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
# win32text.py - LF <-> CRLF/CR translation utilities for Windows/Mac users
#
# Copyright 2005, 2007-2009 Matt Mackall <mpm@selenic.com> and others
#
# This software may be used and distributed according to the terms of the
# GNU General Public License version 2 or any later version.
'''perform automatic newline conversion (DEPRECATED)
Deprecation: The win32text extension requires each user to configure
the extension again and again for each clone since the configuration
is not copied when cloning.
We have therefore made the ``eol`` as an alternative. The ``eol``
uses a version controlled file for its configuration and each clone
will therefore use the right settings from the start.
To perform automatic newline conversion, use::
[extensions]
win32text =
[encode]
** = cleverencode:
# or ** = macencode:
[decode]
** = cleverdecode:
# or ** = macdecode:
If not doing conversion, to make sure you do not commit CRLF/CR by accident::
[hooks]
pretxncommit.crlf = python:hgext.win32text.forbidcrlf
# or pretxncommit.cr = python:hgext.win32text.forbidcr
To do the same check on a server to prevent CRLF/CR from being
pushed or pulled::
[hooks]
pretxnchangegroup.crlf = python:hgext.win32text.forbidcrlf
# or pretxnchangegroup.cr = python:hgext.win32text.forbidcr
'''
from __future__ import absolute_import
import re
from mercurial.i18n import _
from mercurial.node import (
short,
)
from mercurial import (
pycompat,
registrar,
)
from mercurial.utils import (
stringutil,
)
# Note for extension authors: ONLY specify testedwith = 'ships-with-hg-core' for
# extensions which SHIP WITH MERCURIAL. Non-mainline extensions should
# be specifying the version(s) of Mercurial they are tested with, or
# leave the attribute unspecified.
testedwith = 'ships-with-hg-core'
configtable = {}
configitem = registrar.configitem(configtable)
configitem('win32text', 'warn',
default=True,
)
# regexp for single LF without CR preceding.
re_single_lf = re.compile('(^|[^\r])\n', re.MULTILINE)
newlinestr = {'\r\n': 'CRLF', '\r': 'CR'}
filterstr = {'\r\n': 'clever', '\r': 'mac'}
def checknewline(s, newline, ui=None, repo=None, filename=None):
# warn if already has 'newline' in repository.
# it might cause unexpected eol conversion.
# see issue 302:
# https://bz.mercurial-scm.org/302
if newline in s and ui and filename and repo:
ui.warn(_('WARNING: %s already has %s line endings\n'
'and does not need EOL conversion by the win32text plugin.\n'
'Before your next commit, please reconsider your '
'encode/decode settings in \nMercurial.ini or %s.\n') %
(filename, newlinestr[newline], repo.vfs.join('hgrc')))
def dumbdecode(s, cmd, **kwargs):
checknewline(s, '\r\n', **kwargs)
# replace single LF to CRLF
return re_single_lf.sub('\\1\r\n', s)
def dumbencode(s, cmd):
return s.replace('\r\n', '\n')
def macdumbdecode(s, cmd, **kwargs):
checknewline(s, '\r', **kwargs)
return s.replace('\n', '\r')
def macdumbencode(s, cmd):
return s.replace('\r', '\n')
def cleverdecode(s, cmd, **kwargs):
if not stringutil.binary(s):
return dumbdecode(s, cmd, **kwargs)
return s
def cleverencode(s, cmd):
if not stringutil.binary(s):
return dumbencode(s, cmd)
return s
def macdecode(s, cmd, **kwargs):
if not stringutil.binary(s):
return macdumbdecode(s, cmd, **kwargs)
return s
def macencode(s, cmd):
if not stringutil.binary(s):
return macdumbencode(s, cmd)
return s
_filters = {
'dumbdecode:': dumbdecode,
'dumbencode:': dumbencode,
'cleverdecode:': cleverdecode,
'cleverencode:': cleverencode,
'macdumbdecode:': macdumbdecode,
'macdumbencode:': macdumbencode,
'macdecode:': macdecode,
'macencode:': macencode,
}
def forbidnewline(ui, repo, hooktype, node, newline, **kwargs):
halt = False
seen = set()
# we try to walk changesets in reverse order from newest to
# oldest, so that if we see a file multiple times, we take the
# newest version as canonical. this prevents us from blocking a
# changegroup that contains an unacceptable commit followed later
# by a commit that fixes the problem.
tip = repo['tip']
for rev in pycompat.xrange(repo.changelog.tiprev(),
repo[node].rev() - 1, -1):
c = repo[rev]
for f in c.files():
if f in seen or f not in tip or f not in c:
continue
seen.add(f)
data = c[f].data()
if not stringutil.binary(data) and newline in data:
if not halt:
ui.warn(_('attempt to commit or push text file(s) '
'using %s line endings\n') %
newlinestr[newline])
ui.warn(_('in %s: %s\n') % (short(c.node()), f))
halt = True
if halt and hooktype == 'pretxnchangegroup':
crlf = newlinestr[newline].lower()
filter = filterstr[newline]
ui.warn(_('\nTo prevent this mistake in your local repository,\n'
'add to Mercurial.ini or .hg/hgrc:\n'
'\n'
'[hooks]\n'
'pretxncommit.%s = python:hgext.win32text.forbid%s\n'
'\n'
'and also consider adding:\n'
'\n'
'[extensions]\n'
'win32text =\n'
'[encode]\n'
'** = %sencode:\n'
'[decode]\n'
'** = %sdecode:\n') % (crlf, crlf, filter, filter))
return halt
def forbidcrlf(ui, repo, hooktype, node, **kwargs):
return forbidnewline(ui, repo, hooktype, node, '\r\n', **kwargs)
def forbidcr(ui, repo, hooktype, node, **kwargs):
return forbidnewline(ui, repo, hooktype, node, '\r', **kwargs)
def reposetup(ui, repo):
if not repo.local():
return
for name, fn in _filters.iteritems():
repo.adddatafilter(name, fn)
def extsetup(ui):
# deprecated config: win32text.warn
if ui.configbool('win32text', 'warn'):
ui.warn(_("win32text is deprecated: "
"https://mercurial-scm.org/wiki/Win32TextExtension\n"))