Enable sync for the settings from the Extension Settings API.

chrome/browser/extensions/syncable_extension_settings_storage.cc

Index: chrome/browser/extensions/syncable_extension_settings_storage.cc
diff --git a/chrome/browser/extensions/syncable_extension_settings_storage.cc b/chrome/browser/extensions/syncable_extension_settings_storage.cc
new file mode 100644
index 0000000000000000000000000000000000000000..970057d98535d34070f34e29aa13cc1a6324e862
--- /dev/null
+++ b/chrome/browser/extensions/syncable_extension_settings_storage.cc
@@ -0,0 +1,311 @@
+// Copyright (c) 2011 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/extensions/syncable_extension_settings_storage.h"
+
+#include "base/bind.h"
+#include "base/memory/scoped_ptr.h"
+#include "base/message_loop.h"
+#include "base/task.h"
+#include "chrome/browser/extensions/extension_settings_sync_util.h"
+#include "chrome/browser/sync/api/sync_data.h"
+#include "chrome/browser/sync/protocol/extension_setting_specifics.pb.h"
+#include "content/browser/browser_thread.h"
+
+SyncableExtensionSettingsStorage::SyncableExtensionSettingsStorage(
+    std::string extension_id, ExtensionSettingsStorage* delegate)
+    : extension_id_(extension_id), delegate_(delegate), sync_processor_(NULL) {}
+
+SyncableExtensionSettingsStorage::~SyncableExtensionSettingsStorage() {}
+
+ExtensionSettingsStorage::Result SyncableExtensionSettingsStorage::Get(
+    const std::string& key) {
+  return delegate_->Get(key);
+}
+
+ExtensionSettingsStorage::Result SyncableExtensionSettingsStorage::Get(
+    const std::vector<std::string>& keys) {
+  return delegate_->Get(keys);
+}
+
+ExtensionSettingsStorage::Result SyncableExtensionSettingsStorage::Get() {
+  return delegate_->Get();
+}
+
+ExtensionSettingsStorage::Result SyncableExtensionSettingsStorage::Set(
+    const std::string& key, const Value& value) {
+  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::FILE));
+  Result result = delegate_->Set(key, value);
+  if (result.HasError()) {
+    return result;
+  }
+  if (sync_processor_ != NULL) {
+    SendAddsOrUpdatesToSync(*result.GetSettings());
+  }
+  return result;
+}
+
+ExtensionSettingsStorage::Result SyncableExtensionSettingsStorage::Set(
+    const DictionaryValue& values) {
+  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::FILE));
+  Result result = delegate_->Set(values);
+  if (result.HasError()) {
+    return result;
+  }
+  if (sync_processor_ != NULL) {
+    SendAddsOrUpdatesToSync(*result.GetSettings());
+  }
+  return result;
+}
+
+ExtensionSettingsStorage::Result SyncableExtensionSettingsStorage::Remove(
+    const std::string& key) {
+  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::FILE));
+  Result result = delegate_->Remove(key);
+  if (result.HasError()) {
+    return result;
+  }
+  if (sync_processor_ != NULL) {
+    std::vector<std::string> keys;
+    keys.push_back(key);
+    SendDeletesToSync(keys);
+  }
+  return result;
+}
+
+ExtensionSettingsStorage::Result SyncableExtensionSettingsStorage::Remove(
+    const std::vector<std::string>& keys) {
+  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::FILE));
+  Result result = delegate_->Remove(keys);
+  if (result.HasError()) {
+    return result;
+  }
+  if (sync_processor_ != NULL) {
+    SendDeletesToSync(keys);
+  }
+  return result;
+}
+
+ExtensionSettingsStorage::Result SyncableExtensionSettingsStorage::Clear() {
+  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::FILE));
+  Result result = delegate_->Clear();
+  if (result.HasError()) {
+    return result;
+  }
+  if (sync_processor_ != NULL) {
+    std::vector<std::string> keys;
+    keys.insert(keys.end(), synced_keys_.begin(), synced_keys_.end());
+    SendDeletesToSync(keys);
+  }
+  return result;
+}
+
+// Sync-related methods.
+
+void SyncableExtensionSettingsStorage::StartSyncing(
+    const DictionaryValue& sync_state, SyncChangeProcessor* sync_processor) {
+  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::FILE));
+  DCHECK(sync_processor_ == NULL);
+  DCHECK(synced_keys_.empty());
+  sync_processor_ = sync_processor;
