/*
   Copyright (c) 2020, 2025, Oracle and/or its affiliates.

   This program is free software; you can redistribute it and/or modify
   it under the terms of the GNU General Public License, version 2.0,
   as published by the Free Software Foundation.

   This program is designed to work with certain software (including
   but not limited to OpenSSL) that is licensed under separate terms,
   as designated in a particular file or component or in included license
   documentation.  The authors of MySQL hereby grant you an additional
   permission to link the program and your derivative works with the
   separately licensed software that they have either included with
   the program or referenced in the documentation.

   This program is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   GNU General Public License, version 2.0, for more details.

   You should have received a copy of the GNU General Public License
   along with this program; if not, write to the Free Software
   Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301  USA
*/

#include <gmock/gmock.h>
#include <gtest/gtest.h>
#include <deque>

#include "mem_root_deque.h"
#include "my_alloc.h"
#include "sql/mem_root_allocator.h"
#include "unittest/gunit/benchmark.h"

using testing::ElementsAre;

TEST(MemRootDequeTest, Basic) {
  MEM_ROOT mem_root;
  mem_root_deque<int> d(&mem_root);
  EXPECT_TRUE(d.empty());

  d.push_back(1);
  d.push_back(2);
  d.push_back(3);
  EXPECT_THAT(d, ElementsAre(1, 2, 3));
  EXPECT_EQ(3, d.size());
  EXPECT_FALSE(d.empty());

  d.push_front(0);
  d.push_front(-1);
  EXPECT_THAT(d, ElementsAre(-1, 0, 1, 2, 3));
  EXPECT_EQ(5, d.size());
  EXPECT_FALSE(d.empty());

  EXPECT_EQ(-1, d[0]);
  EXPECT_EQ(0, d[1]);
  EXPECT_EQ(1, d[2]);
  EXPECT_EQ(2, d[3]);
  EXPECT_EQ(3, d[4]);

  d.pop_front();
  EXPECT_THAT(d, ElementsAre(0, 1, 2, 3));
  EXPECT_EQ(0, d[0]);
  EXPECT_EQ(1, d[1]);
  EXPECT_EQ(2, d[2]);
  EXPECT_EQ(3, d[3]);

  d.pop_back();
  d.pop_back();
  EXPECT_THAT(d, ElementsAre(0, 1));

  d.push_front(1234);
  EXPECT_THAT(d, ElementsAre(1234, 0, 1));
}

TEST(MemRootDequeTest, EraseInsert) {
  MEM_ROOT mem_root;
  mem_root_deque<int> d(&mem_root);

  d.push_back(1);
  d.push_back(2);
  d.push_back(3);
  d.push_back(4);
  d.push_back(5);

  auto it = d.erase(d.begin() + 1, d.begin() + 3);
  EXPECT_THAT(d, ElementsAre(1, 4, 5));

  int new_elems[] = {200, 300, 400, 500};
  it = d.insert(it, std::begin(new_elems), std::end(new_elems));
  EXPECT_THAT(d, ElementsAre(1, 200, 300, 400, 500, 4, 5));
  EXPECT_EQ(it, d.begin() + 1);

  it = d.insert(d.begin() + 3, 350);
  EXPECT_THAT(d, ElementsAre(1, 200, 300, 350, 400, 500, 4, 5));
  EXPECT_EQ(it, d.begin() + 3);
  EXPECT_EQ(350, *it);
}

TEST(MemRootDequeTest, Sort) {
  MEM_ROOT mem_root;
  mem_root_deque<std::string> d(&mem_root);

  d.push_back("a");
  d.push_back("zzzzzzzzzzzzzzzzzzzzzz");
  d.push_back("x");
  d.push_back("12345");
  d.push_back("hello");

  std::sort(d.begin(), d.end());

  EXPECT_THAT(
      d, ElementsAre("12345", "a", "hello", "x", "zzzzzzzzzzzzzzzzzzzzzz"));
}

TEST(MemRootDequeTest, PointerStability) {
  MEM_ROOT mem_root;
  mem_root_deque<int> d(&mem_root);

  d.push_back(1);
  d.push_back(2);
  d.push_back(3);
  int *ptr = &d[1];
  d.push_front(0);
  EXPECT_EQ(2, *ptr);
  d.push_back(4);
  EXPECT_EQ(2, *ptr);
  d.pop_back();
  d.pop_back();
  EXPECT_EQ(2, *ptr);
  d.pop_front();
  d.pop_front();
  EXPECT_EQ(2, *ptr);

