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gzip.py

ofrak_components.gzip

GzipData (GenericBinary)

A gzip binary blob.

GzipPacker (Packer)

Pack data into a compressed gzip file.

pack(self, resource, config=None) async

Pack the given resource.

Users should not call this method directly; rather, they should run Resource.run or Resource.pack.

Parameters:

Name Type Description Default
resource Resource required
config

Optional config for packing. If an implementation provides a default, this default will always be used when config would otherwise be None. Note that a copy of the default config will be passed, so the default config values cannot be modified persistently by a component run.

None
Source code in ofrak_components/gzip.py
async def pack(self, resource: Resource, config=None):
    gzip_view = await resource.view_as(GzipData)

    result = BytesIO()
    with GzipFile(fileobj=result, mode="w") as gzip_file:
        gzip_child_r = await gzip_view.get_file()
        gzip_data = await gzip_child_r.get_data()
        gzip_file.write(gzip_data)

    original_gzip_size = await gzip_view.resource.get_data_length()
    resource.queue_patch(Range(0, original_gzip_size), result.getvalue())

GzipUnpacker (Unpacker)

Unpack (decompress) a gzip file.

unpack(self, resource, config=None) async

Unpack the given resource.

Users should not call this method directly; rather, they should run Resource.run or Resource.unpack.

Parameters:

Name Type Description Default
resource Resource

The resource that is being unpacked

required
config

Optional config for unpacking. If an implementation provides a default, this default will always be used when config would otherwise be None. Note that a copy of the default config will be passed, so the default config values cannot be modified persistently by a component run.

None
Source code in ofrak_components/gzip.py
async def unpack(self, resource: Resource, config=None):
    # Create temporary file with .gz xtension
    with tempfile.NamedTemporaryFile(suffix=".gz") as temp_file:
        temp_file.write(await resource.get_data())
        temp_file.flush()
        command = ["gzip", "-d", "-c", temp_file.name]  # Decompress to stdout
        try:
            run_result = subprocess.run(command, check=True, capture_output=True)
            data = run_result.stdout
        except subprocess.CalledProcessError as e:
            # Forward any gzip warning message and continue
            if e.returncode == -2 or e.returncode == 2:
                LOGGER.warning(e.stderr)
                data = e.stdout
            else:
                raise UnpackerError(format_called_process_error(e))

        await resource.create_child(
            tags=(GenericBinary,),
            data=data,
        )