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

#include "config.h"

#include "PODRedBlackTree.h"

#include "ArenaTestHelpers.h"
#include "TreeTestHelpers.h"
#include <gtest/gtest.h>
#include <wtf/Vector.h>

namespace WebCore {

using ArenaTestHelpers::TrackedAllocator;
using TreeTestHelpers::generateSeed;
using TreeTestHelpers::initRandom;
using TreeTestHelpers::nextRandom;

TEST(PODRedBlackTreeTest, TestTreeAllocatesFromArena)
{
    RefPtr<TrackedAllocator> allocator = TrackedAllocator::create();
    {
        RefPtr<PODArena> arena = PODArena::create(allocator);
        PODRedBlackTree<int> tree(arena);
        int numAdditions = 2 * PODArena::DefaultChunkSize / sizeof(int);
        for (int i = 0; i < numAdditions; ++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 treeSize)
{
    initRandom(seed);
    const int maximumValue = treeSize;
    // Build the tree.
    PODRedBlackTree<int> tree;
    Vector<int> values;
    for (int i = 0; i < treeSize; i++) {
        int value = nextRandom(maximumValue);
        tree.add(value);
        ASSERT_TRUE(tree.checkInvariants()) << "Test failed for seed " << seed;
        values.append(value);
    }
    // Churn the tree's contents.
    for (int i = 0; i < treeSize; i++) {
        // Pick a random value to remove.
        int index = nextRandom(treeSize);
        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(maximumValue);
        values[index] = value;
        tree.add(value);
        ASSERT_TRUE(tree.checkInvariants()) << "Test failed for seed " << seed;
    }
}
} // anonymous namespace

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

TEST(PODRedBlackTreeTest, TestRandomDeletionAndInsertion)
{
    InsertionAndDeletionTest(generateSeed(), 100);
}

} // namespace WebCore