Fix #1114: make BufferRecyclerPool generic

src/main/java/com/fasterxml/jackson/core/JsonFactory.java

@@ -262,7 +262,7 @@ public static int collectDefaults() {
     /**
      * @since 2.16
      */
-    protected BufferRecyclerPool _bufferRecyclerPool;
+    protected BufferRecyclerPool<BufferRecycler> _bufferRecyclerPool;
 
     /**
      * Object that implements conversion functionality between
@@ -2159,7 +2159,7 @@ public BufferRecycler _getBufferRecycler()
      *
      * @since 2.16
      */
-    public BufferRecyclerPool _getBufferRecyclerPool() {
+    public BufferRecyclerPool<BufferRecycler> _getBufferRecyclerPool() {
         // 23-Apr-2015, tatu: Let's allow disabling of buffer recycling
         //   scheme, for cases where it is considered harmful (possibly
         //   on Android, for example)

src/main/java/com/fasterxml/jackson/core/TSFBuilder.java

@@ -8,6 +8,7 @@
 import com.fasterxml.jackson.core.io.OutputDecorator;
 import com.fasterxml.jackson.core.json.JsonReadFeature;
 import com.fasterxml.jackson.core.json.JsonWriteFeature;
+import com.fasterxml.jackson.core.util.BufferRecycler;
 import com.fasterxml.jackson.core.util.BufferRecyclerPool;
 import com.fasterxml.jackson.core.util.JsonGeneratorDecorator;
 
@@ -74,7 +75,7 @@ public abstract class TSFBuilder<F extends JsonFactory,
     /**
      * @since 2.16
      */
-    protected BufferRecyclerPool _bufferRecyclerPool;
+    protected BufferRecyclerPool<BufferRecycler> _bufferRecyclerPool;
 
     /**
      * Optional helper object that may decorate input sources, to do
@@ -169,7 +170,7 @@ protected static <T> List<T> _copy(List<T> src) {
     public int streamReadFeatures() { return _streamReadFeatures; }
     public int streamWriteFeatures() { return _streamWriteFeatures; }
 
-    public BufferRecyclerPool bufferRecyclerPool() {
+    public BufferRecyclerPool<BufferRecycler> bufferRecyclerPool() {
         return _bufferRecyclerPool;
     }
 
@@ -321,7 +322,7 @@ public B configure(JsonWriteFeature f, boolean state) {
      *
      * @since 2.16
      */
-    public B bufferRecyclerPool(BufferRecyclerPool p) {
+    public B bufferRecyclerPool(BufferRecyclerPool<BufferRecycler> p) {
         _bufferRecyclerPool = Objects.requireNonNull(p);
         return _this();
     }

src/main/java/com/fasterxml/jackson/core/util/BufferRecycler.java

@@ -18,6 +18,7 @@
  * Rewritten in 2.16 to work with {@link BufferRecyclerPool} abstraction.
  */
 public class BufferRecycler
+    implements BufferRecyclerPool.WithPool<BufferRecycler>
 {
     /**
      * Buffer used for reading byte-based input.
@@ -86,7 +87,7 @@ public class BufferRecycler
     // Note: changed from simple array in 2.10:
     protected final AtomicReferenceArray<char[]> _charBuffers;
 
-    private BufferRecyclerPool _pool;
+    private BufferRecyclerPool<BufferRecycler> _pool;
 
     /*
     /**********************************************************
@@ -202,7 +203,8 @@ protected int charBufferLength(int ix) {
      *
      * @since 2.16
      */
-    BufferRecycler withPool(BufferRecyclerPool pool) {
+    @Override
+    public BufferRecycler withPool(BufferRecyclerPool<BufferRecycler> pool) {
         if (this._pool != null) {
             throw new IllegalStateException("BufferRecycler already linked to pool: "+pool);
         }
@@ -220,7 +222,7 @@ BufferRecycler withPool(BufferRecyclerPool pool) {
      */
     public void release() {
         if (_pool != null) {
-            BufferRecyclerPool tmpPool = _pool;
+            BufferRecyclerPool<BufferRecycler> tmpPool = _pool;
             // nullify the reference to the pool in order to avoid the risk of releasing
             // the same BufferRecycler more than once, thus compromising the pool integrity
             _pool = null;

