benchmark.py 文件源码

def gen_file(fname, nbytes):

    nelems = int(nbytes / 4)

    data = np.random.randint(0, 2 ** 32, nelems, dtype=np.uint32)

    # zero out 10% so there is something to compress
    zeros = np.random.randint(0, nelems, int(nelems / 10.0))
    data[zeros] = 0
    data = data.tostring()

    # write 1GB max at a time - the gzip
    # module doesn't like writing >= 4GB
    # in one go.
    chunksize = 1073741824

    while len(data) > 0:
        chunk = data[:chunksize]
        data  = data[chunksize:]
        with gzip.open(fname, 'ab') as outf:
            outf.write(chunk)