From: Jeff Davis <jdavis@postgresql.org>
To: pgsql-committers@lists.postgresql.org
Subject: pgsql: Make regex "max_chr" depend on encoding, not provider.
Date: Mon, 01 Dec 2025 19:09:19 +0000
Message-ID: <E1vQ9Gw-002Jme-2n@gemulon.postgresql.org> (raw)
Make regex "max_chr" depend on encoding, not provider.
The regex mechanism scans through the first "max_chr" character values
to cache character property ranges (isalpha, etc.). For single-byte
encodings, there's no sense in scanning beyond UCHAR_MAX; but for
UTF-8 it makes sense to cache higher code point values (though not all
of them; only up to MAX_SIMPLE_CHR).
Prior to 5a38104b36, the logic about how many character values to scan
was based on the pg_regex_strategy, which was dependent on the
provider. Commit 5a38104b36 preserved that logic exactly, allowing
different providers to define the "max_chr".
Now, change it to depend only on the encoding and whether
ctype_is_c. For this specific calculation, distinguishing between
providers creates more complexity than it's worth.
Discussion: https://postgr.es/m/450ceb6260cad30d7afdf155d991a9caafee7c0d.camel@j-davis.com
Reviewed-by: Chao Li <li.evan.chao@gmail.com>
Branch
------
master
Details
-------
https://git.postgresql.org/pg/commitdiff/19b966243c38196a33b033fb0c259dcf760c0d69
Modified Files
--------------
src/backend/regex/regc_pg_locale.c | 18 ++++++++++--------
src/backend/utils/adt/pg_locale_libc.c | 2 --
src/include/utils/pg_locale.h | 6 ------
3 files changed, 10 insertions(+), 16 deletions(-)
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To: pgsql-committers@postgresql.org
Cc: jdavis@postgresql.org, pgsql-committers@lists.postgresql.org
Subject: Re: pgsql: Make regex "max_chr" depend on encoding, not provider.
In-Reply-To: <E1vQ9Gw-002Jme-2n@gemulon.postgresql.org>
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