/* This file is part of libmspack.
  * (C) 2003-2004 Stuart Caie.
  *
  * The deflate method was created by Phil Katz. MSZIP is equivalent to the
  * deflate method.
  *
  * libmspack is free software; you can redistribute it and/or modify it under
  * the terms of the GNU Lesser General Public License (LGPL) version 2.1
  *
  * For further details, see the file COPYING.LIB distributed with libmspack
  */
 
 #ifndef MSPACK_MSZIP_H
 #define MSPACK_MSZIP_H 1
 
 #ifdef __cplusplus
 extern "C" {
 #endif
 
 /* MSZIP (deflate) compression / (inflate) decompression definitions */
 
 #define MSZIP_FRAME_SIZE          (32768) /* size of LZ history window */
 #define MSZIP_LITERAL_MAXSYMBOLS  (288)   /* literal/length huffman tree */
 #define MSZIP_LITERAL_TABLEBITS   (9)
 #define MSZIP_DISTANCE_MAXSYMBOLS (32)    /* distance huffman tree */
 #define MSZIP_DISTANCE_TABLEBITS  (6)
 
 /* if there are less direct lookup entries than symbols, the longer
  * code pointers will be <= maxsymbols. This must not happen, or we
  * will decode entries badly */
 #if (1 << MSZIP_LITERAL_TABLEBITS) < (MSZIP_LITERAL_MAXSYMBOLS * 2)
 # define MSZIP_LITERAL_TABLESIZE (MSZIP_LITERAL_MAXSYMBOLS * 4)
 #else
 # define MSZIP_LITERAL_TABLESIZE ((1 << MSZIP_LITERAL_TABLEBITS) + \

                                   (MSZIP_LITERAL_MAXSYMBOLS * 2))

 #endif
 
 #if (1 << MSZIP_DISTANCE_TABLEBITS) < (MSZIP_DISTANCE_MAXSYMBOLS * 2)
 # define MSZIP_DISTANCE_TABLESIZE (MSZIP_DISTANCE_MAXSYMBOLS * 4)
 #else
 # define MSZIP_DISTANCE_TABLESIZE ((1 << MSZIP_DISTANCE_TABLEBITS) + \

                                   (MSZIP_DISTANCE_MAXSYMBOLS * 2))

 #endif
 
 struct mszipd_stream {
   struct mspack_system *sys;            /* I/O routines          */
   struct mspack_file   *input;          /* input file handle     */
   struct mspack_file   *output;         /* output file handle    */
   unsigned int window_posn;             /* offset within window  */
 
   /* inflate() will call this whenever the window should be emptied. */
   int (*flush_window)(struct mszipd_stream *, unsigned int);
 
   int error, repair_mode, bytes_output;
 
   /* I/O buffering */
   unsigned char *inbuf, *i_ptr, *i_end, *o_ptr, *o_end, input_end;
   unsigned int bit_buffer, bits_left, inbuf_size;
 
 
   /* huffman code lengths */
   unsigned char  LITERAL_len[MSZIP_LITERAL_MAXSYMBOLS];
   unsigned char  DISTANCE_len[MSZIP_DISTANCE_MAXSYMBOLS];
 
   /* huffman decoding tables */
   unsigned short LITERAL_table [MSZIP_LITERAL_TABLESIZE];
   unsigned short DISTANCE_table[MSZIP_DISTANCE_TABLESIZE];
 
   /* 32kb history window */
   unsigned char window[MSZIP_FRAME_SIZE];
 };
 
 /* allocates MS-ZIP decompression stream for decoding the given stream.
  *
  * - uses system->alloc() to allocate memory
  *
  * - returns NULL if not enough memory
  *
  * - input_buffer_size is how many bytes to use as an input bitstream buffer
  *
  * - if repair_mode is non-zero, errors in decompression will be skipped
  *   and 'holes' left will be filled with zero bytes. This allows at least
  *   a partial recovery of erroneous data.
  */
 extern struct mszipd_stream *mszipd_init(struct mspack_system *system,

                                         struct mspack_file *input,
                                         struct mspack_file *output,
                                         int input_buffer_size,
                                         int repair_mode);

 
 /* decompresses, or decompresses more of, an MS-ZIP stream.
  *
  * - out_bytes of data will be decompressed and the function will return
  *   with an MSPACK_ERR_OK return code.
  *
  * - decompressing will stop as soon as out_bytes is reached. if the true
  *   amount of bytes decoded spills over that amount, they will be kept for
  *   a later invocation of mszipd_decompress().
  *
  * - the output bytes will be passed to the system->write() function given in
  *   mszipd_init(), using the output file handle given in mszipd_init(). More
  *   than one call may be made to system->write()
  *
  * - MS-ZIP will read input bytes as necessary using the system->read()
  *   function given in mszipd_init(), using the input file handle given in
  *   mszipd_init(). This will continue until system->read() returns 0 bytes,
  *   or an error.
  */
 extern int mszipd_decompress(struct mszipd_stream *zip, off_t out_bytes);
 
 /* decompresses an entire MS-ZIP stream in a KWAJ file. Acts very much
  * like mszipd_decompress(), but doesn't take an out_bytes parameter
  */
 extern int mszipd_decompress_kwaj(struct mszipd_stream *zip);
 
 /* frees all stream associated with an MS-ZIP data stream
  *
  * - calls system->free() using the system pointer given in mszipd_init()
  */
 void mszipd_free(struct mszipd_stream *zip);
 
 #ifdef __cplusplus
 }
 #endif
 
 #endif