First part of Steves changes in preparation for a high performance multiplexing proxy:

1) Introduce partial support for caching the underlying byte arrays during message deserialization, so re-serialization can be skipped in the case where a message is not modified.
 
 2) Add c'tors that allow a message to be configured to lazily parse on-demand.
 
 Note that the getters/setters that make lazy parsing transparent are coming in future commits.

TODO

@@ -23,3 +23,15 @@ Cleanup:
    - Find a way to avoid some horrid hacks when shutting down the network connection.
    - Implement a BitCoin class that encapsulates a BigInteger and formatting.
    - Make NetworkParameters use subclasses instead of static methods to construct.
+
+
+
+==========
+
+Impacts from Steves changes:
+- Reformat affected files
+- JavaDocs for the c'tors that take parseLazy/parseRetain
+- Copyright header/correct author for EmptyMessage/ChildMessage
+- Remove superfluous empty lines in ListMessage.java
+- Remove VersionMessage check in Message serialization roundtrip checks
+- Delete dead code in Message.checkParsed

src/com/google/bitcoin/core/AddressMessage.java

@@ -8,12 +8,20 @@ public class AddressMessage extends Message {
     private static final long MAX_ADDRESSES = 1024;
     List<PeerAddress> addresses;
 
+    AddressMessage(NetworkParameters params, byte[] payload, int offset, boolean parseLazy, boolean parseRetain) throws ProtocolException {
+        super(params, payload, offset, parseLazy, parseRetain);
+    }
+    
+    AddressMessage(NetworkParameters params, byte[] payload, boolean parseLazy, boolean parseRetain) throws ProtocolException {
+        super(params, payload, 0, parseLazy, parseRetain);
+    }
+    
     AddressMessage(NetworkParameters params, byte[] payload, int offset) throws ProtocolException {
-        super(params, payload, offset);
+        super(params, payload, offset, false, false);
     }
 
     AddressMessage(NetworkParameters params, byte[] payload) throws ProtocolException {
-        super(params, payload, 0);
+        super(params, payload, 0, false, false);
     }
 
     @Override
@@ -24,7 +32,7 @@ public class AddressMessage extends Message {
             throw new ProtocolException("Address message too large.");
         addresses = new ArrayList<PeerAddress>((int)numAddresses);
         for (int i = 0; i < numAddresses; i++) {
-            PeerAddress addr = new PeerAddress(params, bytes, cursor, protocolVersion);
+            PeerAddress addr = new PeerAddress(params, bytes, cursor, protocolVersion, this, parseLazy, parseRetain);
             addresses.add(addr);
             cursor += addr.getMessageSize();
         }

src/com/google/bitcoin/core/Block.java

@@ -79,6 +79,10 @@ public class Block extends Message {
         super(params, payloadBytes, 0);
     }
     
+    public Block(NetworkParameters params, byte[] payloadBytes, boolean parseLazy, boolean parseRetain) throws ProtocolException {
+        super(params, payloadBytes, 0, parseLazy, parseRetain);
+    }
+
     private void readObject(ObjectInputStream ois) throws ClassNotFoundException, IOException {
         ois.defaultReadObject();
         // This code is not actually necessary, as transient fields are initialized to the default value which is in
@@ -104,7 +108,7 @@ public class Block extends Message {
         int numTransactions = (int) readVarInt();
         transactions = new ArrayList<Transaction>(numTransactions);
         for (int i = 0; i < numTransactions; i++) {
-            Transaction tx = new Transaction(params, bytes, cursor);
+            Transaction tx = new Transaction(params, bytes, cursor, this, parseLazy, parseRetain);
             transactions.add(tx);
             cursor += tx.getMessageSize();
         }
@@ -120,13 +124,13 @@ public class Block extends Message {
     }
     
