app_list: Search result launch history and boost.

chrome/browser/ui/app_list/search/history.cc

+// Copyright 2013 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/ui/app_list/search/history.h"
+
+#include "base/files/file_path.h"
+#include "base/string_util.h"
+#include "base/utf_string_conversions.h"
+#include "chrome/browser/ui/app_list/search/history_data.h"
+#include "chrome/browser/ui/app_list/search/history_data_store.h"
+#include "chrome/browser/ui/app_list/search/tokenized_string.h"
+#include "content/public/browser/browser_context.h"
+
+namespace app_list {
+
+namespace {
+
+// Normalize the given string by joining all its tokens with a space.
+std::string NormalizeString(const std::string& utf8) {
+  TokenizedString tokenized(UTF8ToUTF16(utf8));
+  return UTF16ToUTF8(JoinString(tokenized.tokens(), ' '));
+}
+
+}  // namespace
+
+History::History(content::BrowserContext* context)
+    : browser_context_(context),
+      data_loaded_(false) {
+  const char kStoreDataFileName[] = "App Launcher Search";

[James Cook, 2013/05/23 21:51:08]

nit: Consider giving the file an extension, like .json or .txt

[xiyuan, 2013/05/23 22:38:13]

I did not add an extension because all files under user data dir does not have
one. It might be better to be consistent. What do you think?

[James Cook, 2013/05/24 03:57:05]

Consistency is more important than having an extension - keep it as is.

+  const size_t kMaxQueryEntries = 1000;
+  const size_t kMaxSecondaryQueries = 5;
+
+  const base::FilePath data_file =
+      browser_context_->GetPath().AppendASCII(kStoreDataFileName);
+  store_ = new HistoryDataStore(data_file);
+  data_.reset(new HistoryData(store_, kMaxQueryEntries, kMaxSecondaryQueries));
+  data_->AddObserver(this);
+}
+
+History::~History() {
+  data_->RemoveObserver(this);
+}
+
+bool History::IsReady() const {
+  return data_loaded_;
+}
+
+void History::AddLaunchEvent(const std::string& query,
+                             const std::string& result_id) {
+  DCHECK(IsReady());
+  data_->Add(NormalizeString(query), result_id);
+}
+
+scoped_ptr<KnownResults> History::GetKnownResults(
+    const std::string& query) const {
+  DCHECK(IsReady());
+  return data_->GetKnownResults(NormalizeString(query)).Pass();
+}
+
+void History::OnHistoryDataLoadedFromStore() {
+  data_loaded_ = true;
+}
+
+}  // namespace app_list