  EXPECT_THAT(d, ElementsAre(2));
}

TEST(MemRootDequeTest, Iteration) {
  MEM_ROOT mem_root;
  mem_root_deque<int> d(&mem_root);

  d.push_back(1);
  d.push_back(2);
  d.push_back(3);
  d.push_back(4);
  d.push_back(5);

  auto it = d.begin();
  EXPECT_EQ(d.begin(), it);
  EXPECT_NE(d.end(), it);
  EXPECT_EQ(1, *it++);
  EXPECT_EQ(2, *it++);
  EXPECT_EQ(4, *++it);
  it -= 2;
  EXPECT_EQ(2, *it);
  it += 2;
  EXPECT_EQ(4, *it--);
  EXPECT_EQ(3, *it--);
  EXPECT_EQ(1, *--it);
  EXPECT_EQ(d.end(), it + 5);
}

TEST(MemRootDequeTest, OperatorArrow) {
  MEM_ROOT mem_root;
  mem_root_deque<std::string> d(&mem_root);

  d.push_back("a");
  d.push_back("aa");
  d.push_back("aaa");

  auto it = d.begin();
  EXPECT_EQ(1, it->size());
  ++it;
  EXPECT_EQ(2, it->size());
  ++it;
  EXPECT_EQ(3, it->size());
}

// The other tests can also be used for stressing multi-block code,
// if you force FindElementsPerBlock() to return 1.
TEST(MemRootDequeTest, MultipleBlocks) {
  MEM_ROOT mem_root;
  mem_root_deque<int> d(&mem_root);

  for (int i = 0; i < 5000; ++i) {
    d.push_back(i);
  }
  EXPECT_EQ(5000, d.size());
  for (int i = 0; i < 1000; ++i) {
    d.pop_front();
  }
  for (int i = 0; i < 1000; ++i) {
    d.pop_back();
  }
  EXPECT_EQ(3000, d.size());
  EXPECT_EQ(1000, d.front());
  EXPECT_EQ(3999, d.back());
}

TEST(MemRootDequeTest, Copy) {
  MEM_ROOT mem_root;
  mem_root_deque<int> d(&mem_root);
  d.push_back(1);
  d.push_back(2);
  d.push_back(3);
  mem_root_deque<int> e(d);
  e[0] = 5;
  EXPECT_THAT(d, ElementsAre(1, 2, 3));
  EXPECT_THAT(e, ElementsAre(5, 2, 3));

  d = e;
  d[1] = 10;
  EXPECT_THAT(d, ElementsAre(5, 10, 3));
  EXPECT_THAT(e, ElementsAre(5, 2, 3));
}

TEST(MemRootDequeTest, Move) {
  MEM_ROOT mem_root;
  mem_root_deque<int> d(&mem_root);
  d.push_back(1);
  d.push_back(2);
  d.push_back(3);
  mem_root_deque<int> e(std::move(d));
  EXPECT_TRUE(d.empty());
  EXPECT_THAT(e, ElementsAre(1, 2, 3));

  d = std::move(e);
  EXPECT_THAT(d, ElementsAre(1, 2, 3));
  EXPECT_TRUE(e.empty());
}

TEST(MemRootDequeTest, ReverseIteration) {
  MEM_ROOT mem_root;
  mem_root_deque<int> d(&mem_root);
  d.push_back(1);
  d.push_back(2);
  d.push_back(3);
  mem_root_deque<int> e(&mem_root);
  for (auto it = d.rbegin(); it != d.rend(); ++it) {
    e.push_back(*it);
  }
  EXPECT_THAT(e, ElementsAre(3, 2, 1));

  const mem_root_deque<int> &d_ref = d;
  for (auto it = d_ref.rbegin(); it != d_ref.rend(); ++it) {
    e.push_back(*it);
  }
}

TEST(MemRootDequeTest, ConvertIterators) {
  MEM_ROOT mem_root;
  mem_root_deque<int> d(&mem_root);
  mem_root_deque<int>::iterator i = d.begin();
  mem_root_deque<int>::const_iterator j{i};
}

// Microbenchmarks.

