////////////////////////////////////////////////////////////////////////////////
/// @brief test suite for arangodb::cache::PlainBucket
///
/// @file
///
/// DISCLAIMER
///
/// Copyright 2017 ArangoDB GmbH, Cologne, Germany
///
/// 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.
///
/// Copyright holder is ArangoDB GmbH, Cologne, Germany
///
/// @author Daniel H. Larkin
/// @author Copyright 2017, ArangoDB GmbH, Cologne, Germany
////////////////////////////////////////////////////////////////////////////////

#include "Cache/PlainBucket.h"
#include "Basics/Common.h"
#include "Basics/debugging.h"

#include "gtest/gtest.h"

#include <stdint.h>
#include <string>

using namespace arangodb::cache;

TEST(CachePlainBucketTest, verify_that_insertion_works_correctly) {
  auto bucket = std::make_unique<PlainBucket>();
  bool success;

  uint32_t hashes[11] = {1, 2, 3, 4,  5, 6,
                         7, 8, 9, 10, 11};  // don't have to be real, but should be unique and non-zero
  uint64_t keys[11] = {0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10};
  uint64_t values[11] = {0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10};
  CachedValue* ptrs[11];
  for (size_t i = 0; i < 11; i++) {
    ptrs[i] = CachedValue::construct(&(keys[i]), sizeof(uint64_t), &(values[i]),
                                     sizeof(uint64_t));
    TRI_ASSERT(ptrs[i] != nullptr);
  }

  success = bucket->lock(-1LL);
  ASSERT_TRUE(success);

  // insert ten to fill
  ASSERT_FALSE(bucket->isFull());
  for (size_t i = 0; i < 10; i++) {
    bucket->insert(hashes[i], ptrs[i]);
    if (i < 9) {
      ASSERT_FALSE(bucket->isFull());
    } else {
      ASSERT_TRUE(bucket->isFull());
    }
  }
  for (size_t i = 0; i < 10; i++) {
    CachedValue* res = bucket->find(hashes[i], ptrs[i]->key(), ptrs[i]->keySize());
    ASSERT_EQ(res, ptrs[i]);
  }

  // check that insert is ignored if full
  bucket->insert(hashes[10], ptrs[10]);
  CachedValue* res = bucket->find(hashes[10], ptrs[10]->key(), ptrs[10]->keySize());
  ASSERT_EQ(nullptr, res);

  bucket->unlock();

  // cleanup
  for (size_t i = 0; i < 11; i++) {
    delete ptrs[i];
  }
}

TEST(CachePlainBucketTest, verify_removal_works_correctly) {
  auto bucket = std::make_unique<PlainBucket>();
  bool success;

  uint32_t hashes[3] = {1, 2, 3};  // don't have to be real, but should be unique and non-zero
  uint64_t keys[3] = {0, 1, 2};
  uint64_t values[3] = {0, 1, 2};
  CachedValue* ptrs[3];
  for (size_t i = 0; i < 3; i++) {
    ptrs[i] = CachedValue::construct(&(keys[i]), sizeof(uint64_t), &(values[i]),
                                     sizeof(uint64_t));
    TRI_ASSERT(ptrs[i] != nullptr);
  }

  success = bucket->lock(-1LL);
  ASSERT_TRUE(success);

  for (size_t i = 0; i < 3; i++) {
    bucket->insert(hashes[i], ptrs[i]);
  }
  for (size_t i = 0; i < 3; i++) {
    CachedValue* res = bucket->find(hashes[i], ptrs[i]->key(), ptrs[i]->keySize());
    ASSERT_EQ(res, ptrs[i]);
  }

  CachedValue* res;
  res = bucket->remove(hashes[1], ptrs[1]->key(), ptrs[1]->keySize());
  ASSERT_EQ(res, ptrs[1]);
  res = bucket->find(hashes[1], ptrs[1]->key(), ptrs[1]->keySize());
  ASSERT_EQ(nullptr, res);
  res = bucket->remove(hashes[0], ptrs[0]->key(), ptrs[0]->keySize());
  ASSERT_EQ(res, ptrs[0]);
  res = bucket->find(hashes[0], ptrs[0]->key(), ptrs[0]->keySize());
  ASSERT_EQ(nullptr, res);
  res = bucket->remove(hashes[2], ptrs[2]->key(), ptrs[2]->keySize());
  ASSERT_EQ(res, ptrs[2]);
  res = bucket->find(hashes[2], ptrs[2]->key(), ptrs[2]->keySize());
  ASSERT_EQ(nullptr, res);

  bucket->unlock();

  // cleanup
  for (size_t i = 0; i < 3; i++) {
    delete ptrs[i];
  }
}

TEST(CachePlainBucketTest, verify_eviction_works_correctly) {
  auto bucket = std::make_unique<PlainBucket>();
  bool success;

  uint32_t hashes[11] = {1, 2, 3, 4,  5, 6,
                         7, 8, 9, 10, 11};  // don't have to be real, but should be unique and non-zero
  uint64_t keys[11] = {0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10};
  uint64_t values[11] = {0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10};
  CachedValue* ptrs[11];
  for (size_t i = 0; i < 11; i++) {
    ptrs[i] = CachedValue::construct(&(keys[i]), sizeof(uint64_t), &(values[i]),
                                     sizeof(uint64_t));
    TRI_ASSERT(ptrs[i] != nullptr);
  }

  success = bucket->lock(-1LL);
  ASSERT_TRUE(success);

  // insert five to fill
  ASSERT_FALSE(bucket->isFull());
  for (size_t i = 0; i < 10; i++) {
    bucket->insert(hashes[i], ptrs[i]);
    if (i < 9) {
      ASSERT_FALSE(bucket->isFull());
    } else {
      ASSERT_TRUE(bucket->isFull());
    }
  }
  for (size_t i = 0; i < 10; i++) {
    CachedValue* res = bucket->find(hashes[i], ptrs[i]->key(), ptrs[i]->keySize());
    ASSERT_EQ(res, ptrs[i]);
  }

  // check that we get proper eviction candidate
  CachedValue* candidate = bucket->evictionCandidate();
  ASSERT_EQ(candidate, ptrs[0]);
  bucket->evict(candidate, false);
  CachedValue* res = bucket->find(hashes[0], ptrs[0]->key(), ptrs[0]->keySize());
  ASSERT_EQ(nullptr, res);
  ASSERT_FALSE(bucket->isFull());

  // check that we still find the right candidate if not full
  candidate = bucket->evictionCandidate();
  ASSERT_EQ(candidate, ptrs[1]);
  bucket->evict(candidate, true);
  res = bucket->find(hashes[1], ptrs[1]->key(), ptrs[1]->keySize());
  ASSERT_EQ(nullptr, res);
  ASSERT_FALSE(bucket->isFull());

  // check that we can insert now after eviction optimized for insertion
  bucket->insert(hashes[10], ptrs[10]);
  res = bucket->find(hashes[10], ptrs[10]->key(), ptrs[10]->keySize());
  ASSERT_EQ(res, ptrs[10]);

  bucket->unlock();

  // cleanup
  for (size_t i = 0; i < 11; i++) {
    delete ptrs[i];
  }
}