Updated SPI model and added examples

src/test/java/net/openhft/chronicle/map/LoggingMapEntryOperations.java

@@ -0,0 +1,41 @@
+/*
+ * Copyright 2015 Higher Frequency Trading
+ *
+ *  http://www.higherfrequencytrading.com
+ *  
+ *  Licensed under the Apache License, Version 2.0 (the "License");
+ *  you may not use this file except in compliance with the License.
+ *  You may obtain a copy of the License at
+ *  
+ *  http://www.apache.org/licenses/LICENSE-2.0
+ *  
+ *  Unless required by applicable law or agreed to in writing, software
+ *  distributed under the License is distributed on an "AS IS" BASIS,
+ *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ *  See the License for the specific language governing permissions and
+ *  limitations under the License.
+ */
+
+package net.openhft.chronicle.map;
+
+import net.openhft.chronicle.hash.Value;
+import org.jetbrains.annotations.NotNull;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+class LoggingMapEntryOperations<K, V> implements MapEntryOperations<K, V> {
+
+    static final Logger LOG = LoggerFactory.getLogger(LoggingMapEntryOperations.class);
+    
+    @Override
+    public boolean replaceValue(@NotNull MapEntry<K, V> entry, Value<V, ?> newValue) {
+        if (MapEntryOperations.shouldModify(entry)) {
+            LOG.info("replace: old key: {}, old value: {}, new value: {}",
+                    entry.key(), entry.value(), newValue);
+            entry.doReplaceValue(newValue);
+            return true;
+        } else {
+            return false;
+        }
+    }
+}

src/test/java/net/openhft/chronicle/map/MaximizingValueMapEntryOperations.java

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+/*
+ * Copyright 2015 Higher Frequency Trading
+ *
+ *  http://www.higherfrequencytrading.com
+ *
+ *  Licensed under the Apache License, Version 2.0 (the "License");
+ *  you may not use this file except in compliance with the License.
+ *  You may obtain a copy of the License at
+ *
+ *  http://www.apache.org/licenses/LICENSE-2.0
+ *
+ *  Unless required by applicable law or agreed to in writing, software
+ *  distributed under the License is distributed on an "AS IS" BASIS,
+ *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ *  See the License for the specific language governing permissions and
+ *  limitations under the License.
+ */
+
+package net.openhft.chronicle.map;
+
+import net.openhft.chronicle.hash.Value;
+import net.openhft.chronicle.hash.replication.ReplicationContext;
+import org.jetbrains.annotations.NotNull;
+
+public class MaximizingValueMapEntryOperations<K, V extends Comparable<? super V>>
+        implements MapEntryOperations<K, V> {
+
+    @Override
+    public boolean replaceValue(@NotNull MapEntry<K, V> entry, Value<V, ?> newValue) {
+        if (entry.context() instanceof ReplicationContext) {
+            if (newValue.get().compareTo(entry.value().get()) > 0) {
+                // replace, if the new value is greater
+                entry.doReplaceValue(newValue);
+                return true;
+            } else {
+                // always fail, if the value came via replication is lesser than the current value.
+                return false;
+            }
+        } else {
+            return MapEntryOperations.super.replaceValue(entry, newValue);
+        }
+    }
+}