mercurial/cacheutil.py

exchangev2: use filesdata

filesdata is a more efficient mechanism for bulk fetching files data for a
range of changesets. Let's use it in exchangev2.

With this change, a client performing a full clone of mozilla-unified
transmits substantially fewer bytes across the wire:

before: 139,124,863 bytes sent
after:   20,522,499 bytes sent

The bulk of the remaining bytes is likely the transfer of ~1M nodes for
changesets and manifests. We can eliminate this by making requests in
terms of node ranges instead of explicit node lists...

Differential Revision: https://phab.mercurial-scm.org/D4982

# scmutil.py - Mercurial core utility functions
#
#  Copyright Matt Mackall <[e-mail]> and other
#
# 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 repoview

def cachetocopy(srcrepo):
    """return the list of cache file valuable to copy during a clone"""
    # In local clones we're copying all nodes, not just served
    # ones. Therefore copy all branch caches over.
    cachefiles = ['branch2']
    cachefiles += ['branch2-%s' % f for f in repoview.filtertable]
    cachefiles += ['rbc-names-v1', 'rbc-revs-v1']
    cachefiles += ['tags2']
    cachefiles += ['tags2-%s' % f for f in repoview.filtertable]
    cachefiles += ['hgtagsfnodes1']
    return cachefiles