import json
import hashlib


def hexdigest(jsonable):
    """
    Calculate hex digest of a `jsonable` object.

    >>> hexdigest({'a': 1, 'b': 2, 'c': 3})
    'e20096b15530bd66a35a7332619f6666e2322070'

    """
    string = json.dumps(jsonable, sort_keys=True).encode()
    return hashlib.sha1(string).hexdigest()