mercurial/hgweb/__init__.py

rebase: use matcher to optimize manifestmerge

The old merge code would call manifestmerge and calculate the complete diff
between the source to the destination. In many cases, like rebase, the vast
majority of differences between the source and destination are irrelevant
because they are differences between the destination and the common ancestor
only, and therefore don't affect the merge. Since most actions are 'keep', all
the effort to compute them is wasted.

Instead, let's compute the difference between the source and the common ancestor
and only perform the diff of those files against the merge destination. When
using treemanifest, this lets us avoid loading almost the entire tree when
rebasing from a very old ancestor. This speeds up rebase of an old stack of 27
commits by 20x.

In mozilla-central, without treemanifest, when rebasing a commit from
default~100000 to default, this speeds up the manifestmerge step from 2.6s to
1.2s.  However, the additional diff adds an overhead to all manifestmerge calls,
especially for flat manifests. When rebasing a commit from default~1 to default
it appears to add 100ms in mozilla-central. While we could put this optimization
behind a flag, I think the fact that it makes merge O(number of changes being
applied) instead of O(number of changes between X and Y) justifies it.

# hgweb/__init__.py - web interface to a mercurial repository
#
# Copyright 21 May 2005 - (c) 2005 Jake Edge <[e-mail]>
# Copyright 2005 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

import os

from ..i18n import _

from .. import (
    error,
    util,
)

from . import (
    hgweb_mod,
    hgwebdir_mod,
    server,
)

def hgweb(config, name=None, baseui=None):
    '''create an hgweb wsgi object

    config can be one of:
    - repo object (single repo view)
    - path to repo (single repo view)
    - path to config file (multi-repo view)
    - dict of virtual:real pairs (multi-repo view)
    - list of virtual:real tuples (multi-repo view)
    '''

    if ((isinstance(config, str) and not os.path.isdir(config)) or
        isinstance(config, dict) or isinstance(config, list)):
        # create a multi-dir interface
        return hgwebdir_mod.hgwebdir(config, baseui=baseui)
    return hgweb_mod.hgweb(config, name=name, baseui=baseui)

def hgwebdir(config, baseui=None):
    return hgwebdir_mod.hgwebdir(config, baseui=baseui)

class httpservice(object):
    def __init__(self, ui, app, opts):
        self.ui = ui
        self.app = app
        self.opts = opts

    def init(self):
        util.setsignalhandler()
        self.httpd = server.create_server(self.ui, self.app)

        if self.opts['port'] and not self.ui.verbose:
            return

        if self.httpd.prefix:
            prefix = self.httpd.prefix.strip('/') + '/'
        else:
            prefix = ''

        port = ':%d' % self.httpd.port
        if port == ':80':
            port = ''

        bindaddr = self.httpd.addr
        if bindaddr == '0.0.0.0':
            bindaddr = '*'
        elif ':' in bindaddr: # IPv6
            bindaddr = '[%s]' % bindaddr

        fqaddr = self.httpd.fqaddr
        if ':' in fqaddr:
            fqaddr = '[%s]' % fqaddr
        if self.opts['port']:
            write = self.ui.status
        else:
            write = self.ui.write
        write(_('listening at http://%s%s/%s (bound to %s:%d)\n') %
              (fqaddr, port, prefix, bindaddr, self.httpd.port))
        self.ui.flush()  # avoid buffering of status message

    def run(self):
        self.httpd.serve_forever()

def createapp(baseui, repo, webconf):
    if webconf:
        return hgwebdir_mod.hgwebdir(webconf, baseui=baseui)
    else:
        if not repo:
            raise error.RepoError(_("there is no Mercurial repository"
                                    " here (.hg not found)"))
        return hgweb_mod.hgweb(repo, baseui=baseui)