src/main/java/com/fasterxml/jackson/core/util/BufferRecyclerPool.java

@@ -35,8 +35,12 @@
  *
  * @since 2.16
  */
-public interface BufferRecyclerPool extends Serializable
+public interface BufferRecyclerPool<P extends BufferRecyclerPool.WithPool<P>> extends Serializable
 {
+    public interface WithPool<P extends WithPool<P>> {
+        P withPool(BufferRecyclerPool<P> pool);
+    }
+
     /**
      * Method called to acquire a {@link BufferRecycler} from this pool
      * AND make sure it is linked back to this
@@ -51,15 +55,15 @@ public interface BufferRecyclerPool extends Serializable
      * @return {@link BufferRecycler} for caller to use; caller expected
      *   to call {@link #releaseBufferRecycler} after it is done using recycler.
      */
-    default BufferRecycler acquireAndLinkBufferRecycler() {
+    default P acquireAndLinkBufferRecycler() {
         return acquireBufferRecycler().withPool(this);
     }
 
     /**
      * Method for sub-classes to implement for actual acquire logic; called
      * by {@link #acquireAndLinkBufferRecycler()}.
      */
-    BufferRecycler acquireBufferRecycler();
+    P acquireBufferRecycler();
 
     /**
      * Method that should be called when previously acquired (see {@link #acquireAndLinkBufferRecycler})
@@ -68,30 +72,30 @@ default BufferRecycler acquireAndLinkBufferRecycler() {
      *
      * @param recycler
      */
-    void releaseBufferRecycler(BufferRecycler recycler);
+    void releaseBufferRecycler(P recycler);
 
     /**
      * @return the default {@link BufferRecyclerPool} implementation
      *   which is the thread local based one:
      *   basically alias to {@link #threadLocalPool()}).
      */
-    static BufferRecyclerPool defaultPool() {
+    static BufferRecyclerPool<BufferRecycler> defaultPool() {
         return threadLocalPool();
     }
 
     /**
      * @return Globally shared instance of {@link ThreadLocalPool}; same as calling
      *   {@link ThreadLocalPool#shared()}.
      */
-    static BufferRecyclerPool threadLocalPool() {
+    static BufferRecyclerPool<BufferRecycler> threadLocalPool() {
         return ThreadLocalPool.shared();
     }
 
     /**
      * @return Globally shared instance of {@link NonRecyclingPool}; same as calling
      *   {@link NonRecyclingPool#shared()}.
      */
-    static BufferRecyclerPool nonRecyclingPool() {
+    static BufferRecyclerPool<BufferRecycler> nonRecyclingPool() {
         return NonRecyclingPool.shared();
     }
 
@@ -112,11 +116,11 @@ static BufferRecyclerPool nonRecyclingPool() {
      * Android), or on platforms where {@link java.lang.Thread}s are not
      * long-living or reused (like Project Loom).
      */
-    class ThreadLocalPool implements BufferRecyclerPool
+    class ThreadLocalPool implements BufferRecyclerPool<BufferRecycler>
     {
         private static final long serialVersionUID = 1L;
 
-        private static final BufferRecyclerPool GLOBAL = new ThreadLocalPool();
+        private static final ThreadLocalPool GLOBAL = new ThreadLocalPool();
 
         /**
          * Accessor for the global, shared instance of {@link ThreadLocal}-based
@@ -125,7 +129,7 @@ class ThreadLocalPool implements BufferRecyclerPool
          *
          * @return Shared pool instance
          */
-        public static BufferRecyclerPool shared() {
+        public static ThreadLocalPool shared() {
             return GLOBAL;
         }
 
@@ -160,11 +164,11 @@ public void releaseBufferRecycler(BufferRecycler recycler) {
      * {@link BufferRecyclerPool} implementation that does not use
      * any pool but simply creates new instances when necessary.
      */
-    class NonRecyclingPool implements BufferRecyclerPool
+    class NonRecyclingPool implements BufferRecyclerPool<BufferRecycler>
     {
         private static final long serialVersionUID = 1L;
 
