symbian-qemu-0.9.1-12/python-2.6.1/Demo/zlib/zlibdemo.py
author johnathan.white@2718R8BGH51.accenture.com
Mon, 08 Mar 2010 18:45:03 +0000
changeset 46 b6935a90ca64
parent 1 2fb8b9db1c86
permissions -rw-r--r--
Modify framebuffer and NGA framebuffer to read screen size from board model dtb file. Optimise memory usuage of frame buffer Add example minigui application with hooks to profiler (which writes results to S:\). Modified NGA framebuffer to run its own dfc queue at high priority

#!/usr/bin/env python

# Takes an optional filename, defaulting to this file itself.
# Reads the file and compresses the content using level 1 and level 9
# compression, printing a summary of the results.

import zlib, sys

def main():
    if len(sys.argv) > 1:
        filename = sys.argv[1]
    else:
        filename = sys.argv[0]
    print 'Reading', filename

    f = open(filename, 'rb')           # Get the data to compress
    s = f.read()
    f.close()

    # First, we'll compress the string in one step
    comptext = zlib.compress(s, 1)
    decomp = zlib.decompress(comptext)

    print '1-step compression: (level 1)'
    print '    Original:', len(s), 'Compressed:', len(comptext),
    print 'Uncompressed:', len(decomp)

    # Now, let's compress the string in stages; set chunk to work in smaller steps

    chunk = 256
    compressor = zlib.compressobj(9)
    decompressor = zlib.decompressobj()
    comptext = decomp = ''
    for i in range(0, len(s), chunk):
        comptext = comptext+compressor.compress(s[i:i+chunk])
    # Don't forget to call flush()!!
    comptext = comptext + compressor.flush()

    for i in range(0, len(comptext), chunk):
        decomp = decomp + decompressor.decompress(comptext[i:i+chunk])
    decomp=decomp+decompressor.flush()

    print 'Progressive compression (level 9):'
    print '    Original:', len(s), 'Compressed:', len(comptext),
    print 'Uncompressed:', len(decomp)

if __name__ == '__main__':
    main()