Password sync refactoring: implemented ProcessSyncChanges() and GetAllSyncData()

chrome/browser/password_manager/password_syncable_service.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/password_manager/password_syncable_service.h"
 
 #include "base/location.h"
 #include "base/memory/scoped_vector.h"
 #include "base/metrics/histogram.h"
 #include "base/strings/utf_string_conversions.h"
@@ skipping 96 matching lines @@
 syncer::SyncMergeResult PasswordSyncableService::MergeDataAndStartSyncing(
     syncer::ModelType type,
     const syncer::SyncDataList& initial_sync_data,
     scoped_ptr<syncer::SyncChangeProcessor> sync_processor,
     scoped_ptr<syncer::SyncErrorFactory> sync_error_factory) {
   DCHECK_EQ(syncer::PASSWORDS, type);
   syncer::SyncMergeResult merge_result(type);
   sync_error_factory_ = sync_error_factory.Pass();
   sync_processor_ = sync_processor.Pass();
 
+  // We add all the db entries as |new_local_entries| initially. During model
+  // association entries that match a sync entry will be removed and this list
+  // will only contain entries that are not in sync.
   ScopedVector<autofill::PasswordForm> password_entries;
-  if (!password_store_->FillAutofillableLogins(&password_entries.get())) {
-    // Password store often fails to load passwords. Track failures with UMA.
-    // (http://crbug.com/249000)
-    UMA_HISTOGRAM_ENUMERATION("Sync.LocalDataFailedToLoad",
-                              syncer::PASSWORDS,
-                              syncer::MODEL_TYPE_COUNT);
+  PasswordEntryMap new_local_entries;
+  if (!ReadFromPasswordStore(&password_entries, &new_local_entries)) {
+    DCHECK(sync_error_factory_);
     merge_result.set_error(sync_error_factory_->CreateAndUploadError(
         FROM_HERE,
         "Failed to get passwords from store."));
     return merge_result;
   }
 
-  PasswordEntryMap new_local_entries;
-  for (PasswordForms::iterator it = password_entries.begin();
-       it != password_entries.end(); ++it) {
-     autofill::PasswordForm* password_form = *it;
-     // We add all the db entries as |new_local_entries| initially. During
-     // model association entries that match a sync entry will be
-     // removed and this list will only contain entries that are not in sync.
-     new_local_entries.insert(
-         std::make_pair(MakePasswordSyncTag(*password_form), password_form));
-  }
-
   merge_result.set_num_items_before_association(new_local_entries.size());
 
   // List that contains the entries that are known only to sync.
   ScopedVector<autofill::PasswordForm> new_sync_entries;
 
   // List that contains the entries that are known to both sync and db but
   // have updates in sync. They need to be updated in the passwords db.
   ScopedVector<autofill::PasswordForm> updated_sync_entries;
 
   // Changes from password db that need to be propagated to sync.
   syncer::SyncChangeList updated_db_entries;
   for (syncer::SyncDataList::const_iterator sync_iter =
            initial_sync_data.begin();
        sync_iter != initial_sync_data.end(); ++sync_iter) {
     CreateOrUpdateEntry(*sync_iter,
                         &new_local_entries,
                         &new_sync_entries,
                         &updated_sync_entries,
                         &updated_db_entries);
   }
 
   WriteToPasswordStore(new_sync_entries.get(),
-                       updated_sync_entries.get());
+                       updated_sync_entries.get(),
+                       PasswordForms());
 
   merge_result.set_num_items_after_association(
       merge_result.num_items_before_association() + new_sync_entries.size());
 
   merge_result.set_num_items_added(new_sync_entries.size());
 
   merge_result.set_num_items_modified(updated_sync_entries.size());
 
   for (PasswordEntryMap::iterator it = new_local_entries.begin();
        it != new_local_entries.end();
        ++it) {
     updated_db_entries.push_back(
         syncer::SyncChange(FROM_HERE,
                            syncer::SyncChange::ACTION_ADD,
                            SyncDataFromPassword(*it->second)));
   }
 
