annotate mercurial/remotenames.py @ 35305:483b5dd0f1aa

push: restrict common discovery to the pushed set

This changeset make use of the ability of the set discovery to only search
common changeset for a subset of the repository. Restricting that search to the
pushed set avoid potential waste of time finding out the status of many
unrelated related revision.

Repository with many heads were especially badly affected by this. Here is an
example of findcommonhead discovery for pushing 11 outgoing changeset on a
repository with tens of thousand of unrelated heads. (discovery run over a ssh
link to localhost).

Before:
    queries: 92
    time:    44.1996s

After:
    queries: 3
    time:    0.6938s

A x63 speedup even with a network link without latency.

# remotenames.py
#
# Copyright 2017 Augie Fackler <[e-mail]>
# Copyright 2017 Sean Farley <[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 .node import hex

from . import (
    vfs as vfsmod,
)

# directory name in .hg/ in which remotenames files will be present
remotenamedir = 'remotenames'

def readremotenamefile(repo, filename):
    """
    reads a file from .hg/remotenames/ directory and yields it's content
    filename: the file to be read
    yield a tuple (node, remotepath, name)
    """

    vfs = vfsmod.vfs(repo.vfs.join(remotenamedir))
    if not vfs.exists(filename):
        return
    f = vfs(filename)
    lineno = 0
    for line in f:
        line = line.strip()
        if not line:
            continue
        # contains the version number
        if lineno == 0:
            lineno += 1
        try:
            node, remote, rname = line.split('\0')
            yield node, remote, rname
        except ValueError:
            pass

    f.close()

def readremotenames(repo):
    """
    read the details about the remotenames stored in .hg/remotenames/ and
    yields a tuple (node, remotepath, name). It does not yields information
    about whether an entry yielded is branch or bookmark. To get that
    information, call the respective functions.
    """

    for bmentry in readremotenamefile(repo, 'bookmarks'):
        yield bmentry
    for branchentry in readremotenamefile(repo, 'branches'):
        yield branchentry

def writeremotenamefile(repo, remotepath, names, nametype):
    vfs = vfsmod.vfs(repo.vfs.join(remotenamedir))
    f = vfs(nametype, 'w', atomictemp=True)
    # write the storage version info on top of file
    # version '0' represents the very initial version of the storage format
    f.write('0\n\n')

    olddata = set(readremotenamefile(repo, nametype))
    # re-save the data from a different remote than this one.
    for node, oldpath, rname in sorted(olddata):
        if oldpath != remotepath:
            f.write('%s\0%s\0%s\n' % (node, oldpath, rname))

    for name, node in sorted(names.iteritems()):
        if nametype == "branches":
            for n in node:
                f.write('%s\0%s\0%s\n' % (n, remotepath, name))
        elif nametype == "bookmarks":
            if node:
                f.write('%s\0%s\0%s\n' % (node, remotepath, name))

    f.close()

def saveremotenames(repo, remotepath, branches=None, bookmarks=None):
    """
    save remotenames i.e. remotebookmarks and remotebranches in their
    respective files under ".hg/remotenames/" directory.
    """
    wlock = repo.wlock()
    try:
        if bookmarks:
            writeremotenamefile(repo, remotepath, bookmarks, 'bookmarks')
        if branches:
            writeremotenamefile(repo, remotepath, branches, 'branches')
    finally:
        wlock.release()

def pullremotenames(localrepo, remoterepo):
    """
    pulls bookmarks and branches information of the remote repo during a
    pull or clone operation.
    localrepo is our local repository
    remoterepo is the peer instance
    """
    remotepath = remoterepo.url()
    bookmarks = remoterepo.listkeys('bookmarks')
    # on a push, we don't want to keep obsolete heads since
    # they won't show up as heads on the next pull, so we
    # remove them here otherwise we would require the user
    # to issue a pull to refresh the storage
    bmap = {}
    repo = localrepo.unfiltered()
    for branch, nodes in remoterepo.branchmap().iteritems():
        bmap[branch] = []
        for node in nodes:
            if node in repo and not repo[node].obsolete():
                bmap[branch].append(hex(node))

    saveremotenames(localrepo, remotepath, bmap, bookmarks)