magic.py

ofrak.core.magic

Magic (ResourceAttributes) dataclass

Magic(mime: str, descriptor: str)

MagicAnalyzer (Analyzer)

Analyze a binary blob to extract its mimetype and magic description.

analyze(self, resource, config=None) async

Analyze a resource for to extract specific ResourceAttributes.

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

Parameters:

Name	Type	Description	Default
resource	Resource	The resource that is being analyzed	required
config		Optional config for analyzing. 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

Returns:

Type	Description
Magic	The analysis results

Source code in ofrak/core/magic.py

async def analyze(self, resource: Resource, config=None) -> Magic:
    data = await resource.get_data()
    if not MAGIC_INSTALLED:
        raise ComponentMissingDependencyError(self, LIBMAGIC_DEP)
    else:
        magic_mime = magic.from_buffer(data, mime=True)
        magic_description = magic.from_buffer(data)
        return Magic(magic_mime, magic_description)

MagicDescriptionIdentifier (Identifier)

Identify and add the appropriate tag for a given resource based on its mime description.

identify(self, resource, config) async

Perform identification on the given resource.

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

Parameters:

Name	Type	Description	Default
resource	Resource		required
config		Optional config for identifying. 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.	required

Source code in ofrak/core/magic.py

async def identify(self, resource: Resource, config):
    _magic = await resource.analyze(Magic)
    magic_description = _magic.descriptor
    for matcher, resource_type in self._matchers.items():
        if matcher(magic_description):
            resource.add_tag(resource_type)

register(resource, matcher) classmethod

Register a virtual subclass of an ABC.

Returns the subclass, to allow usage as a class decorator.

Source code in ofrak/core/magic.py

@classmethod
def register(cls, resource: ResourceTag, matcher: Callable):
    if matcher in cls._matchers:
        raise AlreadyExistError("Registering already-registered matcher")
    cls._matchers[matcher] = resource

MagicMimeIdentifier (Identifier)

Identify and add the appropriate tag for a given resource based on its mimetype.

identify(self, resource, config=None) async

Perform identification on the given resource.

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

Parameters:

Name	Type	Description	Default
resource	Resource		required
config		Optional config for identifying. 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/magic.py

async def identify(self, resource: Resource, config=None):
    _magic = await resource.analyze(Magic)
    magic_mime = _magic.mime
    tag = MagicMimeIdentifier._tags_by_mime.get(magic_mime)
    if tag is not None:
        resource.add_tag(tag)

register(resource, mime_types) classmethod

Register a virtual subclass of an ABC.

Returns the subclass, to allow usage as a class decorator.

Source code in ofrak/core/magic.py

@classmethod
def register(cls, resource: ResourceTag, mime_types: Union[Iterable[str], str]):
    if isinstance(mime_types, str):
        mime_types = [mime_types]
    for mime_type in mime_types:
        if mime_type in cls._tags_by_mime:
            raise AlreadyExistError(f"Registering already-registered mime type: {mime_type}")
        cls._tags_by_mime[mime_type] = resource

_LibmagicDependency (ComponentExternalTool) private

__init__(self) special

Initialize self. See help(type(self)) for accurate signature.

Source code in ofrak/core/magic.py

def __init__(self):
    super().__init__(
        "libmagic",
        "https://www.darwinsys.com/file/",
        install_check_arg="",
        apt_package="libmagic1",
        brew_package="libmagic",
    )

    try:
        import magic as _magic

        _LibmagicDependency._magic = _magic
    except ImportError:
        _LibmagicDependency._magic = None

is_tool_installed(self) async

Check if a tool is installed by running it with the install_check_arg. This method runs <tool> <install_check_arg>.

Returns:

Type	Description
bool	True if the tool command returned zero, False if tool could not be found or returned non-zero exit code.

Source code in ofrak/core/magic.py

async def is_tool_installed(self) -> bool:
    return MAGIC_INSTALLED