Refactoring of job dispatch in HostResolverImpl in preparation for DnsClient.

net/base/priority_queue_unittest.cc

+// Copyright (c) 2011 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "net/base/priority_queue.h"
+#include "testing/gtest/include/gtest/gtest.h"
+
+namespace net {
+
+namespace {
+
+const size_t kPriorities[] = { 2, 1, 2, 0, 4, 3, 1, 4, 0 };
+const size_t kNumPriorities = 5;  // max(kPriorities) + 1
+const size_t kNumElements = arraysize(kPriorities);
+const size_t kMinOrder[kNumElements] = { 3, 8, 1, 6, 0, 2, 5, 4, 7 };
+const size_t kMaxOrder[kNumElements] = { 4, 7, 5, 0, 2, 1, 6, 3, 8 };
+
+void CheckEmpty(PriorityQueue<size_t>* queue) {
+  EXPECT_EQ(0u, queue->size());
+  EXPECT_TRUE(queue->FirstMin().is_null());
+  EXPECT_TRUE(queue->LastMin().is_null());
+  EXPECT_TRUE(queue->FirstMax().is_null());
+  EXPECT_TRUE(queue->LastMax().is_null());
+}
+
+TEST(PriorityQueueTest, AddAndClear) {
+  PriorityQueue<size_t> queue(kNumPriorities);
+  PriorityQueue<size_t>::Pointer pointers[kNumElements];
+
+  CheckEmpty(&queue);
+  for (size_t i = 0; i < kNumElements; ++i) {
+    EXPECT_EQ(i, queue.size());
+    pointers[i] = queue.Insert(i, kPriorities[i]);
+  }
+  EXPECT_EQ(kNumElements, queue.size());
+
+  for (size_t i = 0; i < kNumElements; ++i) {
+    EXPECT_EQ(kPriorities[i], pointers[i].priority());
+    EXPECT_EQ(i, pointers[i].value());
+  }
+
+  queue.Clear();
+  CheckEmpty(&queue);
+}
+
+TEST(PriorityQueueTest, FirstMinOrder) {
+  PriorityQueue<size_t> queue(kNumPriorities);
+  PriorityQueue<size_t>::Pointer pointers[kNumElements];
+
+  for (size_t i = 0; i < kNumElements; ++i) {
+    pointers[i] = queue.Insert(i, kPriorities[i]);
+  }
+
+  for (size_t i = 0; i < kNumElements; ++i) {
+    EXPECT_EQ(kNumElements - i, queue.size());
+    // Also check Equals.
+    EXPECT_TRUE(queue.FirstMin().Equals(pointers[kMinOrder[i]]));
+    EXPECT_EQ(kMinOrder[i], queue.FirstMin().value());
+    queue.Erase(queue.FirstMin());
+  }
+  CheckEmpty(&queue);
+}
+
+TEST(PriorityQueueTest, LastMinOrder) {
+  PriorityQueue<size_t> queue(kNumPriorities);
+
+  for (size_t i = 0; i < kNumElements; ++i) {
+    queue.Insert(i, kPriorities[i]);
+  }
+
+  for (size_t i = 0; i < kNumElements; ++i) {
+    EXPECT_EQ(kMaxOrder[kNumElements - i - 1], queue.LastMin().value());

[cbentzel, 2012/01/05 18:32:20]

Clever reuse of kMaxOrder - but may be clearer to just explicitly list the order
desired. 

+    queue.Erase(queue.LastMin());
+  }
+  CheckEmpty(&queue);
+}
+
+TEST(PriorityQueueTest, FirstMaxOrder) {
+  PriorityQueue<size_t> queue(kNumPriorities);
+
+  for (size_t i = 0; i < kNumElements; ++i) {
+    queue.Insert(i, kPriorities[i]);
+  }
+
+  for (size_t i = 0; i < kNumElements; ++i) {
+    EXPECT_EQ(kMaxOrder[i], queue.FirstMax().value());
+    queue.Erase(queue.FirstMax());
+  }
+  CheckEmpty(&queue);
+}
+
+TEST(PriorityQueueTest, LastMaxOrder) {
+  PriorityQueue<size_t> queue(kNumPriorities);
+
+  for (size_t i = 0; i < kNumElements; ++i) {
+    queue.Insert(i, kPriorities[i]);
+  }
+
+  for (size_t i = 0; i < kNumElements; ++i) {
+    EXPECT_EQ(kMinOrder[kNumElements - i - 1], queue.LastMax().value());
+    queue.Erase(queue.LastMax());
+  }
+  CheckEmpty(&queue);
+}
+
+TEST(PriorityQueueTest, EraseFromMiddle) {
+  PriorityQueue<size_t> queue(kNumPriorities);
+  PriorityQueue<size_t>::Pointer pointers[kNumElements];
+
+  for (size_t i = 0; i < kNumElements; ++i) {
+    pointers[i] = queue.Insert(i, kPriorities[i]);
+  }
+
+  queue.Erase(pointers[2]);
+  queue.Erase(pointers[3]);
+
+  size_t expected_order[] = { 8, 1, 6, 0, 5, 4, 7 };
+
+  for (size_t i = 0; i < arraysize(expected_order); ++i) {
+    EXPECT_EQ(expected_order[i], queue.FirstMin().value());
+    queue.Erase(queue.FirstMin());
+  }
+  CheckEmpty(&queue);
+}
+
+}  // namespace
+
+}  // namespace net
+