compress_xz.h

   1 /*
   2  * Copyright (c) 2010, Charles Wilson
   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 Charles Wilson <cygwin@cygwin.com>
  13  *
  14  */
  15
  16 #ifndef SETUP_COMPRESS_XZ_H
  17 #define SETUP_COMPRESS_XZ_H
  18
  19 #include "compress.h"
  20 #include <lzma.h>
  21
  22 class compress_xz:public compress
  23 {
  24 public:
  25   compress_xz (io_stream *); /* decompress (read) only */
  26   virtual ssize_t read (void *buffer, size_t len);
  27   virtual ssize_t write (const void *buffer, size_t len); /* not implemented */
  28   virtual ssize_t peek (void *buffer, size_t len);
  29   virtual off_t tell (); /* not implemented */
  30   virtual off_t seek (off_t where, io_stream_seek_t whence);
  31   virtual int error ();
  32   virtual const char *next_file_name () { return NULL; };
  33   virtual int set_mtime (time_t);
  34   virtual time_t get_mtime ();
  35   virtual mode_t get_mode ();
  36   virtual size_t get_size () {return 0;};
  37   virtual ~compress_xz ();
  38   virtual void init_decoder (void);
  39   static bool is_xz_or_lzma (void *buffer, size_t len);
  40   static int  bid_xz   (void *buffer, size_t len);
  41   static int  bid_lzma (void *buffer, size_t len);
  42   virtual void release_original(); /* give up ownership of original io_stream */
  43
  44 private:
  45   compress_xz () {};
  46
  47   io_stream *original;
  48   bool owns_original;
  49   char peekbuf[512];
  50   size_t peeklen;
  51   int lasterr;
  52   void create ();
  53   void destroy ();
  54
  55   struct private_data {
  56     lzma_stream      stream;
  57     unsigned char   *out_block;
  58     size_t           out_block_size;
  59     uint64_t         total_out;
  60     char             eof; /* True = found end of compressed data. */
  61     unsigned char   *in_block;
  62     size_t           in_block_size;
  63     uint64_t         total_in;
  64     unsigned char   *out_p;
  65     size_t           in_pos;
  66     size_t           out_pos;
  67     size_t           in_size;
  68     size_t           in_processed;
  69     size_t           out_processed;
  70   };
  71
  72   typedef enum {
  73     COMPRESSION_UNKNOWN = -1,
  74     COMPRESSION_XZ,
  75     COMPRESSION_LZMA
  76   } compression_type_t;
  77
  78   compression_type_t compression_type;
  79
  80   static const size_t out_block_size = 64 * 1024;
  81   static const size_t in_block_size = 64 * 1024;
  82   struct private_data *state;
  83 };
  84
  85 #endif /* SETUP_COMPRESS_XZ_H */