annotate mercurial/help/extensions.txt @ 27592:7c9eb2927879

dirstate: add a C implementation for nonnormalentries

Before this patch, there was only a python version of nonnormalentries.
On mozilla-central we have a 10x win by putting this function in C:
% python -m timeit -s \
        'from mercurial import hg, ui, parsers; \
        repo = hg.repository(ui.ui(), "mozilla-central"); \
        m = repo.dirstate._map' \
        'parsers.nonnormalentries(m)'

100 loops, best of 3: 3.15 msec per loop

The python implementation runs in 31ms, a similar test gives:
10 loops, best of 3: 31.7 msec per loop

On our big repos, the win is still of 10x with the python implementation running
in 350ms and the C implementation running in 30ms.

Mercurial has the ability to add new features through the use of
extensions. Extensions may add new commands, add options to
existing commands, change the default behavior of commands, or
implement hooks.

To enable the "foo" extension, either shipped with Mercurial or in the
Python search path, create an entry for it in your configuration file,
like this::

  [extensions]
  foo =

You may also specify the full path to an extension::

  [extensions]
  myfeature = ~/.hgext/myfeature.py

See :hg:`help config` for more information on configuration files.

Extensions are not loaded by default for a variety of reasons:
they can increase startup overhead; they may be meant for advanced
usage only; they may provide potentially dangerous abilities (such
as letting you destroy or modify history); they might not be ready
for prime time; or they may alter some usual behaviors of stock
Mercurial. It is thus up to the user to activate extensions as
needed.

To explicitly disable an extension enabled in a configuration file of
broader scope, prepend its path with !::

  [extensions]
  # disabling extension bar residing in /path/to/extension/bar.py
  bar = !/path/to/extension/bar.py
  # ditto, but no path was supplied for extension baz
  baz = !