[PATCH 1 of 2 V3] chgserver: add utilities to calculate mtimehash

[Yuya Nishihara]

On Sun, 28 Feb 2016 12:17:25 +0000, Jun Wu wrote:
> # HG changeset patch
> # User Jun Wu <quark at fb.com>
> # Date 1456498779 0
> #      Fri Feb 26 14:59:39 2016 +0000
> # Node ID 94fd1cecd935b7ce05a5b435ddb82a1eb610ec85
> # Parent  10eaae94523c790d7b77c52a4cb4bfcf406021ef
> chgserver: add utilities to calculate mtimehash

Pushed modified version to the clowncopter, thanks!

> +def _getmtimepaths(ui):
> +    """get a list of paths that should be checked to detect change
> +
> +    The list will include:
> +    - extensions (will not cover all files for complex extensions)
> +    - mercurial/__version__.py
> +    - hg binary
> +    - python binary
> +    """
> +    modules = [m for n, m in extensions.extensions(ui)]
> +    try:
> +        from mercurial import __version__
> +        modules.append(__version__)
> +    except ImportError:
> +        pass
> +    files = [sys.executable, util.hgcmd()]
> +    for m in modules:
> +        try:
> +            files.append(inspect.getabsfile(m))
> +        except TypeError:
> +            pass
> +    return sorted(set(files))

I've removed util.hgcmd() because

 a) we have __version__.py
 b) util.hgcmd() returns a list of command args, which isn't hashable
    (e.g. ['/usr/bin/hg'] on Unix, and ['python', '\\path\\to\\hg'] on Windows)

I noticed that inspect.getabsfile() is undocumented. But using getabsfile()
won't cause problems, since it exists in Python 2.6, 2.7, and 3.5.

https://bugs.python.org/issue12317