compress_zstd.h

   1 /*
   2  * Copyright (c) 2018, Cygwin
   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  */
  13
  14 #ifndef SETUP_COMPRESS_ZSTD_H
  15 #define SETUP_COMPRESS_ZSTD_H
  16
  17 #include "compress.h"
  18 #include <zstd.h>
  19 #include <stdint.h>
  20
  21 class compress_zstd:public compress
  22 {
  23 public:
  24   compress_zstd (io_stream *); /* decompress (read) only */
  25   virtual ssize_t read (void *buffer, size_t len);
  26   virtual ssize_t write (const void *buffer, size_t len); /* not implemented */
  27   virtual ssize_t peek (void *buffer, size_t len);
  28   virtual off_t tell (); /* not implemented */
  29   virtual off_t seek (off_t where, io_stream_seek_t whence);
  30   virtual int error ();
  31   virtual const char *next_file_name () { return NULL; };
  32   virtual int set_mtime (time_t);
  33   virtual time_t get_mtime ();
  34   virtual mode_t get_mode ();
  35   virtual size_t get_size () {return 0;};
  36   virtual ~compress_zstd ();
  37   static bool is_zstd (void *buffer, size_t len);
  38   virtual void release_original(); /* give up ownership of original io_stream */
  39
  40 private:
  41   compress_zstd () {};
  42
  43   io_stream *original;
  44   bool owns_original;
  45   int lasterr;
  46   void create ();
  47   void destroy ();
  48
  49   struct private_data {
  50     ZSTD_DStream    *stream;
  51     ZSTD_outBuffer   out_block;
  52     size_t           out_bsz;
  53     size_t           out_pos;
  54     uint64_t         total_out;
  55     char             eof; /* True = found end of compressed data. */
  56     ZSTD_inBuffer    in_block;
  57     size_t           in_bsz;
  58     size_t           in_pos;
  59     uint64_t         total_in;
  60     size_t           in_processed;
  61     size_t           out_processed;
  62   };
  63
  64   struct private_data *state;
  65 };
  66
  67 #endif /* SETUP_COMPRESS_ZSTD_H */