#!/usr/bin/python
"""
    copy the uncopied portion of a file
    Copyright (C) 2008  James Cameron (quozl@us.netrek.org)

    This program is free software; you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
    the Free Software Foundation; either version 2 of the License, or
    (at your option) any later version.

    This program is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    GNU General Public License for more details.

    You should have received a copy of the GNU General Public License
    along with this program; if not, write to the Free Software
    Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
"""
import os, sys, time

r = open(sys.argv[1], 'r') # input file
a = open(sys.argv[2], 'a') # output file, may already exist

# seek input to end to determine current size
r.seek(0, os.SEEK_END)
rs = r.tell()
print rs, "size of input."

# seek output to end
a.seek(0, os.SEEK_END)

# get output file length
as = a.tell()
uncopied = rs - as
print as, "size of output,", uncopied, "to be moved."

# position input to current output position
r.seek(as, os.SEEK_SET)

start = time.time()
copied = 0
size = max(uncopied/10, 8192*1024)

# loop reading and writing until end of file on input
chunk = r.read(size)
while chunk != '':
    a.write(chunk)
    copied += len(chunk)
    print r.tell(), "moved", len(chunk), "chunk", copied, "copied"
    chunk = r.read(size)

# generate summary
elapsed = time.time() - start
bps = int(copied / elapsed)
print r.tell(), "eof", copied, "copied", bps, "bytes per second"