-        private static final BufferRecyclerPool GLOBAL = new NonRecyclingPool();
+        private static final NonRecyclingPool GLOBAL = new NonRecyclingPool();
 
         // No instances beyond shared one should be constructed
         private NonRecyclingPool() { }
@@ -175,7 +179,7 @@ private NonRecyclingPool() { }
          *
          * @return Shared pool instance
          */
-        public static BufferRecyclerPool shared() {
+        public static NonRecyclingPool shared() {
             return GLOBAL;
         }
 
@@ -208,7 +212,8 @@ public void releaseBufferRecycler(BufferRecycler recycler) {
      * special handling with respect to JDK serialization, to retain
      * "global" reference distinct from non-shared ones.
      */
-    public abstract static class StatefulImplBase implements BufferRecyclerPool
+    public abstract static class StatefulImplBase<P extends WithPool<P>>
+        implements BufferRecyclerPool<P>
     {
         private static final long serialVersionUID = 1L;
 
@@ -227,7 +232,7 @@ protected StatefulImplBase(int serialization) {
             _serialization = serialization;
         }
 
-        protected Optional<BufferRecyclerPool> _resolveToShared(BufferRecyclerPool shared) {
+        protected Optional<StatefulImplBase<P>> _resolveToShared(StatefulImplBase<P> shared) {
             if (_serialization == SERIALIZATION_SHARED) {
                 return Optional.of(shared);
             }
@@ -241,7 +246,7 @@ protected Optional<BufferRecyclerPool> _resolveToShared(BufferRecyclerPool share
      *<p>
      * Pool is unbounded: see {@link BufferRecyclerPool} what this means.
      */
-    class ConcurrentDequePool extends StatefulImplBase
+    class ConcurrentDequePool extends StatefulImplBase<BufferRecycler>
     {
         private static final long serialVersionUID = 1L;
 
@@ -308,7 +313,7 @@ protected Object readResolve() {
      * Pool is unbounded: see {@link BufferRecyclerPool} for
      * details on what this means.
      */
-    class LockFreePool extends StatefulImplBase
+    class LockFreePool extends StatefulImplBase<BufferRecycler>
     {
         private static final long serialVersionUID = 1L;
 
@@ -405,7 +410,7 @@ private static class Node {
      * {@link BufferRecycler} instances than its size configuration:
      * the default size is {@link BoundedPool#DEFAULT_CAPACITY}.
      */
-    class BoundedPool extends StatefulImplBase
+    class BoundedPool extends StatefulImplBase<BufferRecycler>
     {
         private static final long serialVersionUID = 1L;
 

src/main/java/com/fasterxml/jackson/core/util/JsonBufferRecyclerPools.java

@@ -0,0 +1,15 @@
+package com.fasterxml.jackson.core.util;
+
+import com.fasterxml.jackson.core.JsonFactory;
+
+/**
+ * Set of {@link BufferRecyclerPool} implementations to be used by the default
+ * JSON-backed {@link JsonFactory} for recycling {@link BufferRecycler}
+ * containers.
+ *
+ * @since 2.16
+ */
+public final class JsonBufferRecyclerPools
+{
+
+}

src/test/java/com/fasterxml/jackson/core/io/BufferRecyclerPoolTest.java

@@ -37,7 +37,8 @@ public void testPluggingPool() throws Exception {
         checkBufferRecyclerPoolImpl(new TestPool(), true);
     }
 
-    private void checkBufferRecyclerPoolImpl(BufferRecyclerPool pool, boolean checkPooledResource) throws Exception {
+    private void checkBufferRecyclerPoolImpl(BufferRecyclerPool<BufferRecycler> pool,
+            boolean checkPooledResource) throws Exception {
         JsonFactory jsonFactory = JsonFactory.builder()
                 .bufferRecyclerPool(pool)
                 .build();
@@ -82,7 +83,7 @@ private static class NopOutputStream extends OutputStream {
 
 
     @SuppressWarnings("serial")
-    class TestPool implements BufferRecyclerPool
+    class TestPool implements BufferRecyclerPool<BufferRecycler>
     {
         private BufferRecycler bufferRecycler;