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, 364 insertions, 0 deletions

diff --git a/chrome/browser/sync/engine/syncer_session.h b/chrome/browser/sync/engine/syncer_session.h
new file mode 100644
index 0000000..e90930f
--- /dev/null
+++ b/chrome/browser/sync/engine/syncer_session.h
@@ -0,0 +1,364 @@
+// Copyright (c) 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.
+//
+// SyncerSession holds the entire state of a single sync cycle;
+// GetUpdates, Commit, and Conflict Resolution. After said cycle, the
+// Session may contain items that were unable to be processed because of
+// errors.
+//
+// THIS CLASS PROVIDES NO SYNCHRONIZATION GUARANTEES.
+
+#ifndef CHROME_BROWSER_SYNC_ENGINE_SYNCER_SESSION_H_
+#define CHROME_BROWSER_SYNC_ENGINE_SYNCER_SESSION_H_
+
+#include <utility>
+#include <vector>
+
+#include "chrome/browser/sync/engine/net/server_connection_manager.h"
+#include "chrome/browser/sync/engine/sync_cycle_state.h"
+#include "chrome/browser/sync/engine/sync_process_state.h"
+#include "chrome/browser/sync/engine/syncer_status.h"
+#include "chrome/browser/sync/engine/syncer_types.h"
+#include "chrome/browser/sync/engine/syncproto.h"
+#include "chrome/browser/sync/util/event_sys.h"
+#include "chrome/browser/sync/util/pthread_helpers.h"
+#include "chrome/browser/sync/util/sync_types.h"
+#include "testing/gtest/include/gtest/gtest_prod.h"  // For FRIEND_TEST
+
+namespace browser_sync {
+
+class ConflictResolver;
+class ModelSafeWorker;
+class ServerConnectionManager;
+class SyncerStatus;
+struct SyncerEvent;
+
+class SyncerSession {
+  friend class ConflictResolutionView;
+  friend class SyncerStatus;
+ public:
+  // A utility to set the session's write transaction member,
+  // and later clear it when it the utility falls out of scope.
+  class ScopedSetWriteTransaction {
+   public:
+    ScopedSetWriteTransaction(SyncerSession* session,
+                              syncable::WriteTransaction* trans)
+        : session_(session) {
+      session_->set_write_transaction(trans);
+    }
+    ~ScopedSetWriteTransaction() {
+      session_->ClearWriteTransaction();
+    }
+   private:
+    SyncerSession* session_;
+    DISALLOW_COPY_AND_ASSIGN(ScopedSetWriteTransaction);
+  };
+
+  SyncerSession(SyncCycleState* cycle_state, SyncProcessState* process_state)
+      : sync_process_state_(process_state),
+        sync_cycle_state_(cycle_state),
+        source_(sync_pb::GetUpdatesCallerInfo::UNKNOWN),
+        notifications_enabled_(false) {
+    DCHECK(NULL != process_state);
+    DCHECK(NULL != cycle_state);
+  }
+
+  // Perhaps this should dictate the next step. (ie, don't do apply if you
+  // didn't get any from download). or put it in the while loop.
+  void set_update_response(const ClientToServerResponse& update_response) {
+    sync_cycle_state_->set_update_response(update_response);
+  }
+
+  const ClientToServerResponse& update_response() const {
+    return sync_cycle_state_->update_response();
+  }
+
+  void set_commit_response(const ClientToServerResponse& commit_response) {
+    sync_cycle_state_->set_commit_response(commit_response);
+  }
+
+  const ClientToServerResponse& commit_response() const {
+    return sync_cycle_state_->commit_response();
+  }
+
+  void AddVerifyResult(const VerifyResult& verify_result,
+                       const sync_pb::SyncEntity& entity) {
+    sync_cycle_state_->AddVerifyResult(verify_result, entity);
+  }
+
+  bool HasVerifiedUpdates() const {
+    return sync_cycle_state_->HasVerifiedUpdates();
+  }
+
