From 7664c826ef2a55c67a4b55fbe61e33203355f2ee Mon Sep 17 00:00:00 2001
From: paulsowden <paulsowden@google.com>
Date: Thu, 8 Feb 2018 11:58:11 -0800
Subject: [PATCH] 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.

-------------
Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=185029279
---
 .../java/com/bumptech/glide/load/Options.java |  3 +-
 .../glide/request/RequestOptions.java         |  6 +--
 .../glide/util/CachedHashCodeArrayMap.java    | 48 +++++++++++++++++++
 3 files changed, 53 insertions(+), 4 deletions(-)
 create mode 100644 library/src/main/java/com/bumptech/glide/util/CachedHashCodeArrayMap.java

diff --git a/library/src/main/java/com/bumptech/glide/load/Options.java b/library/src/main/java/com/bumptech/glide/load/Options.java
index bf2685323e..6609a080f6 100644
--- a/library/src/main/java/com/bumptech/glide/load/Options.java
+++ b/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);
diff --git a/library/src/main/java/com/bumptech/glide/request/RequestOptions.java b/library/src/main/java/com/bumptech/glide/request/RequestOptions.java
index 4e416b6490..81da8c75ce 100644
--- a/library/src/main/java/com/bumptech/glide/request/RequestOptions.java
+++ b/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;
diff --git a/library/src/main/java/com/bumptech/glide/util/CachedHashCodeArrayMap.java b/library/src/main/java/com/bumptech/glide/util/CachedHashCodeArrayMap.java
new file mode 100644
index 0000000000..6d6b2fbf71
--- /dev/null
+++ b/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;
+  }
+}