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

sync/sessions/data_type_tracker.cc

-// Copyright 2013 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/sessions/data_type_tracker.h"
-
-#include <stddef.h>
-
-#include <algorithm>
-
-#include "base/logging.h"
-#include "sync/internal_api/public/base/invalidation_interface.h"
-#include "sync/sessions/nudge_tracker.h"
-
-namespace syncer {
-namespace sessions {
-
-DataTypeTracker::DataTypeTracker()
-    : local_nudge_count_(0),
-      local_refresh_request_count_(0),
-      payload_buffer_size_(NudgeTracker::kDefaultMaxPayloadsPerType),
-      initial_sync_required_(false),
-      sync_required_to_resolve_conflict_(false) {
-}
-
-DataTypeTracker::~DataTypeTracker() { }
-
-base::TimeDelta DataTypeTracker::RecordLocalChange() {
-  local_nudge_count_++;
-  return nudge_delay_;
-}
-
-void DataTypeTracker::RecordLocalRefreshRequest() {
-  local_refresh_request_count_++;
-}
-
-void DataTypeTracker::RecordRemoteInvalidation(
-    std::unique_ptr<InvalidationInterface> incoming) {
-  DCHECK(incoming);
-
-  // Merge the incoming invalidation into our list of pending invalidations.
-  //
-  // We won't use STL algorithms here because our concept of equality doesn't
-  // quite fit the expectations of set_intersection.  In particular, two
-  // invalidations can be equal according to the SingleObjectInvalidationSet's
-  // rules (ie. have equal versions), but still have different AckHandle values
-  // and need to be acknowledged separately.
-  //
-  // The invalidations service can only track one outsanding invalidation per
-  // type and version, so the acknowledgement here should be redundant.  We'll
-  // acknowledge them anyway since it should do no harm, and makes this code a
-  // bit easier to test.
-  //
-  // Overlaps should be extremely rare for most invalidations.  They can happen
-  // for unknown version invalidations, though.
-
-  ScopedVector<InvalidationInterface>::iterator it =
-      pending_invalidations_.begin();
-
-  // Find the lower bound.
-  while (it != pending_invalidations_.end() &&
-         InvalidationInterface::LessThanByVersion(**it, *incoming)) {
-    it++;
-  }
-
-  if (it != pending_invalidations_.end() &&
-      !InvalidationInterface::LessThanByVersion(*incoming, **it) &&
-      !InvalidationInterface::LessThanByVersion(**it, *incoming)) {
-    // Incoming overlaps with existing.  Either both are unknown versions
-    // (likely) or these two have the same version number (very unlikely).
-    // Acknowledge and overwrite existing.
-
-    // Insert before the existing and get iterator to inserted.
-    ScopedVector<InvalidationInterface>::iterator it2 =
-        pending_invalidations_.insert(it, incoming.release());
-
-    // Increment that iterator to the old one, then acknowledge and remove it.
-    ++it2;
-    (*it2)->Acknowledge();
-    pending_invalidations_.erase(it2);
-  } else {
-    // The incoming has a version not in the pending_invalidations_ list.
-    // Add it to the list at the proper position.
-    pending_invalidations_.insert(it, incoming.release());
-  }
-
-  // The incoming invalidation may have caused us to exceed our buffer size.
-  // Trim some items from our list, if necessary.
-  while (pending_invalidations_.size() > payload_buffer_size_) {
-    last_dropped_invalidation_.reset(pending_invalidations_.front());
-    last_dropped_invalidation_->Drop();
-    pending_invalidations_.weak_erase(pending_invalidations_.begin());
-  }
-}
-
-void DataTypeTracker::RecordInitialSyncRequired() {
-  initial_sync_required_ = true;
-}
-
-void DataTypeTracker::RecordCommitConflict() {
-  sync_required_to_resolve_conflict_ = true;
-}
-
-void DataTypeTracker::RecordSuccessfulSyncCycle() {
-  // If we were throttled, then we would have been excluded from this cycle's
-  // GetUpdates and Commit actions.  Our state remains unchanged.
-  if (IsThrottled())
-    return;
-
-  local_nudge_count_ = 0;
-  local_refresh_request_count_ = 0;
-
-  // TODO(rlarocque): If we want this to be correct even if we should happen to
-  // crash before writing all our state, we should wait until the results of
-  // this sync cycle have been written to disk before updating the invalidations
-  // state.  See crbug.com/324996.
