view tests/flagprocessorext.py @ 37766:925707ac2855

lfs: add the 'Authorization' property to the Batch API response, if present

The client copies all of these properties under 'header' to the HTTP Headers of
the subsequent GET or PUT request that it performs.  That allows the Basic HTTP
authentication used to authorize the Batch API request to also authorize the
upload/download action.

There's likely further work to do here.  There's an 'authenticated' boolean key
in the Batch API response that can be set, and there is an 'LFS-Authenticate'
header that is used instead of 'WWW-Authenticate'[1].  (We likely need to
support both, since some hosting solutions are likely to only respond with the
latter.)  In any event, this works with SCM Manager, so there is real world
benefit.

I'm limiting the headers returned to 'Basic', because that's all the lfs spec
calls out.  In practice, I've seen gitbucket emit custom header content[2].

[1] https://github.com/git-lfs/git-lfs/blob/master/docs/api/batch.md#response-errors
[2] https://github.com/gitbucket/gitbucket/blob/35655f33c7713f08515ed640ece0948acd6d6168/src/main/scala/gitbucket/core/servlet/GitRepositoryServlet.scala#L119

# coding=UTF-8

from __future__ import absolute_import

import base64
import zlib

from mercurial import (
    changegroup,
    exchange,
    extensions,
    revlog,
    util,
)

# Test only: These flags are defined here only in the context of testing the
# behavior of the flag processor. The canonical way to add flags is to get in
# touch with the community and make them known in revlog.
REVIDX_NOOP = (1 << 3)
REVIDX_BASE64 = (1 << 2)
REVIDX_GZIP = (1 << 1)
REVIDX_FAIL = 1

def validatehash(self, text):
    return True

def bypass(self, text):
    return False

def noopdonothing(self, text):
    return (text, True)

def b64encode(self, text):
    return (base64.b64encode(text), False)

def b64decode(self, text):
    return (base64.b64decode(text), True)

def gzipcompress(self, text):
    return (zlib.compress(text), False)

def gzipdecompress(self, text):
    return (zlib.decompress(text), True)

def supportedoutgoingversions(orig, repo):
    versions = orig(repo)
    versions.discard(b'01')
    versions.discard(b'02')
    versions.add(b'03')
    return versions

def allsupportedversions(orig, ui):
    versions = orig(ui)
    versions.add(b'03')
    return versions

def makewrappedfile(obj):
    class wrappedfile(obj.__class__):
        def addrevision(self, text, transaction, link, p1, p2,
                        cachedelta=None, node=None,
                        flags=revlog.REVIDX_DEFAULT_FLAGS):
            if b'[NOOP]' in text:
                flags |= REVIDX_NOOP

            if b'[BASE64]' in text:
                flags |= REVIDX_BASE64

            if b'[GZIP]' in text:
                flags |= REVIDX_GZIP

            # This addrevision wrapper is meant to add a flag we will not have
            # transforms registered for, ensuring we handle this error case.
            if b'[FAIL]' in text:
                flags |= REVIDX_FAIL

            return super(wrappedfile, self).addrevision(text, transaction, link,
                                                        p1, p2,
                                                        cachedelta=cachedelta,
                                                        node=node,
                                                        flags=flags)

    obj.__class__ = wrappedfile

def reposetup(ui, repo):
    class wrappingflagprocessorrepo(repo.__class__):
        def file(self, f):
            orig = super(wrappingflagprocessorrepo, self).file(f)
            makewrappedfile(orig)
            return orig

    repo.__class__ = wrappingflagprocessorrepo

def extsetup(ui):
    # Enable changegroup3 for flags to be sent over the wire
    wrapfunction = extensions.wrapfunction
    wrapfunction(changegroup,
                 'supportedoutgoingversions',
                 supportedoutgoingversions)
    wrapfunction(changegroup,
                 'allsupportedversions',
                 allsupportedversions)

    # Teach revlog about our test flags
    flags = [REVIDX_NOOP, REVIDX_BASE64, REVIDX_GZIP, REVIDX_FAIL]
    revlog.REVIDX_KNOWN_FLAGS |= util.bitsfrom(flags)
    revlog.REVIDX_FLAGS_ORDER.extend(flags)

    # Teach exchange to use changegroup 3
    for k in exchange._bundlespeccontentopts.keys():
        exchange._bundlespeccontentopts[k]["cg.version"] = "03"

    # Register flag processors for each extension
    revlog.addflagprocessor(
        REVIDX_NOOP,
        (
            noopdonothing,
            noopdonothing,
            validatehash,
        )
    )
    revlog.addflagprocessor(
        REVIDX_BASE64,
        (
            b64decode,
            b64encode,
            bypass,
        ),
    )
    revlog.addflagprocessor(
        REVIDX_GZIP,
        (
            gzipdecompress,
            gzipcompress,
            bypass
        )
    )