template <class T>
using std_mem_root_deque = std::deque<T, Mem_root_allocator<T>>;

static void BM_EmptyConstruct(size_t num_iterations) {
  MEM_ROOT mem_root;
  for (size_t i = 0; i < num_iterations; ++i) {
    { mem_root_deque<int> d(&mem_root); }
    mem_root.ClearForReuse();
  }
}
BENCHMARK(BM_EmptyConstruct)

static void BM_EmptyConstructStdDeque(size_t num_iterations) {
  MEM_ROOT mem_root;
  for (size_t i = 0; i < num_iterations; ++i) {
    { std_mem_root_deque<int> d{Mem_root_allocator<int>(&mem_root)}; }
    mem_root.ClearForReuse();
  }
}
BENCHMARK(BM_EmptyConstructStdDeque)

static void BM_PushBackAndFront(size_t num_iterations) {
  MEM_ROOT mem_root;
  for (size_t i = 0; i < num_iterations; ++i) {
    {
      mem_root_deque<int> d(&mem_root);
      for (size_t j = 0; j < 1000; ++j) {
        d.push_back(j);
      }
      for (size_t j = 0; j < 1000; ++j) {
        d.push_front(j);
      }
    }
    mem_root.ClearForReuse();
  }
}
BENCHMARK(BM_PushBackAndFront)

static void BM_PushBackAndFrontStdDeque(size_t num_iterations) {
  MEM_ROOT mem_root;
  for (size_t i = 0; i < num_iterations; ++i) {
    {
      std_mem_root_deque<int> d{Mem_root_allocator<int>(&mem_root)};
      for (size_t j = 0; j < 1000; ++j) {
        d.push_back(j);
      }
      for (size_t j = 0; j < 1000; ++j) {
        d.push_front(j);
      }
    }
    mem_root.ClearForReuse();
  }
}
BENCHMARK(BM_PushBackAndFrontStdDeque)

static void BM_RandomAccess(size_t num_iterations) {
  StopBenchmarkTiming();
  MEM_ROOT mem_root;
  mem_root_deque<unsigned> d(&mem_root);
  for (size_t j = 0; j < 1024; ++j) {
    d.push_back(j + 1);
  }
  for (size_t j = 0; j < 1024; ++j) {
    d.push_front(j + 1);
  }
  StartBenchmarkTiming();

  unsigned sum = 0;  // To prevent it from being optimized away.
  for (size_t i = 0; i < num_iterations; ++i) {
    for (size_t j = 0; j < 1024; ++j) {  // We can't show less than ns.
      sum += d[((i + j) * 997) % 2048];
    }
  }
  if (sum == 0) abort();
}
BENCHMARK(BM_RandomAccess)

static void BM_RandomAccessStdDeque(size_t num_iterations) {
  StopBenchmarkTiming();
  MEM_ROOT mem_root;
  std_mem_root_deque<unsigned> d{Mem_root_allocator<unsigned>(&mem_root)};
  for (size_t j = 0; j < 1024; ++j) {
    d.push_back(j + 1);
  }
  for (size_t j = 0; j < 1024; ++j) {
    d.push_front(j + 1);
  }
  StartBenchmarkTiming();

  unsigned sum = 0;  // To prevent it from being optimized away.
  for (size_t i = 0; i < num_iterations; ++i) {
    for (size_t j = 0; j < 1024; ++j) {  // We can't show less than ns.
      sum += d[((i + j) * 997) % 2048];
    }
  }
  if (sum == 0) abort();
}
BENCHMARK(BM_RandomAccessStdDeque)

static void BM_Iteration(size_t num_iterations) {
  StopBenchmarkTiming();
  MEM_ROOT mem_root;
  mem_root_deque<unsigned> d(&mem_root);
  for (size_t j = 0; j < 1024; ++j) {
    d.push_back(j + 1);
  }
  for (size_t j = 0; j < 1024; ++j) {
    d.push_front(j + 1);
  }
  StartBenchmarkTiming();

  unsigned sum = 0;  // To prevent it from being optimized away.
  for (size_t i = 0; i < num_iterations; ++i) {
    for (unsigned x : d) {
      sum += x;
    }
  }
  if (sum == 0) abort();
}
BENCHMARK(BM_Iteration)

static void BM_IterationStdDeque(size_t num_iterations) {
  StopBenchmarkTiming();
  MEM_ROOT mem_root;
  std_mem_root_deque<unsigned> d{Mem_root_allocator<unsigned>(&mem_root)};
  for (size_t j = 0; j < 1024; ++j) {
    d.push_back(j + 1);
  }
  for (size_t j = 0; j < 1024; ++j) {
    d.push_front(j + 1);
  }
  StartBenchmarkTiming();

  unsigned sum = 0;  // To prevent it from being optimized away.
  for (size_t i = 0; i < num_iterations; ++i) {
    for (unsigned x : d) {
      sum += x;
    }
  }
  if (sum == 0) abort();
}
BENCHMARK(BM_IterationStdDeque)