Password sync refactoring: implemented |MergeDataAndStartSyncing| and unit_tests

chrome/browser/password_manager/password_syncable_service.cc

Index: chrome/browser/password_manager/password_syncable_service.cc
diff --git a/chrome/browser/password_manager/password_syncable_service.cc b/chrome/browser/password_manager/password_syncable_service.cc
index 7f3710913247228c337653f1ce81ecd083fb20ba..7525bbee83e0c1ab9e964f81ca5d681b1cb0f1bc 100644
--- a/chrome/browser/password_manager/password_syncable_service.cc
+++ b/chrome/browser/password_manager/password_syncable_service.cc
@@ -5,6 +5,8 @@
 #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 "chrome/browser/password_manager/password_store.h"
 #include "components/autofill/core/common/password_form.h"
@@ -13,6 +15,65 @@
 
 namespace {
 
+// 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(
+    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;
+  }
+
+  // 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 true;
+}
+
+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) + "|" +
+         net::EscapePath(password_element) + "|" +
+         net::EscapePath(signon_realm);
+}
+
+std::string MakePasswordSyncTag(const autofill::PasswordForm& password) {
+  return MakePasswordSyncTag(password.origin.spec(),
+                             base::UTF16ToUTF8(password.username_element),
+                             base::UTF16ToUTF8(password.username_value),
+                             base::UTF16ToUTF8(password.password_element),
+                             password.signon_realm);
+}
+
 syncer::SyncChange::SyncChangeType GetSyncChangeType(
     PasswordStoreChange::Type type) {
   switch (type) {
@@ -36,19 +97,82 @@ PasswordSyncableService::PasswordSyncableService(
 
 PasswordSyncableService::~PasswordSyncableService() {}
 
-syncer::SyncMergeResult
-PasswordSyncableService::MergeDataAndStartSyncing(
+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();
 
-  merge_result.set_error(sync_error_factory->CreateAndUploadError(
-      FROM_HERE,
-      "Password Syncable Service Not Implemented."));
+  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);
+    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());
+
+  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;
 }
 
@@ -81,72 +205,87 @@ void PasswordSyncableService::ActOnPasswordStoreChanges(
   for (PasswordStoreChangeList::const_iterator it = local_changes.begin();
        it != local_changes.end();
        ++it) {
-    sync_changes.push_back(syncer::SyncChange(FROM_HERE,
-                                              GetSyncChangeType(it->type()),
-                                              CreateSyncData(it->form())));
+    sync_changes.push_back(
+        syncer::SyncChange(FROM_HERE,
+                           GetSyncChangeType(it->type()),
+                           SyncDataFromPassword(it->form())));
   }
   sync_processor_->ProcessSyncChanges(FROM_HERE, sync_changes);
 }
 
-// static
-std::string PasswordSyncableService::MakeTag(
-    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) + "|" +
-         net::EscapePath(password_element) + "|" +
-         net::EscapePath(signon_realm);
-}
-
-// static
-std::string PasswordSyncableService::MakeTag(
-    const autofill::PasswordForm& password) {
-  return MakeTag(password.origin.spec(),
-                 base::UTF16ToUTF8(password.username_element),
-                 base::UTF16ToUTF8(password.username_value),
-                 base::UTF16ToUTF8(password.password_element),
-                 password.signon_realm);
-}
-
-// static
-std::string PasswordSyncableService::MakeTag(
-    const sync_pb::PasswordSpecificsData& password) {
-  return MakeTag(password.origin(),
-                 password.username_element(),
-                 password.username_value(),
-                 password.password_element(),
-                 password.signon_realm());
-}
-
 void PasswordSyncableService::WriteToPasswordStore(
-    PasswordForms* new_entries,
-    PasswordForms* updated_entries) {
+    const PasswordForms& new_entries,
+    const PasswordForms& updated_entries) {
   for (std::vector<autofill::PasswordForm*>::const_iterator it =
-           new_entries->begin();
-       it != new_entries->end();
+           new_entries.begin();
+       it != new_entries.end();
        ++it) {
     password_store_->AddLoginImpl(**it);
   }
 
   for (std::vector<autofill::PasswordForm*>::const_iterator it =
-           updated_entries->begin();
-       it != updated_entries->end();
+           updated_entries.begin();
+       it != updated_entries.end();
        ++it) {
     password_store_->UpdateLoginImpl(**it);
   }
 
-  if (!new_entries->empty() || !updated_entries->empty()) {
+  if (!new_entries.empty() || !updated_entries.empty()) {
     // We have to notify password store observers of the change by hand since
     // we use internal password store interfaces to make changes synchronously.
-    password_store_->PostNotifyLoginsChanged();
+    NotifyPasswordStoreOfLoginChanges();
   }
 }
 
-syncer::SyncData PasswordSyncableService::CreateSyncData(
+void PasswordSyncableService::NotifyPasswordStoreOfLoginChanges() {
+  password_store_->PostNotifyLoginsChanged();
+}
+
+void PasswordSyncableService::CreateOrUpdateEntry(
+    const syncer::SyncData& data,
+    PasswordEntryMap* umatched_data_from_password_db,
+    ScopedVector<autofill::PasswordForm>* new_sync_entries,
+    ScopedVector<autofill::PasswordForm>* updated_sync_entries,
+    syncer::SyncChangeList* updated_db_entries) {
+  const sync_pb::EntitySpecifics& specifics = data.GetSpecifics();
+  const sync_pb::PasswordSpecificsData& password_specifics(
+      specifics.password().client_only_encrypted_data());
+  std::string tag = MakePasswordSyncTag(password_specifics);
+
+  // Check whether the data from sync is already in the password store.
+  PasswordEntryMap::iterator existing_local_entry_iter =
+      umatched_data_from_password_db->find(tag);
+  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());
+    }
+    // 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) {
   sync_pb::EntitySpecifics password_data;
   sync_pb::PasswordSpecificsData* password_specifics =
@@ -169,6 +308,35 @@ syncer::SyncData PasswordSyncableService::CreateSyncData(
       password_form.date_created.ToInternalValue());
   password_specifics->set_blacklisted(password_form.blacklisted_by_user);
 
-  std::string tag = MakeTag(*password_specifics);
+  std::string tag = MakePasswordSyncTag(*password_specifics);
   return syncer::SyncData::CreateLocalData(tag, tag, password_data);
 }
+
+void PasswordFromSpecifics(const sync_pb::PasswordSpecificsData& password,
+                           autofill::PasswordForm* new_password) {
+  new_password->scheme =
+      static_cast<autofill::PasswordForm::Scheme>(password.scheme());
+  new_password->signon_realm = password.signon_realm();
+  new_password->origin = GURL(password.origin());
+  new_password->action = GURL(password.action());
+  new_password->username_element =
+      base::UTF8ToUTF16(password.username_element());
+  new_password->password_element =
+      base::UTF8ToUTF16(password.password_element());
+  new_password->username_value = base::UTF8ToUTF16(password.username_value());
+  new_password->password_value = base::UTF8ToUTF16(password.password_value());
+  new_password->ssl_valid = password.ssl_valid();
+  new_password->preferred = password.preferred();
+  new_password->date_created =
+      base::Time::FromInternalValue(password.date_created());
+  new_password->blacklisted_by_user = password.blacklisted();
+}
+
+std::string MakePasswordSyncTag(
+    const sync_pb::PasswordSpecificsData& password) {
+  return MakePasswordSyncTag(password.origin(),
+                             password.username_element(),
+                             password.username_value(),
+                             password.password_element(),
+                             password.signon_realm());
+}