Optimize escaping of JSON strings There were quite a few places where we either had a non-NUL-terminated string or a text Datum which we needed to call escape_json() on. Many of these places required that a temporary string was created due to the fact that escape_json() needs a NUL-terminated cstring. For text types, those first had to be converted to cstring before calling escape_json() on them.
Here we introduce two new functions to make escaping JSON more optimal: escape_json_text() can be given a text Datum to append onto the given buffer. This is more optimal as it foregoes the need to convert the text Datum into a cstring. A temporary allocation is only required if the text Datum needs to be detoasted. escape_json_with_len() can be used when the length of the cstring is already known or the given string isn't NUL-terminated. Having this allows various places which were creating a temporary NUL-terminated string to just call escape_json_with_len() without any temporary memory allocations. Discussion: https://postgr.es/m/caaphdvplxwmzvbckcdgfu9xqjgcdm7tfprdtxub9pvgpnuy...@mail.gmail.com Reviewed-by: Melih Mutlu, Heikki Linnakangas Branch ------ master Details ------- https://git.postgresql.org/pg/commitdiff/17a5871d9d58ea639b6d1ba4f0ce58462d55a33c Modified Files -------------- contrib/hstore/hstore_io.c | 41 ++++----- src/backend/backup/backup_manifest.c | 2 +- src/backend/utils/adt/json.c | 156 +++++++++++++++++++++++------------ src/backend/utils/adt/jsonb.c | 2 +- src/backend/utils/adt/jsonfuncs.c | 34 ++++---- src/backend/utils/adt/jsonpath.c | 15 +++- src/include/utils/json.h | 2 + 7 files changed, 151 insertions(+), 101 deletions(-)
