source: vbox/trunk/src/libs/liblzma-5.4.1/simple/simple_private.h

///////////////////////////////////////////////////////////////////////////////
//
/// \file       simple_private.h
/// \brief      Private definitions for so called simple filters
//
//  Author:     Lasse Collin
//
//  This file has been put into the public domain.
//  You can do whatever you want with this file.
//
///////////////////////////////////////////////////////////////////////////////

#ifndef LZMA_SIMPLE_PRIVATE_H
#define LZMA_SIMPLE_PRIVATE_H

#include "simple_coder.h"


typedef struct {
        /// Next filter in the chain
        lzma_next_coder next;

        /// True if the next coder in the chain has returned LZMA_STREAM_END.
        bool end_was_reached;

        /// True if filter() should encode the data; false to decode.
        /// Currently all simple filters use the same function for encoding
        /// and decoding, because the difference between encoders and decoders
        /// is very small.
        bool is_encoder;

        /// Pointer to filter-specific function, which does
        /// the actual filtering.
        size_t (*filter)(void *simple, uint32_t now_pos,
                        bool is_encoder, uint8_t *buffer, size_t size);

        /// Pointer to filter-specific data, or NULL if filter doesn't need
        /// any extra data.
        void *simple;

        /// The lowest 32 bits of the current position in the data. Most
        /// filters need this to do conversions between absolute and relative
        /// addresses.
        uint32_t now_pos;

        /// Size of the memory allocated for the buffer.
        size_t allocated;

        /// Flushing position in the temporary buffer. buffer[pos] is the
        /// next byte to be copied to out[].
        size_t pos;

        /// buffer[filtered] is the first unfiltered byte. When pos is smaller
        /// than filtered, there is unflushed filtered data in the buffer.
        size_t filtered;

        /// Total number of bytes (both filtered and unfiltered) currently
        /// in the temporary buffer.
        size_t size;

        /// Temporary buffer
        uint8_t buffer[];
} lzma_simple_coder;


extern lzma_ret lzma_simple_coder_init(lzma_next_coder *next,
                const lzma_allocator *allocator,
                const lzma_filter_info *filters,
                size_t (*filter)(void *simple, uint32_t now_pos,
                        bool is_encoder, uint8_t *buffer, size_t size),
                size_t simple_size, size_t unfiltered_max,
                uint32_t alignment, bool is_encoder);

#endif