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
  28 #include "io_stream.h"
  29 #include "compress.h"
  30 #include "zlib/zlib.h"
  31 #include "compress_gz.h"
  32 #include "compress_bz.h"
  33
  34 /* In case you are wondering why the file magic is not in one place:
  35  * It could be. But there is little (any?) benefit.
  36  * What is important is that the file magic required for any _task_ is centralised.
  37  * One such task is identifying compresss
  38  *
  39  * to federate into each class one might add a magic parameter to the constructor, which
  40  * the class could test itself.
  41  */
  42
  43 #define longest_magic 3
  44
  45 io_stream *
  46 compress::decompress (io_stream * original)
  47 {
  48   if (!original)
  49     return NULL;
  50   char magic[longest_magic];
  51   if (original->peek (magic, longest_magic) > 0)
  52     {
  53       if (memcmp (magic, "\037\213", 2) == 0)
  54         {
  55           /* tar */
  56           compress_gz *rv = new compress_gz (original);
  57           if (!rv->error ())
  58             return rv;
  59           return NULL;
  60         }
  61       else if (memcmp (magic, "BZh", 3) == 0)
  62         {
  63           compress_bz *rv = new compress_bz (original);
  64           if (!rv->error ())
  65             return rv;
  66           return NULL;
  67         }
  68     }
  69   return NULL;
  70 }
  71
  72 ssize_t
  73 compress::read (void *buffer, size_t len)
  74 {
  75   log (LOG_TIMESTAMP, "compress::read called");
  76   return 0;
  77 }
  78
  79 ssize_t
  80 compress::write (void *buffer, size_t len)
  81 {
  82   log (LOG_TIMESTAMP, "compress::write called");
  83   return 0;
  84 }
  85
  86 ssize_t
  87 compress::peek (void *buffer, size_t len)
  88 {
  89   log (LOG_TIMESTAMP, "compress::peek called");
  90   return 0;
  91 }
  92
  93 long
  94 compress::tell ()
  95 {
  96   log (LOG_TIMESTAMP, "bz::tell called");
  97   return 0;
  98 }
  99
 100 int
 101 compress::error ()
 102 {
 103   log (LOG_TIMESTAMP, "compress::error called");
 104   return 0;
 105 }
 106
 107 const char *
 108 compress::next_file_name ()
 109 {
 110   log (LOG_TIMESTAMP, "compress::next_file_name called");
 111   return NULL;
 112 }
 113
 114 compress::~compress ()
 115 {
 116   log (LOG_BABBLE, "compress::~compress called");
 117   return;
 118 }