Avoid unnecessary creation of new empty arrays

Summary: $title Reviewed By: zielinskimz Differential Revision: D63393025 fbshipit-source-id: 4228c448e6300ff3c4b178e8c77a3f048da4e8bd
facebook · Sep 26, 2024 · 3304452 · 3304452
1 parent d005f45
commit 3304452
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Showing 3 changed files with 15 additions and 8 deletions.
diff --git a/litho-core/src/main/java/com/facebook/litho/Component.java b/litho-core/src/main/java/com/facebook/litho/Component.java
@@ -116,6 +116,8 @@ public abstract class Component implements Cloneable, Equivalence<Component>, At
   private static final String NULL_KEY_SET = "Component:NullKeySet";
   private static final AtomicInteger sIdGenerator = new AtomicInteger(1);
 
+  protected static final Object[] EMPTY_ARRAY = new Object[0];
+
   /**
    * @return the globally unique ID associated with {@param type}, creating one if necessary.
    *     Allocated IDs map 1-to-1 with objects passed to this method.

diff --git a/litho-it/src/test/java/com/facebook/litho/specmodels/generator/ComponentBodyGeneratorTest.kt b/litho-it/src/test/java/com/facebook/litho/specmodels/generator/ComponentBodyGeneratorTest.kt
@@ -104,7 +104,7 @@ class ComponentBodyGeneratorTest {
             """
             @java.lang.Override
             protected final java.lang.Object[] getProps() {
-              return new java.lang.Object[] {};
+              return com.facebook.litho.Component.EMPTY_ARRAY;
             }
             
             """

diff --git a/...ocessor/src/main/java/com/facebook/litho/specmodels/generator/ComponentBodyGenerator.java b/...ocessor/src/main/java/com/facebook/litho/specmodels/generator/ComponentBodyGenerator.java
@@ -579,13 +579,18 @@ static MethodSpec generateGetPropsMethod(SpecModel specModel) {
         sb.append(prop.getName());
       }
     }
-    return MethodSpec.methodBuilder("getProps")
-        .addAnnotation(Override.class)
-        .addModifiers(Modifier.PROTECTED)
-        .addModifiers(Modifier.FINAL)
-        .returns(ArrayTypeName.of(Object.class))
-        .addStatement("return new $T[] {$L}", Object.class, sb.toString())
-        .build();
+    MethodSpec.Builder builder =
+        MethodSpec.methodBuilder("getProps")
+            .addAnnotation(Override.class)
+            .addModifiers(Modifier.PROTECTED)
+            .addModifiers(Modifier.FINAL)
+            .returns(ArrayTypeName.of(Object.class));
+    if (sb.length() == 0) {
+      builder.addStatement("return $T.EMPTY_ARRAY", ClassNames.COMPONENT);
+    } else {
+      builder.addStatement("return new $T[] {$L}", Object.class, sb.toString());
+    }
+    return builder.build();
   }
 
   static MethodSpec generateIsEquivalentPropsMethod(SpecModel specModel, EnumSet<RunMode> runMode) {