shelve: add minimal documentation to all functions

There is a lot of functions in this extension. We had a small documentation help
people getting started.

hgext/shelve.py

@@ -1,616 +1,632 b''
 # shelve.py - save/restore working directory state
 #
 # Copyright 2013 Facebook, Inc.
 #
 # This software may be used and distributed according to the terms of the
 # GNU General Public License version 2 or any later version.
 
 """save and restore changes to the working directory
 
 The "hg shelve" command saves changes made to the working directory
 and reverts those changes, resetting the working directory to a clean
 state.
 
 Later on, the "hg unshelve" command restores the changes saved by "hg
 shelve". Changes can be restored even after updating to a different
 parent, in which case Mercurial's merge machinery will resolve any
 conflicts if necessary.
 
 You can have more than one shelved change outstanding at a time; each
 shelved change has a distinct name. For details, see the help for "hg
 shelve".
 """
 
 from mercurial.i18n import _
 from mercurial.node import nullid, bin, hex
 from mercurial import changegroup, cmdutil, scmutil, phases
 from mercurial import error, hg, mdiff, merge, patch, repair, util
 from mercurial import templatefilters
 from mercurial import lock as lockmod
 import errno
 
 cmdtable = {}
 command = cmdutil.command(cmdtable)
 testedwith = 'internal'
 
 class shelvedfile(object):
-    """Handles common functions on shelve files (.hg/.files/.patch) using
+    """Helper for the file storing a single shelve
+
+    Handles common functions on shelve files (.hg/.files/.patch) using
     the vfs layer"""
     def __init__(self, repo, name, filetype=None):
         self.repo = repo
         self.name = name
         self.vfs = scmutil.vfs(repo.join('shelved'))
         if filetype:
             self.fname = name + '.' + filetype
         else:
             self.fname = name
 
     def exists(self):
         return self.vfs.exists(self.fname)
 
     def filename(self):
         return self.vfs.join(self.fname)
 
     def unlink(self):
         util.unlink(self.filename())
 
     def stat(self):
         return self.vfs.stat(self.fname)
 
     def opener(self, mode='rb'):
         try:
             return self.vfs(self.fname, mode)
         except IOError, err:
             if err.errno != errno.ENOENT:
                 raise
             if mode[0] in 'wa':
                 try:
                     self.vfs.mkdir()
                     return self.vfs(self.fname, mode)
                 except IOError, err:
                     if err.errno != errno.EEXIST:
                         raise
             elif mode[0] == 'r':
                 raise util.Abort(_("shelved change '%s' not found") %
                                  self.name)
 
 class shelvedstate(object):
-    """Handles saving and restoring a shelved state. Ensures that different
+    """Handle persistences during unshelving operation.
+
+    Handles saving and restoring a shelved state. Ensures that different
     versions of a shelved state are possible and handles them appropriate"""
     _version = 1
     _filename = 'shelvedstate'
 
     @classmethod
     def load(cls, repo):
         fp = repo.opener(cls._filename)
         try:
             version = int(fp.readline().strip())
 
             if version != cls._version:
                 raise util.Abort(_('this version of shelve is incompatible '
                                    'with the version used in this repo'))
             name = fp.readline().strip()
             parents = [bin(h) for h in fp.readline().split()]
             stripnodes = [bin(h) for h in fp.readline().split()]
         finally:
             fp.close()
 
         obj = cls()
         obj.name = name
         obj.parents = parents
         obj.stripnodes = stripnodes
 
         return obj
 
     @classmethod
     def save(cls, repo, name, stripnodes):
         fp = repo.opener(cls._filename, 'wb')
         fp.write('%i\n' % cls._version)
         fp.write('%s\n' % name)
         fp.write('%s\n' % ' '.join([hex(p) for p in repo.dirstate.parents()]))
         fp.write('%s\n' % ' '.join([hex(n) for n in stripnodes]))
         fp.close()
 
     @classmethod
     def clear(cls, repo):
         util.unlinkpath(repo.join(cls._filename), ignoremissing=True)
 
 def createcmd(ui, repo, pats, opts):
+    """subcommand that create a new shelve"""
+
     def publicancestors(ctx):
         """Compute the heads of the public ancestors of a commit.
 
