Initial commit of sync engine code to browser/sync.

The code is not built on any platform yet.  That will arrive
as a subsequent checkin.

This is an implementation of the interface exposed earlier
through syncapi.h.  It is the client side of a sync
protocol that lets users sync their browser data
(currently, just bookmarks) with their Google Account.

Table of contents:

browser/sync/
  protocol - The protocol definition, and
             other definitions necessary to connect to
             the service.
  syncable/ - defines a data model for syncable objects,
              and provides a sqlite-based backing store
              for this model.
  engine/ - includes the core sync logic, including commiting
            changes to the server, downloading changes from
            the server, resolving conflicts, other parts of
            the sync algorithm.
  engine/net - parts of the sync engine focused on the
               business of talking to the server.  Some of
               this is binds a generic "server connection"
               interface to a concrete implementation
               provided by Chromium.
  notifier - the part of the syncer focused on the business
             of sending and receiving xmpp notifications.
             Notifications are used instead of polling to
             achieve very low latency change propagation.
  util - not necessarily sync specific utility code.  Much
         of this is scaffolding which should either be
         replaced by, or merged with, the utility code
         in base/.

BUG=none
TEST=this code includes its own suite of unit tests.

Review URL: http://codereview.chromium.org/194065

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@25850 0039d316-1c4b-4281-b951-d872f2087c98

