hgext/share.py

largefiles: fix cat for largefiles (issue3352)

This is a fix to largefiles so that 'hg cat' will work correctly when a
largefile is specified.

As per discussion on Issue 3352:

1) The file will be printed regardless if it is binary or large.
2) The file is downloaded if it is not readily available (not found in
   the system cache), so that it can be printed.  If the download fails,
   then we abort.

# Copyright 2006, 2007 Matt Mackall <[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.

'''share a common history between several working directories'''

from mercurial.i18n import _
from mercurial import hg, commands, util

def share(ui, source, dest=None, noupdate=False):
    """create a new shared repository

    Initialize a new repository and working directory that shares its
    history with another repository.

    .. note::
       using rollback or extensions that destroy/modify history (mq,
       rebase, etc.) can cause considerable confusion with shared
       clones. In particular, if two shared clones are both updated to
       the same changeset, and one of them destroys that changeset
       with rollback, the other clone will suddenly stop working: all
       operations will fail with "abort: working directory has unknown
       parent". The only known workaround is to use debugsetparents on
       the broken clone to reset it to a changeset that still exists
       (e.g. tip).
    """

    return hg.share(ui, source, dest, not noupdate)

def unshare(ui, repo):
    """convert a shared repository to a normal one

    Copy the store data to the repo and remove the sharedpath data.
    """

    if repo.sharedpath == repo.path:
        raise util.Abort(_("this is not a shared repo"))

    destlock = lock = None
    lock = repo.lock()
    try:
        # we use locks here because if we race with commit, we
        # can end up with extra data in the cloned revlogs that's
        # not pointed to by changesets, thus causing verify to
        # fail

        destlock = hg.copystore(ui, repo, repo.path)

        sharefile = repo.join('sharedpath')
        util.rename(sharefile, sharefile + '.old')

        repo.requirements.discard('sharedpath')
        repo._writerequirements()
    finally:
        destlock and destlock.release()
        lock and lock.release()

    # update store, spath, sopener and sjoin of repo
    repo.__init__(ui, repo.root)

cmdtable = {
    "share":
    (share,
     [('U', 'noupdate', None, _('do not create a working copy'))],
     _('[-U] SOURCE [DEST]')),
    "unshare":
    (unshare,
    [],
    ''),
}

commands.norepo += " share"