-  for (ScopedVector<InvalidationInterface>::const_iterator it =
-           pending_invalidations_.begin();
-       it != pending_invalidations_.end();
-       ++it) {
-    (*it)->Acknowledge();
-  }
-  pending_invalidations_.clear();
-
-  if (last_dropped_invalidation_) {
-    last_dropped_invalidation_->Acknowledge();
-    last_dropped_invalidation_.reset();
-  }
-
-  initial_sync_required_ = false;
-  sync_required_to_resolve_conflict_ = false;
-}
-
-// This limit will take effect on all future invalidations received.
-void DataTypeTracker::UpdatePayloadBufferSize(size_t new_size) {
-  payload_buffer_size_ = new_size;
-}
-
-bool DataTypeTracker::IsSyncRequired() const {
-  return !IsThrottled() && (HasLocalChangePending() || IsGetUpdatesRequired());
-}
-
-bool DataTypeTracker::IsGetUpdatesRequired() const {
-  return !IsThrottled() &&
-         (HasRefreshRequestPending() || HasPendingInvalidation() ||
-          IsInitialSyncRequired() || IsSyncRequiredToResolveConflict());
-}
-
-bool DataTypeTracker::HasLocalChangePending() const {
-  return local_nudge_count_ > 0;
-}
-
-bool DataTypeTracker::HasRefreshRequestPending() const {
-  return local_refresh_request_count_ > 0;
-}
-
-bool DataTypeTracker::HasPendingInvalidation() const {
-  return !pending_invalidations_.empty() || last_dropped_invalidation_;
-}
-
-bool DataTypeTracker::IsInitialSyncRequired() const {
-  return initial_sync_required_;
-}
-
-bool DataTypeTracker::IsSyncRequiredToResolveConflict() const {
-  return sync_required_to_resolve_conflict_;
-}
-
-void DataTypeTracker::SetLegacyNotificationHint(
-    sync_pb::DataTypeProgressMarker* progress) const {
-  DCHECK(!IsThrottled())
-      << "We should not make requests if the type is throttled.";
-
-  if (!pending_invalidations_.empty() &&
-      !pending_invalidations_.back()->IsUnknownVersion()) {
-    // The old-style source info can contain only one hint per type.  We grab
-    // the most recent, to mimic the old coalescing behaviour.
-    progress->set_notification_hint(
-        pending_invalidations_.back()->GetPayload());
-  } else if (HasLocalChangePending()) {
-    // The old-style source info sent up an empty string (as opposed to
-    // nothing at all) when the type was locally nudged, but had not received
-    // any invalidations.
-    progress->set_notification_hint(std::string());
-  }
-}
-
-void DataTypeTracker::FillGetUpdatesTriggersMessage(
-    sync_pb::GetUpdateTriggers* msg) const {
-  // Fill the list of payloads, if applicable.  The payloads must be ordered
-  // oldest to newest, so we insert them in the same order as we've been storing
-  // them internally.
-  for (ScopedVector<InvalidationInterface>::const_iterator it =
-           pending_invalidations_.begin();
-       it != pending_invalidations_.end();
-       ++it) {
-    if (!(*it)->IsUnknownVersion()) {
-      msg->add_notification_hint((*it)->GetPayload());
-    }
-  }
-
-  msg->set_server_dropped_hints(
-      !pending_invalidations_.empty() &&
-      (*pending_invalidations_.begin())->IsUnknownVersion());
-  msg->set_client_dropped_hints(!!last_dropped_invalidation_);
-  msg->set_local_modification_nudges(local_nudge_count_);
-  msg->set_datatype_refresh_nudges(local_refresh_request_count_);
-  msg->set_initial_sync_in_progress(initial_sync_required_);
-  msg->set_sync_for_resolve_conflict_in_progress(
-      sync_required_to_resolve_conflict_);
-}
-
-bool DataTypeTracker::IsThrottled() const {
-  return !unthrottle_time_.is_null();
-}
-
-base::TimeDelta DataTypeTracker::GetTimeUntilUnthrottle(
-    base::TimeTicks now) const {
-  if (!IsThrottled()) {
-    NOTREACHED();
-    return base::TimeDelta::FromSeconds(0);
-  }
-  return std::max(base::TimeDelta::FromSeconds(0),
-                  unthrottle_time_ - now);
-}
-
-void DataTypeTracker::ThrottleType(base::TimeDelta duration,
-                                      base::TimeTicks now) {
-  unthrottle_time_ = std::max(unthrottle_time_, now + duration);
-}
-
-void DataTypeTracker::UpdateThrottleState(base::TimeTicks now) {
-  if (now >= unthrottle_time_) {
-    unthrottle_time_ = base::TimeTicks();
-  }
-}
-
-void DataTypeTracker::UpdateLocalNudgeDelay(base::TimeDelta delay) {
-  nudge_delay_ = delay;
-}
-
-}  // namespace sessions
-}  // namespace syncer