snappy.hh

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//
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//
// A light-weight compression algorithm.  It is designed for speed of
// compression and decompression, rather than for the utmost in space
// savings.
//
// For getting better compression ratios when you are compressing data
// with long repeated sequences or compressing data that is similar to
// other data, while still compressing fast, you might look at first
// using BMDiff and then compressing the output of BMDiff with
// Snappy.
//
//
// The snappy code is modified quite a bit for openMSX. The original
// verion can be obtained here:
//    http://code.google.com/p/snappy/
//
// The main difference are:
// - Rewritten to reuse existing openMSX helper functions and style.
// - Removed possibility to operate on chunks of data, the current code
//   requires the full to-be-(de)compressed memory block in one go.
// - Removed all safety checks during decompression. The original code
//   would return an error on invalid input, this code will crash on
//   such input (but that shouldn't happen because we only feed input
//   that was previously produced by the compression routine (and always
//   keeping that compressed block in memory).
// The motivation for this rewrite is to:
// - Reduce code duplication between the snappy code and the rest of
//   openMSX.
// - Gain some extra speed at the expense of flexibility (which we don't
//   need in openMSX).
//

#ifndef SNAPPY_HH
#define SNAPPY_HH

#include <cstddef>

namespace snappy {
        void compress(const char* input, size_t inLen,
                      char* output, size_t& outLen);
        void uncompress(const char* input, size_t inLen,
                        char* output, size_t outLen);
        size_t maxCompressedLength(size_t inLen);
}

#endif