From 38bc3120042a61e0a15a5e02a82f489af71b25df Mon Sep 17 00:00:00 2001
From: Andrew Meadows <andrew@highfidelity.io>
Date: Tue, 13 Feb 2018 11:25:34 -0800
Subject: [PATCH] faster and const EntityTree::findByID()

---
 libraries/entities/src/EntityTree.cpp      | 21 ++++++++++++++-------
 libraries/entities/src/EntityTree.h        |  6 +++---
 libraries/shared/src/SpatialParentFinder.h |  2 +-
 3 files changed, 18 insertions(+), 11 deletions(-)

diff --git a/libraries/entities/src/EntityTree.cpp b/libraries/entities/src/EntityTree.cpp
index bf29f3bec9..60bcc85575 100644
--- a/libraries/entities/src/EntityTree.cpp
+++ b/libraries/entities/src/EntityTree.cpp
@@ -913,18 +913,25 @@ void EntityTree::findEntities(RecurseOctreeOperation& elementFilter,
     recurseTreeWithOperation(elementFilter, nullptr);
 }
 
-EntityItemPointer EntityTree::findEntityByID(const QUuid& id) {
+EntityItemPointer EntityTree::findEntityByID(const QUuid& id) const {
     EntityItemID entityID(id);
     return findEntityByEntityItemID(entityID);
 }
 
-EntityItemPointer EntityTree::findEntityByEntityItemID(const EntityItemID& entityID) /*const*/ {
-    EntityItemPointer foundEntity = NULL;
-    EntityTreeElementPointer containingElement = getContainingElement(entityID);
-    if (containingElement) {
-        foundEntity = containingElement->getEntityWithEntityItemID(entityID);
+EntityItemPointer EntityTree::findEntityByEntityItemID(const EntityItemID& entityID) const {
+    EntityItemPointer foundEntity = nullptr;
+    {
+        QReadLocker locker(&_entityMapLock);
+        foundEntity = _entityMap.value(entityID);
+    }
+    if (foundEntity && !foundEntity->getElement()) {
+        // special case to maintain legacy behavior:
+        // if the entity is in the map but not in the tree
+        // then pretend the entity doesn't exist
+        return EntityItemPointer(nullptr);
+    } else {
+        return foundEntity;
     }
-    return foundEntity;
 }
 
 void EntityTree::fixupTerseEditLogging(EntityItemProperties& properties, QList<QString>& changedProperties) {
diff --git a/libraries/entities/src/EntityTree.h b/libraries/entities/src/EntityTree.h
index 8cb89d6493..90fe342f57 100644
--- a/libraries/entities/src/EntityTree.h
+++ b/libraries/entities/src/EntityTree.h
@@ -132,9 +132,9 @@ public:
     /// \param position point of query in world-frame (meters)
     /// \param targetRadius radius of query (meters)
     EntityItemPointer findClosestEntity(const glm::vec3& position, float targetRadius);
-    EntityItemPointer findEntityByID(const QUuid& id);
-    EntityItemPointer findEntityByEntityItemID(const EntityItemID& entityID);
-    virtual SpatiallyNestablePointer findByID(const QUuid& id) override { return findEntityByID(id); }
+    EntityItemPointer findEntityByID(const QUuid& id) const;
+    EntityItemPointer findEntityByEntityItemID(const EntityItemID& entityID) const;
+    virtual SpatiallyNestablePointer findByID(const QUuid& id) const override { return findEntityByID(id); }
 
     EntityItemID assignEntityID(const EntityItemID& entityItemID); /// Assigns a known ID for a creator token ID
 
diff --git a/libraries/shared/src/SpatialParentFinder.h b/libraries/shared/src/SpatialParentFinder.h
index aae7d9f040..c19babbc7f 100644
--- a/libraries/shared/src/SpatialParentFinder.h
+++ b/libraries/shared/src/SpatialParentFinder.h
@@ -21,7 +21,7 @@ using SpatiallyNestableWeakPointer = std::weak_ptr<SpatiallyNestable>;
 using SpatiallyNestablePointer = std::shared_ptr<SpatiallyNestable>;
 class SpatialParentTree {
 public:
-    virtual SpatiallyNestablePointer findByID(const QUuid& id) { return nullptr; }
+    virtual SpatiallyNestablePointer findByID(const QUuid& id) const { return nullptr; }
 };
 class SpatialParentFinder : public Dependency {