system/ulib/blobfs/include/blobfs/compression/zstd.h

// Copyright 2019 The Fuchsia Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#pragma once

#include <blobfs/compression/compressor.h>
#include <fbl/unique_ptr.h>
#include <zircon/types.h>
#include <zstd/zstd.h>

namespace blobfs {

class ZSTDCompressor : public Compressor {
public:
    // Returns the maximum possible size a buffer would need to be
    // in order to compress data of size |input_length|.
    static size_t BufferMax(size_t input_length);

    static zx_status_t Create(size_t input_size, void* compression_buffer,
                              size_t compression_buffer_length,
                              fbl::unique_ptr<ZSTDCompressor>* out);
    ~ZSTDCompressor();

    ////////////////////////////////////////
    // Compressor interface
    size_t Size() const final;
    zx_status_t Update(const void* input_data, size_t input_length) final;
    zx_status_t End() final;

private:
    ZSTDCompressor(ZSTD_CCtx* ctx, void* compression_buffer, size_t compression_buffer_length);

    ZSTD_CCtx* stream_ = nullptr;
    ZSTD_outBuffer output_ = {};
};

// Decompress the source buffer into the target buffer, until either the source is drained or
// the target is filled (or both).
zx_status_t ZSTDDecompress(void* target_buf, size_t* target_size, const void* src_buf,
                           size_t* src_size);

} // namespace blobfs