text: // Copyright 2017 The Chromium Authors. All rights reserved.
  // Use of this source code is governed by a BSD-style license that can be
  // found in the LICENSE file.
  
  #include <cstddef>
  #include <cstdint>
  #include <random>
  
  #include "base/logging.h"
  #include "testing/libfuzzer/fuzzers/color_space_data.h"
  #include "third_party/qcms/src/qcms.h"
  
  static constexpr size_t kPixels = 2048 / 4;
  
  static uint32_t pixels[kPixels];
  
  static void GeneratePixels(size_t hash) {
    static std::uniform_int_distribution<uint32_t> uniform(0u, ~0u);
  
    std::mt19937_64 random(hash);
    for (size_t i = 0; i < arraysize(pixels); ++i)
      pixels[i] = uniform(random);
  }
  
  static qcms_profile* test;
  static qcms_profile* srgb;
  
  static void ColorTransform(bool input) {
    if (!test)
      return;
  
    const qcms_intent intent = QCMS_INTENT_DEFAULT;
    const qcms_data_type format = QCMS_DATA_RGBA_8;
  
    auto* transform =
        input ? qcms_transform_create(test, format, srgb, format, intent)
              : qcms_transform_create(srgb, format, test, format, intent);
    if (!transform)
      return;
  
    static uint32_t output[kPixels];
  
    qcms_transform_data(transform, pixels, output, kPixels);
    qcms_transform_release(transform);
  }
  
  static qcms_profile* SelectProfile(size_t hash) {
    static qcms_profile* profiles[4] = {
        qcms_profile_from_memory(kSRGBData, arraysize(kSRGBData)),
        qcms_profile_from_memory(kSRGBPara, arraysize(kSRGBPara)),
        qcms_profile_from_memory(kAdobeData, arraysize(kAdobeData)),
        qcms_profile_sRGB(),
    };
  
    return profiles[hash & 3];
  }
  
  inline size_t Hash(const char* data, size_t size, size_t hash = ~0) {
    for (size_t i = 0; i < size; ++i)
      hash = hash * 131 + *data++;
    return hash;
  }
  
  extern "C" int LLVMFuzzerTestOneInput(const uint8_t* data, size_t size) {
    constexpr size_t kSizeLimit = 4 * 1024 * 1024;
    if (size < 128 || size > kSizeLimit)
      return 0;
  
    test = qcms_profile_from_memory(data, size);
    if (!test)
      return 0;
  
    const size_t hash = Hash(reinterpret_cast<const char*>(data), size);
    srgb = SelectProfile(hash);
    GeneratePixels(hash);
  
    qcms_profile_precache_output_transform(srgb);
    ColorTransform(true);
  
    qcms_profile_precache_output_transform(test);
    ColorTransform(false);
  
    qcms_profile_release(test);
    return 0;
  }
  