annotate hgext/lfs/__init__.py @ 35506:fa865878a849

lfs: show a friendly message when pushing lfs to a server without lfs enabled

Upfront disclaimer: I don't know anything about the wire protocol, and this was
pretty much cargo-culted from largefiles, and then clonebundles, since it seems
more modern.  I was surprised that exchange.push() will ensure all of the proper
requirements when exchanging between two local repos, but doesn't care when one
is remote.

All this new capability marker does is inform the client that the extension is
enabled remotely.  It may or may not contain commits with external blobs.

Open issues:

  - largefiles uses 'largefiles=serve' for its capability.  Someday I hope to
    be able to push lfs blobs to an `hg serve` instance.  That will probably
    require a distinct capability.  Should it change to '=serve' then?  Or just
    add an 'lfs-serve' capability then?

  - The flip side of this is more complicated.  It looks like largefiles adds an
    'lheads' command for the client to signal to the server that the extension
    is loaded.  That is then converted to 'heads' and sent through the normal
    wire protocol plumbing.  A client using the 'heads' command directly is
    kicked out with a message indicating that the largefiles extension must be
    loaded.  We could do similar with 'lfsheads', but then a repo with both
    largefiles and lfs blobs can't be pushed over the wire.  Hopefully somebody
    with more wire protocol experience can think of something else.  I see
    'x-hgarg-1' on some commands in the tests, but not on heads, and didn't dig
    any further.

# lfs - hash-preserving large file support using Git-LFS protocol
#
# Copyright 2017 Facebook, Inc.
#
# This software may be used and distributed according to the terms of the
# GNU General Public License version 2 or any later version.

"""lfs - large file support (EXPERIMENTAL)

Configs::

    [lfs]
    # Remote endpoint. Multiple protocols are supported:
    # - http(s)://user:[e-mail]/path
    #   git-lfs endpoint
    # - file:///tmp/path
    #   local filesystem, usually for testing
    # if unset, lfs will prompt setting this when it must use this value.
    # (default: unset)
    url = https://example.com/lfs

    # size of a file to make it use LFS
    threshold = 10M

    # how many times to retry before giving up on transferring an object
    retry = 5

    # the local directory to store lfs files for sharing across local clones.
    # If not set, the cache is located in an OS specific cache location.
    usercache = /path/to/global/cache
"""

from __future__ import absolute_import

from mercurial.i18n import _

from mercurial import (
    bundle2,
    changegroup,
    context,
    exchange,
    extensions,
    filelog,
    hg,
    localrepo,
    node,
    registrar,
    revlog,
    scmutil,
    upgrade,
    vfs as vfsmod,
    wireproto,
)

from . import (
    blobstore,
    wrapper,
)

# 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('experimental', 'lfs.user-agent',
    default=None,
)

configitem('lfs', 'url',
    default=configitem.dynamicdefault,
)
configitem('lfs', 'usercache',
    default=None,
)
configitem('lfs', 'threshold',
    default=None,
)
configitem('lfs', 'retry',
    default=5,
)
# Deprecated
configitem('lfs', 'remotestore',
    default=None,
)
# Deprecated
configitem('lfs', 'dummy',
    default=None,
)
# Deprecated
configitem('lfs', 'git-lfs',
    default=None,
)

cmdtable = {}
command = registrar.command(cmdtable)

templatekeyword = registrar.templatekeyword()

def featuresetup(ui, supported):
    # don't die on seeing a repo with the lfs requirement
    supported |= {'lfs'}

def uisetup(ui):
    localrepo.localrepository.featuresetupfuncs.add(featuresetup)

def reposetup(ui, repo):
    # Nothing to do with a remote repo
    if not repo.local():
        return

    threshold = repo.ui.configbytes('lfs', 'threshold')

    repo.svfs.options['lfsthreshold'] = threshold
    repo.svfs.lfslocalblobstore = blobstore.local(repo)
    repo.svfs.lfsremoteblobstore = blobstore.remote(repo)

