Jungfraujoch/compression/JFJochCompressor.h

// SPDX-FileCopyrightText: 2024 Filip Leonarski, Paul Scherrer Institute <filip.leonarski@psi.ch>
// SPDX-License-Identifier: GPL-3.0-only

#pragma once

#include <bitshuffle/bitshuffle.h>

#include <vector>
#include <cstdint>
#include <cstddef>
#include "CompressionAlgorithmEnum.h"
#include "MaxCompressedSize.h"

#include "JFJochZstdCompressor.h"

class JFJochBitShuffleCompressor {
    JFJochZstdCompressor zstd_compressor;
    CompressionAlgorithm algorithm;
    std::vector<char> tmp_space;

    size_t CompressBlock(char *dest, const char * source, size_t nelements, size_t elem_size);
public:
    constexpr static const size_t DefaultBlockSize = 4096;

    explicit JFJochBitShuffleCompressor(CompressionAlgorithm algorithm);

    template<class T>
    size_t Compress(void *dest, const std::vector<T> &src) {
        return Compress((char *) dest, (char *) src.data(), src.size(), sizeof(T));
    };

    template<class T>
    std::vector<uint8_t> Compress(const std::vector<T> &src) {
        return Compress(src.data(), src.size(), sizeof(T));
    }
    std::vector<uint8_t> Compress(const void* source, size_t nelements, size_t elem_size);
    size_t Compress(void *dest, const void* source, size_t nelements, size_t elem_size);
private:
    char scratch[DefaultBlockSize * sizeof(uint64_t)];
};

template <class T> std::vector<T> bitshuffle(const std::vector<T> &input, size_t block_size) {
    std::vector<T> ret(input.size());
    bshuf_bitshuffle(input.data(), ret.data(), input.size(), sizeof(T), block_size);
    return ret;
}