WriteBlockedList for QUIC that prioritizes Crypto and Headers streams

net/quic/quic_write_blocked_list_test.cc

Index: net/quic/quic_write_blocked_list_test.cc
diff --git a/net/quic/quic_write_blocked_list_test.cc b/net/quic/quic_write_blocked_list_test.cc
new file mode 100644
index 0000000000000000000000000000000000000000..63b237b15379eed18581f11cd8ffd0d5f415703f
--- /dev/null
+++ b/net/quic/quic_write_blocked_list_test.cc
@@ -0,0 +1,106 @@
+// Copyright (c) 2014 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/quic/quic_write_blocked_list.h"
+
+#include "testing/gtest/include/gtest/gtest.h"
+
+namespace net {
+namespace test {
+namespace {
+
+TEST(QuicWriteBlockedListTest, PriorityOrder) {
+  QuicWriteBlockedList write_blocked_list;
+
+  // Mark streams blocked in roughly reverse priority order, and
+  // verify that streams are sorted.
+  write_blocked_list.PushBack(40,
+                              QuicWriteBlockedList::kLowestPriority,
+                              QUIC_VERSION_13);
+  write_blocked_list.PushBack(23,
+                              QuicWriteBlockedList::kHighestPriority,
+                              QUIC_VERSION_13);
+  write_blocked_list.PushBack(17,
+                              QuicWriteBlockedList::kHighestPriority,
+                              QUIC_VERSION_13);
+  write_blocked_list.PushBack(kHeadersStreamId,
+                              QuicWriteBlockedList::kHighestPriority,
+                              QUIC_VERSION_13);
+  write_blocked_list.PushBack(kCryptoStreamId,
+                              QuicWriteBlockedList::kHighestPriority,
+                              QUIC_VERSION_13);
+
+  EXPECT_EQ(5u, write_blocked_list.NumBlockedStreams());
+  EXPECT_TRUE(write_blocked_list.HasWriteBlockedStreams());
+  // The Crypto stream is highest priority.
+  EXPECT_EQ(kCryptoStreamId, write_blocked_list.PopFront());
+  // Followed by the Headers stream.
+  EXPECT_EQ(kHeadersStreamId, write_blocked_list.PopFront());
+  // Streams with same priority are popped in the order they were inserted.
+  EXPECT_EQ(23u, write_blocked_list.PopFront());
+  EXPECT_EQ(17u, write_blocked_list.PopFront());
+  // Low priority stream appears last.
+  EXPECT_EQ(40u, write_blocked_list.PopFront());
+
+  EXPECT_EQ(0u, write_blocked_list.NumBlockedStreams());
+  EXPECT_FALSE(write_blocked_list.HasWriteBlockedStreams());
+}
+
+TEST(QuicWriteBlockedListTest, CryptoStream) {
+  QuicWriteBlockedList write_blocked_list;
+  write_blocked_list.PushBack(kCryptoStreamId,
+                              QuicWriteBlockedList::kHighestPriority,
+                              QUIC_VERSION_13);
+
+  EXPECT_EQ(1u, write_blocked_list.NumBlockedStreams());
+  EXPECT_TRUE(write_blocked_list.HasWriteBlockedStreams());
+  EXPECT_EQ(kCryptoStreamId, write_blocked_list.PopFront());
+  EXPECT_EQ(0u, write_blocked_list.NumBlockedStreams());
+  EXPECT_FALSE(write_blocked_list.HasWriteBlockedStreams());
+}
+
+TEST(QuicWriteBlockedListTest, HeadersStream) {
+  QuicWriteBlockedList write_blocked_list;
+  write_blocked_list.PushBack(kHeadersStreamId,
+                              QuicWriteBlockedList::kHighestPriority,
+                              QUIC_VERSION_13);
+
+  EXPECT_EQ(1u, write_blocked_list.NumBlockedStreams());
+  EXPECT_TRUE(write_blocked_list.HasWriteBlockedStreams());
+  EXPECT_EQ(kHeadersStreamId, write_blocked_list.PopFront());
+  EXPECT_EQ(0u, write_blocked_list.NumBlockedStreams());
+  EXPECT_FALSE(write_blocked_list.HasWriteBlockedStreams());
+}
+
+TEST(QuicWriteBlockedListTest, NoHeadersStreamInVersion12) {
+  for (int idx = 0; idx < 2; ++idx) {
+    QuicVersion version = ((idx == 0) ? QUIC_VERSION_13 : QUIC_VERSION_12);
+    QuicWriteBlockedList write_blocked_list;
+    write_blocked_list.PushBack(5,
+                                QuicWriteBlockedList::kHighestPriority,
+                                version);
+    write_blocked_list.PushBack(kHeadersStreamId,
+                                QuicWriteBlockedList::kHighestPriority,
+                                version);
+
+    EXPECT_EQ(2u, write_blocked_list.NumBlockedStreams());
+    EXPECT_TRUE(write_blocked_list.HasWriteBlockedStreams());
+    if (version > QUIC_VERSION_12) {
+      // In newer QUIC versions, there is a headers stream which is
+      // higher priority than data streams.
+      EXPECT_EQ(kHeadersStreamId, write_blocked_list.PopFront());
+      EXPECT_EQ(5u, write_blocked_list.PopFront());
+    } else {
+      // In older QUIC versions, there is no reserved headers stream id.
+      EXPECT_EQ(5u, write_blocked_list.PopFront());
+      EXPECT_EQ(kHeadersStreamId, write_blocked_list.PopFront());
+    }
+    EXPECT_EQ(0u, write_blocked_list.NumBlockedStreams());
+    EXPECT_FALSE(write_blocked_list.HasWriteBlockedStreams());
+  }
+}
+
+}  // namespace
+}  // namespace test
+}  // namespace net