1 files changed, 335 insertions, 0 deletions

diff --git a/chrome/browser/sync/engine/all_status.cc b/chrome/browser/sync/engine/all_status.cc
new file mode 100644
index 0000000..e1bc5c7
--- /dev/null
+++ b/chrome/browser/sync/engine/all_status.cc
@@ -0,0 +1,335 @@
+// Copyright (c) 2006-2009 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/sync/engine/all_status.h"
+
+#include <algorithm>
+
+#include "base/logging.h"
+#include "base/port.h"
+#include "base/rand_util.h"
+#include "chrome/browser/sync/engine/auth_watcher.h"
+#include "chrome/browser/sync/engine/net/gaia_authenticator.h"
+#include "chrome/browser/sync/engine/net/server_connection_manager.h"
+#include "chrome/browser/sync/engine/syncer.h"
+#include "chrome/browser/sync/engine/syncer_thread.h"
+#include "chrome/browser/sync/engine/syncproto.h"
+#include "chrome/browser/sync/notifier/listener/talk_mediator.h"
+#include "chrome/browser/sync/protocol/service_constants.h"
+#include "chrome/browser/sync/syncable/directory_manager.h"
+#include "chrome/browser/sync/util/event_sys-inl.h"
+
+namespace browser_sync {
+
+static const time_t kMinSyncObserveInterval = 10;  // seconds
+
+// Backoff interval randomization factor.
+static const int kBackoffRandomizationFactor = 2;
+
+const char* AllStatus::GetSyncStatusString(SyncStatus icon) {
+  const char* strings[] = {"OFFLINE", "OFFLINE_UNSYNCED", "SYNCING", "READY",
+      "CONFLICT", "OFFLINE_UNUSABLE"};
+  COMPILE_ASSERT(ARRAYSIZE(strings) == ICON_STATUS_COUNT, enum_indexed_array);
+  if (icon < 0 || icon >= ARRAYSIZE(strings))
+    LOG(FATAL) << "Illegal Icon State:" << icon;
+  return strings[icon];
+}
+
+static const AllStatus::Status init_status =
+  { AllStatus::OFFLINE };
+
+static const AllStatusEvent shutdown_event =
+  { AllStatusEvent::SHUTDOWN, init_status };
+
+AllStatus::AllStatus() : channel_(new Channel(shutdown_event)),
+                         status_(init_status) {
+  status_.initial_sync_ended = true;
+  status_.notifications_enabled = false;
+}
+
+AllStatus::~AllStatus() {
+  delete channel_;
+}
+
+void AllStatus::WatchConnectionManager(ServerConnectionManager* conn_mgr) {
+  conn_mgr_hookup_.reset(NewEventListenerHookup(conn_mgr->channel(), this,
+                         &AllStatus::HandleServerConnectionEvent));
+}
+
+void AllStatus::WatchAuthenticator(GaiaAuthenticator* gaia) {
+  gaia_hookup_.reset(NewEventListenerHookup(gaia->channel(), this,
+                     &AllStatus::HandleGaiaAuthEvent));
+}
+
+void AllStatus::WatchAuthWatcher(AuthWatcher* auth_watcher) {
+  authwatcher_hookup_.reset(
+      NewEventListenerHookup(auth_watcher->channel(), this,
+                             &AllStatus::HandleAuthWatcherEvent));
+}
+
+void AllStatus::WatchSyncerThread(SyncerThread* syncer_thread) {
+  syncer_thread_hookup_.reset(
+      NewEventListenerHookup(syncer_thread->channel(), this,
+                             &AllStatus::HandleSyncerEvent));
+}
+
+AllStatus::Status AllStatus::CreateBlankStatus() const {
+  Status status = status_;
+  status.syncing = true;
+  status.unsynced_count = 0;
+  status.conflicting_count = 0;
+  status.initial_sync_ended = false;
+  status.syncer_stuck = false;
+  status.max_consecutive_errors = 0;
+  status.server_broken = false;
+  status.updates_available = 0;
+  status.updates_received = 0;
+  return status;
+}
+
+AllStatus::Status AllStatus::CalcSyncing(const SyncerEvent &event) const {
+  Status status = CreateBlankStatus();
+  SyncerStatus syncerStatus(event.last_session);
+  status.unsynced_count += syncerStatus.unsynced_count();
+  status.conflicting_count += syncerStatus.conflicting_commits();
+  if (syncerStatus.current_sync_timestamp() ==
+      syncerStatus.servers_latest_timestamp()) {
+    status.conflicting_count += syncerStatus.conflicting_updates();
+  }
+  status.syncing |= syncerStatus.syncing();
+  // Show a syncer as syncing if it's got stalled updates.
+  status.syncing = event.last_session->ShouldSyncAgain();
+  status.initial_sync_ended |= syncerStatus.IsShareUsable();
