Expose the chunkSize used by PooledByteBufAllocator.

Motivation:

Sometimes it may be useful to know the used chunkSize.

Modifications:

Add method to expose chunkSize.

Result:

More exposed details.

buffer/src/main/java/io/netty/buffer/PooledByteBufAllocator.java

@@ -146,6 +146,7 @@ public class PooledByteBufAllocator extends AbstractByteBufAllocator {
     private final List<PoolArenaMetric> heapArenaMetrics;
     private final List<PoolArenaMetric> directArenaMetrics;
     private final PoolThreadLocalCache threadCache;
+    private final int chunkSize;
 
     public PooledByteBufAllocator() {
         this(false);
@@ -199,7 +200,7 @@ public class PooledByteBufAllocator extends AbstractByteBufAllocator {
         this.tinyCacheSize = tinyCacheSize;
         this.smallCacheSize = smallCacheSize;
         this.normalCacheSize = normalCacheSize;
-        final int chunkSize = validateAndCalculateChunkSize(pageSize, maxOrder);
+        chunkSize = validateAndCalculateChunkSize(pageSize, maxOrder);
 
         if (nHeapArena < 0) {
             throw new IllegalArgumentException("nHeapArena: " + nHeapArena + " (expected: >= 0)");
@@ -511,6 +512,13 @@ public class PooledByteBufAllocator extends AbstractByteBufAllocator {
         return normalCacheSize;
     }
 
+    /**
+     * Return the chunk size for an arena.
+     */
+    public final int chunkSize() {
+        return chunkSize;
+    }
+
     final PoolThreadCache threadCache() {
         return threadCache.get();
     }