   merge_result.set_error(
       sync_processor_->ProcessSyncChanges(FROM_HERE, updated_db_entries));
   return merge_result;
 }
 
 void PasswordSyncableService::StopSyncing(syncer::ModelType type) {
   sync_processor_.reset();
   sync_error_factory_.reset();
 }
 
 syncer::SyncDataList PasswordSyncableService::GetAllSyncData(
     syncer::ModelType type) const {
+  DCHECK_EQ(syncer::PASSWORDS, type);
+  ScopedVector<autofill::PasswordForm> password_entries;
+  ReadFromPasswordStore(&password_entries, NULL);
+
   syncer::SyncDataList sync_data;
+  for (PasswordForms::iterator it = password_entries.begin();
+       it != password_entries.end(); ++it) {
+    sync_data.push_back(SyncDataFromPassword(**it));
+  }
   return sync_data;
 }
 
 syncer::SyncError PasswordSyncableService::ProcessSyncChanges(
     const tracked_objects::Location& from_here,
     const syncer::SyncChangeList& change_list) {
-  syncer::SyncError error(FROM_HERE,
-                          syncer::SyncError::UNRECOVERABLE_ERROR,
-                          "Password Syncable Service Not Implemented.",
-                          syncer::PASSWORDS);
-  return error;
+  // The |db_entries_map| and associated vectors are filled only in case of
+  // add/update change.

[Ilya Sherman, 2014/02/11 07:59:46]

nit: Now only on an update change, right?

[vasilii, 2014/02/11 12:23:33]

Done.

+  PasswordEntryMap db_entries_map;
+  ScopedVector<autofill::PasswordForm> password_db_entries;
+  ScopedVector<autofill::PasswordForm> new_sync_entries;
+  ScopedVector<autofill::PasswordForm> updated_sync_entries;
+  ScopedVector<autofill::PasswordForm> deleted_entries;
+  bool has_read_passwords = false;
+
+  for (syncer::SyncChangeList::const_iterator it = change_list.begin();
+       it != change_list.end();
+       ++it) {
+    switch (it->change_type()) {
+      case syncer::SyncChange::ACTION_ADD: {
+        const sync_pb::EntitySpecifics& specifics =
+            it->sync_data().GetSpecifics();
+        new_sync_entries.push_back(new autofill::PasswordForm);
+        PasswordFromSpecifics(specifics.password().client_only_encrypted_data(),
+                              new_sync_entries.back());
+        break;
+      }
+      case syncer::SyncChange::ACTION_UPDATE: {
+        if (!has_read_passwords) {
+          if (ReadFromPasswordStore(&password_db_entries,
+                                    &db_entries_map)) {
+            has_read_passwords = true;
+          } else {
+            return sync_error_factory_->CreateAndUploadError(
+                FROM_HERE,
+                "Failed to get passwords from store.");
+          }
+        }
+        syncer::SyncChangeList sync_changes;
+
+        CreateOrUpdateEntry(it->sync_data(),
+                            &db_entries_map,
+                            &new_sync_entries,
+                            &updated_sync_entries,
+                            &sync_changes);

[Ilya Sherman, 2014/02/11 07:59:46]

Would be nice to DCHECK that sync_changes remains empty after this call.

[vasilii, 2014/02/11 12:23:33]

CreateOrUpdateEntry() is written in the way that it pushes updates to both sync
and local db. Do you think it should be fixed?

[Ilya Sherman, 2014/02/11 21:58:25]

Ah.  Yes, I do think it should be fixed -- it's unnecessary to generate the
extra updates, and it can make invariants like this one clearer.

[vasilii, 2014/02/12 13:27:12]

Done.

[Ilya Sherman, 2014/02/12 22:58:50]

Thanks!  (Still LGTM, so the CQ doesn't freak out.)

