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"
@@ skipping 39 matching lines @@
   }
   void set_allow_huffman_compression(bool allow) {
     encoder_->allow_huffman_compression_ = allow;
   }
   void EmitString(StringPiece str) {
     encoder_->EmitString(str);
   }
   void TakeString(string* out) {
     encoder_->output_stream_.TakeString(out);
   }
+  void UpdateCharacterCounts(StringPiece str) {
+    encoder_->UpdateCharacterCounts(str);
+  }
   static void CookieToCrumbs(StringPiece cookie,
                              std::vector<StringPiece>* out) {
     Representations tmp;
     HpackEncoder::CookieToCrumbs(make_pair("", cookie), &tmp);
 
     out->clear();
     for (size_t i = 0; i != tmp.size(); ++i) {
       out->push_back(tmp[i].second);
     }
   }
@@ skipping 343 matching lines @@
   peer.CookieToCrumbs("baz=bing", &out);
   EXPECT_THAT(out, ElementsAre("baz=bing"));
 
   peer.CookieToCrumbs("", &out);
   EXPECT_THAT(out, ElementsAre(""));
 
   peer.CookieToCrumbs("foo;bar; baz;bing;", &out);
   EXPECT_THAT(out, ElementsAre("foo", "bar", "baz", "bing", ""));
 }
 
+TEST_F(HpackEncoderTest, UpdateCharacterCounts) {
+  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