Prefetch cache pt1 - MRU

chrome/browser/autocomplete/answers_cache_unittest.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 "chrome/browser/autocomplete/answers_cache.h"
+
+#include "base/strings/utf_string_conversions.h"
+#include "testing/gtest/include/gtest/gtest.h"
+
+TEST(AnswersCacheTest, CacheStartsEmpty) {
+  AnswersCache cache(1);
+  EXPECT_TRUE(cache.empty());
+}
+
+TEST(AnswersCacheTest, UpdatePopulatesCache) {
+  AnswersCache cache(1);
+  cache.UpdateRecentAnswers(base::ASCIIToUTF16("weather los angeles"),
+                            base::ASCIIToUTF16("2334"));
+  EXPECT_FALSE(cache.empty());
+}
+
+TEST(AnswersCacheTest, GetWillRetrieveMatchingInfo) {
+  AnswersCache cache(1);
+
+  base::string16 full_query_text = base::ASCIIToUTF16("weather los angeles");
+  base::string16 query_type = base::ASCIIToUTF16("2334");
+  cache.UpdateRecentAnswers(full_query_text, query_type);
+
+  // Partial prefixes retrieve info.
+  AnswersQueryData data = cache.GetTopAnswerEntry(full_query_text.substr(0, 8));
+  EXPECT_EQ(full_query_text, data.full_query_text);
+  EXPECT_EQ(query_type, data.query_type);
+
+  // Mismatched prefix retrieves empty data.
+  data = cache.GetTopAnswerEntry(full_query_text.substr(1, 8));
+  EXPECT_TRUE(data.full_query_text.empty() && data.query_type.empty());
+
+  // Full match retrieves info.
+  data = cache.GetTopAnswerEntry(full_query_text);
+  EXPECT_EQ(full_query_text, data.full_query_text);
+  EXPECT_EQ(query_type, data.query_type);
+}
+
+TEST(AnswersCacheTest, MatchMostRecent) {
+  AnswersCache cache(2);
+
+  base::string16 query_weather_la = base::ASCIIToUTF16("weather los angeles");
+  base::string16 query_weather_lv = base::ASCIIToUTF16("weather las vegas");
+  base::string16 query_type = base::ASCIIToUTF16("2334");
+
+  cache.UpdateRecentAnswers(query_weather_lv, query_type);
+  cache.UpdateRecentAnswers(query_weather_la, query_type);
+
+  // "weather los angeles" is most recent match to "weather l".
+  AnswersQueryData data =
+      cache.GetTopAnswerEntry(base::ASCIIToUTF16("weather l"));
+  EXPECT_EQ(query_weather_la, data.full_query_text);
+
+  // Update recency for "weather las vegas".
+  cache.GetTopAnswerEntry(query_weather_lv);
+
+  // "weather las vegas" should now be the most recent match to "weather l".
+  data = cache.GetTopAnswerEntry(base::ASCIIToUTF16("weather l"));
+  EXPECT_EQ(query_weather_lv, data.full_query_text);
+}
+
+TEST(AnswersCacheTest, LeastRecentItemIsEvicted) {
+  AnswersCache cache(2);
+
+  base::string16 query_weather_la = base::ASCIIToUTF16("weather los angeles");
+  base::string16 query_weather_lv = base::ASCIIToUTF16("weather las vegas");
+  base::string16 query_weather_lb = base::ASCIIToUTF16("weather long beach");
+  base::string16 query_type = base::ASCIIToUTF16("2334");
+
+  cache.UpdateRecentAnswers(query_weather_lb, query_type);
+  cache.UpdateRecentAnswers(query_weather_lv, query_type);
+  EXPECT_FALSE(
+      cache.GetTopAnswerEntry(query_weather_lb).full_query_text.empty());
+  EXPECT_FALSE(
+      cache.GetTopAnswerEntry(query_weather_lv).full_query_text.empty());
+  EXPECT_TRUE(
+      cache.GetTopAnswerEntry(query_weather_la).full_query_text.empty());
+
+  cache.UpdateRecentAnswers(query_weather_la, query_type);
+  EXPECT_TRUE(
+      cache.GetTopAnswerEntry(query_weather_lb).full_query_text.empty());
+  EXPECT_FALSE(
+      cache.GetTopAnswerEntry(query_weather_lv).full_query_text.empty());
+  EXPECT_FALSE(
+      cache.GetTopAnswerEntry(query_weather_la).full_query_text.empty());
+}
+
+TEST(AnswersCacheTest, DuplicateEntries) {
+  AnswersCache cache(2);
+
+  base::string16 query_weather_lv = base::ASCIIToUTF16("weather las vegas");
+  base::string16 query_weather_lb = base::ASCIIToUTF16("weather long beach");
+  base::string16 query_weather_l = base::ASCIIToUTF16("weather l");
+  base::string16 query_type = base::ASCIIToUTF16("2334");
+
+  cache.UpdateRecentAnswers(query_weather_lb, query_type);
+  cache.UpdateRecentAnswers(query_weather_lv, query_type);
+
+  // Test that duplicate entries update recency.
+  cache.UpdateRecentAnswers(query_weather_lb, query_type);
+  EXPECT_EQ(query_weather_lb,
+            cache.GetTopAnswerEntry(query_weather_l).full_query_text);
+
+  // Test duplicate do not evict other entries. LV should still be in cache.
+  cache.UpdateRecentAnswers(query_weather_lb, query_type);
+  EXPECT_FALSE(
+      cache.GetTopAnswerEntry(query_weather_lv).full_query_text.empty());
+}