compress.cc

   1 /*
   2  * Copyright (c) 2001, Robert Collins.
   3  *
   4  *     This program is free software; you can redistribute it and/or modify
   5  *     it under the terms of the GNU General Public License as published by
   6  *     the Free Software Foundation; either version 2 of the License, or
   7  *     (at your option) any later version.
   8  *
   9  *     A copy of the GNU General Public License can be found at
  10  *     http://www.gnu.org/
  11  *
  12  * Written by Robert Collins  <rbtcollins@hotmail.com>
  13  *
  14  */
  15
  16 /* Archive IO operations
  17  */
  18
  19 #if 0
  20 static const char *cvsid =
  21   "\n%%% $Id$\n";
  22 #endif
  23
  24 #include "win32.h"
  25 #include <stdio.h>
  26 #include "log.h"
  27 #include "port.h"
  28
  29 #include "io_stream.h"
  30 #include "compress.h"
  31 #include "zlib/zlib.h"
  32 #include "compress_gz.h"
  33 #include "compress_bz.h"
  34
  35 /* In case you are wondering why the file magic is not in one place:
  36  * It could be. But there is little (any?) benefit.
  37  * What is important is that the file magic required for any _task_ is centralised.
  38  * One such task is identifying compresss
  39  *
  40  * to federate into each class one might add a magic parameter to the constructor, which
  41  * the class could test itself.
  42  */
  43
  44 #define longest_magic 3
  45
  46 io_stream *
  47 compress::decompress (io_stream * original)
  48 {
  49   if (!original)
  50     return NULL;
  51   char magic[longest_magic];
  52   if (original->peek (magic, longest_magic) > 0)
  53     {
  54       if (memcmp (magic, "\037\213", 2) == 0)
  55         {
  56           /* tar */
  57           compress_gz *rv = new compress_gz (original);
  58           if (!rv->error ())
  59             return rv;
  60           return NULL;
  61         }
  62       else if (memcmp (magic, "BZh", 3) == 0)
  63         {
  64           compress_bz *rv = new compress_bz (original);
  65           if (!rv->error ())
  66             return rv;
  67           return NULL;
  68         }
  69     }
  70   return NULL;
  71 }
  72
  73 ssize_t
  74 compress::read (void *buffer, size_t len)
  75 {
  76   log (LOG_TIMESTAMP, "compress::read called");
  77   return 0;
  78 }
  79
  80 ssize_t
  81 compress::write (void *buffer, size_t len)
  82 {
  83   log (LOG_TIMESTAMP, "compress::write called");
  84   return 0;
  85 }
  86
  87 ssize_t
  88 compress::peek (void *buffer, size_t len)
  89 {
  90   log (LOG_TIMESTAMP, "compress::peek called");
  91   return 0;
  92 }
  93
  94 long
  95 compress::tell ()
  96 {
  97   log (LOG_TIMESTAMP, "bz::tell called");
  98   return 0;
  99 }
 100
 101 int
 102 compress::error ()
 103 {
 104   log (LOG_TIMESTAMP, "compress::error called");
 105   return 0;
 106 }
 107
 108 const char *
 109 compress::next_file_name ()
 110 {
 111   log (LOG_TIMESTAMP, "compress::next_file_name called");
 112   return NULL;
 113 }
 114
 115 compress::~compress ()
 116 {
 117   log (LOG_BABBLE, "compress::~compress called");
 118   return;
 119 }