From dc5ec1a2204398fa25390f31771eaa57816a96a1 Mon Sep 17 00:00:00 2001 From: Nathan Bossart Date: Thu, 7 Dec 2023 16:45:45 -0600 Subject: [PATCH v2 1/1] avoid some strlen() calls in json.c --- src/backend/utils/adt/json.c | 20 +++++++++++++++----- 1 file changed, 15 insertions(+), 5 deletions(-) diff --git a/src/backend/utils/adt/json.c b/src/backend/utils/adt/json.c index cb4311e75f..640d9123ed 100644 --- a/src/backend/utils/adt/json.c +++ b/src/backend/utils/adt/json.c @@ -218,13 +218,17 @@ datum_to_json_internal(Datum val, bool is_null, StringInfo result, outputstr = OidOutputFunctionCall(outfuncoid, val); /* - * Don't call escape_json for a non-key if it's a valid JSON - * number. + * Don't quote a non-key if it's a valid JSON number. Since we + * know this is a numeric data type's output, we simplify and + * open-code the validation for better performance. */ - if (!key_scalar && IsValidJsonNumber(outputstr, strlen(outputstr))) + if (!key_scalar && + ((*outputstr >= '0' && *outputstr <= '9') || + (*outputstr == '-' && + (outputstr[1] >= '0' && outputstr[1] <= '9')))) appendStringInfoString(result, outputstr); else - escape_json(result, outputstr); + appendStringInfo(result, "\"%s\"", outputstr); pfree(outputstr); break; case JSONTYPE_DATE: @@ -502,8 +506,14 @@ composite_to_json(Datum composite, StringInfo result, bool use_line_feeds) int i; bool needsep = false; const char *sep; + int seplen; + /* + * We can avoid expensive strlen() calls by precalculating the separator + * length. + */ sep = use_line_feeds ? ",\n " : ","; + seplen = use_line_feeds ? sizeof(",\n ") - 1 : sizeof(",") - 1; td = DatumGetHeapTupleHeader(composite); @@ -532,7 +542,7 @@ composite_to_json(Datum composite, StringInfo result, bool use_line_feeds) continue; if (needsep) - appendStringInfoString(result, sep); + appendBinaryStringInfo(result, sep, seplen); needsep = true; attname = NameStr(att->attname); -- 2.25.1