Home Original page

Backport 7157 to v6.x (buffer: speed up swap16/32, add swap64) by addaleax · Pull Request #7546 · nodejs/node

@zbjornson @addaleax 

* Speed up buffer.swap16 and swap32 by using builtins. Up to ~6x gain.
  Drop transition point between JS and C++ implementations accordingly.
  Amount of performance improvement not only depends on buffer size but
  also memory alignment.
* Fix tests: C++ impl tests were testing 0-filled buffers so were
  always passing.
* Add similar buffer.swap64 method.
* Make buffer-swap benchmark mirror JS impl.

doc/api/buffer.markdown has an entry of "added: REPLACEME" that should
be changed to the correct release number before tagged.

Because node is currently using a very old version of cpplint.py it
doesn't know that std::swap() has moved from <algorithm> to <utility> in
c++11. So until cpplint.py is updated simply NOLINT the line.
Technically it should be NOLINT(build/include_what_you_use), but that
puts the line over 80 characters causing another lint error.

PR-URL: nodejs#7157
Reviewed-By: Trevor Norris <trev.norris@gmail.com>
Reviewed-By: James M Snell <jasnell@gmail.com>

@addaleax added buffer

Issues and PRs related to the buffer subsystem.

v6.x labels

Jul 5, 2016

@nodejs-github-bot nodejs-github-bot added the c++

Issues and PRs that require attention from people who are familiar with C++.

label

Jul 5, 2016

Fishrock123 pushed a commit that referenced this pull request

Jul 5, 2016 
* Speed up buffer.swap16 and swap32 by using builtins. Up to ~6x gain.
  Drop transition point between JS and C++ implementations accordingly.
  Amount of performance improvement not only depends on buffer size but
  also memory alignment.
* Fix tests: C++ impl tests were testing 0-filled buffers so were
  always passing.
* Add similar buffer.swap64 method.
* Make buffer-swap benchmark mirror JS impl.

doc/api/buffer.markdown has an entry of "added: REPLACEME" that should
be changed to the correct release number before tagged.

Because node is currently using a very old version of cpplint.py it
doesn't know that std::swap() has moved from <algorithm> to <utility> in
c++11. So until cpplint.py is updated simply NOLINT the line.
Technically it should be NOLINT(build/include_what_you_use), but that
puts the line over 80 characters causing another lint error.

PR-URL: #7157
Reviewed-By: Trevor Norris <trev.norris@gmail.com>
Reviewed-By: James M Snell <jasnell@gmail.com>

Backport-URL: #7546