Reduce compile target to Java 5, address serialization issues and improve performance

code/pom.xml

@@ -43,15 +43,17 @@
         <plugins>
             <plugin>
                 <!--
-                    Configure javac compiler for Java 6 compatibility.
-                    Note that actually the library might also be compatible with Java 5, but this has not been tested.
+                    Configure javac compiler for Java 5 compatibility.
                 -->
                 <groupId>org.apache.maven.plugins</groupId>
                 <artifactId>maven-compiler-plugin</artifactId>
                 <version>2.3.2</version>
                 <configuration>
-                    <source>1.6</source>
-                    <target>1.6</target>
+                    <source>1.5</source>
+                    <target>1.5</target>
+                    <showWarnings>true</showWarnings>
+                    <showDeprecation>true</showDeprecation>
+                    <compilerArgument>-Xlint:all,-options,-processing</compilerArgument>
                 </configuration>
             </plugin>
             <plugin>
@@ -76,6 +78,9 @@
                     <archive>
                         <!-- This is required by bnd-maven-plugin -->
                         <manifestFile>${project.build.outputDirectory}/META-INF/MANIFEST.MF</manifestFile>
+                        <manifestEntries>
+                            <Automatic-Module-Name>${project.groupId}.${project.artifactId}</Automatic-Module-Name>
+                        </manifestEntries>
                     </archive>
                 </configuration>
             </plugin>
@@ -107,6 +112,27 @@
                     </execution>
                 </executions>
             </plugin>
+            <plugin>
+                <!-- Make sure no APIs are included that are newer then Java 5 -->
+                <groupId>org.codehaus.mojo</groupId>
+                <artifactId>animal-sniffer-maven-plugin</artifactId>
+                <version>1.16</version>
+                <executions>
+                    <execution>
+                        <phase>test</phase>
+                        <goals>
+                            <goal>check</goal>
+                        </goals>
+                        <configuration>
+                            <signature>
+                                <groupId>org.codehaus.mojo.signature</groupId>
+                                <artifactId>java15</artifactId>
+                                <version>1.0</version>
+                            </signature>
+                        </configuration>
+                    </execution>
+                </executions>
+            </plugin>
         </plugins>
     </build>
     <dependencies>

code/src/main/java/com/googlecode/concurrenttrees/common/CharSequences.java

@@ -1,4 +1,4 @@
-/**
+/*
  * Copyright 2012-2013 Niall Gallagher
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
@@ -15,12 +15,6 @@
  */
 package com.googlecode.concurrenttrees.common;
 
-import java.io.UnsupportedEncodingException;
-import java.nio.ByteBuffer;
-import java.nio.CharBuffer;
-import java.nio.charset.Charset;
-import java.nio.charset.CharsetEncoder;
-import java.nio.charset.CodingErrorAction;
 import java.util.Iterator;
 
 /**

code/src/main/java/com/googlecode/concurrenttrees/common/Iterables.java

@@ -1,4 +1,4 @@
-/**
+/*
  * Copyright 2012-2013 Niall Gallagher
  *
  * Licensed under the Apache License, Version 2.0 (the "License");

code/src/main/java/com/googlecode/concurrenttrees/common/KeyValuePair.java

@@ -1,4 +1,4 @@
-/**
+/*
  * Copyright 2012-2013 Niall Gallagher
  *
  * Licensed under the Apache License, Version 2.0 (the "License");

code/src/main/java/com/googlecode/concurrenttrees/common/LazyIterator.java

@@ -1,4 +1,4 @@
-/**
+/*
  * Copyright 2012-2013 Niall Gallagher
  * Copyright 2007 The Guava Authors
  *

code/src/main/java/com/googlecode/concurrenttrees/common/PrettyPrinter.java

@@ -1,4 +1,4 @@
-/**
+/*
  * Copyright 2012-2013 Niall Gallagher
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
@@ -16,6 +16,7 @@
 package com.googlecode.concurrenttrees.common;
 
