From 7fb7e503f9e66a426056bc7657f5e1163efdacd0 Mon Sep 17 00:00:00 2001
From: Andrew Meadows <andrew@highfidelity.io>
Date: Wed, 17 Apr 2019 14:43:49 -0700
Subject: [PATCH] reduce footprint of ShapeManager::_shapeMap

---
 libraries/shared/src/HashKey.cpp   |  6 +++---
 libraries/shared/src/HashKey.h     | 19 ++++++++++++-------
 libraries/shared/src/ShapeInfo.cpp | 24 ++++++++++++------------
 3 files changed, 27 insertions(+), 22 deletions(-)

diff --git a/libraries/shared/src/HashKey.cpp b/libraries/shared/src/HashKey.cpp
index 488eccb1bf..8c5303028b 100644
--- a/libraries/shared/src/HashKey.cpp
+++ b/libraries/shared/src/HashKey.cpp
@@ -51,15 +51,15 @@ float HashKey::getNumQuantizedValuesPerMeter() {
     return QUANTIZED_VALUES_PER_METER;
 }
 
-void HashKey::hashUint64(uint64_t data) {
+void HashKey::Hasher::hashUint64(uint64_t data) {
     _hash += squirrel3_64(data, ++_hashCount);
 }
 
-void HashKey::hashFloat(float data) {
+void HashKey::Hasher::hashFloat(float data) {
     _hash += squirrel3_64((uint64_t)((int64_t)(data * QUANTIZED_VALUES_PER_METER)), ++_hashCount);
 }
 
-void HashKey::hashVec3(const glm::vec3& data) {
+void HashKey::Hasher::hashVec3(const glm::vec3& data) {
     _hash += squirrel3_64((uint64_t)((int64_t)(data[0] * QUANTIZED_VALUES_PER_METER)), ++_hashCount);
     _hash *= squirrel3_64((uint64_t)((int64_t)(data[1] * QUANTIZED_VALUES_PER_METER)), ++_hashCount);
     _hash ^= squirrel3_64((uint64_t)((int64_t)(data[2] * QUANTIZED_VALUES_PER_METER)), ++_hashCount);
diff --git a/libraries/shared/src/HashKey.h b/libraries/shared/src/HashKey.h
index 446eb4c25f..071b162a50 100644
--- a/libraries/shared/src/HashKey.h
+++ b/libraries/shared/src/HashKey.h
@@ -30,6 +30,18 @@
 
 class HashKey {
 public:
+    class Hasher {
+    public:
+        Hasher() {}
+        void hashUint64(uint64_t data);
+        void hashFloat(float data);
+        void hashVec3(const glm::vec3& data);
+        uint64_t getHash64() const { return _hash; }
+    private:
+        uint64_t _hash { 0 };
+        uint8_t _hashCount { 0 };
+    };
+
     static float getNumQuantizedValuesPerMeter();
 
     HashKey() {}
@@ -39,16 +51,9 @@ public:
     bool equals(const HashKey& other) const { return _hash == other._hash; }
     int32_t getHash() const { return (int32_t)((uint32_t)_hash); }
 
-    // These methods for accumulating a hash.
-    void hashUint64(uint64_t data);
-    void hashFloat(float data);
-    void hashVec3(const glm::vec3& data);
-
     uint64_t getHash64() const { return _hash; }
-
 private:
     uint64_t _hash { 0 };
-    uint8_t _hashCount { 0 };
 };
 
 #endif // hifi_HashKey_h
diff --git a/libraries/shared/src/ShapeInfo.cpp b/libraries/shared/src/ShapeInfo.cpp
index bf51e455c5..1b9054c4d6 100644
--- a/libraries/shared/src/ShapeInfo.cpp
+++ b/libraries/shared/src/ShapeInfo.cpp
@@ -273,18 +273,18 @@ float ShapeInfo::computeVolume() const {
 uint64_t ShapeInfo::getHash() const {
     // NOTE: we cache the key so we only ever need to compute it once for any valid ShapeInfo instance.
     if (_hash64 == 0 && _type != SHAPE_TYPE_NONE) {
-        HashKey hashKey;
+        HashKey::Hasher hasher;
         // The key is not yet cached therefore we must compute it.
 
-        hashKey.hashUint64((uint64_t)_type);
+        hasher.hashUint64((uint64_t)_type);
         if (_type == SHAPE_TYPE_MULTISPHERE) {
             for (auto &sphereData : _sphereCollection) {
-                hashKey.hashVec3(glm::vec3(sphereData));
-                hashKey.hashFloat(sphereData.w);
+                hasher.hashVec3(glm::vec3(sphereData));
+                hasher.hashFloat(sphereData.w);
             }
         } else if (_type != SHAPE_TYPE_SIMPLE_HULL) {
-            hashKey.hashVec3(_halfExtents);
-            hashKey.hashVec3(_offset);
+            hasher.hashVec3(_halfExtents);
+            hasher.hashVec3(_offset);
         } else {
             // TODO: we could avoid hashing all of these points if we were to supply the ShapeInfo with a unique
             // descriptive string.  Shapes that are uniquely described by their type and URL could just put their
@@ -294,7 +294,7 @@ uint64_t ShapeInfo::getHash() const {
             const int numPoints = (int)points.size();
 
             for (int i = 0; i < numPoints; ++i) {
-                hashKey.hashVec3(points[i]);
+                hasher.hashVec3(points[i]);
             }
         }
 
@@ -302,19 +302,19 @@ uint64_t ShapeInfo::getHash() const {
         if (!url.isEmpty()) {
             QByteArray baUrl = url.toLocal8Bit();
             uint32_t urlHash = qChecksum(baUrl.data(), baUrl.size());
-            hashKey.hashUint64((uint64_t)urlHash);
+            hasher.hashUint64((uint64_t)urlHash);
         }
 
         if (_type == SHAPE_TYPE_COMPOUND || _type == SHAPE_TYPE_SIMPLE_COMPOUND) {
             uint64_t numHulls = (uint64_t)_pointCollection.size();
-            hashKey.hashUint64(numHulls);
+            hasher.hashUint64(numHulls);
         } else if (_type == SHAPE_TYPE_MULTISPHERE) {
             uint64_t numSpheres = (uint64_t)_sphereCollection.size();
-            hashKey.hashUint64(numSpheres);
+            hasher.hashUint64(numSpheres);
         } else if (_type == SHAPE_TYPE_SIMPLE_HULL) {
-            hashKey.hashUint64(1);
+            hasher.hashUint64(1);
         }
-        _hash64 = hashKey.getHash64();
+        _hash64 = hasher.getHash64();
     }
     return _hash64;
 }