/* Copyright 2022 The TensorFlow Authors. All Rights Reserved.

Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at

http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.
==============================================================================*/
#if GOOGLE_CUDA && GOOGLE_TENSORRT

#include "tensorflow/compiler/tf2tensorrt/convert/timing_cache.h"

#include <unordered_map>

#include "tensorflow/compiler/tf2tensorrt/common/utils.h"
#include "tensorflow/core/platform/errors.h"
#include "third_party/tensorrt/NvInfer.h"

namespace tensorflow {
namespace tensorrt {
namespace convert {

StatusOr<TimingCacheRegistry::TimingCachePtr> TimingCacheRegistry::LookUp(
    const string& name, nvinfer1::IBuilderConfig* builder_config) {
#if IS_TRT_VERSION_GE(8, 0, 0, 0)
  TRT_ENSURE(builder_config != nullptr);
  mutex_lock scoped_lock(mu_);
  if (map_.find(name) != map_.end()) {
    const std::vector<uint8_t>& data = map_[name];
    return std::unique_ptr<nvinfer1::ITimingCache>(
        builder_config->createTimingCache(data.data(), data.size()));
  }

  // If no such timing cache exists, create a new timing cache.
  return std::unique_ptr<nvinfer1::ITimingCache>(
      builder_config->createTimingCache(nullptr, 0));
#endif  // IS_TRT_VERSION_GE(8, 0, 0, 0)
  return errors::Unimplemented(
      "serializable timing cache does not exist in TensorRT versions < 8.0");
}

void TimingCacheRegistry::Upsert(const string& name, TimingCache* cache) {
#if IS_TRT_VERSION_GE(8, 0, 0, 0)
  nvinfer1::IHostMemory* memory = cache->serialize();
  if (memory == nullptr) {
    return;
  }

  if (map_.find(name) == map_.end()) {
    // If the timing cache with the given name does not exist, emplace the
    // serialized buffer.
    std::vector<uint8_t> mem(memory->size());
    std::copy_n(static_cast<uint8_t*>(memory->data()), memory->size(),
                mem.begin());
    {
      mutex_lock scoped_lock(mu_);
      map_.emplace(name, std::move(mem));
    }
  } else {
    // If the timing cache does exist, use the existing buffer.
    mutex_lock scoped_lock(mu_);
    std::vector<uint8_t>& mem = map_[name];
    mem.resize(memory->size());
    std::copy_n(static_cast<uint8_t*>(memory->data()), memory->size(),
                mem.begin());
  }
  memory->destroy();
#endif  // IS_TRT_VERSION_GE(8, 0, 0, 0)
}

TimingCacheRegistry* GetTimingCacheRegistry() {
  static TimingCacheRegistry* registry = new TimingCacheRegistry();
  return registry;
}

}  // namespace convert
}  // namespace tensorrt
}  // namespace tensorflow

#endif  // GOOGLE_CUDA && GOOGLE_TENSORRT