Merge pull request square#377 from square/dimitris/threadlocal

Use ThreadLocal StringBuilder, no iterator on batch delivery.

Author: JakeWharton

picasso/src/main/java/com/squareup/picasso/BitmapHunter.java

@@ -45,6 +45,12 @@ abstract class BitmapHunter implements Runnable {
    */
   private static final Object DECODE_LOCK = new Object();
 
+  private static final ThreadLocal<StringBuilder> NAME_BUILDER = new ThreadLocal<StringBuilder>() {
+    @Override protected StringBuilder initialValue() {
+      return new StringBuilder(Utils.THREAD_PREFIX);
+    }
+  };
+
   final Picasso picasso;
   final Dispatcher dispatcher;
   final Cache cache;
@@ -78,7 +84,7 @@ protected void setExifRotation(int exifRotation) {
 
   @Override public void run() {
     try {
-      Thread.currentThread().setName(Utils.THREAD_PREFIX + data.getName());
+      updateThreadName(data);
 
       result = hunt();
 
@@ -188,6 +194,16 @@ Picasso.LoadedFrom getLoadedFrom() {
     return loadedFrom;
   }
 
+  static void updateThreadName(Request data) {
+    String name = data.getName();
+
+    StringBuilder builder = NAME_BUILDER.get();
+    builder.ensureCapacity(Utils.THREAD_PREFIX.length() + name.length());
+    builder.replace(Utils.THREAD_PREFIX.length(), builder.length(), name);
+
+    Thread.currentThread().setName(builder.toString());
+  }
+
   static BitmapHunter forRequest(Context context, Picasso picasso, Dispatcher dispatcher,
       Cache cache, Stats stats, Action action, Downloader downloader) {
     if (action.getData().resourceId != 0) {

picasso/src/main/java/com/squareup/picasso/Picasso.java

@@ -85,7 +85,9 @@ public interface RequestTransformer {
       switch (msg.what) {
         case HUNTER_BATCH_COMPLETE: {
           @SuppressWarnings("unchecked") List<BitmapHunter> batch = (List<BitmapHunter>) msg.obj;
-          for (BitmapHunter hunter : batch) {
+          //noinspection ForLoopReplaceableByForEach
+          for (int i = 0, n = batch.size(); i < n; i++) {
+            BitmapHunter hunter = batch.get(i);
             hunter.picasso.complete(hunter);
           }
           break;