         Much faster than the revset heads(ancestors(ctx) - draft())"""
         seen = set()
         visit = util.deque()
         visit.append(ctx)
         while visit:
             ctx = visit.popleft()
             for parent in ctx.parents():
                 rev = parent.rev()
                 if rev not in seen:
                     seen.add(rev)
                     if parent.mutable():
                         visit.append(parent)
                     else:
                         yield parent.node()
 
     wctx = repo[None]
     parents = wctx.parents()
     if len(parents) > 1:
         raise util.Abort(_('cannot shelve while merging'))
     parent = parents[0]
 
     # we never need the user, so we use a generic user for all shelve operations
     user = 'shelve@localhost'
     label = repo._bookmarkcurrent or parent.branch() or 'default'
 
     # slashes aren't allowed in filenames, therefore we rename it
     origlabel, label = label, label.replace('/', '_')
 
     def gennames():
         yield label
         for i in xrange(1, 100):
             yield '%s-%02d' % (label, i)
 
     shelvedfiles = []
 
     def commitfunc(ui, repo, message, match, opts):
         # check modified, added, removed, deleted only
         for flist in repo.status(match=match)[:4]:
             shelvedfiles.extend(flist)
         hasmq = util.safehasattr(repo, 'mq')
         if hasmq:
             saved, repo.mq.checkapplied = repo.mq.checkapplied, False
         try:
             return repo.commit(message, user, opts.get('date'), match)
         finally:
             if hasmq:
                 repo.mq.checkapplied = saved
 
     if parent.node() != nullid:
         desc = parent.description().split('\n', 1)[0]
     else:
         desc = '(empty repository)'
 
     if not opts['message']:
         opts['message'] = desc
 
     name = opts['name']
 
     wlock = lock = tr = bms = None
     try:
         wlock = repo.wlock()
         lock = repo.lock()
 
         bms = repo._bookmarks.copy()
         # use an uncommited transaction to generate the bundle to avoid
         # pull races. ensure we don't print the abort message to stderr.
         tr = repo.transaction('commit', report=lambda x: None)
 
         if name:
             if shelvedfile(repo, name, 'hg').exists():
                 raise util.Abort(_("a shelved change named '%s' already exists")
                                  % name)
         else:
             for n in gennames():
                 if not shelvedfile(repo, n, 'hg').exists():
                     name = n
                     break
             else:
                 raise util.Abort(_("too many shelved changes named '%s'") %
                                  label)
 
         # ensure we are not creating a subdirectory or a hidden file
         if '/' in name or '\\' in name:
             raise util.Abort(_('shelved change names may not contain slashes'))
         if name.startswith('.'):
             raise util.Abort(_("shelved change names may not start with '.'"))
 
         node = cmdutil.commit(ui, repo, commitfunc, pats, opts)
 
         if not node:
             stat = repo.status(match=scmutil.match(repo[None], pats, opts))
             if stat[3]:
                 ui.status(_("nothing changed (%d missing files, see "
                             "'hg status')\n") % len(stat[3]))
             else:
                 ui.status(_("nothing changed\n"))
             return 1
 
         phases.retractboundary(repo, phases.secret, [node])
 
         fp = shelvedfile(repo, name, 'files').opener('wb')
         fp.write('\0'.join(shelvedfiles))
 
         bases = list(publicancestors(repo[node]))
         cg = repo.changegroupsubset(bases, [node], 'shelve')
         changegroup.writebundle(cg, shelvedfile(repo, name, 'hg').filename(),
                                 'HG10UN')
         cmdutil.export(repo, [node],
                        fp=shelvedfile(repo, name, 'patch').opener('wb'),
                        opts=mdiff.diffopts(git=True))
 
 
         if ui.formatted():
             desc = util.ellipsis(desc, ui.termwidth())
         ui.status(_('shelved as %s\n') % name)
         hg.update(repo, parent.node())
     finally:
         if bms:
             # restore old bookmarks
             repo._bookmarks.update(bms)
             repo._bookmarks.write()
         if tr:
             tr.abort()
         lockmod.release(lock, wlock)
 
 def cleanupcmd(ui, repo):
+    """subcommand that delete all shelves"""
+
     wlock = None
     try:
         wlock = repo.wlock()
         for (name, _) in repo.vfs.readdir('shelved'):
             suffix = name.rsplit('.', 1)[-1]
             if suffix in ('hg', 'files', 'patch'):
                 shelvedfile(repo, name).unlink()
     finally:
         lockmod.release(wlock)
 
