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 {
+
+TEST(PriorityQueueTest, OrderEraseAndClear) {
+  PriorityQueue<size_t> queue;
+  RequestPriority priorities[] = {
+      LOW,
+      MEDIUM,
+      LOW,
+      HIGHEST,
+      IDLE,
+      LOWEST,
+      MEDIUM,
+      IDLE,
+      HIGHEST,
+  };
+  const size_t kNumPriorities = arraysize(priorities);
+  size_t expected_order[kNumPriorities] = { 3, 8, 1, 6, 0, 2, 5, 4, 7 };
+  size_t oldest_lowest[kNumPriorities] = { 4, 7, 5, 0, 2, 1, 6, 3, 8 };
+  PriorityQueue<size_t>::Pointer pointers[kNumPriorities];
+
+  // Check queue is empty.
+  EXPECT_EQ(0u, queue.size());
+  EXPECT_TRUE(queue.First().is_null());
+  EXPECT_TRUE(queue.Last().is_null());
+
+  for (size_t i = 0; i < kNumPriorities; ++i) {
+    EXPECT_EQ(i, queue.size());
+    pointers[i] = queue.Insert(i, priorities[i]);
+  }
+  EXPECT_EQ(kNumPriorities, queue.size());
+
+  for (size_t i = 0; i < kNumPriorities; ++i) {
+    EXPECT_EQ(priorities[i], pointers[i].priority());
+    EXPECT_EQ(i, pointers[i].value());
+  }
+
+  // Test forward direction.
+  for (size_t i = 0; i < kNumPriorities; ++i) {
+    EXPECT_EQ(expected_order[i], queue.First().value());
+    EXPECT_EQ(kNumPriorities - i, queue.size());
+    queue.Erase(queue.First());
+  }
+  EXPECT_EQ(0u, queue.size());
+  EXPECT_TRUE(queue.First().is_null());
+  EXPECT_TRUE(queue.Last().is_null());
+
+  for (size_t i = 0; i < kNumPriorities; ++i) {
+    pointers[i] = queue.Insert(i, priorities[i]);
+  }
+
+  // Test backward direction.
+  for (size_t i = 0; i < kNumPriorities; ++i) {
+    EXPECT_EQ(expected_order[kNumPriorities - i - 1], queue.Last().value());
+    queue.Erase(queue.Last());
+  }
+  EXPECT_EQ(0u, queue.size());
+
+  for (size_t i = 0; i < kNumPriorities; ++i) {
+    pointers[i] = queue.Insert(i, priorities[i]);
+  }
+
+  // Test OldestLowest.
+  for (size_t i = 0; i < kNumPriorities; ++i) {
+    EXPECT_EQ(oldest_lowest[i], queue.OldestLowest().value());
+    queue.Erase(queue.OldestLowest());
+  }
+  EXPECT_EQ(0u, queue.size());
+
+  // Add them once more to test Clear.
+  for (size_t i = 0; i < kNumPriorities; ++i) {
+    pointers[i] = queue.Insert(i, priorities[i]);
+  }
+  EXPECT_EQ(kNumPriorities, queue.size());
+
+  queue.Clear();
+
+  EXPECT_EQ(0u, queue.size());
+}
+
+TEST(PriorityQueueTest, UpdatePriority) {
+  PriorityQueue<size_t> queue;
+  RequestPriority priorities[] = {
+      LOW,
+      MEDIUM,
+      LOW,
+      HIGHEST,
+      IDLE,
+      LOWEST,
+      MEDIUM,
+      IDLE,
+      HIGHEST,
+  };
+  const size_t kNumPriorities = arraysize(priorities);
+  PriorityQueue<size_t>::Pointer pointers[kNumPriorities];
+
+  for (size_t i = 0; i < kNumPriorities; ++i) {
+    pointers[i] = queue.Insert(i, priorities[i]);
+  }
+
+  // Current order: 3, 8, 1, 6, 0, 2, 5, 4, 7.
+  pointers[2] = queue.Move(pointers[2], HIGHEST);
+  EXPECT_EQ(HIGHEST, pointers[2].priority());
+  EXPECT_EQ(2u, pointers[2].value());
+  queue.Move(pointers[3], IDLE);
+  queue.Move(pointers[1], MEDIUM);  // No change.
+  size_t expected_order[kNumPriorities] = { 8, 2, 1, 6, 0, 5, 4, 7, 3 };
+
+  for (size_t i = 0; i < kNumPriorities; ++i) {
+    EXPECT_EQ(expected_order[i], queue.First().value());
+    queue.Erase(queue.First());
+  }
+  EXPECT_EQ(0u, queue.size());
+}
+
+}  // namespace
+
+}  // namespace net
+