extract_utility.py 文件源码

def limit_geom_chars(geom, limit=8000000, step=0.0001):
    """Limit chars in geom geojson string by simplification

    Default limit for character count is 8000000
        (8MB - MongoDB max document size is 16MB)
    Default step for simplication is 0.0001
    """
    geom = shape(geom)
    curr_geom = geom
    ix = 0
    while len(str(curr_geom)) > limit:
        ix = ix + 1
        curr_geom = geom.simplify(step * ix)

    simplify_tolerance = step * ix
    return curr_geom.__geo_interface__, simplify_tolerance