sync: Report GetUpdate triggers to the server

sync/sessions/nudge_tracker.cc

Index: sync/sessions/nudge_tracker.cc
diff --git a/sync/sessions/nudge_tracker.cc b/sync/sessions/nudge_tracker.cc
index 714b67d13f14582e427fdf544c40bc44a067dab8..7eae5eccb4620d88b2f3dda0a2f83efc9821dcb4 100644
--- a/sync/sessions/nudge_tracker.cc
+++ b/sync/sessions/nudge_tracker.cc
@@ -3,47 +3,197 @@
 // found in the LICENSE file.
 
 #include "sync/sessions/nudge_tracker.h"
+
+#include "sync/internal_api/public/base/invalidation.h"
+#include "sync/internal_api/public/sessions/sync_source_info.h"
 #include "sync/protocol/sync.pb.h"
 
 namespace syncer {
 namespace sessions {
 
-NudgeTracker::NudgeTracker() { }
+size_t NudgeTracker::kDefaultMaxPayloadsPerType = 10;
+
+NudgeTracker::NudgeTracker()
+    : updates_source_(sync_pb::GetUpdatesCallerInfo::UNKNOWN),
+      invalidations_enabled_(false),
+      invalidations_out_of_sync_(true),
+      num_payloads_per_type_(kDefaultMaxPayloadsPerType) { }
 
 NudgeTracker::~NudgeTracker() { }
 
-void NudgeTracker::CoalesceSources(const SyncSourceInfo& source) {
-  CoalesceStates(source.types, &source_info_.types);
-  source_info_.updates_source = source.updates_source;
+bool NudgeTracker::IsSyncRequired() {
+  if (!local_nudge_counts_.empty()) {
+    return true;
+  } else if (!refresh_requested_counts_.empty()) {
+    return true;
+  } else if (!payload_list_map_.empty()) {
+    return true;
+  } else {
+    return false;
+  }
+}
+
+void NudgeTracker::RecordSuccessfulSyncCycle() {
+  updates_source_ = sync_pb::GetUpdatesCallerInfo::UNKNOWN;
+  local_nudge_counts_.clear();
+  refresh_requested_counts_.clear();
+  payload_list_map_.clear();
+  locally_dropped_payload_types_.Clear();
+  server_dropped_payload_types_.Clear();
+
+  // A successful cycle while invalidations are enabled puts us back into sync.
+  invalidations_out_of_sync_ = !invalidations_enabled_;
+}
+
+void NudgeTracker::RecordLocalChange(ModelTypeSet types) {
+  // Don't overwrite an NOTIFICATION or DATATYPE_REFRESH source.  The server
+  // makes some assumptions about the source; overriding these sources with
+  // LOCAL could lead to incorrect behaviour.  This is part of the reason why
+  // we're deprecating 'source' in favor of 'origin'.
+  if (updates_source_ != sync_pb::GetUpdatesCallerInfo::NOTIFICATION
+      && updates_source_ != sync_pb::GetUpdatesCallerInfo::DATATYPE_REFRESH) {
+    updates_source_ = sync_pb::GetUpdatesCallerInfo::LOCAL;
+  }
+
+  for (ModelTypeSet::Iterator it = types.First(); it.Good(); it.Inc()) {
+    local_nudge_counts_[it.Get()]++;
+  }
+}
+
+void NudgeTracker::RecordLocalRefreshRequest(ModelTypeSet types) {
+  // Don't overwrite an NOTIFICATION source.  The server makes some assumptions
+  // about the source.  Overriding this source with LOCAL could lead to
+  // incorrect behaviour.  This is part of the reason why we're deprecating
+  // 'source' in favor of 'origin'.
+  if (updates_source_ != sync_pb::GetUpdatesCallerInfo::NOTIFICATION) {
+    updates_source_ = sync_pb::GetUpdatesCallerInfo::DATATYPE_REFRESH;
+  }
+
+  for (ModelTypeSet::Iterator it = types.First(); it.Good(); it.Inc()) {
+    refresh_requested_counts_[it.Get()]++;
+  }
 }
 
-bool NudgeTracker::IsEmpty() {
-  return source_info_.types.empty();
+void NudgeTracker::RecordRemoteInvalidation(
+    const ModelTypeInvalidationMap& invalidation_map) {
+  updates_source_ = sync_pb::GetUpdatesCallerInfo::NOTIFICATION;
+
+  for (ModelTypeInvalidationMap::const_iterator i = invalidation_map.begin();
+       i != invalidation_map.end(); ++i) {
+    const ModelType type = i->first;
+    const std::string& payload = i->second.payload;
+
+    payload_list_map_[type].push_back(payload);
+
+    // Respect the size limits on locally queued invalidation hints.
+    if (payload_list_map_[type].size() > num_payloads_per_type_) {
+      payload_list_map_[type].pop_front();
+      locally_dropped_payload_types_.Put(type);
+    }
+  }
 }
 