+  for (DictionaryValue::key_iterator it = sync_state.begin_keys();
+      it != sync_state.end_keys(); ++it) {
+    synced_keys_.insert(*it);
+  }
+
+  Result maybe_settings = delegate_->Get();
+  if (maybe_settings.HasError()) {
+    LOG(WARNING) << "Failed to get local settings to send to sync: " <<
+        maybe_settings.GetError();
+    return;
+  }
+  DictionaryValue* settings = maybe_settings.GetSettings();
+
+  if (sync_state.empty()) {
+    SendLocalSettingsToSync(*settings);
+  } else {
+    OverwriteLocalSettingsWithSync(sync_state, *settings);
+  }
+}
+
+void SyncableExtensionSettingsStorage::SendLocalSettingsToSync(
+    const DictionaryValue& settings) {
+  SyncChangeList changes;
+  for (DictionaryValue::key_iterator it = settings.begin_keys();
+      it != settings.end_keys(); ++it) {
+    Value* value;
+    settings.GetWithoutPathExpansion(*it, &value);
+    changes.push_back(
+        extension_settings_sync_util::CreateAdd(extension_id_, *it, *value));
+  }
+
+  if (changes.empty()) {
+    return;
+  }
+
+  SyncError error = sync_processor_->ProcessSyncChanges(FROM_HERE, changes);
+  if (error.IsSet()) {
+    LOG(WARNING) << "Failed to send changes to sync: " << error.message();
+    return;
+  }
+
+  for (DictionaryValue::key_iterator it = settings.begin_keys();
+      it != settings.end_keys(); ++it) {
+    synced_keys_.insert(*it);
+  }
+}
+
+void SyncableExtensionSettingsStorage::OverwriteLocalSettingsWithSync(
+    const DictionaryValue& sync_state, const DictionaryValue& settings) {
+  // Treat this as a list of changes to sync and use ProcessSyncChanges.
+  // This gives notifications etc for free.
+  scoped_ptr<DictionaryValue> new_sync_state(sync_state.DeepCopy());
+
+  ExtensionSettingSyncDataList changes;
+  for (DictionaryValue::key_iterator it = settings.begin_keys();
+      it != settings.end_keys(); ++it) {
+    Value* sync_value;
+    if (new_sync_state->RemoveWithoutPathExpansion(*it, &sync_value)) {
+      Value* local_value;
+      settings.GetWithoutPathExpansion(*it, &local_value);
+      if (!local_value->Equals(sync_value)) {
+        // Sync value is different, update local setting with new value.
+        changes.push_back(
+            ExtensionSettingSyncData(
+                SyncChange::ACTION_UPDATE, "", *it, sync_value));
+      }
+    } else {
+      // Not synced, delete local setting.
+      changes.push_back(
+          ExtensionSettingSyncData(
+              SyncChange::ACTION_DELETE, "", *it, new DictionaryValue()));
+    }
+  }
+
+  // Add all new settings to local settings.
+  while (!new_sync_state->empty()) {
+    std::string key = *new_sync_state->begin_keys();
+    Value* value;
+    new_sync_state->RemoveWithoutPathExpansion(key, &value);
+    changes.push_back(
+        ExtensionSettingSyncData(SyncChange::ACTION_ADD, "", key, value));
+  }
+
+  if (!changes.empty()) {
+    ProcessSyncChanges(changes);
+  }
+}
+
+void SyncableExtensionSettingsStorage::StopSyncing() {
+  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::FILE));
+  DCHECK(sync_processor_ != NULL);
+  sync_processor_ = NULL;
+  synced_keys_.clear();
+}
+
+void SyncableExtensionSettingsStorage::ProcessSyncChanges(
+    const ExtensionSettingSyncDataList& sync_changes) {
+  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::FILE));
+  DCHECK(sync_processor_ != NULL);
+  DCHECK(!sync_changes.empty()) << "No sync changes for " << extension_id_;
+
+  for (ExtensionSettingSyncDataList::const_iterator it = sync_changes.begin();
+      it != sync_changes.end(); ++it) {
+    switch (it->change_type()) {
+      case SyncChange::ACTION_ADD:
+      case SyncChange::ACTION_UPDATE: {
+        synced_keys_.insert(it->key());
+        Result result = delegate_->Set(it->key(), *it->value());
+        if (result.HasError()) {
+          LOG(WARNING) << "Error pushing sync change to local settings: " <<
+              result.GetError();
+        }
+        break;
+      }
+
+      case SyncChange::ACTION_DELETE: {
+        synced_keys_.erase(it->key());
+        Result result = delegate_->Remove(it->key());

