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 /* this is the parent class for all compress IO operations.
  20  */
  21
  22 #include "compress.h"
  23 #include <lzma.h>
  24
  25 class compress_xz:public compress
  26 {
  27 public:
  28   compress_xz (io_stream *); /* decompress (read) only */
  29   virtual ssize_t read (void *buffer, size_t len);
  30   virtual ssize_t write (const void *buffer, size_t len); /* not implemented */
  31   virtual ssize_t peek (void *buffer, size_t len);
  32   virtual long tell (); /* not implemented */
  33   virtual int seek (long where, io_stream_seek_t whence); /* not implemented */
  34   virtual int error ();
  35   virtual const char *next_file_name () { return NULL; };
  36   virtual int set_mtime (time_t);
  37   virtual time_t get_mtime ();
  38   virtual mode_t get_mode ();
  39   virtual size_t get_size () {return 0;};
  40   virtual ~compress_xz ();
  41   virtual void init_decoder (void);
  42   static bool is_xz_or_lzma (void *buffer, size_t len);
  43   static int  bid_xz   (void *buffer, size_t len);
  44   static int  bid_lzma (void *buffer, size_t len);
  45   virtual void release_original(); /* give up ownership of original io_stream */
  46
  47 private:
  48   compress_xz () {};
  49
  50   io_stream *original;
  51   bool owns_original;
  52   char peekbuf[512];
  53   size_t peeklen;
  54   int lasterr;
  55   void destroy ();
  56
  57   struct private_data {
  58     lzma_stream      stream;
  59     unsigned char   *out_block;
  60     size_t           out_block_size;
  61     uint64_t         total_out;
  62     char             eof; /* True = found end of compressed data. */
  63     unsigned char   *in_block;
  64     size_t           in_block_size;
  65     uint64_t         total_in;
  66     unsigned char   *out_p;
  67     size_t           in_pos;
  68     size_t           out_pos;
  69     size_t           in_size;
  70     size_t           in_processed;
  71     size_t           out_processed;
  72   };
  73
  74   typedef enum {
  75     COMPRESSION_UNKNOWN = -1,
  76     COMPRESSION_XZ,
  77     COMPRESSION_LZMA
  78   } compression_type_t;
  79
  80   compression_type_t compression_type;
  81
  82   static const size_t out_block_size = 64 * 1024;
  83   static const size_t in_block_size = 64 * 1024;
  84   struct private_data *state;
  85 };
  86
  87 #endif /* SETUP_COMPRESS_XZ_H */