 def deletecmd(ui, repo, pats):
+    """subcommand that delete a specific shelve"""
     if not pats:
         raise util.Abort(_('no shelved changes specified!'))
     wlock = None
     try:
         wlock = repo.wlock()
         try:
             for name in pats:
                 for suffix in 'hg files patch'.split():
                     shelvedfile(repo, name, suffix).unlink()
         except OSError, err:
             if err.errno != errno.ENOENT:
                 raise
             raise util.Abort(_("shelved change '%s' not found") % name)
     finally:
         lockmod.release(wlock)
 
 def listshelves(repo):
+    """return all shelves in repo as list of  (time, filename)"""
     try:
         names = repo.vfs.readdir('shelved')
     except OSError, err:
         if err.errno != errno.ENOENT:
             raise
         return []
     info = []
     for (name, _) in names:
         pfx, sfx = name.rsplit('.', 1)
         if not pfx or sfx != 'patch':
             continue
         st = shelvedfile(repo, name).stat()
         info.append((st.st_mtime, shelvedfile(repo, pfx).filename()))
     return sorted(info, reverse=True)
 
 def listcmd(ui, repo, pats, opts):
+    """subcommand that display the list of shelve"""
     pats = set(pats)
     width = 80
     if not ui.plain():
         width = ui.termwidth()
     namelabel = 'shelve.newest'
     for mtime, name in listshelves(repo):
         sname = util.split(name)[1]
         if pats and sname not in pats:
             continue
         ui.write(sname, label=namelabel)
         namelabel = 'shelve.name'
         if ui.quiet:
             ui.write('\n')
             continue
         ui.write(' ' * (16 - len(sname)))
         used = 16
         age = '(%s)' % templatefilters.age(util.makedate(mtime), abbrev=True)
         ui.write(age, label='shelve.age')
         ui.write(' ' * (12 - len(age)))
         used += 12
         fp = open(name + '.patch', 'rb')
         try:
             while True:
                 line = fp.readline()
                 if not line:
                     break
                 if not line.startswith('#'):
                     desc = line.rstrip()
                     if ui.formatted():
                         desc = util.ellipsis(desc, width - used)
                     ui.write(desc)
                     break
             ui.write('\n')
             if not (opts['patch'] or opts['stat']):
                 continue
             difflines = fp.readlines()
             if opts['patch']:
                 for chunk, label in patch.difflabel(iter, difflines):
                     ui.write(chunk, label=label)
             if opts['stat']:
                 for chunk, label in patch.diffstatui(difflines, width=width,
                                                      git=True):
                     ui.write(chunk, label=label)
         finally:
             fp.close()
 
 def readshelvedfiles(repo, basename):
+    """return the list of file touched in a shelve"""
     fp = shelvedfile(repo, basename, 'files').opener()
     return fp.read().split('\0')
 
 def checkparents(repo, state):
+    """check parent while resuming an unshelve"""
     if state.parents != repo.dirstate.parents():
         raise util.Abort(_('working directory parents do not match unshelve '
                            'state'))
 
 def unshelveabort(ui, repo, state, opts):
+    """subcommand that abort an in-progress unshelve"""
     wlock = repo.wlock()
     lock = None
     try:
         checkparents(repo, state)
         lock = repo.lock()
         merge.mergestate(repo).reset()
         if opts['keep']:
             repo.setparents(repo.dirstate.parents()[0])
         else:
             revertfiles = readshelvedfiles(repo, state.name)
             wctx = repo.parents()[0]
             cmdutil.revert(ui, repo, wctx, [wctx.node(), nullid],
                            *revertfiles, **{'no_backup': True})
             # fix up the weird dirstate states the merge left behind
             mf = wctx.manifest()
             dirstate = repo.dirstate
             for f in revertfiles:
                 if f in mf:
                     dirstate.normallookup(f)
                 else:
                     dirstate.drop(f)
             dirstate._pl = (wctx.node(), nullid)
             dirstate._dirty = True
         repair.strip(ui, repo, state.stripnodes, backup='none', topic='shelve')
         shelvedstate.clear(repo)
         ui.warn(_("unshelve of '%s' aborted\n") % state.name)
     finally:
         lockmod.release(lock, wlock)
 
 def unshelvecleanup(ui, repo, name, opts):
+    """remove related file after an unshelve"""
     if not opts['keep']:
         for filetype in 'hg files patch'.split():
             shelvedfile(repo, name, filetype).unlink()
 
 def finishmerge(ui, repo, ms, stripnodes, name, opts):
     # Reset the working dir so it's no longer in a merge state.
     dirstate = repo.dirstate
     dirstate.setparents(dirstate._pl[0])
     shelvedstate.clear(repo)
 
