/*
 * stream.h - streaming I/O definitions
 *
 * Copyright (C) 2019 Emmanuel Marty
 *
 * This software is provided 'as-is', without any express or implied
 * warranty.  In no event will the authors be held liable for any damages
 * arising from the use of this software.
 *
 * Permission is granted to anyone to use this software for any purpose,
 * including commercial applications, and to alter it and redistribute it
 * freely, subject to the following restrictions:
 *
 * 1. The origin of this software must not be misrepresented; you must not
 *    claim that you wrote the original software. If you use this software
 *    in a product, an acknowledgment in the product documentation would be
 *    appreciated but is not required.
 * 2. Altered source versions must be plainly marked as such, and must not be
 *    misrepresented as being the original software.
 * 3. This notice may not be removed or altered from any source distribution.
 */

/*
 * Uses the libdivsufsort library Copyright (c) 2003-2008 Yuta Mori
 *
 * Inspired by LZ4 by Yann Collet. https://github.com/lz4/lz4
 * With help, ideas, optimizations and speed measurements by spke <zxintrospec@gmail.com>
 * With ideas from Lizard by Przemyslaw Skibinski and Yann Collet. https://github.com/inikep/lizard
 * Also with ideas from smallz4 by Stephan Brumme. https://create.stephan-brumme.com/smallz4/
 *
 */

#ifndef _STREAM_H
#define _STREAM_H

#ifdef __cplusplus
extern "C" {
#endif

/** High level status for compression and decompression */
typedef enum _lzsa_status_t {
   LZSA_OK = 0,                           /**< Success */
   LZSA_ERROR_SRC,                        /**< Error reading input */
   LZSA_ERROR_DST,                        /**< Error reading output */
   LZSA_ERROR_DICTIONARY,                 /**< Error reading dictionary */
   LZSA_ERROR_MEMORY,                     /**< Out of memory */

   /* Compression-specific status codes */
   LZSA_ERROR_COMPRESSION,                /**< Internal compression error */
   LZSA_ERROR_RAW_TOOLARGE,               /**< Input is too large to be compressed to a raw block */
   LZSA_ERROR_RAW_UNCOMPRESSED,           /**< Input is incompressible and raw blocks don't support uncompressed data */

   /* Decompression-specific status codes */
   LZSA_ERROR_FORMAT,                     /**< Invalid input format or magic number when decompressing */
   LZSA_ERROR_DECOMPRESSION               /**< Internal decompression error */
} lzsa_status_t;

/* I/O stream */
typedef struct _lzsa_stream_t {
   /** Opaque stream-specific pointer */
   void *obj;

   /**
    * Read from stream
    *
    * @param stream stream
    * @param ptr buffer to read into
    * @param size number of bytes to read
    *
    * @return number of bytes read
    */
   size_t(*read)(struct _lzsa_stream_t *stream, void *ptr, size_t size);

   /**
    * Write to stream
    *
    * @param stream stream
    * @param ptr buffer to write from
    * @param size number of bytes to write
    *
    * @return number of bytes written
    */
   size_t(*write)(struct _lzsa_stream_t *stream, void *ptr, size_t size);


   /**
    * Check if stream has reached the end of the data
    *
    * @param stream stream
    *
    * @return nonzero if the end of the data has been reached, 0 if there is more data
    */
   int(*eof)(struct _lzsa_stream_t *stream);

   /**
    * Close stream
    *
    * @param stream stream
    */
   void(*close)(struct _lzsa_stream_t *stream);
} lzsa_stream_t;

/**
 * Open file and create an I/O stream from it
 *
 * @param stream stream to fill out
 * @param pszInFilename filename
 * @param pszMode open mode, as with fopen()
 *
 * @return 0 for success, nonzero for failure
 */
int lzsa_filestream_open(lzsa_stream_t *stream, const char *pszInFilename, const char *pszMode);

#ifdef __cplusplus
}
#endif

#endif /* _STREAM_H */