Module refinery.units.meta.cm

Classes

class cm (invert=False, all=False, reset=False, size=False, ext=False, entropy=False, ic=False, magic=False, sha1=False, sha256=False, crc32=False, md5=False, hashes=False, *names)

Populate the set of meta variables of the current chunk with commonly used metadata.

The Common Meta variables unit populates the set of meta variables of the current chunk with commonly used metadata. The unit has no effect outside a frame.

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class cm(Unit):
    """
    Populate the set of meta variables of the current chunk with commonly used metadata.

    The Common Meta variables unit populates the set of meta variables of the current chunk
    with commonly used metadata. The unit has no effect outside a frame.
    """
    def __init__(
        self,
        invert: Param[bool, Arg.Switch('-x', group='ALL', help='populate only options that have not been specified')] = False,
        all: Param[bool, Arg.Switch('-a', group='ALL', help='populate all options')] = False,
        reset: Param[bool, Arg.Switch('-r', help='discard all meta variables that were not explicitly specified')] = False,
        size: Param[bool, Arg.Switch('-S', help='size of the chunk')] = False,
        ext: Param[bool, Arg.Switch('-X', help='guess file extension')] = False,
        entropy: Param[bool, Arg.Switch('-E', help='compute data entropy')] = False,
        ic: Param[bool, Arg.Switch('-C', help='compute the index of coincidence')] = False,
        magic: Param[bool, Arg.Switch('-M', help='compute file magic')] = False,
        sha1: Param[bool, Arg.Switch('-1', help='compute hash: SHA-1')] = False,
        sha256: Param[bool, Arg.Switch('-2', help='compute hash: SHA-256')] = False,
        crc32: Param[bool, Arg.Switch('-3', help='compute hash: CRC32')] = False,
        md5: Param[bool, Arg.Switch('-5', help='compute hash: MD5')] = False,
        hashes: Param[bool, Arg.Switch('-H', help='compute all common hashes')] = False,
        *names: Param[str, Arg.String(metavar='name', help=(
            F'A variable name that can include the common properties: {_COMMON_PROPERTIES_LIST}.'
            R' If none is given, the size variable is populated. For most of these, an optional '
            R'argument is available that can be used as a shorthand:'))]
    ):
        def stringify(name):
            if isinstance(name, (bytes, bytearray)):
                return name.decode(self.codec)
            if isinstance(name, str):
                return name
            raise TypeError(F'Invalid type for name: {name!r}')

        _names = {
            stringify(name) for name in names}
        if hashes:
            md5 = sha256 = sha1 = crc32 = True
        if size:
            _names.add('size')
        if ext:
            _names.add('ext')
        if entropy:
            _names.add('entropy')
        if ic:
            _names.add('ic')
        if magic:
            _names.add('magic')
        if sha1:
            _names.add('sha1')
        if sha256:
            _names.add('sha256')
        if crc32:
            _names.add('crc32')
        if md5:
            _names.add('md5')
        if not _names and not reset:
            _names.add('size')
        if all:
            if invert:
                raise ValueError('invert and all are both enabled, resulting in empty configuration.')
            _names = set(LazyMetaOracle.derivations)
        elif invert:
            _names = set(LazyMetaOracle.derivations) - _names
        super().__init__(names=list(_names), reset=reset)

    def process(self, data):
        return data

    def filter(self, chunks):
        names = self.args.names
        reset = self.args.reset
        for chunk in chunks:
            if not chunk.visible:
                yield chunk
                continue
            meta = metavars(chunk)
            if reset:
                chunk.meta.clear()
            for name in names:
                chunk[name] = meta[name]
            yield chunk

Ancestors

• Unit
• UnitBase
• Entry

Subclasses

• cm

Class variables

var reverse

The type of the None singleton.

Inherited members

• Unit:
  • console
  • optional_dependencies
  • required_dependencies
• Unit:
  • FilterEverything
  • Requires
  • act
  • assemble
  • codec
  • finish
  • handles
  • is_quiet
  • is_reversible
  • isatty
  • labelled
  • leniency
  • log_always
  • log_debug
  • log_detach
  • log_fail
  • log_info
  • log_level
  • log_warn
  • logger
  • name
  • nozzle
  • read
  • read1
  • reset
  • run
  • source
  • superinit
• UnitBase:
  • filter
  • process