[Sync] Move //sync to //components/sync.

sync/engine/worker_entity_tracker.cc

-// Copyright 2014 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 "sync/engine/worker_entity_tracker.h"
-
-#include <stdint.h>
-
-#include "base/logging.h"
-#include "sync/internal_api/public/base/model_type.h"
-#include "sync/internal_api/public/non_blocking_sync_common.h"
-#include "sync/syncable/syncable_util.h"
-#include "sync/util/time.h"
-
-namespace syncer_v2 {
-
-WorkerEntityTracker::WorkerEntityTracker(const std::string& id,
-                                         const std::string& client_tag_hash)
-    : id_(id),
-      client_tag_hash_(client_tag_hash),
-      highest_commit_response_version_(0),
-      highest_gu_response_version_(0),
-      sequence_number_(0),
-      base_version_(kUncommittedVersion) {
-  DCHECK(!client_tag_hash_.empty());
-}
-
-WorkerEntityTracker::~WorkerEntityTracker() {}
-
-bool WorkerEntityTracker::HasPendingCommit() const {
-  return !!pending_commit_;
-}
-
-void WorkerEntityTracker::PopulateCommitProto(
-    sync_pb::SyncEntity* commit_entity) const {
-  DCHECK(HasPendingCommit());
-  DCHECK(!client_tag_hash_.empty());
-
-  if (!id_.empty()) {
-    commit_entity->set_id_string(id_);
-  }
-
-  const EntityData& entity = pending_commit_->entity.value();
-  DCHECK_EQ(client_tag_hash_, entity.client_tag_hash);
-
-  commit_entity->set_client_defined_unique_tag(client_tag_hash_);
-  commit_entity->set_version(base_version_);
-  commit_entity->set_deleted(entity.is_deleted());
-
-  // TODO(stanisc): This doesn't support bookmarks yet.
-  DCHECK(entity.parent_id.empty());
-  commit_entity->set_folder(false);
-
-  commit_entity->set_name(entity.non_unique_name);
-  if (!entity.is_deleted()) {
-    commit_entity->set_ctime(syncer::TimeToProtoTime(entity.creation_time));
-    commit_entity->set_mtime(syncer::TimeToProtoTime(entity.modification_time));
-    commit_entity->mutable_specifics()->CopyFrom(entity.specifics);
-  }
-}
-
-void WorkerEntityTracker::RequestCommit(const CommitRequestData& data) {
-  DCHECK_GE(data.base_version, base_version_)
-      << "Base version should never decrease";
-
-  DCHECK_GE(data.sequence_number, sequence_number_)
-      << "Sequence number should never decrease";
-
-  // Update our book-keeping counters.
-  base_version_ = data.base_version;
-  sequence_number_ = data.sequence_number;
-  pending_commit_specifics_hash_ = data.specifics_hash;
-
-  // Don't commit deletions of server-unknown items.
-  if (data.entity->is_deleted() && !IsServerKnown()) {
-    ClearPendingCommit();
-    return;
-  }
-
-  // We intentionally don't update the id_ here.  Good ID values come from the
-  // server and always pass through the sync thread first.  There's no way the
-  // model thread could have a better ID value than we do.
-
-  // This entity is identified by its client tag.  That value can never change.
-  DCHECK_EQ(client_tag_hash_, data.entity->client_tag_hash);
-  // TODO(stanisc): consider simply copying CommitRequestData instead of
-  // allocating one dynamically.
-  pending_commit_.reset(new CommitRequestData(data));
-
-  // Do our counter values indicate a conflict?  If so, don't commit.
-  //
-  // There's no need to inform the model thread of the conflict.  The
-  // conflicting update has already been posted to its task runner; it will
-  // figure it out as soon as it runs that task.
-  //
-  // Note that this check must be after pending_commit_ is set.
-  if (IsInConflict()) {
-    ClearPendingCommit();
-    return;
-  }
-
-  // Otherwise, keep the data associated with this pending commit
-  // so it can be committed at the next possible opportunity.
-}
-
-void WorkerEntityTracker::ReceiveCommitResponse(CommitResponseData* ack) {
-  DCHECK_GT(ack->response_version, highest_commit_response_version_)
-      << "Had expected higher response version."
-      << " id: " << id_;
-
-  // Commit responses, especially after the first commit, can update our ID.
-  id_ = ack->id;
-  highest_commit_response_version_ = ack->response_version;
-
-  // Fill in some cached info for the response data. Since commits happen
-  // synchronously on the sync thread, our item's state is guaranteed to be
-  // the same at the end of the commit as it was at the start.
-  ack->sequence_number = sequence_number_;
-  ack->specifics_hash = pending_commit_specifics_hash_;
-
-  // Because an in-progress commit blocks the sync thread, we can assume that
-  // the item we just committed successfully is exactly the one we have now.
-  // Nothing changed it while the commit was happening.  Since we're now in
-  // sync with the server, we can clear the pending commit.
-  ClearPendingCommit();
-}
-
-void WorkerEntityTracker::ReceiveUpdate(int64_t version) {
-  if (version <= highest_gu_response_version_)
-    return;
-
-  highest_gu_response_version_ = version;
-
-  // Got an applicable update newer than any pending updates.  It must be safe
-  // to discard the old encrypted update, if there was one.
-  ClearEncryptedUpdate();
-
-  if (IsInConflict()) {
-    // Incoming update clobbers the pending commit on the sync thread.
-    // The model thread can re-request this commit later if it wants to.
-    ClearPendingCommit();
-  }
-}
-
-bool WorkerEntityTracker::ReceiveEncryptedUpdate(
-    const UpdateResponseData& data) {
-  if (data.response_version < highest_gu_response_version_)
-    return false;
-
-  highest_gu_response_version_ = data.response_version;
-  encrypted_update_.reset(new UpdateResponseData(data));
-  ClearPendingCommit();
-  return true;
-}
-
-bool WorkerEntityTracker::HasEncryptedUpdate() const {
-  return !!encrypted_update_;
-}
-
-UpdateResponseData WorkerEntityTracker::GetEncryptedUpdate() const {
-  return *encrypted_update_;
-}
-
-void WorkerEntityTracker::ClearEncryptedUpdate() {
-  encrypted_update_.reset();
-}
-
-bool WorkerEntityTracker::IsInConflict() const {
-  if (!HasPendingCommit())
-    return false;
-
-  if (HasEncryptedUpdate())
-    return true;
-
-  if (highest_gu_response_version_ <= highest_commit_response_version_) {
-    // The most recent server state was created in a commit made by this
-    // client.  We're fully up to date, and therefore not in conflict.
-    return false;
-  } else {
-    // The most recent server state was written by someone else.
-    // Did the model thread have the most up to date version when it issued the
-    // commit request?
-    if (base_version_ >= highest_gu_response_version_) {
-      return false;  // Yes.
-    } else {
-      return true;  // No.
-    }
-  }
-}
-
-bool WorkerEntityTracker::IsServerKnown() const {
-  return base_version_ != kUncommittedVersion;
-}
-
-void WorkerEntityTracker::ClearPendingCommit() {
-  pending_commit_.reset();
-  pending_commit_specifics_hash_.clear();
-}
-
-}  // namespace syncer_v2