     @Override
-    void bitcoinSerializeToStream(OutputStream stream) throws IOException {
+    protected void bitcoinSerializeToStream(OutputStream stream) throws IOException {
         writeHeader(stream);
         // We may only have enough data to write the header.
         if (transactions == null) return;
         stream.write(new VarInt(transactions.size()).encode());
         for (Transaction tx : transactions) {
-            tx.bitcoinSerializeToStream(stream);
+            tx.bitcoinSerialize(stream);
         }
     }
 

src/com/google/bitcoin/core/ChildMessage.java

@@ -0,0 +1,63 @@
+package com.google.bitcoin.core;
+
+/**
+ * Represents a Message type that can be contained within another Message.  ChildMessages that have a cached
+ * backing byte array need to invalidate their parent's caches as well as their own if they are modified.
+ * 
+ * @author git
+ *
+ */
+public abstract class ChildMessage extends Message {
+
+	private Message parent;
+	
+	protected ChildMessage() {
+	}
+
+	public ChildMessage(NetworkParameters params) {
+		super(params);
+	}
+
+	public ChildMessage(NetworkParameters params, byte[] msg, int offset, int protocolVersion) throws ProtocolException {
+		super(params, msg, offset, protocolVersion);
+	}
+
+	public ChildMessage(NetworkParameters params, byte[] msg, int offset, int protocolVersion, Message parent, boolean parseLazy,
+			boolean parseRetain) throws ProtocolException {
+		super(params, msg, offset, protocolVersion, parseLazy, parseRetain);
+		this.parent = parent;
+	}
+
+	public ChildMessage(NetworkParameters params, byte[] msg, int offset) throws ProtocolException {
+		super(params, msg, offset);
+	}
+
+	public ChildMessage(NetworkParameters params, byte[] msg, int offset, Message parent, boolean parseLazy, boolean parseRetain)
+			throws ProtocolException {
+		super(params, msg, offset, parseLazy, parseRetain);
+		this.parent = parent;
+	}
+
+	public void setParent(Message parent) {
+		if (this.parent != null && this.parent != parent && parent !=null) {
+			//after old parent is unlinked it won't be able to receive notice if this ChildMessage
+			//changes internally.  To be safe we invalidate the parent cache to ensure it rebuilds
+			//manually on serialization.
+			this.parent.unCache();
+		}
+		this.parent = parent;
+	}
+	
+	/* (non-Javadoc)
+	 * @see com.google.bitcoin.core.Message#unCache()
+	 */
+	@Override
+	protected void unCache() {
+		super.unCache();
+		if (parent != null)
+			parent.unCache();
+	}
+	
+	
+
+}

src/com/google/bitcoin/core/EmptyMessage.java

@@ -4,7 +4,8 @@ import java.io.IOException;
 import java.io.OutputStream;
 
 /**
- * Parent class for header only message that don't have a payload
+ * Parent class for header only messages that don't have a payload.
+ * Currently this includes getaddr, ping, verack as well as the special bitcoinj class UnknownMessage
  * @author git
  *
  */
@@ -17,16 +18,12 @@ public abstract class EmptyMessage extends Message {
 		super(params);
 	}
 
-	public EmptyMessage(NetworkParameters params, byte[] msg, int offset, int protocolVersion) throws ProtocolException {
-		super(params, msg, offset, protocolVersion);
-	}
-
 	public EmptyMessage(NetworkParameters params, byte[] msg, int offset) throws ProtocolException {
 		super(params, msg, offset);
 	}
 
 	@Override
-	final void bitcoinSerializeToStream(OutputStream stream) throws IOException {
+	final protected void bitcoinSerializeToStream(OutputStream stream) throws IOException {
 	}
 
 }

src/com/google/bitcoin/core/GetAddrMessage.java

@@ -17,6 +17,7 @@
 package com.google.bitcoin.core;
 
 public class GetAddrMessage extends EmptyMessage {
+	
 	public GetAddrMessage(NetworkParameters params) {
 		super(params);
 	}

src/com/google/bitcoin/core/GetBlocksMessage.java

@@ -52,7 +52,7 @@ public class GetBlocksMessage extends Message {
         return b.toString();
     }
 
-    void bitcoinSerializeToStream(OutputStream stream) throws IOException {
+    protected void bitcoinSerializeToStream(OutputStream stream) throws IOException {
             // Version, for some reason.
             Utils.uint32ToByteStreamLE(NetworkParameters.PROTOCOL_VERSION, stream);
             // Then a vector of block hashes. This is actually a "block locator", a set of block

src/com/google/bitcoin/core/GetDataMessage.java

@@ -23,6 +23,11 @@ public class GetDataMessage extends ListMessage {
         super(params, payloadBytes);
     }
     
