errcode(ERRCODE_FEATURE_NOT_SUPPORTED), - errmsg("set-valued function called in context that cannot accept a set"))); - if (!(rsinfo->allowedModes & SFRM_Materialize)) - ereport(ERROR, - (errcode(ERRCODE_FEATURE_NOT_SUPPORTED), - errmsg("materialize mode required, but it is not allowed in this context"))); - /* Build a tuple descriptor for our result type */ - if (get_call_result_type(fcinfo, NULL, &tupdesc) != TYPEFUNC_COMPOSITE) - elog(ERROR, "return type must be a row type"); + Tuplestorestate *tupstore = pg_stat_make_tuplestore(fcinfo, &tupdesc); + int num_backends = pgstat_fetch_stat_numbackends(); + char *cmd = text_to_cstring(PG_GETARG_TEXT_PP(0)); /* Translate command name into command type code. */ if (pg_strcasecmp(cmd, "VACUUM") == 0) @@ -499,15 +519,6 @@ pg_stat_get_progress_info(PG_FUNCTION_ARGS) (errcode(ERRCODE_INVALID_PARAMETER_VALUE), errmsg("invalid command name: \"%s\"", cmd))); - per_query_ctx = rsinfo->econtext->ecxt_per_query_memory; - oldcontext = MemoryContextSwitchTo(per_query_ctx); - - tupstore = tuplestore_begin_heap(true, false, work_mem); - rsinfo->returnMode = SFRM_Materialize; - rsinfo->setResult = tupstore; - rsinfo->setDesc = tupdesc; - MemoryContextSwitchTo(oldcontext); - /* 1-based index */ for (curr_backend = 1; curr_backend <= num_backends; curr_backend++) { @@ -568,38 +579,12 @@ Datum pg_stat_get_activity(PG_FUNCTION_ARGS) { #define PG_STAT_GET_ACTIVITY_COLS 30 - int num_backends = pgstat_fetch_stat_numbackends(); - int curr_backend; - int pid = PG_ARGISNULL(0) ? -1 : PG_GETARG_INT32(0); - ReturnSetInfo *rsinfo = (ReturnSetInfo *) fcinfo->resultinfo; TupleDesc tupdesc; - Tuplestorestate *tupstore; - MemoryContext per_query_ctx; - MemoryContext oldcontext; - - /* check to see if caller supports us returning a tuplestore */ - if (rsinfo == NULL || !IsA(rsinfo, ReturnSetInfo)) - ereport(ERROR, - (errcode(ERRCODE_FEATURE_NOT_SUPPORTED), - errmsg("set-valued function called in context that cannot accept a set"))); - if (!(rsinfo->allowedModes & SFRM_Materialize)) - ereport(ERROR, - (errcode(ERRCODE_FEATURE_NOT_SUPPORTED), - errmsg("materialize mode required, but it is not allowed in this context"))); - - /* Build a tuple descriptor for our result type */ - if (get_call_result_type(fcinfo, NULL, &tupdesc) != TYPEFUNC_COMPOSITE) - elog(ERROR, "return type must be a row type"); - - per_query_ctx = rsinfo->econtext->ecxt_per_query_memory; - oldcontext = MemoryContextSwitchTo(per_query_ctx); - - tupstore = tuplestore_begin_heap(true, false, work_mem); - rsinfo->returnMode = SFRM_Materialize; - rsinfo->setResult = tupstore; - rsinfo->setDesc = tupdesc; + int curr_backend; - MemoryContextSwitchTo(oldcontext); + int num_backends = pgstat_fetch_stat_numbackends(); + int pid = PG_ARGISNULL(0) ? -1 : PG_GETARG_INT32(0); + Tuplestorestate *tupstore = pg_stat_make_tuplestore(fcinfo, &tupdesc); /* 1-based index */ for (curr_backend = 1; curr_backend <= num_backends; curr_backend++) @@ -1871,37 +1856,11 @@ Datum pg_stat_get_slru(PG_FUNCTION_ARGS) { #define PG_STAT_GET_SLRU_COLS 9 - ReturnSetInfo *rsinfo = (ReturnSetInfo *) fcinfo->resultinfo; TupleDesc tupdesc; - Tuplestorestate *tupstore; - MemoryContext per_query_ctx; - MemoryContext oldcontext; int i; PgStat_SLRUStats *stats; - /* check to see if caller supports us returning a tuplestore */ - if (rsinfo == NULL || !IsA(rsinfo, ReturnSetInfo)) - ereport(ERROR, - (errcode(ERRCODE_FEATURE_NOT_SUPPORTED), - errmsg("set-valued function called in context that cannot accept a set"))); - if (!(rsinfo->allowedModes & SFRM_Materialize)) - ereport(ERROR, - (errcode(ERRCODE_FEATURE_NOT_SUPPORTED), - errmsg("materialize mode required, but it is not allowed in this context"))); - - /* Build a tuple descriptor for our result type */ - if (get_call_result_type(fcinfo, NULL, &tupdesc) != TYPEFUNC_COMPOSITE) - elog(ERROR, "return type must be a row type"); - - per_query_ctx = rsinfo->econtext->ecxt_per_query_memory; - oldcontext = MemoryContextSwitchTo(per_query_ctx); - - tupstore = tuplestore_begin_heap(true, false, work_mem); - rsinfo->returnMode = SFRM_Materialize; - rsinfo->setResult = tupstore; - rsinfo->setDesc = tupdesc; - - MemoryContextSwitchTo(oldcontext); + Tuplestorestate *tupstore = pg_stat_make_tuplestore(fcinfo, &tupdesc); /* request SLRU stats from the stat collector */ stats = pgstat_fetch_slru(); -- 2.27.0