+        break;
+      }
+
+      case syncer::SyncChange::ACTION_DELETE: {
+        const sync_pb::EntitySpecifics& specifics =
+            it->sync_data().GetSpecifics();
+        const sync_pb::PasswordSpecificsData& password_specifics(
+            specifics.password().client_only_encrypted_data());
+        deleted_entries.push_back(new autofill::PasswordForm);
+        PasswordFromSpecifics(password_specifics, deleted_entries.back());
+        break;
+      }
+      case syncer::SyncChange::ACTION_INVALID:
+        return sync_error_factory_->CreateAndUploadError(
+            FROM_HERE,
+            "Failed to process sync changes for passwords datatype.");
+    }
+  }
+  WriteToPasswordStore(new_sync_entries.get(),
+                       updated_sync_entries.get(),
+                       deleted_entries.get());
+  return syncer::SyncError();
 }
 
 void PasswordSyncableService::ActOnPasswordStoreChanges(
     const PasswordStoreChangeList& local_changes) {
   if (!sync_processor_)
     return;
   syncer::SyncChangeList sync_changes;
   for (PasswordStoreChangeList::const_iterator it = local_changes.begin();
        it != local_changes.end();
        ++it) {
     sync_changes.push_back(
         syncer::SyncChange(FROM_HERE,
                            GetSyncChangeType(it->type()),
                            SyncDataFromPassword(it->form())));
   }
   sync_processor_->ProcessSyncChanges(FROM_HERE, sync_changes);
 }
 
+bool PasswordSyncableService::ReadFromPasswordStore(
+    ScopedVector<autofill::PasswordForm>* password_entries,
+    PasswordEntryMap* passwords_entry_map) const {
+  DCHECK(password_entries);
+  if (!password_store_->FillAutofillableLogins(&password_entries->get()) ||
+      !password_store_->FillBlacklistLogins(&password_entries->get())) {
+    // Password store often fails to load passwords. Track failures with UMA.
+    // (http://crbug.com/249000)
+    UMA_HISTOGRAM_ENUMERATION("Sync.LocalDataFailedToLoad",
+                              ModelTypeToHistogramInt(syncer::PASSWORDS),
+                              syncer::MODEL_TYPE_COUNT);
+    return false;
+  }
+
+  if (!passwords_entry_map)
+    return true;
+
+  for (PasswordForms::iterator it = password_entries->begin();
+       it != password_entries->end(); ++it) {
+     autofill::PasswordForm* password_form = *it;
+     passwords_entry_map->insert(
+         std::make_pair(MakePasswordSyncTag(*password_form), password_form));
+  }
+
+  return true;
+}
+
 void PasswordSyncableService::WriteToPasswordStore(
     const PasswordForms& new_entries,
-    const PasswordForms& updated_entries) {
+    const PasswordForms& updated_entries,
+    const PasswordForms& deleted_entries) {
   PasswordStoreChangeList changes;
   for (std::vector<autofill::PasswordForm*>::const_iterator it =
            new_entries.begin();
        it != new_entries.end();
        ++it) {
     AppendChanges(password_store_->AddLoginImpl(**it), &changes);
   }
 
   for (std::vector<autofill::PasswordForm*>::const_iterator it =
            updated_entries.begin();
        it != updated_entries.end();
        ++it) {
     AppendChanges(password_store_->UpdateLoginImpl(**it), &changes);
   }
 
+  for (std::vector<autofill::PasswordForm*>::const_iterator it =
+           deleted_entries.begin();
+       it != deleted_entries.end();
+       ++it) {
+    AppendChanges(password_store_->RemoveLoginImpl(**it), &changes);
+  }
+
   // We have to notify password store observers of the change by hand since
   // we use internal password store interfaces to make changes synchronously.
   NotifyPasswordStoreOfLoginChanges(changes);
 }
 
 void PasswordSyncableService::NotifyPasswordStoreOfLoginChanges(
     const PasswordStoreChangeList& changes) {
   password_store_->NotifyLoginsChanged(changes);
 }
 
@@ skipping 89 matching lines @@
 }
 
 std::string MakePasswordSyncTag(
     const sync_pb::PasswordSpecificsData& password) {
   return MakePasswordSyncTag(password.origin(),
                              password.username_element(),
                              password.username_value(),
                              password.password_element(),
                              password.signon_realm());
 }