app_list: Search result launch history and boost.

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

Index: chrome/browser/ui/app_list/search/history_data_store.cc
diff --git a/chrome/browser/ui/app_list/search/history_data_store.cc b/chrome/browser/ui/app_list/search/history_data_store.cc
new file mode 100644
index 0000000000000000000000000000000000000000..d204627caeed65bfb12fc933274f8aefdff7b1ec
--- /dev/null
+++ b/chrome/browser/ui/app_list/search/history_data_store.cc
@@ -0,0 +1,236 @@
+// 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_data_store.h"
+
+#include "base/callback.h"
+#include "base/json/json_file_value_serializer.h"
+#include "base/json/json_string_value_serializer.h"
+#include "base/logging.h"
+#include "base/strings/string_number_conversions.h"
+#include "base/task_runner_util.h"
+#include "base/threading/sequenced_worker_pool.h"
+#include "base/values.h"
+#include "content/public/browser/browser_thread.h"
+
+using content::BrowserThread;
+
+namespace app_list {
+
+namespace {
+
+const char kKeyVersion[] = "version";

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

I'm glad you're including a file format version number.

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

Future is always hard to predict. :p

+const char kCurrentVersion[] = "1";
+
+const char kKeyAssociations[] = "associations";
+const char kKeyPrimary[] = "p";
+const char kKeySecondary[] = "s";
+const char kKeyUpdateTime[] = "t";
+
+// Extracts strings from ListValue.
+void GetSecondary(const base::ListValue* list,
+                  HistoryData::SecondaryDeque* secondary) {
+  HistoryData::SecondaryDeque results;
+  for (base::ListValue::const_iterator it = list->begin();
+       it != list->end(); ++it) {
+    std::string str;
+    if (!(*it)->GetAsString(&str))
+      return;
+
+    results.push_back(str);
+  }
+
+  secondary->swap(results);
+}
+
+// V1 format json dictionary:
+//  {
+//    "version": "1",
+//    "associations": {
+//      "user typed query": {
+//        "p" : "result id of primary association",
+//        "s" : [
+//                "result id of 1st (oldest) secondary association",
+//                ...
+//                "result id of the latest secondary association"

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

nit: I would say "newest" instead of "latest" because I get confused about
"late" vs. "old"-est. :-)

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

Done.

+//              ],
+//        "t" : "last_update_timestamp"
+//      },
+//      ...
+//    }
+//  }
+scoped_ptr<HistoryData::Associations> Parse(const base::DictionaryValue& dict) {
+  std::string version;
+  if (!dict.GetStringWithoutPathExpansion(kKeyVersion, &version) ||
+      version != kCurrentVersion) {
+    return scoped_ptr<HistoryData::Associations>();
+  }
+
+  const base::DictionaryValue* assoc_dict = NULL;
+  if (!dict.GetDictionaryWithoutPathExpansion(kKeyAssociations, &assoc_dict) ||
+      !assoc_dict) {
+    return scoped_ptr<HistoryData::Associations>();
+  }
+
+  scoped_ptr<HistoryData::Associations> data(new HistoryData::Associations);
+  for (base::DictionaryValue::Iterator it(*assoc_dict);
+       !it.IsAtEnd(); it.Advance()) {
+    const base::DictionaryValue* entry_dict = NULL;
+    if (!it.value().GetAsDictionary(&entry_dict))
+      continue;
+
+    std::string primary;
+    std::string update_time_string;
+    if (!entry_dict->GetStringWithoutPathExpansion(kKeyPrimary, &primary) ||
+        !entry_dict->GetStringWithoutPathExpansion(kKeyUpdateTime,
+                                                   &update_time_string)) {
+      continue;
+    }
+
+    const base::ListValue* secondary_list = NULL;
+    HistoryData::SecondaryDeque secondary;
+    if (entry_dict->GetListWithoutPathExpansion(kKeySecondary, &secondary_list))
+      GetSecondary(secondary_list, &secondary);
+
+    const std::string& query = it.key();
+    HistoryData::Data& association_data = (*data.get())[query];
+    association_data.primary = primary;
+    association_data.secondary.swap(secondary);
+
+    int64 update_time_val;
+    base::StringToInt64(update_time_string, &update_time_val);
+    association_data.update_time =
+        base::Time::FromInternalValue(update_time_val);
+  }
+
+  return data.Pass();
+}
+
+// An empty callback used to ensure file tasks are cleared.
+void EmptyCallback() {}
+
+}  // namespace
+
+HistoryDataStore::HistoryDataStore(const base::FilePath& data_file)
+    : data_file_(data_file) {
+  std::string token("app-launcher-history-data-store");
+  token.append(data_file.AsUTF8Unsafe());
+
+  base::SequencedWorkerPool* pool = BrowserThread::GetBlockingPool();
+  file_task_runner_ =
+      pool->GetSequencedTaskRunner(pool->GetNamedSequenceToken(token));
+  writer_.reset(new base::ImportantFileWriter(data_file, file_task_runner_));
+
+  cached_json_.reset(new base::DictionaryValue);
+  cached_json_->SetString(kKeyVersion, kCurrentVersion);
+  cached_json_->Set(kKeyAssociations, new base::DictionaryValue);
+}
+
+HistoryDataStore::~HistoryDataStore() {
+  Flush(OnFlushedCallback());

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

Will this force this data store to be written on shutdown? Could we possibly
avoid doing that?  I would prefer to lose one or two associations at shutdown to
adding another blocking write.