    # Push hook
    repo.prepushoutgoinghooks.add('lfs', wrapper.prepush)

    if 'lfs' not in repo.requirements:
        def checkrequireslfs(ui, repo, **kwargs):
            if 'lfs' not in repo.requirements:
                last = kwargs.get('node_last')
                _bin = node.bin
                if last:
                    s = repo.set('%n:%n', _bin(kwargs['node']), _bin(last))
                else:
                    s = repo.set('%n', _bin(kwargs['node']))
            for ctx in s:
                # TODO: is there a way to just walk the files in the commit?
                if any(ctx[f].islfs() for f in ctx.files() if f in ctx):
                    repo.requirements.add('lfs')
                    repo._writerequirements()
                    break

        ui.setconfig('hooks', 'commit.lfs', checkrequireslfs, 'lfs')
        ui.setconfig('hooks', 'pretxnchangegroup.lfs', checkrequireslfs, 'lfs')

def wrapfilelog(filelog):
    wrapfunction = extensions.wrapfunction

    wrapfunction(filelog, 'addrevision', wrapper.filelogaddrevision)
    wrapfunction(filelog, 'renamed', wrapper.filelogrenamed)
    wrapfunction(filelog, 'size', wrapper.filelogsize)

def extsetup(ui):
    wrapfilelog(filelog.filelog)

    wrapfunction = extensions.wrapfunction

    wrapfunction(scmutil, 'wrapconvertsink', wrapper.convertsink)

    wrapfunction(upgrade, '_finishdatamigration',
                 wrapper.upgradefinishdatamigration)

    wrapfunction(upgrade, 'preservedrequirements',
                 wrapper.upgraderequirements)

    wrapfunction(upgrade, 'supporteddestrequirements',
                 wrapper.upgraderequirements)

    wrapfunction(changegroup,
                 'supportedoutgoingversions',
                 wrapper.supportedoutgoingversions)
    wrapfunction(changegroup,
                 'allsupportedversions',
                 wrapper.allsupportedversions)

    wrapfunction(exchange, 'push', wrapper.push)
    wrapfunction(wireproto, '_capabilities', wrapper._capabilities)

    wrapfunction(context.basefilectx, 'cmp', wrapper.filectxcmp)
    wrapfunction(context.basefilectx, 'isbinary', wrapper.filectxisbinary)
    context.basefilectx.islfs = wrapper.filectxislfs

    revlog.addflagprocessor(
        revlog.REVIDX_EXTSTORED,
        (
            wrapper.readfromstore,
            wrapper.writetostore,
            wrapper.bypasscheckhash,
        ),
    )

    wrapfunction(hg, 'clone', wrapper.hgclone)
    wrapfunction(hg, 'postshare', wrapper.hgpostshare)

    # Make bundle choose changegroup3 instead of changegroup2. This affects
    # "hg bundle" command. Note: it does not cover all bundle formats like
    # "packed1". Using "packed1" with lfs will likely cause trouble.
    names = [k for k, v in exchange._bundlespeccgversions.items() if v == '02']
    for k in names:
        exchange._bundlespeccgversions[k] = '03'

    # bundlerepo uses "vfsmod.readonlyvfs(othervfs)", we need to make sure lfs
    # options and blob stores are passed from othervfs to the new readonlyvfs.
    wrapfunction(vfsmod.readonlyvfs, '__init__', wrapper.vfsinit)

    # when writing a bundle via "hg bundle" command, upload related LFS blobs
    wrapfunction(bundle2, 'writenewbundle', wrapper.writenewbundle)

@templatekeyword('lfs_files')
def lfsfiles(repo, ctx, **args):
    """List of strings. LFS files added or modified by the changeset."""
    pointers = wrapper.pointersfromctx(ctx) # {path: pointer}
    return sorted(pointers.keys())

@command('debuglfsupload',
         [('r', 'rev', [], _('upload large files introduced by REV'))])
def debuglfsupload(ui, repo, **opts):
    """upload lfs blobs added by the working copy parent or given revisions"""
    revs = opts.get('rev', [])
    pointers = wrapper.extractpointers(repo, scmutil.revrange(repo, revs))
    wrapper.uploadblobs(repo, pointers)