+  status.syncer_stuck |= syncerStatus.syncer_stuck();
+  if (syncerStatus.consecutive_errors() > status.max_consecutive_errors)
+    status.max_consecutive_errors = syncerStatus.consecutive_errors();
+
+  // 100 is an arbitrary limit.
+  if (syncerStatus.consecutive_transient_error_commits() > 100)
+    status.server_broken = true;
+
+  status.updates_available += syncerStatus.servers_latest_timestamp();
+  status.updates_received += syncerStatus.current_sync_timestamp();
+  return status;
+}
+
+AllStatus::Status AllStatus::CalcSyncing() const {
+  return CreateBlankStatus();
+}
+
+int AllStatus::CalcStatusChanges(Status* old_status) {
+  int what_changed = 0;
+
+  // Calculate what changed and what the new icon should be.
+  if (status_.syncing != old_status->syncing)
+    what_changed |= AllStatusEvent::SYNCING;
+  if (status_.unsynced_count != old_status->unsynced_count)
+    what_changed |= AllStatusEvent::UNSYNCED_COUNT;
+  if (status_.server_up != old_status->server_up)
+    what_changed |= AllStatusEvent::SERVER_UP;
+  if (status_.server_reachable != old_status->server_reachable)
+    what_changed |= AllStatusEvent::SERVER_REACHABLE;
+  if (status_.notifications_enabled != old_status->notifications_enabled)
+    what_changed |= AllStatusEvent::NOTIFICATIONS_ENABLED;
+  if (status_.notifications_received != old_status->notifications_received)
+    what_changed |= AllStatusEvent::NOTIFICATIONS_RECEIVED;
+  if (status_.notifications_sent != old_status->notifications_sent)
+    what_changed |= AllStatusEvent::NOTIFICATIONS_SENT;
+  if (status_.initial_sync_ended != old_status->initial_sync_ended)
+    what_changed |= AllStatusEvent::INITIAL_SYNC_ENDED;
+  if (status_.authenticated != old_status->authenticated)
+    what_changed |= AllStatusEvent::AUTHENTICATED;
+
+  const bool unsynced_changes = status_.unsynced_count > 0;
+  const bool online = status_.authenticated &&
+    status_.server_reachable && status_.server_up && !status_.server_broken;
+  if (online) {
+    if (status_.syncer_stuck)
+      status_.icon = CONFLICT;
+    else if (unsynced_changes || status_.syncing)
+      status_.icon = SYNCING;
+    else
+      status_.icon = READY;
+  } else if (!status_.initial_sync_ended) {
+    status_.icon = OFFLINE_UNUSABLE;
+  } else if (unsynced_changes) {
+    status_.icon = OFFLINE_UNSYNCED;
+  } else {
+    status_.icon = OFFLINE;
+  }
+
+  if (status_.icon != old_status->icon)
+    what_changed |= AllStatusEvent::ICON;
+
+  if (0 == what_changed)
+    return 0;
+  *old_status = status_;
+  return what_changed;
+}
+
+void AllStatus::HandleGaiaAuthEvent(const GaiaAuthEvent& gaia_event) {
+  ScopedStatusLockWithNotify lock(this);
+  switch (gaia_event.what_happened) {
+    case GaiaAuthEvent::GAIA_AUTH_FAILED:
+      status_.authenticated = false;
+      break;
+    case GaiaAuthEvent::GAIA_AUTH_SUCCEEDED:
+      status_.authenticated = true;
+      break;
+    default:
+      lock.set_notify_plan(DONT_NOTIFY);
+      break;
+  }
+}
+
+void AllStatus::HandleAuthWatcherEvent(const AuthWatcherEvent& auth_event) {
+  ScopedStatusLockWithNotify lock(this);
+  switch (auth_event.what_happened) {
+    case AuthWatcherEvent::GAIA_AUTH_FAILED:
+    case AuthWatcherEvent::SERVICE_AUTH_FAILED:
+    case AuthWatcherEvent::SERVICE_CONNECTION_FAILED:
+    case AuthWatcherEvent::AUTHENTICATION_ATTEMPT_START:
+      status_.authenticated = false;
+      break;
+    case AuthWatcherEvent::AUTH_SUCCEEDED:
+      // If we've already calculated that the server is reachable, since we've
+      // successfully authenticated, we can be confident that the server is up.
+      if (status_.server_reachable)
+        status_.server_up = true;
+
+      if (!status_.authenticated) {
+        status_.authenticated = true;
+        status_ = CalcSyncing();
+      } else {
+        lock.set_notify_plan(DONT_NOTIFY);
+      }
+      break;
+    default:
+      lock.set_notify_plan(DONT_NOTIFY);
+      break;
+  }
+}
+
