"""
homer pypy $ /tmp/download/pypy2-v5.7.1-linux64/bin/pypy benchstruct.py 
          unpack str: 0.05 secs
    unpack bytearray: 0.24 secs
        unpack array: 0.34 secs
     unpack np.array: 2.52 secs
           plan pack: 2.56 secs
 pack_into bytearray: 0.36 secs
homer pypy $ pypy benchstruct.py 
          unpack str: 0.05 secs
    unpack bytearray: 0.16 secs
        unpack array: 0.18 secs
     unpack np.array: 0.23 secs
           plan pack: 2.12 secs
 pack_into bytearray: 0.06 secs
"""

import struct
import array
import _numpypy.multiarray as np
import time

N = 10000000
BUF_STR = [struct.pack('qq', 1, 2), struct.pack('qq', 3, 4)]
BUF_BA = map(bytearray, BUF_STR)
BUF_ARRAY = [array.array('b', buf) for buf in BUF_STR]
BUF_NP = [np.array([1, 2]), np.array([3, 4])]


def bench_unpack(title, LST):
    res = 0
    a = time.time()
    for i in range(N):
        buf = LST[i%2]
        val = struct.unpack('qq', buf)[0]
        res += val
    b = time.time()
    print '%20s: %.2f secs' % (title, b-a)
    return res

def bench_pack():
    lst = [None]*N
    buf = struct.pack('q', 4)
    a = time.time()
    for i in range(N):
        buf = struct.pack('q', i)
        lst[i] = buf
    b = time.time()
    print '%20s: %.2f secs' % ('plan pack', b-a)


def bench_pack_into():
    lst = [bytearray(8)]*N
    a = time.time()
    for i, buf in enumerate(lst):
        struct.pack_into('q', buf, 0, i)
    b = time.time()
    print '%20s: %.2f secs' % ('pack_into bytearray', b-a)    

def main():
    bench_unpack('unpack str', BUF_STR)
    bench_unpack('unpack bytearray', BUF_BA)
    bench_unpack('unpack array', BUF_ARRAY)
    bench_unpack('unpack np.array', BUF_NP)
    bench_pack()
    bench_pack_into()

main()