From 273766135a1730642b540324704722c0d7a38030 Mon Sep 17 00:00:00 2001 From: Sami Imseih Date: Tue, 13 Oct 2026 02:55:32 +0000 Subject: [PATCH v1 1/1] pg_stat_statements: simplify SQL API version tracking Adding a new SQL API version to pg_stat_statements required recording its number of output columns in several places: a #define, a case in the switch validating the result descriptor, and a line in the Assert checking the number of columns filled at the end of pg_stat_statements_internal(), on top of a new SQL-callable wrapper function. This commit replaces the per-version #defines, the switch and the Assert expression with a single array of output column counts, indexed by pgssVersion. The descriptor check becomes a simple lookup, keeping the existing special case for the legacy 1.0/1.1 entry point. PGSS_NUM_VERSIONS is added for the number of values in pgssVersion, so that a static assertion can check that the array is in sync with the enum. Assertions are also added to check that the API version is in range and that its number of output columns fits in the values[] and nulls[] arrays. The versioned wrapper functions, along with their PG_FUNCTION_INFO_V1 declarations, are now generated with a macro. This is a refactoring, with no behavior changes. Author: Sami Imseih --- .../pg_stat_statements/pg_stat_statements.c | 203 +++++------------- 1 file changed, 50 insertions(+), 153 deletions(-) diff --git a/contrib/pg_stat_statements/pg_stat_statements.c b/contrib/pg_stat_statements/pg_stat_statements.c index 4562222c9fc..3d47e5e6610 100644 --- a/contrib/pg_stat_statements/pg_stat_statements.c +++ b/contrib/pg_stat_statements/pg_stat_statements.c @@ -117,6 +117,8 @@ typedef enum pgssVersion PGSS_V1_13, } pgssVersion; +#define PGSS_NUM_VERSIONS (PGSS_V1_13 + 1) + typedef enum pgssStoreKind { PGSS_INVALID = -1, @@ -324,14 +326,7 @@ static bool pgss_save = true; /* whether to save stats across shutdown */ PG_FUNCTION_INFO_V1(pg_stat_statements_reset); PG_FUNCTION_INFO_V1(pg_stat_statements_reset_1_7); PG_FUNCTION_INFO_V1(pg_stat_statements_reset_1_11); -PG_FUNCTION_INFO_V1(pg_stat_statements_1_2); -PG_FUNCTION_INFO_V1(pg_stat_statements_1_3); -PG_FUNCTION_INFO_V1(pg_stat_statements_1_8); -PG_FUNCTION_INFO_V1(pg_stat_statements_1_9); -PG_FUNCTION_INFO_V1(pg_stat_statements_1_10); -PG_FUNCTION_INFO_V1(pg_stat_statements_1_11); -PG_FUNCTION_INFO_V1(pg_stat_statements_1_12); -PG_FUNCTION_INFO_V1(pg_stat_statements_1_13); +/* pg_stat_statements_1_N are declared by PG_STAT_STATEMENTS_FUNCTION */ PG_FUNCTION_INFO_V1(pg_stat_statements); PG_FUNCTION_INFO_V1(pg_stat_statements_info); @@ -1546,17 +1541,24 @@ pg_stat_statements_reset(PG_FUNCTION_ARGS) PG_RETURN_VOID(); } -/* Number of output arguments (columns) for various API versions */ -#define PG_STAT_STATEMENTS_COLS_V1_0 14 -#define PG_STAT_STATEMENTS_COLS_V1_1 18 -#define PG_STAT_STATEMENTS_COLS_V1_2 19 -#define PG_STAT_STATEMENTS_COLS_V1_3 23 -#define PG_STAT_STATEMENTS_COLS_V1_8 32 -#define PG_STAT_STATEMENTS_COLS_V1_9 33 -#define PG_STAT_STATEMENTS_COLS_V1_10 43 -#define PG_STAT_STATEMENTS_COLS_V1_11 49 -#define PG_STAT_STATEMENTS_COLS_V1_12 