+void AllStatus::HandleSyncerEvent(const SyncerEvent& event) {
+  ScopedStatusLockWithNotify lock(this);
+  switch (event.what_happened) {
+    case SyncerEvent::SYNC_CYCLE_ENDED:
+    case SyncerEvent::COMMITS_SUCCEEDED:
+      break;
+    case SyncerEvent::STATUS_CHANGED:
+      status_ = CalcSyncing(event);
+      break;
+    case SyncerEvent::SHUTDOWN_USE_WITH_CARE:
+      // We're safe to use this value here because we don't call into the syncer
+      // or block on any processes.
+      lock.set_notify_plan(DONT_NOTIFY);
+      break;
+    case SyncerEvent::OVER_QUOTA:
+      LOG(WARNING) << "User has gone over quota.";
+      lock.NotifyOverQuota();
+      break;
+    case SyncerEvent::REQUEST_SYNC_NUDGE:
+      lock.set_notify_plan(DONT_NOTIFY);
+      break;
+    default:
+      LOG(ERROR) << "Unrecognized Syncer Event: " << event.what_happened;
+      lock.set_notify_plan(DONT_NOTIFY);
+      break;
+  }
+}
+
+void AllStatus::HandleServerConnectionEvent(
+    const ServerConnectionEvent& event) {
+  if (ServerConnectionEvent::STATUS_CHANGED == event.what_happened) {
+    ScopedStatusLockWithNotify lock(this);
+    status_.server_up = IsGoodReplyFromServer(event.connection_code);
+    status_.server_reachable = event.server_reachable;
+  }
+}
+
+void AllStatus::WatchTalkMediator(const TalkMediator* mediator) {
+  status_.notifications_enabled = false;
+  talk_mediator_hookup_.reset(
+      NewEventListenerHookup(mediator->channel(), this,
+                             &AllStatus::HandleTalkMediatorEvent));
+}
+
+void AllStatus::HandleTalkMediatorEvent(
+    const TalkMediatorEvent& event) {
+  ScopedStatusLockWithNotify lock(this);
+  switch (event.what_happened) {
+    case TalkMediatorEvent::SUBSCRIPTIONS_ON:
+      status_.notifications_enabled = true;
+      break;
+    case TalkMediatorEvent::LOGOUT_SUCCEEDED:
+    case TalkMediatorEvent::SUBSCRIPTIONS_OFF:
+    case TalkMediatorEvent::TALKMEDIATOR_DESTROYED:
+      status_.notifications_enabled = false;
+      break;
+    case TalkMediatorEvent::NOTIFICATION_RECEIVED:
+      status_.notifications_received++;
+      break;
+    case TalkMediatorEvent::NOTIFICATION_SENT:
+      status_.notifications_sent++;
+      break;
+    case TalkMediatorEvent::LOGIN_SUCCEEDED:
+    default:
+      lock.set_notify_plan(DONT_NOTIFY);
+      break;
+  }
+}
+
+AllStatus::Status AllStatus::status() const {
+  MutexLock lock(&mutex_);
+  return status_;
+}
+
+int AllStatus::GetRecommendedDelaySeconds(int base_delay_seconds) {
+  if (base_delay_seconds >= kMaxBackoffSeconds)
+    return kMaxBackoffSeconds;
+
+  // This calculates approx. base_delay_seconds * 2 +/- base_delay_seconds / 2
+  int backoff_s = (0 == base_delay_seconds) ? 1 :
+      base_delay_seconds * kBackoffRandomizationFactor;
+
+  // Flip a coin to randomize backoff interval by +/- 50%.
+  int rand_sign = base::RandInt(0, 1) * 2 - 1;
+
+  // Truncation is adequate for rounding here.
+  backoff_s = backoff_s +
+      (rand_sign * (base_delay_seconds / kBackoffRandomizationFactor));
+
+  // Cap the backoff interval.
+  backoff_s = std::min(backoff_s, kMaxBackoffSeconds);
+
+  return backoff_s;
+}
+
+int AllStatus::GetRecommendedDelay(int base_delay_ms) const {
+  return GetRecommendedDelaySeconds(base_delay_ms / 1000) * 1000;
+}
+
+ScopedStatusLockWithNotify::ScopedStatusLockWithNotify(AllStatus* allstatus)
+  : allstatus_(allstatus), plan_(NOTIFY_IF_STATUS_CHANGED) {
+  event_.what_changed = 0;
+  allstatus->mutex_.Lock();
+  event_.status = allstatus->status_;
+}
+
+ScopedStatusLockWithNotify::~ScopedStatusLockWithNotify() {
+  if (DONT_NOTIFY == plan_) {
+    allstatus_->mutex_.Unlock();
+    return;
+  }
+  event_.what_changed |= allstatus_->CalcStatusChanges(&event_.status);
+  allstatus_->mutex_.Unlock();
+  if (event_.what_changed)
+    allstatus_->channel()->NotifyListeners(event_);
+}
+
+void ScopedStatusLockWithNotify::NotifyOverQuota() {
+  event_.what_changed |= AllStatusEvent::OVER_QUOTA;
+}
+
+}  // namespace browser_sync