From 1c99cde2f3440c59f582d45b251412c9a9b54f62 Mon Sep 17 00:00:00 2001 From: Alvaro Herrera Date: Thu, 5 Oct 2023 10:59:08 +0200 Subject: Improve JsonLexContext's freeability Previously, the JSON code didn't have to worry too much about freeing JsonLexContext, because it was never too long-lived. With new features being added for SQL/JSON this is no longer the case. Add a routine that knows how to free this struct and apply that to a few places, to prevent this from becoming problematic. At the same time, we change the API of makeJsonLexContextCstringLen to make it receive a pointer to JsonLexContext for callers that want it to be stack-allocated; it can also be passed as NULL to get the original behavior of a palloc'ed one. This also causes an ABI break due to the addition of flags to JsonLexContext, so we can't easily backpatch it. AFAICS that's not much of a problem; apparently some leaks might exist in JSON usage of text-search, for example via json_to_tsvector, but I haven't seen any complaints about that. Per Coverity complaint about datum_to_jsonb_internal(). Discussion: https://postgr.es/m/20230808174110.oq3iymllsv6amkih@alvherre.pgsql --- src/backend/utils/adt/jsonb.c | 13 +++++++------ 1 file changed, 7 insertions(+), 6 deletions(-) (limited to 'src/backend/utils/adt/jsonb.c') diff --git a/src/backend/utils/adt/jsonb.c b/src/backend/utils/adt/jsonb.c index 9781852b0cb..b10a60ac665 100644 --- a/src/backend/utils/adt/jsonb.c +++ b/src/backend/utils/adt/jsonb.c @@ -252,13 +252,13 @@ jsonb_typeof(PG_FUNCTION_ARGS) static inline Datum jsonb_from_cstring(char *json, int len, bool unique_keys, Node *escontext) { - JsonLexContext *lex; + JsonLexContext lex; JsonbInState state; JsonSemAction sem; memset(&state, 0, sizeof(state)); memset(&sem, 0, sizeof(sem)); - lex = makeJsonLexContextCstringLen(json, len, GetDatabaseEncoding(), true); + makeJsonLexContextCstringLen(&lex, json, len, GetDatabaseEncoding(), true); state.unique_keys = unique_keys; state.escontext = escontext; @@ -271,7 +271,7 @@ jsonb_from_cstring(char *json, int len, bool unique_keys, Node *escontext) sem.scalar = jsonb_in_scalar; sem.object_field_start = jsonb_in_object_field_start; - if (!pg_parse_json_or_errsave(lex, &sem, escontext)) + if (!pg_parse_json_or_errsave(&lex, &sem, escontext)) return (Datum) 0; /* after parsing, the item member has the composed jsonb structure */ @@ -755,11 +755,11 @@ datum_to_jsonb_internal(Datum val, bool is_null, JsonbInState *result, case JSONTYPE_JSON: { /* parse the json right into the existing result object */ - JsonLexContext *lex; + JsonLexContext lex; JsonSemAction sem; text *json = DatumGetTextPP(val); - lex = makeJsonLexContext(json, true); + makeJsonLexContext(&lex, json, true); memset(&sem, 0, sizeof(sem)); @@ -772,7 +772,8 @@ datum_to_jsonb_internal(Datum val, bool is_null, JsonbInState *result, sem.scalar = jsonb_in_scalar; sem.object_field_start = jsonb_in_object_field_start; - pg_parse_json_or_ereport(lex, &sem); + pg_parse_json_or_ereport(&lex, &sem); + freeJsonLexContext(&lex); } break; case JSONTYPE_JSONB: -- cgit v1.2.3