Add timing logs for runners.

library/src/main/java/com/bumptech/glide/load/engine/ResourceRunner.java

 package com.bumptech.glide.load.engine;
 
 import android.os.Handler;
+import android.os.SystemClock;
 import android.util.Log;
 import com.bumptech.glide.Resource;
 import com.bumptech.glide.load.Key;
@@ -72,7 +73,11 @@ public class ResourceRunner<Z, R> implements Runnable {
             return;
         }
 
+        long start = SystemClock.currentThreadTimeMillis();
         Resource<Z> fromCache = loadFromDiskCache();
+        if (Log.isLoggable(TAG, Log.VERBOSE)) {
+            Log.v(TAG, "loaded from disk cache in " + (SystemClock.currentThreadTimeMillis() - start));
+        }
         if (fromCache != null) {
             Resource<R> transcoded = transcoder.transcode(fromCache);
             job.onResourceReady(transcoded);
@@ -94,7 +99,7 @@ public class ResourceRunner<Z, R> implements Runnable {
             }
             if (result == null) {
                 if (Log.isLoggable(TAG, Log.DEBUG)) {
-                    Log.d(TAG, "Failed to decode image from cache");
+                    Log.d(TAG, "Failed to decode image from cache or not present in cache");
                 }
                 diskCache.delete(key);
             }

library/src/main/java/com/bumptech/glide/load/engine/SourceResourceRunner.java

 package com.bumptech.glide.load.engine;
 
+import android.os.SystemClock;
+import android.util.Log;
 import com.bumptech.glide.Priority;
 import com.bumptech.glide.Resource;
 import com.bumptech.glide.load.Key;
 import com.bumptech.glide.load.ResourceDecoder;
 import com.bumptech.glide.load.ResourceEncoder;
 import com.bumptech.glide.load.Transformation;
-import com.bumptech.glide.load.resource.transcode.ResourceTranscoder;
+import com.bumptech.glide.load.data.DataFetcher;
 import com.bumptech.glide.load.engine.cache.DiskCache;
 import com.bumptech.glide.load.engine.executor.Prioritized;
-import com.bumptech.glide.load.data.DataFetcher;
+import com.bumptech.glide.load.resource.transcode.ResourceTranscoder;
 import com.bumptech.glide.request.ResourceCallback;
 
 import java.io.OutputStream;
@@ -21,6 +23,7 @@ import java.io.OutputStream;
  * @param <R> The type of the resource that will be transcoded to from the decoded resource.
  */
 public class SourceResourceRunner<T, Z, R> implements Runnable, DiskCache.Writer, Prioritized {
+    private static final String TAG = "SourceRunner";
     private final Key key;
     private final int width;
     private final int height;
@@ -63,7 +66,12 @@ public class SourceResourceRunner<T, Z, R> implements Runnable, DiskCache.Writer
         }
 
         try {
+            long start = SystemClock.currentThreadTimeMillis();
             final Resource<Z> decoded = decode();
+            if (Log.isLoggable(TAG, Log.VERBOSE)) {
+                Log.v(TAG, "Decoded from source in " + (SystemClock.currentThreadTimeMillis() - start));
+                start = SystemClock.currentThreadTimeMillis();
+            }
             if (decoded != null) {
                 Resource<Z> transformed = transformation.transform(decoded, width, height);
                 if (decoded != transformed) {
@@ -71,10 +79,17 @@ public class SourceResourceRunner<T, Z, R> implements Runnable, DiskCache.Writer
                 }
                 result = transformed;
             }
+            if (Log.isLoggable(TAG, Log.VERBOSE)) {
+                Log.v(TAG, "transformed in " + (SystemClock.currentThreadTimeMillis() - start));
+            }
 
             if (result != null) {
                 diskCache.put(key, this);
+                start = SystemClock.currentThreadTimeMillis();
                 Resource<R> transcoded = transcoder.transcode(result);
+                if (Log.isLoggable(TAG, Log.VERBOSE)) {
+                    Log.d(TAG, "transcoded in " + (SystemClock.currentThreadTimeMillis() - start));
+                }
                 cb.onResourceReady(transcoded);
             } else {
                 cb.onException(null);
@@ -100,7 +115,12 @@ public class SourceResourceRunner<T, Z, R> implements Runnable, DiskCache.Writer
 
     @Override
     public boolean write(OutputStream os) {
-        return encoder.encode(result, os);
+        long start = SystemClock.currentThreadTimeMillis();
+        boolean success = encoder.encode(result, os);
+        if (Log.isLoggable(TAG, Log.VERBOSE)) {
+            Log.v(TAG, "wrote to disk cache in " + (SystemClock.currentThreadTimeMillis() - start));
+        }
+        return success;
     }
 
     @Override

library/src/test/java/com/bumptech/glide/load/engine/SourceResourceRunnerTest.java

@@ -12,6 +12,8 @@ import com.bumptech.glide.load.resource.transcode.ResourceTranscoder;
 import com.bumptech.glide.request.ResourceCallback;
 import org.junit.Before;
 import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.robolectric.RobolectricTestRunner;
 
 import java.io.ByteArrayInputStream;
 import java.io.ByteArrayOutputStream;
@@ -32,6 +34,7 @@ import static org.mockito.Mockito.never;
 import static org.mockito.Mockito.verify;
 import static org.mockito.Mockito.when;
 
+@RunWith(RobolectricTestRunner.class)
 public class SourceResourceRunnerTest {
     private SourceResourceHarness harness;