annotate hgext/lfs/__init__.py @ 37518:092eff6833a7

lfs: infer the blob store URL from paths.default

If `lfs.url` is specified, it takes precedence.  However, now that we support
serving blobs via hgweb, we shouldn't *require* this setting.  Less
configuration is better (things will work out of the box once this is sorted
out), and git has similar functionality.

This is not a complete solution- it isn't able to infer the blob store from an
explicitly supplied path, and it should consider `paths.default-push` for push.
The pull solution for that is a bit hacky, and this alone is an improvement for
the vast majority of cases.

Even though there are only a handful of references to the saved remote store,
the location of them makes things complicated.

  1) downloading files on demand in the revlog flag processor
  2) copying to readonlyvfs with bundlerepo
  3) downloading in the file prefetch hook
  4) the canupload()/skipdownload() checks
  5) uploading blobs

Since revlog doesn't have a repo or ui reference, we can't avoid creating a
remote store when the extension is loaded.  While the long term goal is to make
sure the prefetch hook is invoked early for every command for efficiency, this
handling in the flag processor is needed as a last ditch fetch.

In order to support the clone command, the remote store needs to be created
later than when the extension loads, since `paths.default` isn't set until just
before the files are checked out.  Therefore, this patch changes the prefetch
hook to ignore the saved reference, and build a new one.

The canupload()/skipdownload() checks simply check if the stored instance is a
`_nullremote`.  Since this can only be set via `lfs.url` (which is reflected in
the saved reference), checking only the instance created when the extension
loaded is fine.

The blob uploading function is called from several places:

  1) a prepush hook
  2) when writing a new bundle
  3) from infinitepush

The prepush hook gets an exchange.pushop, so it has a path to where the push is
going.  The bundle writer and infinitepush don't.  Further, bundle creation for
things like strip and amend are causing blobs to be uploaded.  This seems wrong,
but I don't want to side track this sorting that out, so punt on trying to
handle explicit push paths or `paths.default-push`.

I also think that sending blobs to a remote store when pushing to a local repo
is wrong.  This functionality predates the usercache, so perhaps that's the
reason for it.  I've got some patches floating around to stop sending blobs
remotely in this case, and instead write directly to the other repo's blob
store.  But the tests for corruption handling weren't happy with this change,
and I don't have time to rewrite them.  So exclude filesystem based paths from
this for now.

I don't think there's much of a chance to implement `paths.remote:lfsurl` style
configs, given how early these are resolved vs how late the remote store is
created.  But git has it, so I threw a TODO in there, in case anyone has ideas.

I have no idea why this is now doing http auth twice when it wasn't before.  I
don't think the original blobstore's url is ever being used in these cases.

# 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)

This extension allows large files to be tracked outside of the normal
repository storage and stored on a centralized server, similar to the
``largefiles`` extension.  The ``git-lfs`` protocol is used when
communicating with the server, so existing git infrastructure can be
harnessed.  Even though the files are stored outside of the repository,
they are still integrity checked in the same manner as normal files.

The files stored outside of the repository are downloaded on demand,
which reduces the time to clone, and possibly the local disk usage.
This changes fundamental workflows in a DVCS, so careful thought
should be given before deploying it.  :hg:`convert` can be used to
convert LFS repositories to normal repositories that no longer
require this extension, and do so without changing the commit hashes.
This allows the extension to be disabled if the centralized workflow
becomes burdensome.  However, the pre and post convert clones will
not be able to communicate with each other unless the extension is
enabled on both.

To start a new repository, or to add LFS files to an existing one, just
create an ``.hglfs`` file as described below in the root directory of
the repository.  Typically, this file should be put under version
control, so that the settings will propagate to other repositories with
push and pull.  During any commit, Mercurial will consult this file to
determine if an added or modified file should be stored externally.  The
type of storage depends on the characteristics of the file at each
commit.  A file that is near a size threshold may switch back and forth
between LFS and normal storage, as needed.

Alternately, both normal repositories and largefile controlled
repositories can be converted to LFS by using :hg:`convert` and the
``lfs.track`` config option described below.  The ``.hglfs`` file
should then be created and added, to control subsequent LFS selection.
The hashes are also unchanged in this case.  The LFS and non-LFS
repositories can be distinguished because the LFS repository will
abort any command if this extension is disabled.

