mercurial/pushkey.py

dirstate: make functions for backup aware of transaction activity

Some comments in this patch assume that subsequent patch changes
'dirstate.write()' like as below:

    def write(self, repo):
        if not self._dirty:
            return
        tr = repo.currenttransaction()
        if tr:
            tr.addfilegenerator('dirstate', (self._filename,),
                                self._writedirstate, location='plain')
            return # omit actual writing out
        st = self._opener('dirstate', "w", atomictemp=True)
        self._writedirstate(st)

This patch makes '_savebackup()' write in-memory changes out, and it
causes clearing 'self._dirty'. If dirstate isn't changed after
'_savebackup()', subsequent 'dirstate.write()' never invokes
'tr.addfilegenerator()' because 'not self._dirty' is true.

Then, 'tr.writepending()' unintentionally returns False, if there is
no other (e.g. changelog) changes pending, even though dirstate
changes are already written out at '_savebackup()'.

To avoid such situation, this patch makes '_savebackup()' explicitly
invoke 'tr.addfilegenerator()', if transaction is running.

'_savebackup()' should get awareness of transaction before 'write()',
because the former depends on the behavior of the latter before this
patch.

# pushkey.py - dispatching for pushing and pulling keys
#
# Copyright 2010 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.

from __future__ import absolute_import

from . import (
    bookmarks,
    encoding,
    obsolete,
    phases,
)

def _nslist(repo):
    n = {}
    for k in _namespaces:
        n[k] = ""
    if not obsolete.isenabled(repo, obsolete.exchangeopt):
        n.pop('obsolete')
    return n

_namespaces = {"namespaces": (lambda *x: False, _nslist),
               "bookmarks": (bookmarks.pushbookmark, bookmarks.listbookmarks),
               "phases": (phases.pushphase, phases.listphases),
               "obsolete": (obsolete.pushmarker, obsolete.listmarkers),
              }

def register(namespace, pushkey, listkeys):
    _namespaces[namespace] = (pushkey, listkeys)

def _get(namespace):
    return _namespaces.get(namespace, (lambda *x: False, lambda *x: {}))

def push(repo, namespace, key, old, new):
    '''should succeed iff value was old'''
    pk = _get(namespace)[0]
    return pk(repo, key, old, new)

def list(repo, namespace):
    '''return a dict'''
    lk = _get(namespace)[1]
    return lk(repo)

encode = encoding.fromlocal

decode = encoding.tolocal

def encodekeys(keys):
    """encode the content of a pushkey namespace for exchange over the wire"""
    return '\n'.join(['%s\t%s' % (encode(k), encode(v)) for k, v in keys])

def decodekeys(data):
    """decode the content of a pushkey namespace from exchange over the wire"""
    result = {}
    for l in data.splitlines():
        k, v = l.split('\t')
        result[decode(k)] = decode(v)
    return result