sync: Inject sync/'s dependency on invalidations

sync/sessions/data_type_tracker.cc

Index: sync/sessions/data_type_tracker.cc
diff --git a/sync/sessions/data_type_tracker.cc b/sync/sessions/data_type_tracker.cc
index 5e0ee90171e6c2b21ae4356380c4d63faa5d7ac6..e902486724475eda0549e3dc130daf0019056d3e 100644
--- a/sync/sessions/data_type_tracker.cc
+++ b/sync/sessions/data_type_tracker.cc
@@ -5,19 +5,17 @@
 #include "sync/sessions/data_type_tracker.h"
 
 #include "base/logging.h"
-#include "sync/internal_api/public/base/invalidation.h"
-#include "sync/notifier/invalidation_util.h"
-#include "sync/notifier/single_object_invalidation_set.h"
+#include "sync/internal_api/public/base/invalidation_interface.h"
 #include "sync/sessions/nudge_tracker.h"
 
 namespace syncer {
 namespace sessions {
 
-DataTypeTracker::DataTypeTracker(const invalidation::ObjectId& object_id)
-  : local_nudge_count_(0),
-    local_refresh_request_count_(0),
-    payload_buffer_size_(NudgeTracker::kDefaultMaxPayloadsPerType),
-    drop_tracker_(object_id) { }
+DataTypeTracker::DataTypeTracker()
+    : local_nudge_count_(0),
+      local_refresh_request_count_(0),
+      payload_buffer_size_(NudgeTracker::kDefaultMaxPayloadsPerType) {
+}
 
 DataTypeTracker::~DataTypeTracker() { }
 
@@ -29,20 +27,11 @@ void DataTypeTracker::RecordLocalRefreshRequest() {
   local_refresh_request_count_++;
 }
 
-namespace {
-
-bool IsInvalidationVersionLessThan(
-    const Invalidation& a,
-    const Invalidation& b) {
-  InvalidationVersionLessThan comparator;
-  return comparator(a, b);
-}
-
-}  // namespace
+void DataTypeTracker::RecordRemoteInvalidation(
+    scoped_ptr<InvalidationInterface> incoming) {
+  DCHECK(incoming);
 
-void DataTypeTracker::RecordRemoteInvalidations(
-    const SingleObjectInvalidationSet& invalidations) {
-  // Merge the incoming invalidations into our list of pending invalidations.
+  // 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
@@ -50,52 +39,44 @@ void DataTypeTracker::RecordRemoteInvalidations(
   // rules (ie. have equal versions), but still have different AckHandle values
   // and need to be acknowledged separately.
   //
-  // The invalidaitons service can only track one outsanding invalidation per
+  // 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.
-  SingleObjectInvalidationSet::const_iterator incoming_it =
-      invalidations.begin();
-  SingleObjectInvalidationSet::const_iterator existing_it =
+
+  std::list<scoped_ptr<InvalidationInterface> >::iterator it =
       pending_invalidations_.begin();
 
-  while (incoming_it != invalidations.end()) {
-    // Keep existing_it ahead of incoming_it.
-    while (existing_it != pending_invalidations_.end()
-           && IsInvalidationVersionLessThan(*existing_it, *incoming_it)) {
-      existing_it++;
-    }
+  // Find the lower bound.
+  while (it != pending_invalidations_.end() &&
+         InvalidationInterface::LessThan(**it, *incoming)) {
+    it++;
+  }
 
