text: // Copyright (c) 2021 The Khronos Group Inc.
  //
  // 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.
  
  #include <algorithm>
  #include <list>
  #include <utility>
  #include <vector>
  
  #include "gmock/gmock.h"
  #include "source/util/pooled_linked_list.h"
  
  namespace spvtools {
  namespace utils {
  namespace {
  
  using PooledLinkedListTest = ::testing::Test;
  
  template <typename T>
  static std::vector<T> ToVector(const PooledLinkedList<T>& list) {
    std::vector<T> vec;
    for (auto it = list.begin(); it != list.end(); ++it) {
      vec.push_back(*it);
    }
    return vec;
  }
  
  template <typename T>
  static void AppendVector(PooledLinkedList<T>& list, const std::vector<T>& vec) {
    for (const T& t : vec) {
      list.push_back(t);
    }
  }
  
  TEST(PooledLinkedListTest, Empty) {
    PooledLinkedListNodes<uint32_t> pool;
    PooledLinkedList<uint32_t> ll(&pool);
    EXPECT_TRUE(ll.empty());
  
    ll.push_back(1u);
    EXPECT_TRUE(!ll.empty());
  }
  
  TEST(PooledLinkedListTest, Iterator) {
    PooledLinkedListNodes<uint32_t> pool;
    PooledLinkedList<uint32_t> ll(&pool);
  
    EXPECT_EQ(ll.begin(), ll.end());
  
    ll.push_back(1);
    EXPECT_NE(ll.begin(), ll.end());
  
    auto it = ll.begin();
    EXPECT_EQ(*it, 1);
    ++it;
    EXPECT_EQ(it, ll.end());
  }
  
  TEST(PooledLinkedListTest, Iterator_algorithms) {
    PooledLinkedListNodes<uint32_t> pool;
    PooledLinkedList<uint32_t> ll(&pool);
  
    AppendVector(ll, {3, 2, 0, 1});
    EXPECT_EQ(std::distance(ll.begin(), ll.end()), 4);
    EXPECT_EQ(*std::min_element(ll.begin(), ll.end()), 0);
    EXPECT_EQ(*std::max_element(ll.begin(), ll.end()), 3);
  }
  
  TEST(PooledLinkedListTest, FrontBack) {
    PooledLinkedListNodes<uint32_t> pool;
    PooledLinkedList<uint32_t> ll(&pool);
  
    ll.push_back(1);
    EXPECT_EQ(ll.front(), 1);
    EXPECT_EQ(ll.back(), 1);
  
    ll.push_back(2);
    EXPECT_EQ(ll.front(), 1);
    EXPECT_EQ(ll.back(), 2);
  }
  
  TEST(PooledLinkedListTest, PushBack) {
    const std::vector<uint32_t> vec = {1, 2, 3, 4, 5, 6};
  
    PooledLinkedListNodes<uint32_t> pool;
    PooledLinkedList<uint32_t> ll(&pool);
  
    AppendVector(ll, vec);
    EXPECT_EQ(vec, ToVector(ll));
  }
  
  TEST(PooledLinkedListTest, RemoveFirst) {
    const std::vector<uint32_t> vec = {1, 2, 3, 4, 5, 6};
  
    PooledLinkedListNodes<uint32_t> pool;
    PooledLinkedList<uint32_t> ll(&pool);
  
    EXPECT_FALSE(ll.remove_first(0));
    AppendVector(ll, vec);
    EXPECT_FALSE(ll.remove_first(0));
  
    std::vector<uint32_t> tmp = vec;
    while (!tmp.empty()) {
      size_t mid = tmp.size() / 2;
      uint32_t elt = tmp[mid];
      tmp.erase(tmp.begin() + mid);
  
      EXPECT_TRUE(ll.remove_first(elt));
      EXPECT_FALSE(ll.remove_first(elt));
      EXPECT_EQ(tmp, ToVector(ll));
    }
    EXPECT_TRUE(ll.empty());
  }
  
  TEST(PooledLinkedListTest, RemoveFirst_Duplicates) {
    const std::vector<uint32_t> vec = {3, 1, 2, 3, 3, 3, 3, 4, 3, 5, 3, 6, 3};
  
    PooledLinkedListNodes<uint32_t> pool;
    PooledLinkedList<uint32_t> ll(&pool);
    AppendVector(ll, vec);
  
    std::vector<uint32_t> tmp = vec;
    while (!tmp.empty()) {
      size_t mid = tmp.size() / 2;
      uint32_t elt = tmp[mid];
      tmp.erase(std::find(tmp.begin(), tmp.end(), elt));
  
      EXPECT_TRUE(ll.remove_first(elt));
      EXPECT_EQ(tmp, ToVector(ll));
    }
    EXPECT_TRUE(ll.empty());
  }
  
  TEST(PooledLinkedList, MoveTo) {
    const std::vector<uint32_t> vec = {1, 2, 3, 4, 5, 6};
  
    PooledLinkedListNodes<uint32_t> pool;
    PooledLinkedList<uint32_t> ll1(&pool);
    PooledLinkedList<uint32_t> ll2(&pool);
    PooledLinkedList<uint32_t> ll3(&pool);
  
    AppendVector(ll1, vec);
    AppendVector(ll2, vec);
    AppendVector(ll3, vec);
    EXPECT_EQ(pool.total_nodes(), vec.size() * 3);
    EXPECT_EQ(pool.total_nodes(), vec.size() * 3);
    EXPECT_EQ(pool.free_nodes(), 0);
  
    // Move two lists to the new pool
    PooledLinkedListNodes<uint32_t> pool_new;
    ll1.move_nodes(&pool_new);
    ll2.move_nodes(&pool_new);
  
    // Moved nodes should belong to new pool
    EXPECT_EQ(ll1.pool(), &pool_new);
    EXPECT_EQ(ll2.pool(), &pool_new);
  
    // Old pool should be smaller & have free nodes.
    EXPECT_EQ(pool.used_nodes(), vec.size());
    EXPECT_EQ(pool.free_nodes(), vec.size() * 2);
  
    // New pool should be sized exactly and no free nodes.
    EXPECT_EQ(pool_new.total_nodes(), vec.size() * 2);
    EXPECT_EQ(pool_new.used_nodes(), vec.size() * 2);
    EXPECT_EQ(pool_new.free_nodes(), 0);
  
    // All lists should be preserved
    EXPECT_EQ(ToVector(ll1), vec);
    EXPECT_EQ(ToVector(ll2), vec);
    EXPECT_EQ(ToVector(ll3), vec);
  }
  
  }  // namespace
  }  // namespace utils
  }  // namespace spvtools
  