 def unshelvecontinue(ui, repo, state, opts):
+    """subcommand to continue an in-progress unshelve"""
     # We're finishing off a merge. First parent is our original
     # parent, second is the temporary "fake" commit we're unshelving.
     wlock = repo.wlock()
     lock = None
     try:
         checkparents(repo, state)
         ms = merge.mergestate(repo)
         if [f for f in ms if ms[f] == 'u']:
             raise util.Abort(
                 _("unresolved conflicts, can't continue"),
                 hint=_("see 'hg resolve', then 'hg unshelve --continue'"))
         finishmerge(ui, repo, ms, state.stripnodes, state.name, opts)
         lock = repo.lock()
         repair.strip(ui, repo, state.stripnodes, backup='none', topic='shelve')
         unshelvecleanup(ui, repo, state.name, opts)
         ui.status(_("unshelve of '%s' complete\n") % state.name)
     finally:
         lockmod.release(lock, wlock)
 
 @command('unshelve',
          [('a', 'abort', None,
            _('abort an incomplete unshelve operation')),
           ('c', 'continue', None,
            _('continue an incomplete unshelve operation')),
           ('', 'keep', None,
            _('keep shelve after unshelving'))],
          _('hg unshelve [SHELVED]'))
 def unshelve(ui, repo, *shelved, **opts):
     """restore a shelved change to the working directory
 
     This command accepts an optional name of a shelved change to
     restore. If none is given, the most recent shelved change is used.
 
     If a shelved change is applied successfully, the bundle that
     contains the shelved changes is deleted afterwards.
 
     Since you can restore a shelved change on top of an arbitrary
     commit, it is possible that unshelving will result in a conflict
     between your changes and the commits you are unshelving onto. If
     this occurs, you must resolve the conflict, then use
     ``--continue`` to complete the unshelve operation. (The bundle
     will not be deleted until you successfully complete the unshelve.)
 
     (Alternatively, you can use ``--abort`` to abandon an unshelve
     that causes a conflict. This reverts the unshelved changes, and
     does not delete the bundle.)
     """
     abortf = opts['abort']
     continuef = opts['continue']
     if not abortf and not continuef:
         cmdutil.checkunfinished(repo)
 
     if abortf or continuef:
         if abortf and continuef:
             raise util.Abort(_('cannot use both abort and continue'))
         if shelved:
             raise util.Abort(_('cannot combine abort/continue with '
                                'naming a shelved change'))
 
         try:
             state = shelvedstate.load(repo)
         except IOError, err:
             if err.errno != errno.ENOENT:
                 raise
             raise util.Abort(_('no unshelve operation underway'))
 
         if abortf:
             return unshelveabort(ui, repo, state, opts)
         elif continuef:
             return unshelvecontinue(ui, repo, state, opts)
     elif len(shelved) > 1:
         raise util.Abort(_('can only unshelve one change at a time'))
     elif not shelved:
         shelved = listshelves(repo)
         if not shelved:
             raise util.Abort(_('no shelved changes to apply!'))
         basename = util.split(shelved[0][1])[1]
         ui.status(_("unshelving change '%s'\n") % basename)
     else:
         basename = shelved[0]
 
     shelvedfiles = readshelvedfiles(repo, basename)
 
     m, a, r, d = repo.status()[:4]
     unsafe = set(m + a + r + d).intersection(shelvedfiles)
     if unsafe:
         ui.warn(_('the following shelved files have been modified:\n'))
         for f in sorted(unsafe):
             ui.warn('  %s\n' % f)
         ui.warn(_('you must commit, revert, or shelve your changes before you '
                   'can proceed\n'))
         raise util.Abort(_('cannot unshelve due to local changes\n'))
 
     wlock = lock = tr = None
     try:
         lock = repo.lock()
 
         tr = repo.transaction('unshelve', report=lambda x: None)
         oldtiprev = len(repo)
         try:
             fp = shelvedfile(repo, basename, 'hg').opener()
             gen = changegroup.readbundle(fp, fp.name)
             repo.addchangegroup(gen, 'unshelve', 'bundle:' + fp.name)
             nodes = [ctx.node() for ctx in repo.set('%d:', oldtiprev)]
             phases.retractboundary(repo, phases.secret, nodes)
             tr.close()
         finally:
             fp.close()
 
         tip = repo['tip']
         wctx = repo['.']
         ancestor = tip.ancestor(wctx)
 