52 -#define PG_STAT_STATEMENTS_COLS_V1_13 54 +/* Number of output columns for each SQL API version */ +static const int pgss_api_cols[] = +{ + [PGSS_V1_0] = 14, + [PGSS_V1_1] = 18, + [PGSS_V1_2] = 19, + [PGSS_V1_3] = 23, + [PGSS_V1_8] = 32, + [PGSS_V1_9] = 33, + [PGSS_V1_10] = 43, + [PGSS_V1_11] = 49, + [PGSS_V1_12] = 52, + [PGSS_V1_13] = 54, +}; + +StaticAssertDecl(lengthof(pgss_api_cols) == PGSS_NUM_VERSIONS, + "pgss_api_cols must match pgssVersion"); + #define PG_STAT_STATEMENTS_COLS 54 /* maximum of above */ /* @@ -1569,85 +1571,28 @@ pg_stat_statements_reset(PG_FUNCTION_ARGS) * expected API version is identified by embedding it in the C name of the * function. Unfortunately we weren't bright enough to do that for 1.1. */ -Datum -pg_stat_statements_1_13(PG_FUNCTION_ARGS) -{ - bool showtext = PG_GETARG_BOOL(0); - - pg_stat_statements_internal(fcinfo, PGSS_V1_13, showtext); - - return (Datum) 0; -} - -Datum -pg_stat_statements_1_12(PG_FUNCTION_ARGS) -{ - bool showtext = PG_GETARG_BOOL(0); - - pg_stat_statements_internal(fcinfo, PGSS_V1_12, showtext); - - return (Datum) 0; -} - -Datum -pg_stat_statements_1_11(PG_FUNCTION_ARGS) -{ - bool showtext = PG_GETARG_BOOL(0); - - pg_stat_statements_internal(fcinfo, PGSS_V1_11, showtext); - - return (Datum) 0; -} - -Datum -pg_stat_statements_1_10(PG_FUNCTION_ARGS) -{ - bool showtext = PG_GETARG_BOOL(0); - - pg_stat_statements_internal(fcinfo, PGSS_V1_10, showtext); - - return (Datum) 0; -} - -Datum -pg_stat_statements_1_9(PG_FUNCTION_ARGS) -{ - bool showtext = PG_GETARG_BOOL(0); - - pg_stat_statements_internal(fcinfo, PGSS_V1_9, showtext); - - return (Datum) 0; -} - -Datum -pg_stat_statements_1_8(PG_FUNCTION_ARGS) -{ - bool showtext = PG_GETARG_BOOL(0); - - pg_stat_statements_internal(fcinfo, PGSS_V1_8, showtext); - - return (Datum) 0; +#define PG_STAT_STATEMENTS_FUNCTION(funcname, version) \ +PG_FUNCTION_INFO_V1(funcname); \ +Datum \ +funcname(PG_FUNCTION_ARGS) \ +{ \ + bool showtext = PG_GETARG_BOOL(0); \ + \ + pg_stat_statements_internal(fcinfo, version, showtext); \ + \ + return (Datum) 0; \ } -Datum -pg_stat_statements_1_3(PG_FUNCTION_ARGS) -{ - bool showtext = PG_GETARG_BOOL(0); - - pg_stat_statements_internal(fcinfo, PGSS_V1_3, showtext); - - return (Datum) 0; -} +PG_STAT_STATEMENTS_FUNCTION(pg_stat_statements_1_13, PGSS_V1_13) +PG_STAT_STATEMENTS_FUNCTION(pg_stat_statements_1_12, PGSS_V1_12) +PG_STAT_STATEMENTS_FUNCTION(pg_stat_statements_1_11, PGSS_V1_11) +PG_STAT_STATEMENTS_FUNCTION(pg_stat_statements_1_10, PGSS_V1_10) +PG_STAT_STATEMENTS_FUNCTION(pg_stat_statements_1_9, PGSS_V1_9) +PG_STAT_STATEMENTS_FUNCTION(pg_stat_statements_1_8, PGSS_V1_8) +PG_STAT_STATEMENTS_FUNCTION(pg_stat_statements_1_3, PGSS_V1_3) +PG_STAT_STATEMENTS_FUNCTION(pg_stat_statements_1_2, PGSS_V1_2) -Datum -pg_stat_statements_1_2(PG_FUNCTION_ARGS) -{ - bool showtext = PG_GETARG_BOOL(0); - - pg_stat_statements_internal(fcinfo, PGSS_V1_2, showtext); - - return (Datum) 0; -} +#undef PG_STAT_STATEMENTS_FUNCTION /* * Legacy entry point for pg_stat_statements() API versions 1.0 and 1.1. @@ -1697,53 +1642,15 @@ pg_stat_statements_internal(FunctionCallInfo