+  void AddAppliedUpdate(const UpdateAttemptResponse& response,
+                        const syncable::Id& id) {
+    sync_cycle_state_->AddAppliedUpdate(response, id);
+  }
+
+  bool HasAppliedUpdates() const {
+    return sync_cycle_state_->HasAppliedUpdates();
+  }
+
+  PathString account_name() const {
+    return sync_process_state_->account_name();
+  }
+
+  syncable::DirectoryManager* dirman() const {
+    return sync_process_state_->dirman();
+  }
+
+  ServerConnectionManager* connection_manager() const {
+    return sync_process_state_->connection_manager();
+  }
+
+  ConflictResolver* resolver() const {
+    return sync_process_state_->resolver();
+  }
+
+  SyncerEventChannel* syncer_event_channel() const {
+    return sync_process_state_->syncer_event_channel();
+  }
+
+  int conflicting_update_count() const {
+    return sync_process_state_->conflicting_updates();
+  }
+
+  time_t silenced_until() const {
+    return sync_process_state_->silenced_until_;
+  }
+
+  void set_silenced_until(time_t silenced_until) const {
+    sync_process_state_->silenced_until_ = silenced_until;
+  }
+
+  const std::vector<int64>& unsynced_handles() const {
+    return sync_cycle_state_->unsynced_handles();
+  }
+
+  void set_unsynced_handles(const std::vector<int64>& unsynced_handles) {
+    sync_cycle_state_->set_unsynced_handles(unsynced_handles);
+  }
+
+  int64 unsynced_count() const { return sync_cycle_state_->unsynced_count(); }
+
+  const std::vector<syncable::Id>& commit_ids() const {
+    return sync_cycle_state_->commit_ids();
+  }
+
+  void set_commit_ids(const std::vector<syncable::Id>& commit_ids) {
+    sync_cycle_state_->set_commit_ids(commit_ids);
+  }
+
+  bool commit_ids_empty() const {
+    return sync_cycle_state_->commit_ids_empty();
+  }
+
+  syncable::WriteTransaction* write_transaction() const {
+    return sync_cycle_state_->write_transaction();
+  }
+
+  bool has_open_write_transaction() const {
+    return sync_cycle_state_->has_open_write_transaction();
+  }
+
+  ClientToServerMessage* commit_message() const {
+    return sync_cycle_state_->commit_message();
+  }
+
+  void set_commit_message(const ClientToServerMessage& message) {
+    sync_cycle_state_->set_commit_message(message);
+  }
+
+  bool HasRemainingItemsToCommit() const {
+    return commit_ids().size() < unsynced_handles().size();
+  }
+
+  void AddCommitConflict(const syncable::Id& the_id) {
+    sync_process_state_->AddConflictingItem(the_id);
+  }
+
+  void AddBlockedItem(const syncable::Id& the_id) {
+    sync_process_state_->AddBlockedItem(the_id);
+  }
+
+  void EraseCommitConflict(const syncable::Id& the_id) {
+    sync_process_state_->EraseConflictingItem(the_id);
+  }
+
+  void EraseBlockedItem(const syncable::Id& the_id) {
+    sync_process_state_->EraseBlockedItem(the_id);
+  }
+
+  // Returns true if at least one update application failed due to
+  // a conflict during this sync cycle.
+  bool HasConflictingUpdates() const {
+    std::vector<AppliedUpdate>::const_iterator it;
+    for (it = sync_cycle_state_->AppliedUpdatesBegin();
+         it < sync_cycle_state_->AppliedUpdatesEnd();
+         ++it) {
+      if (it->first == CONFLICT) {
+        return true;
+      }
+    }
+    return false;
+  }
+
+  std::vector<VerifiedUpdate>::iterator VerifiedUpdatesBegin() const {
+    return sync_cycle_state_->VerifiedUpdatesBegin();
+  }
+
+  std::vector<VerifiedUpdate>::iterator VerifiedUpdatesEnd() const {
+    return sync_cycle_state_->VerifiedUpdatesEnd();
+  }
+
+  // Returns the number of updates received from the sync server.
