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"
 #include "components/autofill/core/common/password_form.h"
 #include "components/password_manager/core/browser/password_store.h"
 #include "net/base/escape.h"
 #include "sync/api/sync_error_factory.h"
 
 namespace {
 
+// Describes the result of merging sync and local passwords.
+enum MergeResult {
+  IDENTICAL,
+  SYNC,
+  LOCAL,
+};
+
 // Merges the local and sync passwords and outputs the entry into
-// |new_password_form|. Returns true if the local and the sync passwords differ.
-// Returns false if they are identical.
-bool MergeLocalAndSyncPasswords(
+// |new_password_form|. Returns MergeResult value describing the content of
+// |new_password_form|.
+MergeResult MergeLocalAndSyncPasswords(
     const sync_pb::PasswordSpecificsData& password_specifics,
     const autofill::PasswordForm& password_form,
     autofill::PasswordForm* new_password_form) {
   DCHECK(new_password_form);
   if (password_form.scheme == password_specifics.scheme() &&
       password_form.signon_realm == password_specifics.signon_realm() &&
       password_form.origin.spec() == password_specifics.origin() &&
       password_form.action.spec() == password_specifics.action() &&
       base::UTF16ToUTF8(password_form.username_element) ==
           password_specifics.username_element() &&
       base::UTF16ToUTF8(password_form.password_element) ==
           password_specifics.password_element() &&
       base::UTF16ToUTF8(password_form.username_value) ==
           password_specifics.username_value() &&
       base::UTF16ToUTF8(password_form.password_value) ==
           password_specifics.password_value() &&
       password_form.ssl_valid == password_specifics.ssl_valid() &&
       password_form.preferred == password_specifics.preferred() &&
       password_form.date_created.ToInternalValue() ==
           password_specifics.date_created() &&
       password_form.blacklisted_by_user == password_specifics.blacklisted()) {
-    return false;
+    return IDENTICAL;
   }
 
   // If the passwords differ, take the one that was created more recently.
   if (base::Time::FromInternalValue(password_specifics.date_created()) <=
           password_form.date_created) {
     *new_password_form = password_form;
-  } else {
-    PasswordFromSpecifics(password_specifics, new_password_form);
+    return LOCAL;
   }
 
-  return true;
+  PasswordFromSpecifics(password_specifics, new_password_form);
+  return SYNC;
 }
 
 std::string MakePasswordSyncTag(const std::string& origin_url,
                                 const std::string& username_element,
                                 const std::string& username_value,
                                 const std::string& password_element,
                                 const std::string& signon_realm) {
   return net::EscapePath(origin_url) + "|" +
          net::EscapePath(username_element) + "|" +
          net::EscapePath(username_value) + "|" +
@@ skipping 42 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
+  // update change.
+  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);
+        DCHECK(sync_changes.empty());
+        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 14 matching lines @@
   if (existing_local_entry_iter == umatched_data_from_password_db->end()) {
     // The sync data is not in the password store, so we need to create it in
     // the password store. Add the entry to the new_entries list.
     scoped_ptr<autofill::PasswordForm> new_password(new autofill::PasswordForm);
     PasswordFromSpecifics(password_specifics, new_password.get());
     new_sync_entries->push_back(new_password.release());
   } else {
     // The entry is in password store. If the entries are not identical, then
     // the entries need to be merged.
     scoped_ptr<autofill::PasswordForm> new_password(new autofill::PasswordForm);
-    if (MergeLocalAndSyncPasswords(password_specifics,
-                                   *existing_local_entry_iter->second,
-                                   new_password.get())) {
-      // Rather than checking which database -- sync or local -- needs updating,
-      // simply push an update to both. This will end up being a noop for the
-      // database that didn't need an update.
-      updated_db_entries->push_back(
-          syncer::SyncChange(FROM_HERE,
-                             syncer::SyncChange::ACTION_UPDATE,
-                             SyncDataFromPassword(*new_password)));
-
-      updated_sync_entries->push_back(new_password.release());
+    switch (MergeLocalAndSyncPasswords(password_specifics,
+                                       *existing_local_entry_iter->second,
+                                       new_password.get())) {
+      case IDENTICAL:
+        break;
+      case SYNC:
+        updated_sync_entries->push_back(new_password.release());
+        break;
+      case LOCAL:
+        updated_db_entries->push_back(
+            syncer::SyncChange(FROM_HERE,
+                               syncer::SyncChange::ACTION_UPDATE,
+                               SyncDataFromPassword(*new_password)));
+        break;
     }
     // Remove the entry from the entry map to indicate a match has been found.
     // Entries that remain in the map at the end of associating all sync entries
     // will be treated as additions that need to be propagated to sync.
     umatched_data_from_password_db->erase(existing_local_entry_iter);
   }
 }
 
 syncer::SyncData SyncDataFromPassword(
     const autofill::PasswordForm& password_form) {
@@ skipping 43 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());
 }