Go to file
John Naylor 0aba255440 Add optimized C string hashing
Given an already-initialized hash state and a NUL-terminated string,
accumulate the hash of the string into the hash state and return the
length for the caller to (optionally) save for the finalizer. This
avoids a strlen call.

If the string pointer is aligned, we can use a word-at-a-time
algorithm for NUL lookahead. The aligned case is only used on 64-bit
platforms, since it's not worth the extra complexity for 32-bit.

Handling the tail of the string after finishing the word-wise loop
was inspired by NetBSD's strlen(), but no code was taken since that
is written in assembly language.

As demonstration, use this in the search path cache. This brings the
general case performance closer to the special case optimization done
in commit a86c61c9ee. There are other places that could benefit, but
that is left for future work.

Jeff Davis and John Naylor
Reviewed by Heikki Linnakangas, Jian He, Junwang Zhao

Discussion: https://postgr.es/m/3820f030fd008ff14134b3e9ce5cc6dd623ed479.camel%40j-davis.com
Discussion: https://postgr.es/m/b40292c99e623defe5eadedab1d438cf51a4107c.camel%40j-davis.com
2024-01-19 12:56:15 +07:00
config Add copyright notices to a few perl scripts that don't have them 2024-01-05 13:15:50 +00:00
contrib Error message capitalisation 2024-01-18 09:35:12 +01:00
doc Improve some documentation about the bootstrap superuser. 2024-01-18 21:39:51 -06:00
src Add optimized C string hashing 2024-01-19 12:56:15 +07:00
.cirrus.star Remove duplicate words in docs and code comments. 2023-10-09 09:18:47 +05:30
.cirrus.tasks.yml Use "template" data directory in tests 2023-08-24 14:38:02 -07:00
.cirrus.yml ci: Make compute resources for CI configurable 2023-08-23 15:15:28 -07:00
.dir-locals.el Make Emacs perl-mode indent more like perltidy. 2019-01-13 11:32:31 -08:00
.editorconfig Add .editorconfig 2019-12-18 09:13:13 +01:00
.git-blame-ignore-revs Add previous commit to .git-blame-ignore-revs. 2024-01-13 13:56:46 -05:00
.gitattributes Replace Gen_dummy_probes.sed with Gen_dummy_probes.pl 2023-11-14 10:27:10 +01:00
.gitignore Update top-level .gitignore. 2022-12-04 15:23:00 -05:00
aclocal.m4 autoconf: Move export_dynamic determination to configure 2022-12-06 18:55:28 -08:00
configure Update copyright for 2024 2024-01-03 20:49:05 -05:00
configure.ac Update copyright for 2024 2024-01-03 20:49:05 -05:00
COPYRIGHT Update copyright for 2024 2024-01-03 20:49:05 -05:00
GNUmakefile.in Stop generating plain-text INSTALL instructions. 2023-12-22 13:32:15 -05:00
HISTORY Canonicalize some URLs 2020-02-10 20:47:50 +01:00
Makefile Stop generating plain-text INSTALL instructions. 2023-12-22 13:32:15 -05:00
meson_options.txt Update copyright for 2024 2024-01-03 20:49:05 -05:00
meson.build Clarify which xml tools are missing in meson error message 2024-01-11 14:55:43 +01:00
README Stop generating plain-text INSTALL instructions. 2023-12-22 13:32:15 -05:00

PostgreSQL Database Management System
=====================================

This directory contains the source code distribution of the PostgreSQL
database management system.

PostgreSQL is an advanced object-relational database management system
that supports an extended subset of the SQL standard, including
transactions, foreign keys, subqueries, triggers, user-defined types
and functions.  This distribution also contains C language bindings.

Copyright and license information can be found in the file COPYRIGHT.

General documentation about this version of PostgreSQL can be found at:
https://www.postgresql.org/docs/devel/
In particular, information about building PostgreSQL from the source
code can be found at:
https://www.postgresql.org/docs/devel/installation.html

The latest version of this software, and related software, may be
obtained at https://www.postgresql.org/download/.  For more information
look at our web site located at https://www.postgresql.org/.