sr3csample/sr3ctest.d

   1 /* SR3C, a symbol ranking data compressor.
   2  *
   3  * This file implements a fast and effective data compressor.
   4  * The compression is on par (k8: i guess ;-) to gzip -7.
   5  * bzip2 -2 compresses slightly better than SR3C, but takes almost
   6  * three times as long. Furthermore, since bzip2 is  based on
   7  * Burrows-Wheeler block sorting, it can't be used in on-line
   8  * compression tasks.
   9  * Memory consumption of SR3C is currently around 4.5 MB per ongoing
  10  * compression and decompression.
  11  *
  12  * Author: Kenneth Oksanen <cessu@iki.fi>, 2008.
  13  * Copyright (C) Helsinki University of Technology.
  14  * D conversion by Ketmar // Invisible Vector <ketmar@ketmar.no-ip.org>
  15  *
  16  * This code borrows many ideas and some paragraphs of comments from
  17  * Matt Mahoney's s symbol ranking compression program SR2 and Peter
  18  * Fenwicks SRANK, but otherwise all code has been implemented from
  19  * scratch.
  20  *
  21  * This file is distributed under the following license:
  22  *
  23  * The MIT License
  24  * Copyright (c) 2008 Helsinki University of Technology
  25  * Permission is hereby granted, free of charge, to any person obtaining a copy
  26  * of this software and associated documentation files (the "Software"), to deal
  27  * in the Software without restriction, including without limitation the rights
  28  * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
  29  * copies of the Software, and to permit persons to whom the Software is
  30  * furnished to do so, subject to the following conditions:
  31  * The above copyright notice and this permission notice shall be included in
  32  * all copies or substantial portions of the Software.
  33  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  34  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  35  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
  36  * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  37  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
  38  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
  39  * THE SOFTWARE.
  40  */
  41 import std.stdio;
  42 import iv.sr3c;
  43
  44
  45 void main (string[] args) {
  46   assert(args.length == 4);
  47   SR3C ctx;
  48
  49   ubyte[] idata;
  50
  51   {
  52     auto fi = File(args[2]);
  53     idata = new ubyte[](cast(uint)fi.size);
  54     fi.rawRead(idata[]);
  55   }
  56
  57   if (args[1] == "p") {
  58     auto fo = File(args[3], "w");
  59     ctx = new SR3C(
  60       (const(void)[] bytes, bool flush) {
  61         fo.rawWrite(bytes[]);
  62         return 0;
  63       });
  64     auto res = ctx.compress(idata[]);
  65     assert(res == 0);
  66     res = ctx.flush();
  67   } else if (args[1] == "u") {
  68     auto fo = File(args[3], "w");
  69     ctx = new SR3C(
  70       (const(void)[] bytes, bool flush) {
  71         fo.rawWrite(bytes[]);
  72         return 0;
  73       });
  74     auto res = ctx.uncompress(idata[]);
  75     assert(res == 0);
  76   }
  77 }