Create a CachedHashCodeArrayMap subclass to speed up EngineKey hashing.

EngineKey is hashed frequently and caches its own hashCode, however for every request a new EngineKey is created and it rehashes the options and transformations. It's common to cache RequestBuilders for generating multiple requests that have the same options so a handy optimisation is to use an ArrayMap subclass that caches the hashCode to prevent recomputing it every time. This is one of the more expensive atoms in starting a glide request.

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Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=185029279

library/src/main/java/com/bumptech/glide/load/Options.java

@@ -4,13 +4,14 @@
 import android.support.annotation.Nullable;
 import android.support.v4.util.ArrayMap;
 import android.support.v4.util.SimpleArrayMap;
+import com.bumptech.glide.util.CachedHashCodeArrayMap;
 import java.security.MessageDigest;
 
 /**
  * A set of {@link Option Options} to apply to in memory and disk cache keys.
  */
 public final class Options implements Key {
-  private final ArrayMap<Option<?>, Object> values = new ArrayMap<>();
+  private final ArrayMap<Option<?>, Object> values = new CachedHashCodeArrayMap<>();
 
   public void putAll(@NonNull Options other) {
     values.putAll((SimpleArrayMap<Option<?>, Object>) other.values);

library/src/main/java/com/bumptech/glide/request/RequestOptions.java

@@ -32,9 +32,9 @@
 import com.bumptech.glide.load.resource.gif.GifDrawableTransformation;
 import com.bumptech.glide.load.resource.gif.GifOptions;
 import com.bumptech.glide.signature.EmptySignature;
+import com.bumptech.glide.util.CachedHashCodeArrayMap;
 import com.bumptech.glide.util.Preconditions;
 import com.bumptech.glide.util.Util;
-import java.util.HashMap;
 import java.util.Map;
 
 /**
@@ -106,7 +106,7 @@ public class RequestOptions implements Cloneable {
   @NonNull
   private Options options = new Options();
   @NonNull
-  private Map<Class<?>, Transformation<?>> transformations = new HashMap<>();
+  private Map<Class<?>, Transformation<?>> transformations = new CachedHashCodeArrayMap<>();
   @NonNull
   private Class<?> resourceClass = Object.class;
   private boolean isLocked;
@@ -822,7 +822,7 @@ public RequestOptions clone() {
       RequestOptions result = (RequestOptions) super.clone();
       result.options = new Options();
       result.options.putAll(options);
-      result.transformations = new HashMap<>();
+      result.transformations = new CachedHashCodeArrayMap<>();
       result.transformations.putAll(transformations);
       result.isLocked = false;
       result.isAutoCloneEnabled = false;

library/src/main/java/com/bumptech/glide/util/CachedHashCodeArrayMap.java

@@ -0,0 +1,48 @@
+package com.bumptech.glide.util;
+
+import android.support.v4.util.ArrayMap;
+import android.support.v4.util.SimpleArrayMap;
+
+/** An {@link ArrayMap} that caches its hashCode to support efficient lookup. */
+public final class CachedHashCodeArrayMap<K, V> extends ArrayMap<K, V> {
+
+  private int hashCode;
+
+  @Override
+  public void clear() {
+    hashCode = 0;
+    super.clear();
+  }
+
+  @Override
+  public V setValueAt(int index, V value) {
+    hashCode = 0;
+    return super.setValueAt(index, value);
+  }
+
+  @Override
+  public V put(K key, V value) {
+    hashCode = 0;
+    return super.put(key, value);
+  }
+
+  @Override
+  public void putAll(SimpleArrayMap<? extends K, ? extends V> simpleArrayMap) {
+    hashCode = 0;
+    super.putAll(simpleArrayMap);
+  }
+
+  @Override
+  public V removeAt(int index) {
+    hashCode = 0;
+    return super.removeAt(index);
+  }
+
+  @Override
+  public int hashCode() {
+    if (hashCode == 0) {
+      hashCode = super.hashCode();
+    }
+    return hashCode;
+  }
+}