-void NudgeTracker::Reset() {
-  source_info_ = SyncSourceInfo();
+void NudgeTracker::OnInvalidationsEnabled() {
+  invalidations_enabled_ = true;
+}
+
+void NudgeTracker::OnInvalidationsDisabled() {
+  invalidations_enabled_ = false;
+  invalidations_out_of_sync_ = true;
+}
+
+SyncSourceInfo NudgeTracker::GetSourceInfo() const {
+  // The old-style source added an empty hint for all locally nudge types.
+  // This will be overwritten with the proper hint for any types that were both
+  // locally nudged and invalidated.
+  ModelTypeSet nudged_types;
+  for (NudgeMap::const_iterator it = local_nudge_counts_.begin();
+       it != local_nudge_counts_.end(); ++it) {
+    nudged_types.Put(it->first);
+  }
+  ModelTypeInvalidationMap invalidation_map =
+      ModelTypeSetToInvalidationMap(nudged_types, std::string());
+
+  // The old-style source info can contain only one hint per type.  We grab the
+  // most recent, to mimic the old coalescing behaviour.
+  for (PayloadListMap::const_iterator it = payload_list_map_.begin();
+       it != payload_list_map_.end(); ++it) {
+    ModelType type = it->first;
+    const PayloadList& list = it->second;
+
+    if (!list.empty()) {
+      Invalidation invalidation;
+      invalidation.payload = list.back();
+      if (invalidation_map.find(type) != invalidation_map.end()) {
+        invalidation_map[type] = invalidation;
+      } else {
+        invalidation_map.insert(std::make_pair(type, invalidation));
+      }
+    }
+  }
+
+  return SyncSourceInfo(updates_source_, invalidation_map);
 }
 
-// TODO(rlarocque): This function often reports incorrect results.  However, it
-// is compatible with the "classic" behaviour.  We would need to make the nudge
-// tracker stop overwriting its own information (ie. fix crbug.com/231693)
-// before we could even try to report correct results.  The main issue is that
-// an notifications and local modifications nudges may overlap with each other
-// in sych a way that we lose track of which types were or were not locally
-// modified.
 ModelTypeSet NudgeTracker::GetLocallyModifiedTypes() const {
-  ModelTypeSet locally_modified;
+  ModelTypeSet nudged_types;
+  for (NudgeMap::const_iterator it = local_nudge_counts_.begin();
+       it != local_nudge_counts_.end(); ++it) {
+    nudged_types.Put(it->first);
+  }
+  return nudged_types;
+}
+
+sync_pb::GetUpdatesCallerInfo::GetUpdatesSource NudgeTracker::updates_source()
+    const {
+  return updates_source_;
+}
 
-  if (source_info_.updates_source != sync_pb::GetUpdatesCallerInfo::LOCAL) {
-    return locally_modified;
+void NudgeTracker::FillProtoMessage(
+    ModelType type,
+    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.
+  PayloadListMap::const_iterator type_it = payload_list_map_.find(type);
+  if (type_it != payload_list_map_.end()) {
+    const PayloadList& payload_list = type_it->second;
+    for (PayloadList::const_iterator payload_it = payload_list.begin();
+         payload_it != payload_list.end(); ++payload_it) {
+      msg->add_notification_hint(*payload_it);
+    }
   }
 
-  for (ModelTypeInvalidationMap::const_iterator i = source_info_.types.begin();
-       i != source_info().types.end(); ++i) {
-    locally_modified.Put(i->first);
+  // TODO(rlarocque): Support Tango trickles.  See crbug.com/223437.
+  // msg->set_server_dropped_hints(server_dropped_payload_types_.Has(type));
+
+  msg->set_client_dropped_hints(locally_dropped_payload_types_.Has(type));
+  msg->set_invalidations_out_of_sync(invalidations_out_of_sync_);
+
+  {
+    NudgeMap::const_iterator it = local_nudge_counts_.find(type);
+    if (it == local_nudge_counts_.end()) {
+      msg->set_local_modification_nudges(0);
+    } else {
+      msg->set_local_modification_nudges(it->second);
+    }
   }
-  return locally_modified;
+
+  {
+    NudgeMap::const_iterator it = refresh_requested_counts_.find(type);
+    if (it == refresh_requested_counts_.end()) {
+      msg->set_datatype_refresh_nudges(0);
+    } else {
+      msg->set_datatype_refresh_nudges(it->second);
+    }
+  }
+}
+
+void NudgeTracker::SetHintBufferSize(size_t size) {
+  // We could iterate through the list and trim it down to size here, but that
+  // seems unnecessary.  This limit will take effect on all future invalidations
+  // received.
+  num_payloads_per_type_ = size;
 }
 
 }  // namespace sessions