comparison mercurial/bundle2.py @ 20802:520df53ad26a

bundle2: a very first version of bundle2 unbundler

This changeset introduce an unbundler class to match the bundle2 bundler. It is
currently able to unbundle an empty bundle2 only and will gain more feature at
the same pace than the bundler.

It also comes with its special extension command in test.

20801:9c5183cb9bca

  (size = 0) this is interpreted as the end of stream marker.

  Currently forced to 0 in the current state of the implementation
"""

_magicstring = 'HG20'

class bundle20(object):
    """represent an outgoing bundle2 container

        yield '\0\0'
        # no support for parts
        # to be obviously fixed soon.
        assert not self._parts
        yield '\0\0'

20802:520df53ad26a

  (size = 0) this is interpreted as the end of stream marker.

  Currently forced to 0 in the current state of the implementation
"""

import util
import changegroup


_magicstring = 'HG20'

class bundle20(object):
    """represent an outgoing bundle2 container

        yield '\0\0'
        # no support for parts
        # to be obviously fixed soon.
        assert not self._parts
        yield '\0\0'

class unbundle20(object):
    """interpret a bundle2 stream

    (this will eventually yield parts)"""

    def __init__(self, fp):
        # assume the magic string is ok and drop it
        # to be obviously fixed soon.
        self._fp = fp
        self._readexact(4)

    def _unpack(self, format):
        """unpack this struct format from the stream"""
        data = self._readexact(struct.calcsize(format))
        return _unpack(format, data)

    def _readexact(self, size):
        """read exactly <size> bytes from the stream"""
        return changegroup.readexactly(self._fp, size)

    @util.propertycache
    def params(self):
        """dictionnary of stream level parameters"""
        paramsize = self._readexact(2)
        assert paramsize == '\0\0'
        return {}

    def __iter__(self):
        """yield all parts contained in the stream"""
        # make sure param have been loaded
        self.params
        part = self._readpart()
        while part is not None:
            yield part
            part = self._readpart()

    def _readpart(self):
        """return None when an end of stream markers is reach"""
        headersize = self._readexact(2)
        assert headersize == '\0\0'
        return None