##// END OF EJS Templates
exchangev2: fetch manifest revisions...
exchangev2: fetch manifest revisions Now that the server has support for retrieving manifest data, we can implement the client bits to call it. We teach the changeset fetching code to capture the manifest revisions that are encountered on incoming changesets. We then feed this into a new function which filters out known manifests and then batches up manifest data requests to the server. This is different from the previous wire protocol in a few notable ways. First, the client fetches manifest data separately and explicitly. Before, we'd ask the server for data pertaining to some changesets (via a "getbundle" command) and manifests (and files) would be sent automatically. Providing an API for looking up just manifest data separately gives clients much more flexibility for manifest management. For example, a client may choose to only fetch manifest data on demand instead of prefetching it (i.e. partial clone). Second, we send N commands to the server for manifest retrieval instead of 1. This property has a few nice side-effects. One is that the deterministic nature of the requests lends itself to server-side caching. For example, say the remote has 50,000 manifests. If the server is configured to cache responses, each time a new commit arrives, you will have a cache miss and need to regenerate all outgoing data. But if you makes N requests requesting 10,000 manifests each, a new commit will still yield cache hits on the initial, unchanged manifest batches/requests. A derived benefit from these properties is that resumable clone is conceptually simpler to implement. When making a monolithic request for all of the repository data, recovering from an interrupted clone is hard because the server was in the driver's seat and was maintaining state about all the data that needed transferred. With the client driving fetching, the client can persist the set of unfetched entities and retry/resume a fetch if something goes wrong. Or we can fetch all data N changesets at a time and slowly build up a repository. This approach is drastically easier to implement when we have server APIs exposing low-level repository primitives (such as manifests and files). We don't yet support tree manifests. But it should be possible to implement that with the existing wire protocol command. Differential Revision: https://phab.mercurial-scm.org/D4489

File last commit:

r34646:75979c8d default
r39674:d292328e default
Show More
rcutil.py
98 lines | 3.1 KiB | text/x-python | PythonLexer
Jun Wu
rcutil: move scmutil.*rcpath to rcutil (API)...
r31679 # rcutil.py - utilities about config paths, special config sections etc.
#
# Copyright Mercurial Contributors
#
# 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 . import (
encoding,
pycompat,
util,
)
Jun Wu
codemod: use pycompat.iswindows...
r34646 if pycompat.iswindows:
Jun Wu
rcutil: move scmutil.*rcpath to rcutil (API)...
r31679 from . import scmwindows as scmplatform
else:
from . import scmposix as scmplatform
Yuya Nishihara
pager: use less as a fallback on Unix...
r32078 fallbackpager = scmplatform.fallbackpager
Jun Wu
rcutil: move scmutil.*rcpath to rcutil (API)...
r31679 systemrcpath = scmplatform.systemrcpath
userrcpath = scmplatform.userrcpath
Jun Wu
rcutil: extract rc directory listing logic...
r31681 def _expandrcpath(path):
'''path could be a file or a directory. return a list of file paths'''
p = util.expandpath(path)
if os.path.isdir(p):
join = os.path.join
Yuya Nishihara
osutil: proxy through util (and platform) modules (API)...
r32203 return [join(p, f) for f, k in util.listdir(p) if f.endswith('.rc')]
Jun Wu
rcutil: extract rc directory listing logic...
r31681 return [p]
Jun Wu
rcutil: add a method to convert environment variables to config items...
r31684 def envrcitems(env=None):
'''Return [(section, name, value, source)] config items.
The config items are extracted from environment variables specified by env,
used to override systemrc, but not userrc.
If env is not provided, encoding.environ will be used.
'''
if env is None:
env = encoding.environ
checklist = [
('EDITOR', 'ui', 'editor'),
('VISUAL', 'ui', 'editor'),
('PAGER', 'pager', 'pager'),
]
result = []
for envname, section, configname in checklist:
if envname not in env:
continue
result.append((section, configname, env[envname], '$%s' % envname))
return result
Jun Wu
rcutil: split osrcpath to return default.d paths (API)...
r31680 def defaultrcpath():
'''return rc paths in default.d'''
Jun Wu
rcutil: move scmutil.*rcpath to rcutil (API)...
r31679 path = []
defaultpath = os.path.join(util.datapath, 'default.d')
if os.path.isdir(defaultpath):
Jun Wu
rcutil: extract rc directory listing logic...
r31681 path = _expandrcpath(defaultpath)
Jun Wu
rcutil: move scmutil.*rcpath to rcutil (API)...
r31679 return path
Jun Wu
rcutil: rename rcpath to rccomponents (API)
r31682 def rccomponents():
Jun Wu
rcutil: let rccomponents return different types of configs (API)...
r31683 '''return an ordered [(type, obj)] about where to load configs.
respect $HGRCPATH. if $HGRCPATH is empty, only .hg/hgrc of current repo is
used. if $HGRCPATH is not set, the platform default will be used.
if a directory is provided, *.rc files under it will be used.
type could be either 'path' or 'items', if type is 'path', obj is a string,
and is the config file path. if type is 'items', obj is a list of (section,
name, value, source) that should fill the config directly.
'''
Jun Wu
rcutil: let environ override system configs (BC)...
r31685 envrc = ('items', envrcitems())
Jun Wu
rcutil: unindent a block...
r31693 if 'HGRCPATH' in encoding.environ:
# assume HGRCPATH is all about user configs so environments can be
# overridden.
_rccomponents = [envrc]
for p in encoding.environ['HGRCPATH'].split(pycompat.ospathsep):
if not p:
continue
_rccomponents.extend(('path', p) for p in _expandrcpath(p))
else:
Jun Wu
rcutil: extract duplicated logic to a lambda...
r31694 normpaths = lambda paths: [('path', os.path.normpath(p)) for p in paths]
_rccomponents = normpaths(defaultrcpath() + systemrcpath())
Jun Wu
rcutil: unindent a block...
r31693 _rccomponents.append(envrc)
Jun Wu
rcutil: extract duplicated logic to a lambda...
r31694 _rccomponents.extend(normpaths(userrcpath()))
Jun Wu
rcutil: rename rcpath to rccomponents (API)
r31682 return _rccomponents
Jun Wu
pager: set some environment variables if they're not set...
r31954
def defaultpagerenv():
'''return a dict of default environment variables and their values,
intended to be set before starting a pager.
'''
return {'LESS': 'FRX', 'LV': '-c'}