From 6c9e5089e572d774870e86be1bc09ea703d0cb91 Mon Sep 17 00:00:00 2001
From: Vizaxo <vizaxo@mailfence.com>
Date: Tue, 27 Jun 2017 01:49:05 +0100
Subject: [PATCH] Update getEntitiesWith method to iterate over all caches

Also updates the implementation of said method to be a more concise
stream-based operation.
---
 .../entity/internal/PojoEntityCache.java      | 33 +++----------
 .../entity/internal/PojoEntityManager.java    | 46 +------------------
 2 files changed, 8 insertions(+), 71 deletions(-)

diff --git a/engine/src/main/java/org/terasology/entitySystem/entity/internal/PojoEntityCache.java b/engine/src/main/java/org/terasology/entitySystem/entity/internal/PojoEntityCache.java
index 90d8fbe02fa..e309eb33aff 100644
--- a/engine/src/main/java/org/terasology/entitySystem/entity/internal/PojoEntityCache.java
+++ b/engine/src/main/java/org/terasology/entitySystem/entity/internal/PojoEntityCache.java
@@ -17,9 +17,6 @@
 
 import com.google.common.collect.Lists;
 import com.google.common.collect.MapMaker;
-import gnu.trove.iterator.TLongObjectIterator;
-import gnu.trove.list.TLongList;
-import gnu.trove.list.array.TLongArrayList;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 import org.terasology.entitySystem.Component;
@@ -361,30 +358,12 @@ private EntityRef createEntityRef(long entityId) {
     @SafeVarargs
     @Override
     public final Iterable<EntityRef> getEntitiesWith(Class<? extends Component>... componentClasses) {
-        if (componentClasses.length == 0) {
-            return getAllEntities();
-        }
-        TLongList idList = new TLongArrayList();
-        TLongObjectIterator<? extends Component> primeIterator = componentStore.componentIterator(componentClasses[0]);
-        if (primeIterator == null) {
-            return Collections.emptyList();
-        }
-
-        while (primeIterator.hasNext()) {
-            primeIterator.advance();
-            long id = primeIterator.key();
-            boolean discard = false;
-            for (int i = 1; i < componentClasses.length; ++i) {
-                if (componentStore.get(id, componentClasses[i]) == null) {
-                    discard = true;
-                    break;
-                }
-            }
-            if (!discard) {
-                idList.add(primeIterator.key());
-            }
-        }
-        return () -> new EntityIterator(idList.iterator(), this);
+        return () -> entityStore.keySet().stream()
+                //Keep entities which have all of the required components
+                .filter(id -> Arrays.stream(componentClasses)
+                        .allMatch(component -> componentStore.get(id, component) != null))
+                .map(id -> createEntityRef(id))
+                .iterator();
     }
 
     @Override
diff --git a/engine/src/main/java/org/terasology/entitySystem/entity/internal/PojoEntityManager.java b/engine/src/main/java/org/terasology/entitySystem/entity/internal/PojoEntityManager.java
index f80245f49a0..79a4ef2bfcc 100644
--- a/engine/src/main/java/org/terasology/entitySystem/entity/internal/PojoEntityManager.java
+++ b/engine/src/main/java/org/terasology/entitySystem/entity/internal/PojoEntityManager.java
@@ -23,7 +23,6 @@
 import com.google.common.collect.Sets;
 import gnu.trove.iterator.TLongObjectIterator;
 import gnu.trove.list.TLongList;
-import gnu.trove.list.array.TLongArrayList;
 import gnu.trove.set.TLongSet;
 import gnu.trove.set.hash.TLongHashSet;
 import org.slf4j.Logger;
@@ -257,50 +256,9 @@ public Iterable<EntityRef> getAllEntities() {
 
     @SafeVarargs
     @Override
-    //Todo: implement iterating over multiple caches
     public final Iterable<EntityRef> getEntitiesWith(Class<? extends Component>... componentClasses) {
-        if (componentClasses.length == 0) {
-            return getAllEntities();
-        }
-        if (componentClasses.length == 1) {
-            return iterateEntities(componentClasses[0]);
-        }
-        TLongList idList = new TLongArrayList();
-        TLongObjectIterator<? extends Component> primeIterator = globalCache.getComponentStore().componentIterator(componentClasses[0]);
-        if (primeIterator == null) {
-            return Collections.emptyList();
-        }
-
-        while (primeIterator.hasNext()) {
-            primeIterator.advance();
-            long id = primeIterator.key();
-            boolean discard = false;
-            for (int i = 1; i < componentClasses.length; ++i) {
-                if (globalCache.getComponentStore().get(id, componentClasses[i]) == null) {
-                    discard = true;
-                    break;
-                }
-            }
-            if (!discard) {
-                idList.add(primeIterator.key());
-            }
-        }
-        return new EntityIterable(idList);
-    }
-
-    private Iterable<EntityRef> iterateEntities(Class<? extends Component> componentClass) {
-        TLongList idList = new TLongArrayList();
-        TLongObjectIterator<? extends Component> primeIterator = globalCache.getComponentStore().componentIterator(componentClass);
-        if (primeIterator == null) {
-            return Collections.emptyList();
-        }
-
-        while (primeIterator.hasNext()) {
-            primeIterator.advance();
-            long id = primeIterator.key();
-            idList.add(primeIterator.key());
-        }
-        return new EntityIterable(idList);
+        return Iterables.concat(globalCache.getEntitiesWith(componentClasses),
+                sectorManager.getEntitiesWith(componentClasses));
     }
 
     @Override