view hgext/largefiles/proto.py @ 18728:1e636f7b1cfe stable

largefiles: simplify cachelfiles - don't spend a lot of time checking hashes

cachelfiles jumped through loops to handle merges and modified files ... but it
did apparently no longer have a valid reason to do so. It should just always
make sure that the largefiles referenced from the standins are present - no
matter which actual largefile is stored in the working directory. If there is
no standin then there is nothing to fetch.

The old code usually verified the hash of all largefiles every time this
function was invoked - for examply by 'update'.

This change makes a trivial noop update 5-10 seconds faster on our repo (with
the other 50% spent doing another unnecessary hashing of all largefiles).

# Copyright 2011 Fog Creek Software
#
# This software may be used and distributed according to the terms of the
# GNU General Public License version 2 or any later version.

import os
import urllib2

from mercurial import error, httppeer, util, wireproto
from mercurial.wireproto import batchable, future
from mercurial.i18n import _

import lfutil

LARGEFILES_REQUIRED_MSG = ('\nThis repository uses the largefiles extension.'
                           '\n\nPlease enable it in your Mercurial config '
                           'file.\n')

def putlfile(repo, proto, sha):
    '''Put a largefile into a repository's local store and into the
    user cache.'''
    proto.redirect()

    path = lfutil.storepath(repo, sha)
    util.makedirs(os.path.dirname(path))
    tmpfp = util.atomictempfile(path, createmode=repo.store.createmode)

    try:
        try:
            proto.getfile(tmpfp)
            tmpfp._fp.seek(0)
            if sha != lfutil.hexsha1(tmpfp._fp):
                raise IOError(0, _('largefile contents do not match hash'))
            tmpfp.close()
            lfutil.linktousercache(repo, sha)
        except IOError, e:
            repo.ui.warn(_('largefiles: failed to put %s into store: %s') %
                         (sha, e.strerror))
            return wireproto.pushres(1)
    finally:
        tmpfp.discard()

    return wireproto.pushres(0)

def getlfile(repo, proto, sha):
    '''Retrieve a largefile from the repository-local cache or system
    cache.'''
    filename = lfutil.findfile(repo, sha)
    if not filename:
        raise util.Abort(_('requested largefile %s not present in cache') % sha)
    f = open(filename, 'rb')
    length = os.fstat(f.fileno())[6]

    # Since we can't set an HTTP content-length header here, and
    # Mercurial core provides no way to give the length of a streamres
    # (and reading the entire file into RAM would be ill-advised), we
    # just send the length on the first line of the response, like the
    # ssh proto does for string responses.
    def generator():
        yield '%d\n' % length
        for chunk in f:
            yield chunk
    return wireproto.streamres(generator())

def statlfile(repo, proto, sha):
    '''Return '2\n' if the largefile is missing, '0\n' if it seems to be in
    good condition.

    The value 1 is reserved for mismatched checksum, but that is too expensive
    to be verified on every stat and must be caught be running 'hg verify'
    server side.'''
    filename = lfutil.findfile(repo, sha)
    if not filename:
        return '2\n'
    return '0\n'

def wirereposetup(ui, repo):
    class lfileswirerepository(repo.__class__):
        def putlfile(self, sha, fd):
            # unfortunately, httprepository._callpush tries to convert its
            # input file-like into a bundle before sending it, so we can't use
            # it ...
            if issubclass(self.__class__, httppeer.httppeer):
                res = None
                try:
                    res = self._call('putlfile', data=fd, sha=sha,
                        headers={'content-type':'application/mercurial-0.1'})
                    d, output = res.split('\n', 1)
                    for l in output.splitlines(True):
                        self.ui.warn(_('remote: '), l, '\n')
                    return int(d)
                except (ValueError, urllib2.HTTPError):
                    self.ui.warn(_('unexpected putlfile response: %s') % res)
                    return 1
            # ... but we can't use sshrepository._call because the data=
            # argument won't get sent, and _callpush does exactly what we want
            # in this case: send the data straight through
            else:
                try:
                    ret, output = self._callpush("putlfile", fd, sha=sha)
                    if ret == "":
                        raise error.ResponseError(_('putlfile failed:'),
                                output)
                    return int(ret)
                except IOError:
                    return 1
                except ValueError:
                    raise error.ResponseError(
                        _('putlfile failed (unexpected response):'), ret)

        def getlfile(self, sha):
            stream = self._callstream("getlfile", sha=sha)
            length = stream.readline()
            try:
                length = int(length)
            except ValueError:
                self._abort(error.ResponseError(_("unexpected response:"),
                                                length))
            return (length, stream)

        @batchable
        def statlfile(self, sha):
            f = future()
            result = {'sha': sha}
            yield result, f
            try:
                yield int(f.value)
            except (ValueError, urllib2.HTTPError):
                # If the server returns anything but an integer followed by a
                # newline, newline, it's not speaking our language; if we get
                # an HTTP error, we can't be sure the largefile is present;
                # either way, consider it missing.
                yield 2

    repo.__class__ = lfileswirerepository

# advertise the largefiles=serve capability
def capabilities(repo, proto):
    return capabilitiesorig(repo, proto) + ' largefiles=serve'

def heads(repo, proto):
    if lfutil.islfilesrepo(repo):
        return wireproto.ooberror(LARGEFILES_REQUIRED_MSG)
    return wireproto.heads(repo, proto)

def sshrepocallstream(self, cmd, **args):
    if cmd == 'heads' and self.capable('largefiles'):
        cmd = 'lheads'
    if cmd == 'batch' and self.capable('largefiles'):
        args['cmds'] = args['cmds'].replace('heads ', 'lheads ')
    return ssholdcallstream(self, cmd, **args)

def httprepocallstream(self, cmd, **args):
    if cmd == 'heads' and self.capable('largefiles'):
        cmd = 'lheads'
    if cmd == 'batch' and self.capable('largefiles'):
        args['cmds'] = args['cmds'].replace('heads ', 'lheads ')
    return httpoldcallstream(self, cmd, **args)