[Sync] Implementation of model association for passwords using sync API

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 67355e2a9668629a1af517a96612ca85160b350c..9663e279e4269a6a0d961746ab3aaeeb5a1351a9 100644
--- a/chrome/browser/password_manager/password_syncable_service.cc
+++ b/chrome/browser/password_manager/password_syncable_service.cc
@@ -5,6 +5,9 @@
 #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/stl_util.h"
 #include "base/strings/utf_string_conversions.h"
 #include "chrome/browser/password_manager/password_store.h"
 #include "components/autofill/core/common/password_form.h"
@@ -13,32 +16,6 @@
 
 namespace {
 
-// Converts the |PasswordSpecifics| obtained from sync to an
-// object of type |PasswordForm|.
-void ExtractPasswordFromSpecifics(
-     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 =
-      UTF8ToUTF16(password.username_element());
-  new_password->password_element =
-      UTF8ToUTF16(password.password_element());
-  new_password->username_value =
-      UTF8ToUTF16(password.username_value());
-  new_password->password_value =
-      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();
-}
-
 // Merges the sync password (obtained from the password specifics) and
 // local password and stores the output in the |new_password_form| pointer.
 bool MergeLocalAndSyncPasswords(
@@ -71,7 +48,9 @@ bool MergeLocalAndSyncPasswords(
           password_form.date_created) {
     *new_password_form = password_form;
   } else {
-    ExtractPasswordFromSpecifics(password_specifics, new_password_form);
+    PasswordSyncableService::ExtractPasswordFromSpecifics(
+        password_specifics,
+        new_password_form);
   }
 
   return true;
@@ -86,6 +65,50 @@ PasswordSyncableService::PasswordSyncableService(
 
 PasswordSyncableService::~PasswordSyncableService() {}
 
+void PasswordSyncableService::CreateOrUpdateEntry(
+    const syncer::SyncData& data,
+    PasswordEntryMap* loaded_data,
+    ScopedVector<autofill::PasswordForm>* new_entries,
+    ScopedVector<autofill::PasswordForm>* updated_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 = MakeTag(password_specifics);
+
+  // Find if the data from sync is already in password store.
+  PasswordEntryMap::iterator it = loaded_data->find(tag);
+
+  if (it == loaded_data->end()) {
+    // The sync data is not in password store, so we need to create it in
+    // password store. Add the entry to the new_entries list.
+    autofill::PasswordForm* new_password = new autofill::PasswordForm();
+    ExtractPasswordFromSpecifics(password_specifics, new_password);
+    // The new_password pointer is owned by the caller.
+    new_entries->push_back(new_password);
+  } else {
+    // The entry is in password store. If the entries are not identical the
+    // entries need to be merged.
+    scoped_ptr<autofill::PasswordForm> new_password(
+        new autofill::PasswordForm());
+    if (MergeLocalAndSyncPasswords(password_specifics,
+                                   **(it->second),
+                                   new_password.get())) {
+      updated_db_entries->push_back(
+          syncer::SyncChange(FROM_HERE,
+                             syncer::SyncChange::ACTION_UPDATE,
+                             CreateSyncData(*(new_password.get()))));
+
+      updated_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 needs to be propagated to sync.
+    loaded_data->erase(it);
+  }
+}
+
 syncer::SyncMergeResult
 PasswordSyncableService::MergeDataAndStartSyncing(
     syncer::ModelType type,
@@ -96,9 +119,72 @@ PasswordSyncableService::MergeDataAndStartSyncing(
   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_->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);
+    merge_result.set_error(sync_error_factory->CreateAndUploadError(
+        FROM_HERE,
+        "Failed to get passwords from store."));
+    return merge_result;;
+  }
+
+  PasswordEntryMap new_db_entries;
+  for (std::vector<autofill::PasswordForm*>::iterator
+           it = password_entries.begin();
+       it != password_entries.end();
+       ++it) {
+     // We add all the db entries as |new_db_entries| initially. While
+     // association entries with matching sync entries will be removed and this
+     // list will only contain entries that are not in sync.
+     new_db_entries[MakeTag(**it)] = it;
+  }
+
+  merge_result.set_num_items_before_association(new_db_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 to be updated in sync.
+  ScopedVector<autofill::PasswordForm> updated_sync_entries;
+
+  // Changes from password db that needs to be propagated to sync.
+  syncer::SyncChangeList db_changes;
+  for (syncer::SyncDataList::const_iterator sync_iter =
+           initial_sync_data.begin();
+       sync_iter != initial_sync_data.end(); ++sync_iter) {
+    CreateOrUpdateEntry(*sync_iter,
+                        &new_db_entries,
+                        &new_sync_entries,
+                        &updated_sync_entries,
+                        &db_changes);
+  }
+
+  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_db_entries.begin();
+       it != new_db_entries.end();
+       ++it) {
+    db_changes.push_back(syncer::SyncChange(FROM_HERE,
+                              syncer::SyncChange::ACTION_ADD,
+                              CreateSyncData(**(it->second))));
+  }
+
+  merge_result.set_error(
+      sync_processor_->ProcessSyncChanges(FROM_HERE, db_changes));
   return merge_result;
 }
 
@@ -122,29 +208,33 @@ syncer::SyncError PasswordSyncableService::ProcessSyncChanges(
 }
 
 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();
+    NotifyPasswordStore();
   }
 }
 
+void PasswordSyncableService::NotifyPasswordStore() {
+  password_store_->PostNotifyLoginsChanged();
+}
+
 syncer::SyncData PasswordSyncableService::CreateSyncData(
     const autofill::PasswordForm& password_form) {
   sync_pb::EntitySpecifics password_data;
@@ -206,3 +296,28 @@ std::string PasswordSyncableService::MakeTag(
                  password.signon_realm());
 }
 
+// static
+void PasswordSyncableService::ExtractPasswordFromSpecifics(
+     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 =
+      UTF8ToUTF16(password.username_element());
+  new_password->password_element =
+      UTF8ToUTF16(password.password_element());
+  new_password->username_value =
+      UTF8ToUTF16(password.username_value());
+  new_password->password_value =
+      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();
+}
+