Exemplo n.º 1
0
    def resolve_object(self, offset, type, obj, get_ref, get_offset=None):
        """Resolve an object, possibly resolving deltas when necessary.
        
        :return: Tuple with object type and contents.
        """
        if type not in (6, 7): # Not a delta
            return type, obj

        if get_offset is None:
            get_offset = self.get_object_at
      
        if type == 6: # offset delta
            (delta_offset, delta) = obj
            assert isinstance(delta_offset, int)
            assert isinstance(delta, str)
            base_offset = offset-delta_offset
            type, base_obj = get_offset(base_offset)
            assert isinstance(type, int)
        elif type == 7: # ref delta
            (basename, delta) = obj
            assert isinstance(basename, str) and len(basename) == 20
            assert isinstance(delta, str)
            type, base_obj = get_ref(basename)
            assert isinstance(type, int)
            # Can't be a ofs delta, as we wouldn't know the base offset
            assert type != 6
            base_offset = None
        type, base_text = self.resolve_object(base_offset, type, base_obj, get_ref)
        if base_offset is not None:
            self._offset_cache[base_offset] = type, base_text
        ret = (type, apply_delta(base_text, delta))
        return ret
Exemplo n.º 2
0
    def resolve_object(self, offset, type, obj, get_ref=None):
        """Resolve an object, possibly resolving deltas when necessary.

        :return: Tuple with object type and contents.
        """
        if type not in DELTA_TYPES:
            return type, obj

        if get_ref is None:
            get_ref = self.get_ref
        if type == OFS_DELTA:
            (delta_offset, delta) = obj
            # TODO: clean up asserts and replace with nicer error messages
            assert isinstance(offset, int)
            assert isinstance(delta_offset, int)
            base_offset = offset-delta_offset
            type, base_obj = self.get_object_at(base_offset)
            assert isinstance(type, int)
        elif type == REF_DELTA:
            (basename, delta) = obj
            assert isinstance(basename, str) and len(basename) == 20
            base_offset, type, base_obj = get_ref(basename)
            assert isinstance(type, int)
        type, base_chunks = self.resolve_object(base_offset, type, base_obj)
        chunks = apply_delta(base_chunks, delta)
        # TODO(dborowitz): This can result in poor performance if large base
        # objects are separated from deltas in the pack. We should reorganize
        # so that we apply deltas to all objects in a chain one after the other
        # to optimize cache performance.
        if offset is not None:
            self._offset_cache[offset] = type, chunks
        return type, chunks
Exemplo n.º 3
0
    def resolve_object(self, offset, type, obj, get_ref=None):
        """Resolve an object, possibly resolving deltas when necessary.

        :return: Tuple with object type and contents.
        """
        if type not in DELTA_TYPES:
            return type, obj

        if get_ref is None:
            get_ref = self.get_ref
        if type == OFS_DELTA:
            (delta_offset, delta) = obj
            # TODO: clean up asserts and replace with nicer error messages
            assert isinstance(offset, int)
            assert isinstance(delta_offset, int)
            base_offset = offset-delta_offset
            type, base_obj = self.get_object_at(base_offset)
            assert isinstance(type, int)
        elif type == REF_DELTA:
            (basename, delta) = obj
            assert isinstance(basename, str) and len(basename) == 20
            base_offset, type, base_obj = get_ref(basename)
            assert isinstance(type, int)
        type, base_chunks = self.resolve_object(base_offset, type, base_obj)
        chunks = apply_delta(base_chunks, delta)
        # TODO(dborowitz): This can result in poor performance if large base
        # objects are separated from deltas in the pack. We should reorganize
        # so that we apply deltas to all objects in a chain one after the other
        # to optimize cache performance.
        if offset is not None:
            self._offset_cache[offset] = type, chunks
        return type, chunks
Exemplo n.º 4
0
    def resolve_object(self, offset, type, obj, get_ref, get_offset=None):
        """Resolve an object, possibly resolving deltas when necessary.

        :return: Tuple with object type and contents.
        """
        if type not in (6, 7):  # Not a delta
            return type, obj

        if get_offset is None:
            get_offset = self.get_object_at

        if type == 6:  # offset delta
            (delta_offset, delta) = obj
            assert isinstance(delta_offset, int)
            assert isinstance(delta, str)
            base_offset = offset - delta_offset
            type, base_obj = get_offset(base_offset)
            assert isinstance(type, int)
        elif type == 7:  # ref delta
            (basename, delta) = obj
            assert isinstance(basename, str) and len(basename) == 20
            assert isinstance(delta, str)
            type, base_obj = get_ref(basename)
            assert isinstance(type, int)
            # Can't be a ofs delta, as we wouldn't know the base offset
            assert type != 6
            base_offset = None
        type, base_text = self.resolve_object(base_offset, type, base_obj,
                                              get_ref)
        if base_offset is not None:
            self._offset_cache[base_offset] = type, base_text
        ret = (type, apply_delta(base_text, delta))
        return ret