-    if (existing_it != pending_invalidations_.end()
-        && !IsInvalidationVersionLessThan(*incoming_it, *existing_it)
-        && !IsInvalidationVersionLessThan(*existing_it, *incoming_it)) {
-      // Incoming overlaps with existing.  Either both are unknown versions
-      // (likely) or these two have the same version number (very unlikely).
-      // Acknowledge and overwrite existing.
-      SingleObjectInvalidationSet::const_iterator old_inv = existing_it;
-      existing_it++;
-      old_inv->Acknowledge();
-      pending_invalidations_.Erase(old_inv);
-      pending_invalidations_.Insert(*incoming_it);
-      incoming_it++;
-    } else {
-      DCHECK(existing_it == pending_invalidations_.end()
-             || IsInvalidationVersionLessThan(*incoming_it, *existing_it));
-      // The incoming_it points at a version not in the pending_invalidations_
-      // list.  Add it to the list then increment past it.
-      pending_invalidations_.Insert(*incoming_it);
-      incoming_it++;
-    }
+  if (it != pending_invalidations_.end() &&
+      !InvalidationInterface::LessThan(*incoming, **it) &&
+      !InvalidationInterface::LessThan(**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.
+    (*it)->Acknowledge();
+    it->swap(incoming);
+    incoming.reset();
+  } 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.Pass());
   }
 
-  // Those incoming invalidations may have caused us to exceed our buffer size.
+  // The incoming invalidation may have caused us to exceed our buffer size.
   // Trim some items from our list, if necessary.
-  while (pending_invalidations_.GetSize() > payload_buffer_size_) {
-    pending_invalidations_.begin()->Drop(&drop_tracker_);
-    pending_invalidations_.Erase(pending_invalidations_.begin());
+  while (pending_invalidations_.size() > payload_buffer_size_) {
+    last_dropped_invalidation_.reset(pending_invalidations_.front().release());
+    last_dropped_invalidation_->Drop();
+    pending_invalidations_.pop_front();
   }
 }
 
@@ -112,15 +93,17 @@ void DataTypeTracker::RecordSuccessfulSyncCycle() {
   // 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 (SingleObjectInvalidationSet::const_iterator it =
-       pending_invalidations_.begin();
-       it != pending_invalidations_.end(); ++it) {
-    it->Acknowledge();
+  for (std::list<scoped_ptr<InvalidationInterface> >::const_iterator it =
+           pending_invalidations_.begin();
+       it != pending_invalidations_.end();
+       ++it) {
+    (*it)->Acknowledge();
   }
-  pending_invalidations_.Clear();
+  pending_invalidations_.clear();
 
-  if (drop_tracker_.IsRecoveringFromDropEvent()) {
-    drop_tracker_.RecordRecoveryFromDropEvent();
+  if (last_dropped_invalidation_) {
+    last_dropped_invalidation_->Acknowledge();
+    last_dropped_invalidation_.reset();
   }
 }
 
@@ -147,8 +130,7 @@ bool DataTypeTracker::HasRefreshRequestPending() const {
 }
 
 bool DataTypeTracker::HasPendingInvalidation() const {
-  return !pending_invalidations_.IsEmpty()
-      || drop_tracker_.IsRecoveringFromDropEvent();
+  return !pending_invalidations_.empty() || last_dropped_invalidation_;
 }
 
 void DataTypeTracker::SetLegacyNotificationHint(
@@ -156,16 +138,17 @@ void DataTypeTracker::SetLegacyNotificationHint(
   DCHECK(!IsThrottled())
       << "We should not make requests if the type is throttled.";
 
-  if (!pending_invalidations_.IsEmpty() &&
-      !pending_invalidations_.back().is_unknown_version()) {
+  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().payload());
+    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("");
+    progress->set_notification_hint(std::string());
   }
 }
 
@@ -174,17 +157,19 @@ void DataTypeTracker::FillGetUpdatesTriggersMessage(
   // 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 (SingleObjectInvalidationSet::const_iterator it =
-       pending_invalidations_.begin();
-       it != pending_invalidations_.end(); ++it) {
-    if (!it->is_unknown_version()) {
-      msg->add_notification_hint(it->payload());
+  for (std::list<scoped_ptr<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_.StartsWithUnknownVersion());
-  msg->set_client_dropped_hints(drop_tracker_.IsRecoveringFromDropEvent());
+      !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_);
 }