Synnefo » Pithos

0.5 (July 11, 2011)        Object update from another object's data.

X-Source-Object       Update with data from the object at path ``/<container>/<object>`` (optional, to update)

X-Source-Version      The source version to update from (optional, to update)

* Either set ``Content-Type`` to ``application/octet-stream``, or provide an object with ``X-Source-Object``. If ``Content-Type`` has some other value, it will be ignored and only the metadata will be updated.

* If the data is supplied in the request (using ``Content-Type`` instead of ``X-Source-Object``), a valid ``Content-Length`` header is required - except if using chunked transfers (set ``Transfer-Encoding`` to ``chunked``).

* If ``Content-Range`` used has a ``byte-range-resp-spec = *``, data will be appended to the object.

* Partial object updates through POST, using the ``Content-Length``, ``Content-Type``, ``Content-Range`` and ``Transfer-Encoding`` headers. Use another object's data to update with ``X-Source-Object`` and ``X-Source-Version``.

At the object level, tags are implemented by managing metadata keys. The client software should allow the user to use any string as a tag and then set the corresponding ``X-Object-Meta-<tag>`` key at the server. The API extensions provided, allow for listing all tags in a container and filtering object listings based on one or more tags. The tag list is sufficient for implementing the ``tags`` element, either as a special, virtual folder (as done in the first version of Pithos), or as an application menu.

         https://pithos.dev.grnet.gr/v1/user/pithos?meta=favorites

        content_length = get_content_length(request) # Required by the API.

    # A Content-Type or X-Source-Object header indicates data updates.

    src_object = request.META.get('HTTP_X_SOURCE_OBJECT')

    if (not content_type or content_type != 'application/octet-stream') and not src_object:

    if src_object:

        src_container, src_name = split_container_object_string(src_object)

        src_version = request.META.get('HTTP_X_SOURCE_VERSION')

        try:

            src_size, src_hashmap = backend.get_object_hashmap(request.user, v_account, src_container, src_name, src_version)

        except NotAllowedError:

            raise Unauthorized('Access denied')

        except NameError:

            raise ItemNotFound('Source object does not exist')

        if length is None:

            length = src_size

        elif length > src_size:

            raise BadRequest('Object length is smaller than range length')

    else:

        # Require either a Content-Length, or 'chunked' Transfer-Encoding.

        content_length = -1

        if request.META.get('HTTP_TRANSFER_ENCODING') != 'chunked':

            content_length = get_content_length(request)

        if length is None:

            length = content_length

        else:

            if content_length == -1:

                # TODO: Get up to length bytes in chunks.

                length = content_length

            elif length != content_length:

                raise BadRequest('Content length does not match range length')

    if src_object:

        if offset % backend.block_size == 0:

            # Update the hashes only.

            sbi = 0

            while length > 0:

                bi = int(offset / backend.block_size)

                bl = min(length, backend.block_size)

                if bi < len(hashmap):

                    if bl == backend.block_size:

                        hashmap[bi] = src_hashmap[sbi]

                    else:

                        data = backend.get_block(src_hashmap[sbi])

                        hashmap[bi] = backend.update_block(hashmap[bi], data[:bl], 0)

                else:

                    hashmap.append(src_hashmap[sbi])

                offset += bl

                length -= bl

                sbi += 1

        else:

            data = ''

            sbi = 0

            while length > 0:

                data += backend.get_block(src_hashmap[sbi])

                if length < backend.block_size:

                    data = data[:length]

                bytes = put_object_block(hashmap, data, offset)

                offset += bytes

                data = data[bytes:]

                length -= bytes

                sbi += 1

    else:

        sock = raw_input_socket(request)

        data = ''

        for d in socket_read_iterator(sock, length, backend.block_size):

            # TODO: Raise 408 (Request Timeout) if this takes too long.

            # TODO: Raise 499 (Client Disconnect) if a length is defined and we stop before getting this much data.

            data += d

            bytes = put_object_block(hashmap, data, offset)

            offset += bytes

            data = data[bytes:]

        if len(data) > 0:

            put_object_block(hashmap, data, offset)

            backend.update_object_public(request.user, v_account, dest_container, dest_name, public)