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

Made |file_task_runner_| be a SKIP_ON_SHUTDOWN task runner to address the
concern. Flush() here schedules the disk write and if we are really at shutdown,
the task will be dropped.

+}
+
+void HistoryDataStore::Flush(const OnFlushedCallback& on_flushed) {
+  if (writer_->HasPendingWrite())
+    writer_->DoScheduledWrite();
+
+  if (on_flushed.is_null())
+    return;
+
+  file_task_runner_->PostTaskAndReply(
+      FROM_HERE, base::Bind(&EmptyCallback), on_flushed);
+}
+
+void HistoryDataStore::Load(
+    const HistoryDataStore::OnLoadedCallback& on_loaded) {
+  base::PostTaskAndReplyWithResult(
+      file_task_runner_,
+      FROM_HERE,
+      base::Bind(&HistoryDataStore::LoadOnBlockingPool, this),
+      on_loaded);
+}
+
+void HistoryDataStore::SetPrimary(const std::string& query,
+                                  const std::string& result) {
+  base::DictionaryValue* entry_dict = GetEntryDict(query);
+  entry_dict->SetWithoutPathExpansion(kKeyPrimary,
+                                      new base::StringValue(result));
+  writer_->ScheduleWrite(this);
+}
+
+void HistoryDataStore::SetSecondary(
+    const std::string& query,
+    const HistoryData::SecondaryDeque& results) {
+  scoped_ptr<base::ListValue> results_list(new base::ListValue);
+  for (size_t i = 0; i< results.size(); ++i)
+    results_list->AppendString(results[i]);
+
+  base::DictionaryValue* entry_dict = GetEntryDict(query);
+  entry_dict->SetWithoutPathExpansion(kKeySecondary, results_list.release());
+  writer_->ScheduleWrite(this);
+}
+
+void HistoryDataStore::SetUpdateTime(const std::string& query,
+                                     const base::Time& update_time) {
+  base::DictionaryValue* entry_dict = GetEntryDict(query);
+  entry_dict->SetWithoutPathExpansion(kKeyUpdateTime,
+                                      new base::StringValue(base::Int64ToString(
+                                          update_time.ToInternalValue())));
+  writer_->ScheduleWrite(this);
+}
+
+void HistoryDataStore::Delete(const std::string& query) {
+  base::DictionaryValue* assoc_dict = GetAssociationDict();
+  assoc_dict->RemoveWithoutPathExpansion(query, NULL);
+  writer_->ScheduleWrite(this);
+}
+
+base::DictionaryValue* HistoryDataStore::GetAssociationDict() {
+  base::DictionaryValue* assoc_dict = NULL;
+  CHECK(cached_json_->GetDictionary(kKeyAssociations, &assoc_dict) &&
+        assoc_dict);
+
+  return assoc_dict;
+}
+
+base::DictionaryValue* HistoryDataStore::GetEntryDict(
+    const std::string& query) {
+  base::DictionaryValue* assoc_dict = GetAssociationDict();
+
+  base::DictionaryValue* entry_dict = NULL;
+  if (!assoc_dict->GetDictionaryWithoutPathExpansion(query, &entry_dict)) {
+    // Creates one if none exists. Ownership is taken in the set call after.
+    entry_dict = new base::DictionaryValue;
+    assoc_dict->SetWithoutPathExpansion(query, entry_dict);
+  }
+
+  return entry_dict;
+}
+
+scoped_ptr<HistoryData::Associations> HistoryDataStore::LoadOnBlockingPool() {
+  DCHECK(BrowserThread::GetBlockingPool()->RunsTasksOnCurrentThread());

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

I like thread assertions.

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

Me too.

+
+  int error_code = JSONFileValueSerializer::JSON_NO_ERROR;
+  std::string error_message;
+  JSONFileValueSerializer serializer(data_file_);
+  base::Value* value = serializer.Deserialize(&error_code, &error_message);
+  base::DictionaryValue* dict_value = NULL;
+  if (error_code != JSONFileValueSerializer::JSON_NO_ERROR ||
+      !value ||
+      !value->GetAsDictionary(&dict_value) ||
+      !dict_value) {
+    return scoped_ptr<HistoryData::Associations>();
+  }
+
+  cached_json_.reset(dict_value);
+  return Parse(*dict_value).Pass();
+}
+
+bool HistoryDataStore::SerializeData(std::string* data) {
+  JSONStringValueSerializer serializer(data);
+  serializer.set_pretty_print(true);
+  return serializer.Serialize(*cached_json_.get());
+}
+
+}  // namespace app_list