Source code for allensdk.brain_observatory.data_release_utils.metadata_utils.id_generator

import pathlib


class FileIDGenerator(object):
    """
    A class to generate a unique integer ID for each file in the
    data release
    """

    def __init__(self):
        self._id_lookup = dict()
        self._next_id = 0
        self._dummy_value = -999

    @property
    def dummy_value(self) -> int:
        """
        Value reserved for files that are missing from the
        release
        """
        return self._dummy_value

    def id_from_path(self,
                     file_path: pathlib.Path) -> int:
        """
        Get the unique ID for a file path. If the file has already
        been assigned a unique ID, return that. Otherwise, assign
        a unique ID to the file path and return it
        """
        if not isinstance(file_path, pathlib.Path):
            msg = ("file_path must be a pathlib.Path (this is so "
                   "we can resolve it into an absolute path). You passed "
                   f"in a {type(file_path)}")
            raise ValueError(msg)

        if not file_path.is_file():
            msg = f"{file_path} is not a file"
            raise ValueError(msg)

        if file_path.is_symlink():
            msg = f"{file_path} is a symlink; must be an actual path"
            raise ValueError(msg)

        str_path = str(file_path.resolve().absolute())
        if str_path not in self._id_lookup:
            self._id_lookup[str_path] = self._next_id
            self._next_id += 1
            while self._next_id == self.dummy_value:
                self._next_id += 1

        return self._id_lookup[str_path]