From 8d299052fe5858319fbd9be5f234026711bbc91b Mon Sep 17 00:00:00 2001 From: Jeff Davis Date: Wed, 26 Nov 2025 10:05:11 -0800 Subject: [PATCH] Add #define for UNICODE_CASEMAP_BUFSZ. Useful for mapping a single codepoint at a time into a statically-allocated buffer. Discussion: https://postgr.es/m/450ceb6260cad30d7afdf155d991a9caafee7c0d.camel@j-davis.com Reviewed-by: Chao Li --- src/include/utils/pg_locale.h | 14 ++++++++++++++ 1 file changed, 14 insertions(+) diff --git a/src/include/utils/pg_locale.h b/src/include/utils/pg_locale.h index 683e1a0eef8..54193a17a90 100644 --- a/src/include/utils/pg_locale.h +++ b/src/include/utils/pg_locale.h @@ -26,6 +26,20 @@ /* use for libc locale names */ #define LOCALE_NAME_BUFLEN 128 +/* + * Maximum number of bytes needed to map a single codepoint. Useful for + * mapping and processing a single input codepoint at a time with a + * statically-allocated buffer. + * + * With full case mapping, an input codepoint may be mapped to as many as + * three output codepoints. See Unicode 16.0.0, section 5.18.2, "Change in + * Length": + * + * https://www.unicode.org/versions/Unicode16.0.0/core-spec/chapter-5/#G29675 + */ +#define UNICODE_CASEMAP_LEN 3 +#define UNICODE_CASEMAP_BUFSZ (UNICODE_CASEMAP_LEN * sizeof(char32_t)) + /* GUC settings */ extern PGDLLIMPORT char *locale_messages; extern PGDLLIMPORT char *locale_monetary;