LZ4DeflateService.cc

// -*- tab-width: 2; indent-tabs-mode: nil; coding: utf-8-with-signature -*-
//-----------------------------------------------------------------------------
// Copyright 2000-2026 CEA (www.cea.fr) IFPEN (www.ifpenergiesnouvelles.com)
// See the top-level COPYRIGHT file for details.
// SPDX-License-Identifier: Apache-2.0
//-----------------------------------------------------------------------------
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/* LZ4DeflateService.h                                         (C) 2000-2021 */
/*                                                                           */
/* Compression service using the 'lz4' library.                              */
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#include "arcane/utils/IOException.h"
#include "arcane/utils/Array.h"
#include "arcane/utils/TraceInfo.h"
#include "arcane/utils/IDataCompressor.h"
 
#include "arcane/core/FactoryService.h"
#include "arcane/core/AbstractService.h"
#include "arcane/core/IDeflateService.h"
 
#include <lz4.h>
 
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namespace Arcane
{
 
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class LZ4DeflateService
: public AbstractService
, public IDeflateService
{
 public:
 
  explicit LZ4DeflateService(const ServiceBuildInfo& sbi)
  : AbstractService(sbi)
  {
  }
 
 public:
 
  void build() override {}
 
  void compress(ByteConstArrayView values, ByteArray& compressed_values) override
  {
    Integer input_size = values.size();
    int dest_capacity = LZ4_compressBound(input_size);
    // According to the documentation, we must allocate at least 1% more than the
    // input size plus another 600 bytes
    //Integer compressed_init_size = (Integer)(((Real)input_size) * 1.01) + 600;
    compressed_values.resize(dest_capacity);
    //compressed_values.copy(values);
 
    char* dest = reinterpret_cast<char*>(compressed_values.data());
 
    const char* source = reinterpret_cast<const char*>(values.data());
    unsigned int source_len = (unsigned int)input_size;
 
#if 0
    info() << "CHECK COMPRESS dest=" << (void*)dest
           << " dest_len=" << dest_len
           << " source=" << (void*)source
           << " source_len=" << source_len;
#endif
 
    int r = LZ4_compress_default(source, dest, source_len, dest_capacity);
 
    if (r == 0)
      throw IOException(A_FUNCINFO, String::format("io error during compression r={0}", r));
    int dest_len = r;
    Real ratio = (dest_len * 100.0) / source_len;
    info() << "LZ4 compress r=" << r << " source_len=" << source_len
           << " dest_len=" << dest_len << " ratio=" << ratio;
    compressed_values.resize(dest_len);
  }
 
  void decompress(ByteConstArrayView compressed_values, ByteArrayView values) override
  {
    char* dest = reinterpret_cast<char*>(values.data());
    int dest_len = values.size();
 
    const char* source = reinterpret_cast<const char*>(compressed_values.data());
    int source_len = compressed_values.size();
 
    int r = LZ4_decompress_safe(source, dest, source_len, dest_len);
    info() << "LZ4 decompress r=" << r << " source_len=" << source_len << " dest_len=" << dest_len;
    if (r < 0)
      throw IOException(A_FUNCINFO, String::format("io error during decompression r={0}", r));
  }
};
 
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class LZ4DataCompressor
: public AbstractService
, public IDataCompressor
{
 public:
 
  explicit LZ4DataCompressor(const ServiceBuildInfo& sbi)
  : AbstractService(sbi)
  , m_name(sbi.serviceInfo()->localName())
  {
  }
 
 public:
 
  void build() override {}
  String name() const override { return m_name; }
  Int64 minCompressSize() const override { return 512; }
  void compress(Span<const std::byte> values, Array<std::byte>& compressed_values) override
  {
    // Although theoretically supporting an array size of 64 bits,
    // the 'LZ4' algorithm uses 'int' for sizes and does not
    // support values greater than LZ4_MAX_INPUT_SIZE.
    int input_size = _toInt(values.size());
    // Checks if we do not exceed LZ4_MAX_INPUT_SIZE
    if (input_size > LZ4_MAX_INPUT_SIZE)
      ARCANE_THROW(IOException, "Array is too large for LZ4: size={0} max={1}", input_size, LZ4_MAX_INPUT_SIZE);
 
    int dest_capacity = LZ4_compressBound(input_size);
    compressed_values.resize(dest_capacity);
 
    char* dest = reinterpret_cast<char*>(compressed_values.data());
    const char* source = reinterpret_cast<const char*>(values.data());
 
    int r = LZ4_compress_default(source, dest, input_size, dest_capacity);
    if (r == 0)
      ARCANE_THROW(IOException, "IO error during compression r={0}", r);
    int dest_len = r;
    if (input_size > 0) {
      Real ratio = (dest_len * 100.0) / input_size;
      info(5) << "LZ4 compress r=" << r << " source_len=" << input_size
              << " dest_len=" << dest_len << " ratio=" << ratio;
    }
    compressed_values.resize(dest_len);
  }
 
  void decompress(Span<const std::byte> compressed_values, Span<std::byte> values) override
  {
    char* dest = reinterpret_cast<char*>(values.data());
    int dest_len = _toInt(values.size());
 
    const char* source = reinterpret_cast<const char*>(compressed_values.data());
    int source_len = _toInt(compressed_values.size());
 
    int r = LZ4_decompress_safe(source, dest, source_len, dest_len);
    info(5) << "LZ4 decompress r=" << r << " source_len=" << source_len << " dest_len=" << dest_len;
    if (r < 0)
      ARCANE_THROW(IOException, "IO error during decompression r={0}", r);
  }
 
 private:
 
  String m_name;
 
 private:
 
  int _toInt(Int64 vsize)
  {
    // Checks if it fits in an 'int'.
    Int64 max_int_size = std::numeric_limits<int>::max();
    if (vsize > max_int_size)
      ARCANE_THROW(IOException, "Array is too large to fit in 'int' type: size={0} max={1}", vsize, max_int_size);
    return static_cast<int>(vsize);
  }
};
 
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ARCANE_REGISTER_SERVICE(LZ4DeflateService,
                        ServiceProperty("LZ4", ST_Application),
                        ARCANE_SERVICE_INTERFACE(IDeflateService));
 
ARCANE_REGISTER_SERVICE(LZ4DataCompressor,
                        ServiceProperty("LZ4DataCompressor", ST_Application | ST_CaseOption),
                        ARCANE_SERVICE_INTERFACE(IDataCompressor));
 
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} // End namespace Arcane
 
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