rAc i18n: implement storage interface for libaddressinput

third_party/libaddressinput/chromium/chrome_storage_impl.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 "third_party/libaddressinput/chromium/chrome_storage_impl.h"
+
+#include "base/prefs/writeable_pref_store.h"
+#include "base/values.h"
+
+ChromeStorageImpl::ChromeStorageImpl(WriteablePrefStore* store)

[battre, 2013/12/20 12:12:13]

How are you planning to instantiate this class? I am concerned that it gets
linked directly to one of the PrefStores instead of the PrefService which would
be a layering violation.

The PrefService ensures for example that some preferences can be controlled by
policies. If you hook this directly onto the JsonPrefStore, that would not be
possible.

[Evan Stade, 2013/12/20 22:34:12]

A new JsonPrefStore: https://codereview.chromium.org/105823007/

This code actually doesn't have anything to do with prefs, it just wants
on-disk/cached-in-memory json storage.

+    : backing_store_(store),
+      scoped_observer_(this) {
+  scoped_observer_.Add(backing_store_);
+}
+
+ChromeStorageImpl::~ChromeStorageImpl() {
+  // TODO(estade): this shouldn't be necessary.
+  for (std::list<scoped_ptr<Request> >::iterator iter =
+           outstanding_requests_.begin();
+       iter != outstanding_requests_.end(); ++iter) {
+    (*(*iter)->callback)(false, (*iter)->key, std::string());
+  }
+}
+
+void ChromeStorageImpl::Put(const std::string& key, const std::string& data) {
+  backing_store_->SetValue(key, new base::StringValue(data));
+}
+
+void ChromeStorageImpl::ChromeStorageImpl::Get(
+    const std::string& key,
+    scoped_ptr<Storage::Callback> data_ready) const {
+  // |Get()| should not be const, so this is just a thunk that fixes that.
+  const_cast<ChromeStorageImpl*>(this)->DoGet(key, data_ready.Pass());
+}
+
+void ChromeStorageImpl::OnPrefValueChanged(const std::string& key) {}
+
+void ChromeStorageImpl::OnInitializationCompleted(bool succeeded) {
+  for (std::list<scoped_ptr<Request> >::iterator iter =
+           outstanding_requests_.begin();
+       iter != outstanding_requests_.end(); ++iter) {
+    DoGet((*iter)->key, (*iter)->callback.Pass());
+  }
+
+  outstanding_requests_.clear();
+}
+
+void ChromeStorageImpl::ChromeStorageImpl::DoGet(
+    const std::string& key,
+    scoped_ptr<Storage::Callback> data_ready) {
+  if (!backing_store_->IsInitializationComplete()) {
+    outstanding_requests_.push_back(make_scoped_ptr(
+        new Request(key, data_ready.Pass())));
+    return;
+  }
+
+  const base::Value* value;
+  std::string result;
+  if (backing_store_->GetValue(key, &value) &&
+      value->GetAsString(&result)) {
+    (*data_ready)(true, key, result);
+  } else {
+    (*data_ready)(false, key, std::string());
+  }
+}
+
+ChromeStorageImpl::Request::Request(const std::string& key,
+                                    scoped_ptr<Storage::Callback> callback)
+    : key(key),
+      callback(callback.Pass()) {}