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Diffstat (limited to 'src/include/utils/pg_locale.h')
| -rw-r--r-- | src/include/utils/pg_locale.h | 14 |
1 files changed, 14 insertions, 0 deletions
diff --git a/src/include/utils/pg_locale.h b/src/include/utils/pg_locale.h index 3e14a261b16..f41d33975be 100644 --- a/src/include/utils/pg_locale.h +++ b/src/include/utils/pg_locale.h @@ -69,11 +69,25 @@ extern void cache_locale_time(void); /* * We use a discriminated union to hold either a locale_t or an ICU collator. * pg_locale_t is occasionally checked for truth, so make it a pointer. + * + * Also, hold two flags: whether the collation's LC_COLLATE or LC_CTYPE is C + * (or POSIX), so we can optimize a few code paths in various places. For the + * built-in C and POSIX collations, we can know that without even doing a + * cache lookup, but we want to support aliases for C/POSIX too. For the + * "default" collation, there are separate static cache variables, since + * consulting the pg_collation catalog doesn't tell us what we need. + * + * Note that some code relies on the flags not reporting false negatives + * (that is, saying it's not C when it is). For example, char2wchar() + * could fail if the locale is C, so str_tolower() shouldn't call it + * in that case. */ struct pg_locale_struct { char provider; bool deterministic; + bool collate_is_c; + bool ctype_is_c; union { struct |