         wlock = repo.wlock()
 
         if ancestor.node() != wctx.node():
             conflicts = hg.merge(repo, tip.node(), force=True, remind=False)
             ms = merge.mergestate(repo)
             stripnodes = [repo.changelog.node(rev)
                           for rev in xrange(oldtiprev, len(repo))]
             if conflicts:
                 shelvedstate.save(repo, basename, stripnodes)
                 # Fix up the dirstate entries of files from the second
                 # parent as if we were not merging, except for those
                 # with unresolved conflicts.
                 parents = repo.parents()
                 revertfiles = set(parents[1].files()).difference(ms)
                 cmdutil.revert(ui, repo, parents[1],
                                (parents[0].node(), nullid),
                                *revertfiles, **{'no_backup': True})
                 raise error.InterventionRequired(
                     _("unresolved conflicts (see 'hg resolve', then "
                       "'hg unshelve --continue')"))
             finishmerge(ui, repo, ms, stripnodes, basename, opts)
         else:
             parent = tip.parents()[0]
             hg.update(repo, parent.node())
             cmdutil.revert(ui, repo, tip, repo.dirstate.parents(), *tip.files(),
                            **{'no_backup': True})
 
         prevquiet = ui.quiet
         ui.quiet = True
         try:
             repo.rollback(force=True)
         finally:
             ui.quiet = prevquiet
 
         unshelvecleanup(ui, repo, basename, opts)
     finally:
         if tr:
             tr.release()
         lockmod.release(lock, wlock)
 
 @command('shelve',
          [('A', 'addremove', None,
            _('mark new/missing files as added/removed before shelving')),
           ('', 'cleanup', None,
            _('delete all shelved changes')),
           ('', 'date', '',
            _('shelve with the specified commit date'), _('DATE')),
           ('d', 'delete', None,
            _('delete the named shelved change(s)')),
           ('l', 'list', None,
            _('list current shelves')),
           ('m', 'message', '',
            _('use text as shelve message'), _('TEXT')),
           ('n', 'name', '',
            _('use the given name for the shelved commit'), _('NAME')),
           ('p', 'patch', None,
            _('show patch')),
           ('', 'stat', None,
            _('output diffstat-style summary of changes'))],
          _('hg shelve'))
 def shelvecmd(ui, repo, *pats, **opts):
     '''save and set aside changes from the working directory
 
     Shelving takes files that "hg status" reports as not clean, saves
     the modifications to a bundle (a shelved change), and reverts the
     files so that their state in the working directory becomes clean.
 
     To restore these changes to the working directory, using "hg
     unshelve"; this will work even if you switch to a different
     commit.
 
     When no files are specified, "hg shelve" saves all not-clean
     files. If specific files or directories are named, only changes to
     those files are shelved.
 
     Each shelved change has a name that makes it easier to find later.
     The name of a shelved change defaults to being based on the active
     bookmark, or if there is no active bookmark, the current named
     branch.  To specify a different name, use ``--name``.
 
     To see a list of existing shelved changes, use the ``--list``
     option. For each shelved change, this will print its name, age,
     and description; use ``--patch`` or ``--stat`` for more details.
 
     To delete specific shelved changes, use ``--delete``. To delete
     all shelved changes, use ``--cleanup``.
     '''
     cmdutil.checkunfinished(repo)
 
     def checkopt(opt, incompatible):
         if opts[opt]:
             for i in incompatible.split():
                 if opts[i]:
                     raise util.Abort(_("options '--%s' and '--%s' may not be "
                                        "used together") % (opt, i))
             return True
     if checkopt('cleanup', 'addremove delete list message name patch stat'):
         if pats:
             raise util.Abort(_("cannot specify names when using '--cleanup'"))
         return cleanupcmd(ui, repo)
     elif checkopt('delete', 'addremove cleanup list message name patch stat'):
         return deletecmd(ui, repo, pats)
     elif checkopt('list', 'addremove cleanup delete message name'):
         return listcmd(ui, repo, pats, opts)
     else:
         for i in ('patch', 'stat'):
             if opts[i]:
                 raise util.Abort(_("option '--%s' may not be "
                                    "used when shelving a change") % (i,))
         return createcmd(ui, repo, pats, opts)
 
 def extsetup(ui):
     cmdutil.unfinishedstates.append(
         [shelvedstate._filename, False, True, _('unshelve already in progress'),
          _("use 'hg unshelve --continue' or 'hg unshelve --abort'")])