comparison mercurial/wireprotov1peer.py @ 37633:33a6eee08db2

wireproto: remove iterbatch() from peer interface (API)

Good riddance.

Some tests have been ported to the new API. This probably should
have been done in earlier commits. But duplicating the test coverage
would have been difficult. It was easier this way.

.. api::

   The wire protocol peer's ``iterbatch()`` for bulk executing commands
   has been remove.d Use ``peer.commandexecutor()`` instead.

Differential Revision: https://phab.mercurial-scm.org/D3271

37632:6c55ce51d6c3

    def set(self, value):
        if util.safehasattr(self, 'value'):
            raise error.RepoError("future is already set")
        self.value = value

class batcher(object):
    '''base class for batches of commands submittable in a single request

    All methods invoked on instances of this class are simply queued and
    return a a future for the result. Once you call submit(), all the queued
    calls are performed and the results set in their respective futures.
    '''
    def __init__(self):
        self.calls = []
    def __getattr__(self, name):
        def call(*args, **opts):
            resref = future()
            # Please don't invent non-ascii method names, or you will
            # give core hg a very sad time.
            self.calls.append((name.encode('ascii'), args, opts, resref,))
            return resref
        return call
    def submit(self):
        raise NotImplementedError()

class iterbatcher(batcher):

    def submit(self):
        raise NotImplementedError()

    def results(self):
        raise NotImplementedError()

class remoteiterbatcher(iterbatcher):
    def __init__(self, remote):
        super(remoteiterbatcher, self).__init__()
        self._remote = remote

    def __getattr__(self, name):
        # Validate this method is batchable, since submit() only supports
        # batchable methods.
        fn = getattr(self._remote, name)
        if not getattr(fn, 'batchable', None):
            raise error.ProgrammingError('Attempted to batch a non-batchable '
                                         'call to %r' % name)

        return super(remoteiterbatcher, self).__getattr__(name)

    def submit(self):
        """Break the batch request into many patch calls and pipeline them.

        This is mostly valuable over http where request sizes can be
        limited, but can be used in other places as well.
        """
        # 2-tuple of (command, arguments) that represents what will be
        # sent over the wire.
        requests = []

        # 4-tuple of (command, final future, @batchable generator, remote
        # future).
        results = []

        for command, args, opts, finalfuture in self.calls:
            mtd = getattr(self._remote, command)
            batchable = mtd.batchable(mtd.__self__, *args, **opts)

            commandargs, fremote = next(batchable)
            assert fremote
            requests.append((command, commandargs))
            results.append((command, finalfuture, batchable, fremote))

        if requests:
            self._resultiter = self._remote._submitbatch(requests)

        self._results = results

    def results(self):
        for command, finalfuture, batchable, remotefuture in self._results:
            # Get the raw result, set it in the remote future, feed it
            # back into the @batchable generator so it can be decoded, and
            # set the result on the final future to this value.
            remoteresult = next(self._resultiter)
            remotefuture.set(remoteresult)
            finalfuture.set(next(batchable))

            # Verify our @batchable generators only emit 2 values.
            try:
                next(batchable)
            except StopIteration:
                pass
            else:
                raise error.ProgrammingError('%s @batchable generator emitted '
                                             'unexpected value count' % command)

            yield finalfuture.value

def encodebatchcmds(req):
    """Return a ``cmds`` argument value for the ``batch`` command."""
    escapearg = wireprototypes.escapebatcharg

    cmds = []

    """
    def commandexecutor(self):
        return peerexecutor(self)

    # Begin of ipeercommands interface.

    def iterbatch(self):
        return remoteiterbatcher(self)

    @batchable
    def lookup(self, key):
        self.requirecap('lookup', _('look up remote revision'))
        f = future()

37633:33a6eee08db2

    def set(self, value):
        if util.safehasattr(self, 'value'):
            raise error.RepoError("future is already set")
        self.value = value

def encodebatchcmds(req):
    """Return a ``cmds`` argument value for the ``batch`` command."""
    escapearg = wireprototypes.escapebatcharg

    cmds = []

    """
    def commandexecutor(self):
        return peerexecutor(self)

    # Begin of ipeercommands interface.

    @batchable
    def lookup(self, key):
        self.requirecap('lookup', _('look up remote revision'))
        f = future()