 import com.googlecode.concurrenttrees.radix.node.Node;
+import com.googlecode.concurrenttrees.radix.node.NodeList;
 import com.googlecode.concurrenttrees.radix.node.util.PrettyPrintable;
 
 import java.io.IOException;
@@ -83,7 +84,7 @@ static void prettyPrint(Node node, Appendable sb, String prefix, boolean isTail,
             StringBuilder label = new StringBuilder();
             if (isRoot) {
                 label.append("○");
-                if (node.getIncomingEdge().length() > 0) {
+                if (node.getIncomingEdgeLength() > 0) {
                     label.append(" ");
                 }
             }
@@ -92,7 +93,7 @@ static void prettyPrint(Node node, Appendable sb, String prefix, boolean isTail,
                 label.append(" (").append(node.getValue()).append(")");
             }
             sb.append(prefix).append(isTail ? isRoot ? "" : "└── ○ " : "├── ○ ").append(label).append("\n");
-            List<Node> children = node.getOutgoingEdges();
+            NodeList children = node.getOutgoingEdges();
             for (int i = 0; i < children.size() - 1; i++) {
                 prettyPrint(children.get(i), sb, prefix + (isTail ? isRoot ? "" : "    " : "│   "), false, false);
             }

code/src/main/java/com/googlecode/concurrenttrees/common/SetFromMap.java

@@ -0,0 +1,120 @@
+/*
+ * Copyright 2012-2013 Niall Gallagher
+ *
+ * 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 com.googlecode.concurrenttrees.common;
+
+import java.io.IOException;
+import java.io.ObjectInputStream;
+import java.io.Serializable;
+import java.util.*;
+
+/**
+ * A facade implementation of a Java set for representing a Java map implementation.
+ *
+ * @param <E> The element type.
+ */
+public class SetFromMap<E> extends AbstractSet<E> implements Serializable {
+
+    private static final long serialVersionUID = 1L;
+
+    private final Map<E, Boolean> delegate;
+
+    private transient Set<E> keySet;
+
+    public SetFromMap(Map<E, Boolean> delegate) {
+        this.delegate = delegate;
+        keySet = delegate.keySet();
+    }
+
+    private void readObject(ObjectInputStream stream) throws IOException, ClassNotFoundException {
+        stream.defaultReadObject();
+        keySet = delegate.keySet();
+    }
+
+    @Override
+    public int size() {
+        return delegate.size();
+    }
+
+    @Override
+    public boolean isEmpty() {
+        return delegate.isEmpty();
+    }
+
+    @Override
+    public boolean contains(Object o) {
+        return delegate.containsKey(o);
+    }
+
+    @Override
+    public boolean remove(Object o) {
+        return delegate.remove(o) != null;
+    }
+
+    @Override
+    public void clear() {
+        delegate.clear();
+    }
+
+    @Override
+    public boolean add(E e) {
+        return delegate.put(e, Boolean.TRUE) == null;
+    }
+
+    @Override
+    public Iterator<E> iterator() {
+        return keySet.iterator();
+    }
+
+    @Override
+    public Object[] toArray() {
+        return keySet.toArray();
+    }
+
+    @Override
+    public <T> T[] toArray(T[] a) {
+        return keySet.toArray(a);
+    }
+
+    @Override
+    public String toString() {
+        return keySet.toString();
+    }
+
+    @Override
+    public int hashCode() {
+        return keySet.hashCode();
+    }
+
+    @Override
+    public boolean equals(Object o) {
+        return o == this || keySet.equals(o);
+    }
+
+    @Override
+    public boolean containsAll(Collection<?> c) {
+        return keySet.containsAll(c);
+    }
+
+    @Override
+    public boolean removeAll(Collection<?> c) {
+        return keySet.removeAll(c);
+    }
+
+    @Override
+    public boolean retainAll(Collection<?> c) {
+        return keySet.retainAll(c);
+    }
+}