Committed LFS files are held locally, until the repository is pushed.
Prior to pushing the normal repository data, the LFS files that are
tracked by the outgoing commits are automatically uploaded to the
configured central server.  No LFS files are transferred on
:hg:`pull` or :hg:`clone`.  Instead, the files are downloaded on
demand as they need to be read, if a cached copy cannot be found
locally.  Both committing and downloading an LFS file will link the
file to a usercache, to speed up future access.  See the `usercache`
config setting described below.

.hglfs::

    The extension reads its configuration from a versioned ``.hglfs``
    configuration file found in the root of the working directory. The
    ``.hglfs`` file uses the same syntax as all other Mercurial
    configuration files. It uses a single section, ``[track]``.

    The ``[track]`` section specifies which files are stored as LFS (or
    not). Each line is keyed by a file pattern, with a predicate value.
    The first file pattern match is used, so put more specific patterns
    first.  The available predicates are ``all()``, ``none()``, and
    ``size()``. See "hg help filesets.size" for the latter.

    Example versioned ``.hglfs`` file::

      [track]
      # No Makefile or python file, anywhere, will be LFS
      **Makefile = none()
      **.py = none()

      **.zip = all()
      **.exe = size(">1MB")

      # Catchall for everything not matched above
      ** = size(">10MB")

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 assume the repository at ``paths.default`` also handles
    # blob storage for http(s) URLs.  Otherwise, lfs will prompt to set this
    # when it must use this value.
    # (default: unset)
    url = https://example.com/repo.git/info/lfs

    # Which files to track in LFS.  Path tests are "**.extname" for file
    # extensions, and "path:under/some/directory" for path prefix.  Both
    # are relative to the repository root.
    # File size can be tested with the "size()" fileset, and tests can be
    # joined with fileset operators.  (See "hg help filesets.operators".)
    #
    # Some examples:
    # - all()                       # everything
    # - none()                      # nothing
    # - size(">20MB")               # larger than 20MB
    # - !**.txt                     # anything not a *.txt file
    # - **.zip | **.tar.gz | **.7z  # some types of compressed files
    # - path:bin                    # files under "bin" in the project root
    # - (**.php & size(">2MB")) | (**.js & size(">5MB")) | **.tar.gz
    #     | (path:bin & !path:/bin/README) | size(">1GB")
    # (default: none())
    #
    # This is ignored if there is a tracked '.hglfs' file, and this setting
    # will eventually be deprecated and removed.
    track = size(">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,
    cmdutil,
    config,
    context,
    error,
    exchange,
    extensions,
    filelog,
    fileset,
    hg,
    localrepo,
    minifileset,
    node,
    pycompat,
    registrar,
    revlog,
    scmutil,
    templateutil,
    upgrade,
    util,
    vfs as vfsmod,
    wireproto,
    wireprotoserver,
)

from . import (
    blobstore,
    wireprotolfsserver,
    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.serve',
    default=True,
)
configitem('experimental', 'lfs.user-agent',
    default=None,
)
configitem('experimental', 'lfs.worker-enable',
    default=False,
)

configitem('lfs', 'url',
    default=None,
)
configitem('lfs', 'usercache',
    default=None,
)
# Deprecated
configitem('lfs', 'threshold',
    default=None,
)
configitem('lfs', 'track',
    default='none()',
)
configitem('lfs', 'retry',
    default=5,
)

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

templatekeyword = registrar.templatekeyword()
filesetpredicate = registrar.filesetpredicate()

