gzip.py

ofrak.core.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/core/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/core/gzip.py

async def unpack(self, resource: Resource, config=None):
    # Create temporary file with .gz extension
    with tempfile.NamedTemporaryFile(suffix=".gz") as temp_file:
        temp_file.write(await resource.get_data())
        temp_file.flush()
        cmd = [
            "pigz",
            "-d",
            "-c",
            temp_file.name,
        ]
        proc = await asyncio.create_subprocess_exec(
            *cmd,
            stdout=asyncio.subprocess.PIPE,
            stderr=asyncio.subprocess.PIPE,
        )
        stdout, stderr = await proc.communicate()
        data = stdout
        if proc.returncode:
            # Forward any gzip warning message and continue
            if proc.returncode == -2 or proc.returncode == 2:
                LOGGER.warning(stderr)
                data = stdout
            else:
                raise CalledProcessError(returncode=proc.returncode, cmd=cmd)

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