view mercurial/utils/resourceutil.py @ 45869:63edc384d3b7

transaction: drop per-file extra data support

At the moment, transactions support an optional extra data argument for
all files to be stored in addition to the original offset. This is used
in core only by the revlog inline to external data migration. It is used
to memoize the number of revisions before the transaction. That number
of can be computed during the walk easily, so drop the requirement.

Differential Revision: https://phab.mercurial-scm.org/D9275

# resourceutil.py - utility for looking up resources
#
#  Copyright 2005 K. Thananchayan <[e-mail]>
#  Copyright 2005-2007 Matt Mackall <[e-mail]>
#  Copyright 2006 Vadim Gelfer <[e-mail]>
#
# This software may be used and distributed according to the terms of the
# GNU General Public License version 2 or any later version.

from __future__ import absolute_import

import imp
import os
import sys

from .. import pycompat


def mainfrozen():
    """return True if we are a frozen executable.

    The code supports py2exe (most common, Windows only) and tools/freeze
    (portable, not much used).
    """
    return (
        pycompat.safehasattr(sys, "frozen")  # new py2exe
        or pycompat.safehasattr(sys, "importers")  # old py2exe
        or imp.is_frozen("__main__")  # tools/freeze
    )


# the location of data files matching the source code
if mainfrozen() and getattr(sys, "frozen", None) != "macosx_app":
    # executable version (py2exe) doesn't support __file__
    datapath = os.path.dirname(pycompat.sysexecutable)
    _rootpath = datapath

    # The installers store the files outside of library.zip, like
    # C:\Program Files\Mercurial\defaultrc\*.rc.  This strips the
    # leading "mercurial." off of the package name, so that these
    # pseudo resources are found in their directory next to the
    # executable.
    def _package_path(package):
        dirs = package.split(b".")
        assert dirs[0] == b"mercurial"
        return os.path.join(_rootpath, *dirs[1:])


else:
    datapath = os.path.dirname(os.path.dirname(pycompat.fsencode(__file__)))
    _rootpath = os.path.dirname(datapath)

    def _package_path(package):
        return os.path.join(_rootpath, *package.split(b"."))


try:
    # importlib.resources exists from Python 3.7; see fallback in except clause
    # further down
    from importlib import resources

    from .. import encoding

    # Force loading of the resources module
    resources.open_binary  # pytype: disable=module-attr

    def open_resource(package, name):
        return resources.open_binary(  # pytype: disable=module-attr
            pycompat.sysstr(package), pycompat.sysstr(name)
        )

    def is_resource(package, name):
        return resources.is_resource(
            pycompat.sysstr(package), encoding.strfromlocal(name)
        )

    def contents(package):
        for r in resources.contents(pycompat.sysstr(package)):
            yield encoding.strtolocal(r)


except (ImportError, AttributeError):
    # importlib.resources was not found (almost definitely because we're on a
    # Python version before 3.7)

    def open_resource(package, name):
        path = os.path.join(_package_path(package), name)
        return open(path, "rb")

    def is_resource(package, name):
        path = os.path.join(_package_path(package), name)

        try:
            return os.path.isfile(pycompat.fsdecode(path))
        except (IOError, OSError):
            return False

    def contents(package):
        path = pycompat.fsdecode(_package_path(package))

        for p in os.listdir(path):
            yield pycompat.fsencode(p)