+  int64 CountUpdates() const {
+    if (update_response().has_get_updates()) {
+      return update_response().get_updates().entries().size();
+    } else {
+      return 0;
+    }
+  }
+
+  bool got_zero_updates() const {
+    return CountUpdates() == 0;
+  }
+
+  void DumpSessionInfo() const {
+    LOG(INFO) << "Dumping session info";
+    if (update_response().has_get_updates()) {
+      LOG(INFO) << update_response().get_updates().entries().size()
+                << " updates downloaded by last get_updates";
+    } else {
+      LOG(INFO) << "No update response found";
+    }
+    LOG(INFO) << sync_cycle_state_->VerifiedUpdatesSize()
+              << " updates verified";
+    LOG(INFO) << sync_cycle_state_->AppliedUpdatesSize() << " updates applied";
+    LOG(INFO) << count_blocked_updates() << " updates blocked by open entry";
+    LOG(INFO) << commit_ids().size() << " items to commit";
+    LOG(INFO) << unsynced_count() << " unsynced items";
+  }
+
+  int64 count_blocked_updates() const {
+    std::vector<AppliedUpdate>::const_iterator it;
+    int64 count = 0;
+    for (it = sync_cycle_state_->AppliedUpdatesBegin();
+         it < sync_cycle_state_->AppliedUpdatesEnd();
+         ++it) {
+      if (it->first == BLOCKED) {
+        ++count;
+      }
+    }
+    return count;
+  }
+
+  void set_conflict_sets_built(const bool b) {
+    sync_cycle_state_->set_conflict_sets_built(b);
+  }
+
+  bool conflict_sets_built() const {
+    return sync_cycle_state_->conflict_sets_built();
+  }
+
+  void set_conflicts_resolved(const bool b) {
+    sync_cycle_state_->set_conflicts_resolved(b);
+  }
+
+  bool conflicts_resolved() const {
+    return sync_cycle_state_->conflicts_resolved();
+  }
+
+  ModelSafeWorker* model_safe_worker() const {
+    return sync_process_state_->model_safe_worker();
+  }
+
+  void set_items_committed(const bool b) {
+    sync_cycle_state_->set_items_committed(b);
+  }
+
+  void set_item_committed() {
+    sync_cycle_state_->set_item_committed();
+  }
+
+  bool items_committed() const {
+    return sync_cycle_state_->items_committed();
+  }
+
+  void set_over_quota(const bool b) {
+    sync_cycle_state_->set_over_quota(b);
+  }
+
+  // Volitile reader for the source member of the syncer session object.  The
+  // value is set to the SYNC_CYCLE_CONTINUATION value to signal that it has
+  // been read.
+  sync_pb::GetUpdatesCallerInfo::GET_UPDATES_SOURCE TestAndSetSource() {
+    sync_pb::GetUpdatesCallerInfo::GET_UPDATES_SOURCE old_source =
+        source_;
+    set_source(sync_pb::GetUpdatesCallerInfo::SYNC_CYCLE_CONTINUATION);
+    return old_source;
+  }
+
+  void set_source(sync_pb::GetUpdatesCallerInfo::GET_UPDATES_SOURCE source) {
+    source_ = source;
+  }
+
+  bool notifications_enabled() const {
+    return notifications_enabled_;
+  }
+
+  void set_notifications_enabled(const bool state) {
+    notifications_enabled_ = state;
+  }
+
+  void set_timestamp_dirty() {
+    sync_cycle_state_->set_timestamp_dirty();
+  }
+
+  bool timestamp_dirty() const {
+    return sync_cycle_state_->is_timestamp_dirty();
+  }
+
+  // TODO(chron): Unit test for this method.
+  // returns true iff this session contains data that should go through
+  // the sync engine again.
+  bool ShouldSyncAgain() const {
+    return (HasRemainingItemsToCommit() &&
+              sync_process_state_->successful_commits() > 0) ||
+           conflict_sets_built() ||
+           conflicts_resolved() ||
+           // Or, we have conflicting updates, but we're making progress on
+           // resolving them...
+           !got_zero_updates() ||
+           timestamp_dirty();
+  }
+
+ private:
+  // The write transaction must be destructed by the caller of this function.
+  // Here, we just clear the reference.
+  void set_write_transaction(syncable::WriteTransaction* write_transaction) {
+    sync_cycle_state_->set_write_transaction(write_transaction);
+  }
+
+  // sets the write transaction to null, but doesn't free the memory.
+  void ClearWriteTransaction() {
+    sync_cycle_state_->ClearWriteTransaction();
+  }
+
+  SyncProcessState* sync_process_state_;
+  SyncCycleState* sync_cycle_state_;
+
+  // The source for initiating this syncer session.
+  sync_pb::GetUpdatesCallerInfo::GET_UPDATES_SOURCE source_;
+
+  // True if notifications are enabled when this session was created.
+  bool notifications_enabled_;
+
+  FRIEND_TEST(SyncerTest, TestCommitListOrderingCounterexample);
+  DISALLOW_COPY_AND_ASSIGN(SyncerSession);
+};
+
+}  // namespace browser_sync
+
+#endif  // CHROME_BROWSER_SYNC_ENGINE_SYNCER_SESSION_H_