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104 lines
3.9 KiB
Python
104 lines
3.9 KiB
Python
# pyfec -- fast forward error correction library with Python interface
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#
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# Copyright (C) 2007 Allmydata, Inc.
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# Author: Zooko Wilcox-O'Hearn
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# mailto:zooko@zooko.com
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#
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# This file is part of pyfec.
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#
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# This program is free software; you can redistribute it and/or modify it under
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# the terms of the GNU General Public License as published by the Free Software
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# Foundation; either version 2 of the License, or (at your option) any later
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# version. This program also comes with the added permission that, in the case
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# that you are obligated to release a derived work under this licence (as per
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# section 2.b of the GPL), you may delay the fulfillment of this obligation for
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# up to 12 months.
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#
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# This program is distributed in the hope that it will be useful,
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# but WITHOUT ANY WARRANTY; without even the implied warranty of
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# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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# GNU General Public License for more details.
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#
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# You should have received a copy of the GNU General Public License
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# along with this program; if not, write to the Free Software
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# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
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import fec
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import array, random
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def f_easyfec(filesize):
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return bench_encode_to_files_shuffle_decode_from_files(filesize, verbose=False, encodefunc=fec.filefec.encode_to_files_easyfec)
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def f_fec_stringy(filesize):
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return bench_encode_to_files_shuffle_decode_from_files(filesize, verbose=False, encodefunc=fec.filefec.encode_to_files_stringy)
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def f_fec(filesize):
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return bench_encode_to_files_shuffle_decode_from_files(filesize, verbose=False, encodefunc=fec.filefec.encode_to_files)
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def bench_encode_to_files_shuffle_decode_from_files(filesize=1000000, verbose=False, encodefunc=fec.filefec.encode_to_files):
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CHUNKSIZE=4096
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PREFIX="testshare"
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K=25
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M=100
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import os, time
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left=filesize
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outfile = open("tmpranddata", "wb")
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try:
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while left:
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d = os.urandom(min(left, CHUNKSIZE))
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outfile.write(d)
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left -= len(d)
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outfile.flush()
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outfile = None
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infile = open("tmpranddata", "rb")
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st = time.time()
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encodefunc(infile, PREFIX, K, M)
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so = time.time()
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if verbose:
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print "Encoded %s byte file into %d share files in %0.2f seconds, or %0.2f million bytes per second" % (filesize, M, so-st, filesize/((so-st)*filesize),)
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enctime = so-st
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# Now delete m-k of the tempfiles at random.
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tempfs = [ f for f in os.listdir(".") if f.startswith(PREFIX) ]
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random.shuffle(tempfs)
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for victimtempf in tempfs[:M-K]:
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os.remove(victimtempf)
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recoveredfile = open("tmpranddata-recovered", "wb")
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st = time.time()
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fec.filefec.decode_from_files(recoveredfile, filesize, PREFIX, K, M)
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so = time.time()
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if verbose:
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print "Decoded %s byte file from %d share files in %0.2f seconds, or %0.2f million bytes per second" % (filesize, K, so-st, filesize/((so-st)*filesize),)
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return enctime + (so-st)
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finally:
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# os.remove("tmpranddata")
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pass
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def bench_read_encode_and_drop():
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FILESIZE=1000000
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CHUNKSIZE=4096
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import os, time
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left=FILESIZE
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outfile = open("tmpranddata", "wb")
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try:
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while left:
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d = os.urandom(min(left, CHUNKSIZE))
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outfile.write(d)
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left -= len(d)
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outfile.flush()
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outfile = None
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infile = open("tmpranddata", "rb")
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def cb(s, l):
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pass
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st = time.time()
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fec.filefec.encode_file(infile, cb, 25, 100, 4096)
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so = time.time()
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print "Encoded %s byte file in %0.2f seconds, or %0.2f million bytes per second" % (FILESIZE, so-st, FILESIZE/((so-st)*1000000),)
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return so-st
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finally:
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os.remove("tmpranddata")
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if __name__ == "__main__":
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bench_encode_to_files_shuffle_decode_from_files()
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