Mercurial > hg
view mercurial/treediscovery.py @ 30758:76104a4899ad
commands: config option to control bundle compression level
Currently, bundle compression uses the default compression level
for the active compression engine. The default compression level
is tuned as a compromise between speed and size.
Some scenarios may call for a different compression level. For
example, with clone bundles, bundles are generated once and used
several times. Since the cost to generate is paid infrequently,
server operators may wish to trade extra CPU time for better
compression ratios.
This patch introduces an experimental and undocumented config
option to control the bundle compression level. As the inline
comment says, this approach is a bit hacky. I'd prefer for
the compression level to be encoded in the bundle spec. e.g.
"zstd-v2;complevel=15." However, given that the 4.1 freeze is
imminent, I'm not comfortable implementing this user-facing
change without much time to test and consider the implications.
So, we're going with the quick and dirty solution for now.
Having this option in the 4.1 release will enable Mozilla to
easily produce and test zlib and zstd bundles with non-default
compression levels in production. This will help drive future
development of the feature and zstd integration with Mercurial.
author | Gregory Szorc <gregory.szorc@gmail.com> |
---|---|
date | Tue, 10 Jan 2017 11:20:32 -0800 |
parents | 56b2bcea2529 |
children | 0ed11f9368fd |
line wrap: on
line source
# discovery.py - protocol changeset discovery functions # # Copyright 2010 Matt Mackall <mpm@selenic.com> # # 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 collections from .i18n import _ from .node import ( nullid, short, ) from . import ( error, ) def findcommonincoming(repo, remote, heads=None, force=False): """Return a tuple (common, fetch, heads) used to identify the common subset of nodes between repo and remote. "common" is a list of (at least) the heads of the common subset. "fetch" is a list of roots of the nodes that would be incoming, to be supplied to changegroupsubset. "heads" is either the supplied heads, or else the remote's heads. """ knownnode = repo.changelog.hasnode search = [] fetch = set() seen = set() seenbranch = set() base = set() if not heads: heads = remote.heads() if repo.changelog.tip() == nullid: base.add(nullid) if heads != [nullid]: return [nullid], [nullid], list(heads) return [nullid], [], heads # assume we're closer to the tip than the root # and start by examining the heads repo.ui.status(_("searching for changes\n")) unknown = [] for h in heads: if not knownnode(h): unknown.append(h) else: base.add(h) if not unknown: return list(base), [], list(heads) req = set(unknown) reqcnt = 0 # search through remote branches # a 'branch' here is a linear segment of history, with four parts: # head, root, first parent, second parent # (a branch always has two parents (or none) by definition) unknown = collections.deque(remote.branches(unknown)) while unknown: r = [] while unknown: n = unknown.popleft() if n[0] in seen: continue repo.ui.debug("examining %s:%s\n" % (short(n[0]), short(n[1]))) if n[0] == nullid: # found the end of the branch pass elif n in seenbranch: repo.ui.debug("branch already found\n") continue elif n[1] and knownnode(n[1]): # do we know the base? repo.ui.debug("found incomplete branch %s:%s\n" % (short(n[0]), short(n[1]))) search.append(n[0:2]) # schedule branch range for scanning seenbranch.add(n) else: if n[1] not in seen and n[1] not in fetch: if knownnode(n[2]) and knownnode(n[3]): repo.ui.debug("found new changeset %s\n" % short(n[1])) fetch.add(n[1]) # earliest unknown for p in n[2:4]: if knownnode(p): base.add(p) # latest known for p in n[2:4]: if p not in req and not knownnode(p): r.append(p) req.add(p) seen.add(n[0]) if r: reqcnt += 1 repo.ui.progress(_('searching'), reqcnt, unit=_('queries')) repo.ui.debug("request %d: %s\n" % (reqcnt, " ".join(map(short, r)))) for p in xrange(0, len(r), 10): for b in remote.branches(r[p:p + 10]): repo.ui.debug("received %s:%s\n" % (short(b[0]), short(b[1]))) unknown.append(b) # do binary search on the branches we found while search: newsearch = [] reqcnt += 1 repo.ui.progress(_('searching'), reqcnt, unit=_('queries')) for n, l in zip(search, remote.between(search)): l.append(n[1]) p = n[0] f = 1 for i in l: repo.ui.debug("narrowing %d:%d %s\n" % (f, len(l), short(i))) if knownnode(i): if f <= 2: repo.ui.debug("found new branch changeset %s\n" % short(p)) fetch.add(p) base.add(i) else: repo.ui.debug("narrowed branch search to %s:%s\n" % (short(p), short(i))) newsearch.append((p, i)) break p, f = i, f * 2 search = newsearch # sanity check our fetch list for f in fetch: if knownnode(f): raise error.RepoError(_("already have changeset ") + short(f[:4])) base = list(base) if base == [nullid]: if force: repo.ui.warn(_("warning: repository is unrelated\n")) else: raise error.Abort(_("repository is unrelated")) repo.ui.debug("found new changesets starting at " + " ".join([short(f) for f in fetch]) + "\n") repo.ui.progress(_('searching'), None) repo.ui.debug("%d total queries\n" % reqcnt) return base, list(fetch), heads