[Ben Olmstead, 2011/09/14 20:33:24]

Are there any issues with removing a nonexistent key?

[not at google - send to devlin, 2011/09/14 22:45:05]

Not at the moment.  Extensions can remove nonexistent keys too, it's treated
much the same way.

However, there is a problem here with change notifications, we do need to check
whether the key is there or not.  This code in the patch which adds
notifications (... which I will put out for review when this patch is
submitted).

+        if (result.HasError()) {
+          LOG(WARNING) << "Error removing sync change from local settings: " <<
+                result.GetError();
+        }
+        break;
+      }
+
+      default:
+        NOTREACHED();
+    }
+  }
+}
+
+void SyncableExtensionSettingsStorage::SendAddsOrUpdatesToSync(
+    const DictionaryValue& settings) {
+  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::FILE));
+  DCHECK(sync_processor_ != NULL);
+
+  SyncChangeList changes;
+  for (DictionaryValue::key_iterator it = settings.begin_keys();
+      it != settings.end_keys(); ++it) {
+    Value* value = NULL;
+    settings.GetWithoutPathExpansion(*it, &value);
+    DCHECK(value != NULL);
+    if (synced_keys_.count(*it)) {
+      // Key is synced, send ACTION_UPDATE to sync.
+      changes.push_back(
+          extension_settings_sync_util::CreateUpdate(
+              extension_id_, *it, *value));
+    } else {
+      // Key is not synced, send ACTION_ADD to sync.
+      changes.push_back(
+          extension_settings_sync_util::CreateAdd(extension_id_, *it, *value));
+    }
+  }
+
+  if (changes.empty()) {
+    return;
+  }
+
+  SyncError error = sync_processor_->ProcessSyncChanges(FROM_HERE, changes);
+  if (error.IsSet()) {
+    LOG(WARNING) << "Failed to send changes to sync: " << error.message();
+    return;
+  }
+
+  for (DictionaryValue::key_iterator it = settings.begin_keys();
+      it != settings.end_keys(); ++it) {
+    synced_keys_.insert(*it);
+  }
+}
+
+void SyncableExtensionSettingsStorage::SendDeletesToSync(
+    const std::vector<std::string>& keys) {
+  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::FILE));
+  DCHECK(sync_processor_ != NULL);
+
+  SyncChangeList changes;
+  for (std::vector<std::string>::const_iterator it = keys.begin();
+      it != keys.end(); ++it) {
+    // Only remove from sync if it's actually synced.
+    if (synced_keys_.count(*it)) {
+      changes.push_back(
+          extension_settings_sync_util::CreateDelete(extension_id_, *it));
+    }
+  }
+
+  if (changes.empty()) {
+    return;
+  }
+
+  SyncError error = sync_processor_->ProcessSyncChanges(FROM_HERE, changes);
+  if (error.IsSet()) {
+    LOG(WARNING) << "Failed to send changes to sync: " << error.message();
+    return;
+  }
+
+  for (std::vector<std::string>::const_iterator it = keys.begin();
+      it != keys.end(); ++it) {
+    synced_keys_.erase(*it);
+  }
+}