ALLEN INSTITUTE

# Source code for bmtk.builder.id_generator

    # Copyright 2017. Allen Institute. All rights reserved
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    import threading
    import numpy as np

    class IDGenerator(object):
        """ A simple class for fetching global ids. To get a unqiue global ID class next(), which should be thread-safe. It
        Also has a remove_id(gid) in which case next() will never return the gid. The remove_id function is used for cases
        when using imported networks and we want to eliminate previously created id.

        TODO:
         * Implement a bit array to keep track of already existing gids
         * It might be necessary to implement with MPI support?
        """
        def __init__(self, init_val=0):
            self.__counter = init_val
            self.__taken = set()
            self.__lock = threading.Lock()

        def remove_id(self, gid):
            assert(np.issubdtype(type(gid), np.integer))
            self.__taken.add(gid)

        def next(self):
            self.__lock.acquire()
            while self.__counter in self.__taken:
                self.__counter += 1

            gid = self.__counter
            self.remove_id(gid)
            self.__counter += 1
            self.__lock.release()
            return gid

        def get_ids(self, size):
            return [self.next() for _ in range(size)]

        def __contains__(self, gid):
            return gid in self.__taken

        def __call__(self, *args, **kwargs):
            if len(args) == 0 and len(kwargs) == 0:
                return self.next()

            if len(args) == 1:
                return self.get_ids(size=args[0])

            elif 'N' in kwargs:
                return self.get_ids(size=kwargs['N'])

            else:
                raise ValueError('Uknown input to id_generator(): {}'.format(kwargs))