HCOLL-81 StatelessClient : Add a visitor pattern to Chronicle Map ( tested with lamda expressions in java8 )

src/main/java/net/openhft/chronicle/java8/Function.java

@@ -0,0 +1,27 @@
+package net.openhft.chronicle.java8;
+
+import java.io.Serializable;
+
+/**
+ * Represents a function that accepts one argument and produces a result.
+ *
+ * <p>This is a <a href="package-summary.html">functional interface</a> whose functional method is {@link
+ * #apply(Object)}.
+ *
+ * @param <T> the type of the input to the function
+ * @param <R> the type of the result of the function
+ * @since 1.8
+ */
+@FunctionalInterface
+public interface Function<T, R> extends Serializable {
+
+    /**
+     * Applies this function to the given argument.
+     *
+     * @param t the function argument
+     * @return the function result
+     */
+    R apply(T t);
+
+
+}

src/main/java/net/openhft/chronicle/map/StatelessChronicleMap.java

@@ -20,6 +20,7 @@ package net.openhft.chronicle.map;
 
 import com.sun.jdi.connect.spi.ClosedConnectionException;
 import net.openhft.chronicle.hash.RemoteCallTimeoutException;
+import net.openhft.chronicle.java8.Function;
 import net.openhft.lang.io.ByteBufferBytes;
 import net.openhft.lang.io.Bytes;
 import net.openhft.lang.threadlocal.ThreadLocalCopies;
@@ -35,7 +36,6 @@ import java.nio.ByteBuffer;
 import java.nio.ByteOrder;
 import java.nio.channels.SocketChannel;
 import java.util.*;
-import java.util.function.Function;
 
 import static java.nio.ByteBuffer.allocateDirect;
 import static net.openhft.chronicle.map.AbstractChannelReplicator.SIZE_OF_SIZE;
@@ -468,9 +468,9 @@ class StatelessChronicleMap<K, V> implements ChronicleMap<K, V>, Closeable {
 
 
     private <R> void writeObject(@NotNull Function<V, R> function) {
+        long start   = bytes.position();
         for (; ; ) {
             try {
-
                 bytes.writeObject(function);
                 return;
             } catch (IllegalStateException e) {
@@ -480,6 +480,8 @@ class StatelessChronicleMap<K, V> implements ChronicleMap<K, V>, Closeable {
                 if (cause instanceof IOException && cause.getMessage().contains("Not enough available space")) {
                     LOG.debug("resizing buffer");
                     resizeBuffer(buffer.capacity() + 1024);
+                    bytes.limit(bytes.capacity());
+                    bytes.position(start);
 
                 } else
                     throw e;
@@ -557,7 +559,6 @@ class StatelessChronicleMap<K, V> implements ChronicleMap<K, V>, Closeable {
 
             writeKey(key, local);
 
-
             final V value = e.getValue();
 
             final Class<?> valueClass = value.getClass();

src/main/java/net/openhft/chronicle/map/TcpReplicator.java

@@ -21,6 +21,7 @@ package net.openhft.chronicle.map;
 import net.openhft.chronicle.hash.replication.RemoteNodeValidator;
 import net.openhft.chronicle.hash.replication.TcpTransportAndNetworkConfig;
 import net.openhft.chronicle.hash.replication.ThrottlingConfig;
+import net.openhft.chronicle.java8.Function;
 import net.openhft.lang.io.ByteBufferBytes;
 import net.openhft.lang.io.Bytes;
 import net.openhft.lang.threadlocal.ThreadLocalCopies;
@@ -38,7 +39,6 @@ import java.nio.channels.*;
 import java.util.*;
 import java.util.concurrent.atomic.AtomicBoolean;
 import java.util.concurrent.atomic.AtomicReference;
-import java.util.function.Function;
 
 import static java.nio.channels.SelectionKey.*;
 import static java.util.concurrent.TimeUnit.MILLISECONDS;
@@ -1350,10 +1350,15 @@ class StatelessServerConnector<K, V> {
 
         V value = using.getAndSet(null);
         if (value == null) {
-            // a simple way to create a value
-            value = map.getUsing(key, null);
+
+            //value = map.createValueInstance();
+
+            // todo replace this
+            value = map.acquireUsing(key, null);
         }
 
+
+
         final Function<V, ?> o = (Function<V, ?>) reader.readObject();
 
         try (WriteContext<K, V> wc = map.acquireUsingLocked(key, value)) {

src/main/java/net/openhft/chronicle/map/VanillaChronicleMap.java

@@ -29,7 +29,10 @@ import net.openhft.lang.collection.DirectBitSet;
 import net.openhft.lang.collection.SingleThreadedDirectBitSet;
 import net.openhft.lang.io.*;
 import net.openhft.lang.io.serialization.JDKObjectSerializer;
+import net.openhft.lang.io.serialization.impl.AllocateInstanceObjectFactory;
 import net.openhft.lang.io.serialization.impl.VanillaBytesMarshallerFactory;
+import net.openhft.lang.model.Byteable;
+import net.openhft.lang.model.DataValueClasses;
 import net.openhft.lang.model.constraints.Nullable;
 import net.openhft.lang.threadlocal.Provider;
 import net.openhft.lang.threadlocal.ThreadLocalCopies;
@@ -349,6 +352,32 @@ class VanillaChronicleMap<K, KI, MKI extends MetaBytesInterop<K, KI>,
                 replaceIfPresent);
     }
 
+
+    V createValueInstance() {
+
+        if (vClass.isAssignableFrom(Byteable.class))
+            return DataValueClasses.newDirectReference(vClass);
+        else {
+
+
+            try {
+                return vClass.newInstance();
+            } catch (InstantiationException e) {
+                try {
+                    return (V) (new AllocateInstanceObjectFactory<V>(vClass)).create();
+                } catch (Exception e1) {
+                    LOG.error("", e);
+                    return null;
+                }
+            } catch (IllegalAccessException e) {
+                LOG.error("", e);
+                return null;
+            }
+
+
+        }
+    }
+
     enum LockType {READ_LOCK, WRITE_LOCK}
 
     @Override