view tests/flagprocessorext.py @ 31792:55c0c91f55e6

util: document bundle compression

An upcoming patch will add support for documenting bundle
specifications in more detail. As part of this, we'd like to
enumerate available bundle compression formats. In order to do
this, we need to provide the help mechanism a dict of names
and objects with docstrings.

This patch adds docstrings to compengine.bundletype and adds
a function for retrieving a dict of them. The code is not yet
used.

# coding=UTF-8

from __future__ import absolute_import

import base64
import zlib

from mercurial import (
    changegroup,
    extensions,
    filelog,
    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('01')
    versions.discard('02')
    versions.add('03')
    return versions

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

def noopaddrevision(orig, self, text, transaction, link, p1, p2,
                    cachedelta=None, node=None,
                    flags=revlog.REVIDX_DEFAULT_FLAGS):
    if '[NOOP]' in text:
        flags |= REVIDX_NOOP
    return orig(self, text, transaction, link, p1, p2, cachedelta=cachedelta,
                node=node, flags=flags)

def b64addrevision(orig, self, text, transaction, link, p1, p2,
                   cachedelta=None, node=None,
                   flags=revlog.REVIDX_DEFAULT_FLAGS):
    if '[BASE64]' in text:
        flags |= REVIDX_BASE64
    return orig(self, text, transaction, link, p1, p2, cachedelta=cachedelta,
                node=node, flags=flags)

def gzipaddrevision(orig, self, text, transaction, link, p1, p2,
                    cachedelta=None, node=None,
                    flags=revlog.REVIDX_DEFAULT_FLAGS):
    if '[GZIP]' in text:
        flags |= REVIDX_GZIP
    return orig(self, text, transaction, link, p1, p2, cachedelta=cachedelta,
                node=node, flags=flags)

def failaddrevision(orig, self, text, transaction, link, p1, p2,
                    cachedelta=None, node=None,
                    flags=revlog.REVIDX_DEFAULT_FLAGS):
    # This addrevision wrapper is meant to add a flag we will not have
    # transforms registered for, ensuring we handle this error case.
    if '[FAIL]' in text:
        flags |= REVIDX_FAIL
    return orig(self, text, transaction, link, p1, p2, cachedelta=cachedelta,
                node=node, flags=flags)

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)

    # Add wrappers for addrevision, responsible to set flags depending on the
    # revision data contents.
    wrapfunction(filelog.filelog, 'addrevision', noopaddrevision)
    wrapfunction(filelog.filelog, 'addrevision', b64addrevision)
    wrapfunction(filelog.filelog, 'addrevision', gzipaddrevision)
    wrapfunction(filelog.filelog, 'addrevision', failaddrevision)

    # 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
        )
    )