HPACK optimal Huffman code instrumentation and UMA collection.

net/spdy/hpack_encoder_test.cc

 // Copyright 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/spdy/hpack_encoder.h"
 
 #include <map>
 #include <string>
 
 #include "testing/gmock/include/gmock/gmock.h"
 #include "testing/gtest/include/gtest/gtest.h"
 
 namespace net {
 
 using base::StringPiece;
 using std::string;
 using testing::ElementsAre;
 
 namespace test {
 
 class HpackEncoderPeer {
  public:
   explicit HpackEncoderPeer(HpackEncoder* encoder)
       : encoder_(encoder) {}
 
+  void UpdateCharacterCounts(StringPiece str) {
+    encoder_->UpdateCharacterCounts(str);
+  }
   void set_max_string_literal_size(uint32 size) {
     encoder_->max_string_literal_size_ = size;
   }
   static void CookieToCrumbs(StringPiece cookie,
                              std::vector<StringPiece>* out) {
     HpackEncoder::CookieToCrumbs(cookie, out);
   }
  private:
   HpackEncoder* encoder_;
 };
@@ skipping 69 matching lines @@
   std::map<string, string> header_set;
   header_set["name1"] = "too-long value";
   header_set["name2"] = "value2";
 
   // TODO(akalin): Verify that the encoder did not attempt to encode
   // the second header field.
   string encoded_header_set;
   EXPECT_FALSE(encoder.EncodeHeaderSet(header_set, &encoded_header_set));
 }
 
+TEST(HpackEncoderTest, UpdateCharacterCounts) {
+  HpackEncoder encoder;
+  test::HpackEncoderPeer peer(&encoder);
+
+  std::vector<size_t> counts(256, 0);
+  size_t total_counts = 0;
+  encoder.SetCharCountsStorage(&counts, &total_counts);
+
+  char kTestString[] = "foo\0\1\xff""boo";
+  peer.UpdateCharacterCounts(
+      StringPiece(kTestString, arraysize(kTestString) - 1));
+
+  std::vector<size_t> expect(256, 0);
+  expect[static_cast<uint8>('f')] = 1;
+  expect[static_cast<uint8>('o')] = 4;
+  expect[static_cast<uint8>('\0')] = 1;
+  expect[static_cast<uint8>('\1')] = 1;
+  expect[static_cast<uint8>('\xff')] = 1;
+  expect[static_cast<uint8>('b')] = 1;
+
+  EXPECT_EQ(expect, counts);
+  EXPECT_EQ(9u, total_counts);
+}
+
 }  // namespace
 
 }  // namespace net