fcinfo, * being a good safety check, we need a kluge here to detect API version * 1.1, which was wedged into the code in an ill-considered way. */ - switch (rsinfo->setDesc->natts) - { - case PG_STAT_STATEMENTS_COLS_V1_0: - if (api_version != PGSS_V1_0) - elog(ERROR, "incorrect number of output arguments"); - break; - case PG_STAT_STATEMENTS_COLS_V1_1: - /* pg_stat_statements() should have told us 1.0 */ - if (api_version != PGSS_V1_0) - elog(ERROR, "incorrect number of output arguments"); - api_version = PGSS_V1_1; - break; - case PG_STAT_STATEMENTS_COLS_V1_2: - if (api_version != PGSS_V1_2) - elog(ERROR, "incorrect number of output arguments"); - break; - case PG_STAT_STATEMENTS_COLS_V1_3: - if (api_version != PGSS_V1_3) - elog(ERROR, "incorrect number of output arguments"); - break; - case PG_STAT_STATEMENTS_COLS_V1_8: - if (api_version != PGSS_V1_8) - elog(ERROR, "incorrect number of output arguments"); - break; - case PG_STAT_STATEMENTS_COLS_V1_9: - if (api_version != PGSS_V1_9) - elog(ERROR, "incorrect number of output arguments"); - break; - case PG_STAT_STATEMENTS_COLS_V1_10: - if (api_version != PGSS_V1_10) - elog(ERROR, "incorrect number of output arguments"); - break; - case PG_STAT_STATEMENTS_COLS_V1_11: - if (api_version != PGSS_V1_11) - elog(ERROR, "incorrect number of output arguments"); - break; - case PG_STAT_STATEMENTS_COLS_V1_12: - if (api_version != PGSS_V1_12) - elog(ERROR, "incorrect number of output arguments"); - break; - case PG_STAT_STATEMENTS_COLS_V1_13: - if (api_version != PGSS_V1_13) - elog(ERROR, "incorrect number of output arguments"); - break; - default: - elog(ERROR, "incorrect number of output arguments"); - } + Assert(api_version < PGSS_NUM_VERSIONS); + if (api_version == PGSS_V1_0 && + rsinfo->setDesc->natts == pgss_api_cols[PGSS_V1_1]) + api_version = PGSS_V1_1; + else if (rsinfo->setDesc->natts != pgss_api_cols[api_version]) + elog(ERROR, "incorrect number of output arguments"); + + /* values[] and nulls[] below are sized for the largest version */ + Assert(pgss_api_cols[api_version] <= PG_STAT_STATEMENTS_COLS); /* * We'd like to load the query text file (if needed) while not holding any @@ -2005,17 +1912,7 @@ pg_stat_statements_internal(FunctionCallInfo fcinfo, values[i++] = TimestampTzGetDatum(minmax_stats_since); } - Assert(i == (api_version == PGSS_V1_0 ? PG_STAT_STATEMENTS_COLS_V1_0 : - api_version == PGSS_V1_1 ? PG_STAT_STATEMENTS_COLS_V1_1 : - api_version == PGSS_V1_2 ? PG_STAT_STATEMENTS_COLS_V1_2 : - api_version == PGSS_V1_3 ? PG_STAT_STATEMENTS_COLS_V1_3 : - api_version == PGSS_V1_8 ? PG_STAT_STATEMENTS_COLS_V1_8 : - api_version == PGSS_V1_9 ? PG_STAT_STATEMENTS_COLS_V1_9 : - api_version == PGSS_V1_10 ? PG_STAT_STATEMENTS_COLS_V1_10 : - api_version == PGSS_V1_11 ? PG_STAT_STATEMENTS_COLS_V1_11 : - api_version == PGSS_V1_12 ? PG_STAT_STATEMENTS_COLS_V1_12 : - api_version == PGSS_V1_13 ? PG_STAT_STATEMENTS_COLS_V1_13 : - -1 /* fail if you forget to update this assert */ )); + Assert(i == pgss_api_cols[api_version]); tuplestore_putvalues(rsinfo->setResult, rsinfo->setDesc, values, nulls); } -- 2.54.0 (Apple Git-157)