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 * Copyright (C) 2010 Google Inc. All rights reserved.
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// Tests for the red-black tree class.

#include "platform/PODRedBlackTree.h"

#include "platform/testing/ArenaTestHelpers.h"
#include "platform/testing/TreeTestHelpers.h"
#include "platform/wtf/Vector.h"
#include "testing/gtest/include/gtest/gtest.h"

namespace blink {

using ArenaTestHelpers::TrackedAllocator;
using TreeTestHelpers::InitRandom;
using TreeTestHelpers::NextRandom;

TEST(PODRedBlackTreeTest, TestTreeAllocatesFromArena) {
  scoped_refptr<TrackedAllocator> allocator = TrackedAllocator::Create();
  {
    typedef PODFreeListArena<PODRedBlackTree<int>::Node> PODIntegerArena;
    scoped_refptr<PODIntegerArena> arena = PODIntegerArena::Create(allocator);
    PODRedBlackTree<int> tree(arena);
    int num_additions = 2 * PODArena::kDefaultChunkSize / sizeof(int);
    for (int i = 0; i < num_additions; ++i)
      tree.Add(i);
    EXPECT_GT(allocator->NumRegions(), 1);
  }
  EXPECT_EQ(allocator->NumRegions(), 0);
}

TEST(PODRedBlackTreeTest, TestSingleElementInsertion) {
  PODRedBlackTree<int> tree;
  tree.Add(5);
  ASSERT_TRUE(tree.CheckInvariants());
  EXPECT_TRUE(tree.Contains(5));
}

TEST(PODRedBlackTreeTest, TestMultipleElementInsertion) {
  PODRedBlackTree<int> tree;
  tree.Add(4);
  ASSERT_TRUE(tree.CheckInvariants());
  EXPECT_TRUE(tree.Contains(4));
  tree.Add(3);
  ASSERT_TRUE(tree.CheckInvariants());
  EXPECT_TRUE(tree.Contains(3));
  tree.Add(5);
  ASSERT_TRUE(tree.CheckInvariants());
  EXPECT_TRUE(tree.Contains(5));
  EXPECT_TRUE(tree.Contains(4));
  EXPECT_TRUE(tree.Contains(3));
}

TEST(PODRedBlackTreeTest, TestDuplicateElementInsertion) {
  PODRedBlackTree<int> tree;
  tree.Add(3);
  ASSERT_TRUE(tree.CheckInvariants());
  tree.Add(3);
  ASSERT_TRUE(tree.CheckInvariants());
  tree.Add(3);
  ASSERT_TRUE(tree.CheckInvariants());
  EXPECT_EQ(3, tree.size());
  EXPECT_TRUE(tree.Contains(3));
}

TEST(PODRedBlackTreeTest, TestSingleElementInsertionAndDeletion) {
  PODRedBlackTree<int> tree;
  tree.Add(5);
  ASSERT_TRUE(tree.CheckInvariants());
  EXPECT_TRUE(tree.Contains(5));
  tree.Remove(5);
  ASSERT_TRUE(tree.CheckInvariants());
  EXPECT_FALSE(tree.Contains(5));
}

TEST(PODRedBlackTreeTest, TestMultipleElementInsertionAndDeletion) {
  PODRedBlackTree<int> tree;
  tree.Add(4);
  ASSERT_TRUE(tree.CheckInvariants());
  EXPECT_TRUE(tree.Contains(4));
  tree.Add(3);
  ASSERT_TRUE(tree.CheckInvariants());
  EXPECT_TRUE(tree.Contains(3));
  tree.Add(5);
  ASSERT_TRUE(tree.CheckInvariants());
  EXPECT_TRUE(tree.Contains(5));
  EXPECT_TRUE(tree.Contains(4));
  EXPECT_TRUE(tree.Contains(3));
  tree.Remove(4);
  ASSERT_TRUE(tree.CheckInvariants());
  EXPECT_TRUE(tree.Contains(3));
  EXPECT_FALSE(tree.Contains(4));
  EXPECT_TRUE(tree.Contains(5));
  tree.Remove(5);
  ASSERT_TRUE(tree.CheckInvariants());
  EXPECT_TRUE(tree.Contains(3));
  EXPECT_FALSE(tree.Contains(4));
  EXPECT_FALSE(tree.Contains(5));
  EXPECT_EQ(1, tree.size());
}

TEST(PODRedBlackTreeTest, TestDuplicateElementInsertionAndDeletion) {
  PODRedBlackTree<int> tree;
  tree.Add(3);
  ASSERT_TRUE(tree.CheckInvariants());
  tree.Add(3);
  ASSERT_TRUE(tree.CheckInvariants());
  tree.Add(3);
  ASSERT_TRUE(tree.CheckInvariants());
  EXPECT_EQ(3, tree.size());
  EXPECT_TRUE(tree.Contains(3));
  tree.Remove(3);
  ASSERT_TRUE(tree.CheckInvariants());
  tree.Remove(3);
  ASSERT_TRUE(tree.CheckInvariants());
  EXPECT_EQ(1, tree.size());
  EXPECT_TRUE(tree.Contains(3));
  tree.Remove(3);
  ASSERT_TRUE(tree.CheckInvariants());
  EXPECT_EQ(0, tree.size());
  EXPECT_FALSE(tree.Contains(3));
}

TEST(PODRedBlackTreeTest, FailingInsertionRegressionTest1) {
  // These numbers came from a previously-failing randomized test run.
  PODRedBlackTree<int> tree;
  tree.Add(5113);
  ASSERT_TRUE(tree.CheckInvariants());
  tree.Add(4517);
  ASSERT_TRUE(tree.CheckInvariants());
  tree.Add(3373);
  ASSERT_TRUE(tree.CheckInvariants());
  tree.Add(9307);
  ASSERT_TRUE(tree.CheckInvariants());
  tree.Add(7077);
  ASSERT_TRUE(tree.CheckInvariants());
}

namespace {
void InsertionAndDeletionTest(const int32_t seed, const int tree_size) {
  InitRandom(seed);
  const int maximum_value = tree_size;
  // Build the tree.
  PODRedBlackTree<int> tree;
  Vector<int> values;
  for (int i = 0; i < tree_size; i++) {
    int value = NextRandom(maximum_value);
    tree.Add(value);
    ASSERT_TRUE(tree.CheckInvariants()) << "Test failed for seed " << seed;
    values.push_back(value);
  }
  // Churn the tree's contents.
  for (int i = 0; i < tree_size; i++) {
    // Pick a random value to remove.
    int index = NextRandom(tree_size);
    int value = values[index];
    // Remove this value.
    tree.Remove(value);
    ASSERT_TRUE(tree.CheckInvariants()) << "Test failed for seed " << seed;
    // Replace it with a new one.
    value = NextRandom(maximum_value);
    values[index] = value;
    tree.Add(value);
    ASSERT_TRUE(tree.CheckInvariants()) << "Test failed for seed " << seed;
  }
}
}  // anonymous namespace

TEST(PODRedBlackTreeTest, RandomDeletionAndInsertionRegressionTest1) {
  InsertionAndDeletionTest(12311, 100);
}

}  // namespace blink