comparison mercurial/wireprototypes.py @ 37783:9d818539abfa

wireproto: move supportedcompengines out of wireproto

This function is used by both version 1 and version 2. It belongs in
a common module.

"wireprototypes" may not be the best module name. I may rename it...

Differential Revision: https://phab.mercurial-scm.org/D3398

37782:99accae4cc59

    bin,
    hex,
)
from .thirdparty.zope import (
    interface as zi,
)

# Names of the SSH protocol implementations.
SSHV1 = 'ssh-v1'
# These are advertised over the wire. Increment the counters at the end

        if proto.name not in entry.transports:
            return False

        return True

37783:9d818539abfa

    bin,
    hex,
)
from .thirdparty.zope import (
    interface as zi,
)
from .i18n import _
from . import (
    error,
    util,
)

# Names of the SSH protocol implementations.
SSHV1 = 'ssh-v1'
# These are advertised over the wire. Increment the counters at the end

        if proto.name not in entry.transports:
            return False

        return True

def supportedcompengines(ui, role):
    """Obtain the list of supported compression engines for a request."""
    assert role in (util.CLIENTROLE, util.SERVERROLE)

    compengines = util.compengines.supportedwireengines(role)

    # Allow config to override default list and ordering.
    if role == util.SERVERROLE:
        configengines = ui.configlist('server', 'compressionengines')
        config = 'server.compressionengines'
    else:
        # This is currently implemented mainly to facilitate testing. In most
        # cases, the server should be in charge of choosing a compression engine
        # because a server has the most to lose from a sub-optimal choice. (e.g.
        # CPU DoS due to an expensive engine or a network DoS due to poor
        # compression ratio).
        configengines = ui.configlist('experimental',
                                      'clientcompressionengines')
        config = 'experimental.clientcompressionengines'

    # No explicit config. Filter out the ones that aren't supposed to be
    # advertised and return default ordering.
    if not configengines:
        attr = 'serverpriority' if role == util.SERVERROLE else 'clientpriority'
        return [e for e in compengines
                if getattr(e.wireprotosupport(), attr) > 0]

    # If compression engines are listed in the config, assume there is a good
    # reason for it (like server operators wanting to achieve specific
    # performance characteristics). So fail fast if the config references
    # unusable compression engines.
    validnames = set(e.name() for e in compengines)
    invalidnames = set(e for e in configengines if e not in validnames)
    if invalidnames:
        raise error.Abort(_('invalid compression engine defined in %s: %s') %
                          (config, ', '.join(sorted(invalidnames))))

    compengines = [e for e in compengines if e.name() in configengines]
    compengines = sorted(compengines,
                         key=lambda e: configengines.index(e.name()))

    if not compengines:
        raise error.Abort(_('%s config option does not specify any known '
                            'compression engines') % config,
                          hint=_('usable compression engines: %s') %
                          ', '.sorted(validnames))

    return compengines