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

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

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

    repo.svfs.lfslocalblobstore = blobstore.local(repo)
    repo.svfs.lfsremoteblobstore = blobstore.remote(repo)

    class lfsrepo(repo.__class__):
        @localrepo.unfilteredmethod
        def commitctx(self, ctx, error=False):
            repo.svfs.options['lfstrack'] = _trackedmatcher(self)
            return super(lfsrepo, self).commitctx(ctx, error)

    repo.__class__ = lfsrepo

    if 'lfs' not in repo.requirements:
        def checkrequireslfs(ui, repo, **kwargs):
            if 'lfs' not in repo.requirements:
                last = kwargs.get(r'node_last')
                _bin = node.bin
                if last:
                    s = repo.set('%n:%n', _bin(kwargs[r'node']), _bin(last))
                else:
                    s = repo.set('%n', _bin(kwargs[r'node']))
            match = repo.narrowmatch()
            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 and match(f)):
                    repo.requirements.add('lfs')
                    repo._writerequirements()
                    repo.prepushoutgoinghooks.add('lfs', wrapper.prepush)
                    break

        ui.setconfig('hooks', 'commit.lfs', checkrequireslfs, 'lfs')
        ui.setconfig('hooks', 'pretxnchangegroup.lfs', checkrequireslfs, 'lfs')
    else:
        repo.prepushoutgoinghooks.add('lfs', wrapper.prepush)

def _trackedmatcher(repo):
    """Return a function (path, size) -> bool indicating whether or not to
    track a given file with lfs."""
    if not repo.wvfs.exists('.hglfs'):
        # No '.hglfs' in wdir.  Fallback to config for now.
        trackspec = repo.ui.config('lfs', 'track')

        # deprecated config: lfs.threshold
        threshold = repo.ui.configbytes('lfs', 'threshold')
        if threshold:
            fileset.parse(trackspec)  # make sure syntax errors are confined
            trackspec = "(%s) | size('>%d')" % (trackspec, threshold)

        return minifileset.compile(trackspec)

    data = repo.wvfs.tryread('.hglfs')
    if not data:
        return lambda p, s: False

    # Parse errors here will abort with a message that points to the .hglfs file
    # and line number.
    cfg = config.config()
    cfg.parse('.hglfs', data)

    try:
        rules = [(minifileset.compile(pattern), minifileset.compile(rule))
                 for pattern, rule in cfg.items('track')]
    except error.ParseError as e:
        # The original exception gives no indicator that the error is in the
        # .hglfs file, so add that.

        # TODO: See if the line number of the file can be made available.
        raise error.Abort(_('parse error in .hglfs: %s') % e)

    def _match(path, size):
        for pat, rule in rules:
            if pat(path, size):
                return rule(path, size)

        return False

    return _match

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

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

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

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

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

    wrapfunction(exchange, 'push', wrapper.push)
    wrapfunction(wireproto, '_capabilities', wrapper._capabilities)
    wrapfunction(wireprotoserver, 'handlewsgirequest',
                 wireprotolfsserver.handlewsgirequest)

    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)

    scmutil.fileprefetchhooks.add('lfs', wrapper._prefetchfiles)

    # 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.
    exchange._bundlespeccontentopts["v2"]["cg.version"] = "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)

@filesetpredicate('lfs()', callstatus=True)
def lfsfileset(mctx, x):
    """File that uses LFS storage."""
    # i18n: "lfs" is a keyword
    fileset.getargs(x, 0, 0, _("lfs takes no arguments"))
    return [f for f in mctx.subset
            if wrapper.pointerfromctx(mctx.ctx, f, removed=True) is not None]

@templatekeyword('lfs_files', requires={'ctx'})
def lfsfiles(context, mapping):
    """List of strings. All files modified, added, or removed by this
    changeset."""
    ctx = context.resource(mapping, 'ctx')

    pointers = wrapper.pointersfromctx(ctx, removed=True) # {path: pointer}
    files = sorted(pointers.keys())

    def pointer(v):
        # In the file spec, version is first and the other keys are sorted.
        sortkeyfunc = lambda x: (x[0] != 'version', x)
        items = sorted(pointers[v].iteritems(), key=sortkeyfunc)
        return util.sortdict(items)

    makemap = lambda v: {
        'file': v,
        'lfsoid': pointers[v].oid() if pointers[v] else None,
        'lfspointer': templateutil.hybriddict(pointer(v)),
    }

    # TODO: make the separator ', '?
    f = templateutil._showcompatlist(context, mapping, 'lfs_file', files)
    return templateutil.hybrid(f, files, makemap, pycompat.identity)

@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(r'rev', [])
    pointers = wrapper.extractpointers(repo, scmutil.revrange(repo, revs))
    wrapper.uploadblobs(repo, pointers)