from zfec import easyfec, Encoder, filefec
from pyutil import mathutil

import os, sys

from pyutil import benchutil

FNAME="benchrandom.data"

def _make_new_rand_file(size):
    open(FNAME, "wb").write(os.urandom(size))

def donothing(results, reslenthing):
    pass

K=3
M=10

d = ""
ds = []
easyfecenc = None
fecenc = None
def _make_new_rand_data(size, k, m):
    global d, easyfecenc, fecenc, K, M
    K = k
    M = m
    d = os.urandom(size)
    del ds[:]
    ds.extend([None]*k)
    blocksize = mathutil.div_ceil(size, k)
    for i in range(k):
        ds[i] = d[i*blocksize:(i+1)*blocksize]
    ds[-1] = ds[-1] + "\x00" * (len(ds[-2]) - len(ds[-1]))
    easyfecenc = easyfec.Encoder(k, m)
    fecenc = Encoder(k, m)

import sha
hashers = [ sha.new() for i in range(M) ]
def hashem(results, reslenthing):
    for i, result in enumerate(results):
        hashers[i].update(result)

def _encode_file(N):
    filefec.encode_file(open(FNAME, "rb"), donothing, K, M)

def _encode_file_stringy(N):
    filefec.encode_file_stringy(open(FNAME, "rb"), donothing, K, M)

def _encode_file_stringy_easyfec(N):
    filefec.encode_file_stringy_easyfec(open(FNAME, "rb"), donothing, K, M)

def _encode_file_not_really(N):
    filefec.encode_file_not_really(open(FNAME, "rb"), donothing, K, M)

def _encode_file_not_really_and_hash(N):
    filefec.encode_file_not_really_and_hash(open(FNAME, "rb"), donothing, K, M)

def _encode_file_and_hash(N):
    filefec.encode_file(open(FNAME, "rb"), hashem, K, M)

def _encode_data_not_really(N):
    # This function is to see how long it takes to run the Python code
    # that does this benchmarking and accounting and so on but not
    # actually do any erasure-coding, in order to get an idea of how
    # much overhead there is in using Python.  This exercises the
    # basic behavior of allocating buffers to hold the secondary
    # shares.
    sz = N // K
    for i in range(M-K):
        x = '\x00' * sz

def _encode_data_easyfec(N):
    easyfecenc.encode(d)

def _encode_data_fec(N):
    fecenc.encode(ds)

def bench(k, m):
    SIZE = 10**6
    MAXREPS = 64
    # for f in [_encode_file_stringy_easyfec, _encode_file_stringy, _encode_file, _encode_file_not_really,]:
    # for f in [_encode_file,]:
    # for f in [_encode_file_not_really, _encode_file_not_really_and_hash, _encode_file, _encode_file_and_hash,]:
    # for f in [_encode_data_not_really, _encode_data_easyfec, _encode_data_fec,]:
    print "measuring encoding of data with K=%d, M=%d, reporting results in nanoseconds per byte after encoding %d bytes %d times in a row..." % (k, m, SIZE, MAXREPS)
    # for f in [_encode_data_fec, _encode_data_not_really]:
    for f in [_encode_data_fec]:
        def _init_func(size):
            return _make_new_rand_data(size, k, m)
        for BSIZE in [SIZE]:
            results = benchutil.rep_bench(f, n=BSIZE, initfunc=_init_func, MAXREPS=MAXREPS, MAXTIME=None, UNITS_PER_SECOND=1000000000)
            print "and now represented in MB/s..."
            print
            best = results['best']
            mean = results['mean']
            worst = results['worst']
            print "best:  % 4.3f MB/sec" % (10**3 / best)
            print "mean:  % 4.3f MB/sec" % (10**3 / mean)
            print "worst: % 4.3f MB/sec" % (10**3 / worst)

k = K
m = M
for arg in sys.argv:
    if arg.startswith('--k='):
        k = int(arg[len('--k='):])
    if arg.startswith('--m='):
        m = int(arg[len('--m='):])

bench(k, m)