Add nullability annotations to pool package and its dependencies (#2747)

Signed-off-by: Alex Saveau <saveau.alexandre@gmail.com>

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

@@ -515,6 +515,7 @@ private void logWithTimeAndKey(String message, long startTime, String extraArgs)
         + Thread.currentThread().getName());
   }
 
+  @NonNull
   @Override
   public StateVerifier getVerifier() {
     return stateVerifier;

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

@@ -3,6 +3,7 @@
 import android.os.Handler;
 import android.os.Looper;
 import android.os.Message;
+import android.support.annotation.NonNull;
 import android.support.annotation.VisibleForTesting;
 import android.support.v4.util.Pools;
 import com.bumptech.glide.load.DataSource;
@@ -296,6 +297,7 @@ void handleExceptionOnMainThread() {
     release(false /*isRemovedFromQueue*/);
   }
 
+  @NonNull
   @Override
   public StateVerifier getVerifier() {
     return stateVerifier;

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

@@ -90,6 +90,7 @@ public synchronized void recycle() {
     }
   }
 
+  @NonNull
   @Override
   public StateVerifier getVerifier() {
     return stateVerifier;

library/src/main/java/com/bumptech/glide/load/engine/cache/SafeKeyGenerator.java

@@ -1,5 +1,6 @@
 package com.bumptech.glide.load.engine.cache;
 
+import android.support.annotation.NonNull;
 import android.support.v4.util.Pools;
 import com.bumptech.glide.load.Key;
 import com.bumptech.glide.util.LruCache;
@@ -65,6 +66,7 @@ private static final class PoolableDigestContainer implements FactoryPools.Poola
       this.messageDigest = messageDigest;
     }
 
+    @NonNull
     @Override
     public StateVerifier getVerifier() {
       return stateVerifier;

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

@@ -4,6 +4,7 @@
 import android.content.res.Resources.Theme;
 import android.graphics.drawable.Drawable;
 import android.support.annotation.DrawableRes;
+import android.support.annotation.NonNull;
 import android.support.annotation.Nullable;
 import android.support.v4.util.Pools;
 import android.util.Log;
@@ -191,6 +192,7 @@ private void init(
     status = Status.PENDING;
   }
 
+  @NonNull
   @Override
   public StateVerifier getVerifier() {
     return stateVerifier;

library/src/main/java/com/bumptech/glide/util/pool/FactoryPools.java

@@ -18,7 +18,7 @@ public final class FactoryPools {
   private static final int DEFAULT_POOL_SIZE = 20;
   private static final Resetter<Object> EMPTY_RESETTER = new Resetter<Object>() {
     @Override
-    public void reset(Object object) {
+    public void reset(@NonNull Object object) {
       // Do nothing.
     }
   };
@@ -35,7 +35,8 @@ private FactoryPools() { }
    *
    * @param <T> The type of object the pool will contains.
    */
-  public static <T extends Poolable> Pool<T> simple(int size, Factory<T> factory) {
+  @NonNull
+  public static <T extends Poolable> Pool<T> simple(int size, @NonNull Factory<T> factory) {
     return build(new SimplePool<T>(size), factory);
   }
 
@@ -49,7 +50,8 @@ public static <T extends Poolable> Pool<T> simple(int size, Factory<T> factory)
    *
    * @param <T> The type of object the pool will contains.
    */
-  public static <T extends Poolable> Pool<T> threadSafe(int size, Factory<T> factory) {
+  @NonNull
+  public static <T extends Poolable> Pool<T> threadSafe(int size, @NonNull Factory<T> factory) {
     return build(new SynchronizedPool<T>(size), factory);
   }
 
@@ -62,6 +64,7 @@ public static <T extends Poolable> Pool<T> threadSafe(int size, Factory<T> facto
    *
    * @param <T> The type of object that the {@link List Lists} will contain.
    */
+  @NonNull
   public static <T> Pool<List<T>> threadSafeList() {
     return threadSafeList(DEFAULT_POOL_SIZE);
   }
@@ -77,29 +80,35 @@ public static <T> Pool<List<T>> threadSafeList() {
    */
   // Public API.
   @SuppressWarnings("WeakerAccess")
+  @NonNull
   public static <T> Pool<List<T>> threadSafeList(int size) {
     return build(new SynchronizedPool<List<T>>(size), new Factory<List<T>>() {
+      @NonNull
       @Override
       public List<T> create() {
         return new ArrayList<>();
       }
     }, new Resetter<List<T>>() {
       @Override
-      public void reset(List<T> object) {
+      public void reset(@NonNull List<T> object) {
         object.clear();
       }
     });
   }
 
-  private static <T extends Poolable> Pool<T> build(Pool<T> pool, Factory<T> factory) {
+  @NonNull
+  private static <T extends Poolable> Pool<T> build(@NonNull Pool<T> pool,
+      @NonNull Factory<T> factory) {
     return build(pool, factory, FactoryPools.<T>emptyResetter());
   }
 
-  private static <T> Pool<T> build(Pool<T> pool, Factory<T> factory,
-      Resetter<T> resetter) {
+  @NonNull
+  private static <T> Pool<T> build(@NonNull Pool<T> pool, @NonNull Factory<T> factory,
+      @NonNull Resetter<T> resetter) {
     return new FactoryPool<>(pool, factory, resetter);
   }
 
+  @NonNull
   @SuppressWarnings("unchecked")
   private static <T> Resetter<T> emptyResetter() {
     return (Resetter<T>) EMPTY_RESETTER;
@@ -120,14 +129,15 @@ public interface Factory<T> {
    * @param <T> The type of Object that will be reset.
    */
   public interface Resetter<T> {
-    void reset(T object);
+    void reset(@NonNull T object);
   }
 
   /**
    * Allows additional verification to catch errors caused by using objects while they are in
    * an object pool.
    */
   public interface Poolable {
+    @NonNull
     StateVerifier getVerifier();
   }
 
@@ -136,7 +146,7 @@ private static final class FactoryPool<T> implements Pool<T> {
     private final Resetter<T> resetter;
     private final Pool<T> pool;
 
-    FactoryPool(Pool<T> pool, Factory<T> factory, Resetter<T> resetter) {
+    FactoryPool(@NonNull Pool<T> pool, @NonNull Factory<T> factory, @NonNull Resetter<T> resetter) {
       this.pool = pool;
       this.factory = factory;
       this.resetter = resetter;

library/src/main/java/com/bumptech/glide/util/pool/StateVerifier.java

@@ -1,5 +1,6 @@
 package com.bumptech.glide.util.pool;
 
+import android.support.annotation.NonNull;
 import com.bumptech.glide.util.Synthetic;
 
 /**
@@ -11,6 +12,7 @@ public abstract class StateVerifier {
   /**
    * Creates a new {@link StateVerifier} instance.
    */
+  @NonNull
   public static StateVerifier newInstance() {
     if (DEBUG) {
       return new DebugStateVerifier();
@@ -68,9 +70,9 @@ public void throwIfRecycled() {
     @Override
     void setRecycled(boolean isRecycled) {
       if (isRecycled) {
-        this.recycledAtStackTraceException = new RuntimeException("Released");
+        recycledAtStackTraceException = new RuntimeException("Released");
       } else {
-        this.recycledAtStackTraceException = null;
+        recycledAtStackTraceException = null;
       }
     }
   }