view tests/flagprocessorext.py @ 30829:08b34c3a6f74

revlog: give EXTSTORED flag value to narrowhg

Narrowhg has been using "1 << 14" as its revlog flag value for a long
time. We (Google) have many repos with that value in production
already. When the same value was reserved for EXTSTORED, it made those
repos invalid. Upgrading them will be a little painful. We should
clearly have reserved the value for narrowhg a long time ago. Since
the EXTSTORED flag is not yet in any release and Facebook also says
they have not started using it in production, so it should be okay to
change it. This patch gives the current value (1 << 14) back to
narrowhg and gives a new value (1 << 13) to EXTSTORED.

# 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
        )
    )