+    public GetDataMessage(NetworkParameters params, byte[] msg, boolean parseLazy, boolean parseRetain)
+			throws ProtocolException {
+		super(params, msg, parseLazy, parseRetain);
+	}
+
 	public GetDataMessage(NetworkParameters params) {
         super(params);
     }

src/com/google/bitcoin/core/InventoryMessage.java

@@ -23,6 +23,11 @@ public class InventoryMessage extends ListMessage {
         super(params, bytes);
     }
 
+    public InventoryMessage(NetworkParameters params, byte[] msg, boolean parseLazy, boolean parseRetain)
+			throws ProtocolException {
+		super(params, msg, parseLazy, parseRetain);
+	}
+
 	public InventoryMessage(NetworkParameters params) {
         super(params);
     }

src/com/google/bitcoin/core/ListMessage.java

@@ -37,6 +37,14 @@ public abstract class ListMessage extends Message
     }
 
     
+
+    public ListMessage(NetworkParameters params, byte[] msg, boolean parseLazy, boolean parseRetain)
+			throws ProtocolException {
+		super(params, msg, 0, parseLazy, parseRetain);
+	}
+
+
+
 	public ListMessage(NetworkParameters params) {
         super(params);
         items = new ArrayList<InventoryItem>();

src/com/google/bitcoin/core/Message.java

@@ -48,6 +48,10 @@ public abstract class Message implements Serializable {
     // The raw message bytes themselves.
     protected transient byte[] bytes;
     
+    private transient boolean parsed = false;
+    protected transient final boolean parseLazy;
+    protected transient final boolean parseRetain;
+
     protected transient int protocolVersion;
 
     // This will be saved by subclasses that implement Serializable.
@@ -55,20 +59,36 @@ public abstract class Message implements Serializable {
 
     /** This exists for the Java serialization framework to use only. */
     protected Message() {
+    	parsed = true;
+    	parseLazy = false;
+    	parseRetain = false;
     }
     
     Message(NetworkParameters params) {
         this.params = params;
+        parsed = true;
+        parseLazy = false;
+    	parseRetain = false;
+    }
+
+    Message(NetworkParameters params, byte[] msg, int offset, int protocolVersion) throws ProtocolException {
+    	this(params, msg, offset, protocolVersion, false, false);
     }
     
     @SuppressWarnings("unused")
-    Message(NetworkParameters params, byte[] msg, int offset, int protocolVersion) throws ProtocolException {
+    Message(NetworkParameters params, byte[] msg, int offset, int protocolVersion, final boolean parseLazy, final boolean parseRetain) throws ProtocolException {
+        this.parseLazy = parseLazy;
+        this.parseRetain = parseRetain;
     	this.protocolVersion = protocolVersion;
         this.params = params;
         this.bytes = msg;
         this.cursor = this.offset = offset;
+        if (!parseLazy) {
         	parse();
+        	parsed = true;
+        }
         if (SELF_CHECK && !this.getClass().getSimpleName().equals("VersionMessage"))  {
+            checkParse();
         	byte[] msgbytes = new byte[cursor - offset];
             System.arraycopy(msg, offset, msgbytes, 0, cursor - offset);
             byte[] reserialized = bitcoinSerialize();
@@ -77,11 +97,17 @@ public abstract class Message implements Serializable {
                         Utils.bytesToHexString(reserialized) + " vs \n" +
                         Utils.bytesToHexString(msgbytes));
         }
+        if (parseRetain || !parsed)
+        	return;
         this.bytes = null;
     }
 
     Message(NetworkParameters params, byte[] msg, int offset) throws ProtocolException {
-        this(params, msg, offset, NetworkParameters.PROTOCOL_VERSION);
+        this(params, msg, offset, NetworkParameters.PROTOCOL_VERSION, false, false);
+    }
+    
+    Message(NetworkParameters params, byte[] msg, int offset, final boolean parseLazy, final boolean parseRetain) throws ProtocolException {
+        this(params, msg, offset, NetworkParameters.PROTOCOL_VERSION, parseLazy, parseRetain);
     }
     
     // These methods handle the serialization/deserialization using the custom BitCoin protocol.
@@ -90,7 +116,86 @@ public abstract class Message implements Serializable {
     // are serialized to the wallet.
     abstract void parse() throws ProtocolException;
     
+    /**
+     * Ensure the object is parsed if needed.  This should be called in every getter before returning a value.
+     * If the lazy parse flag is not set this is a method returns immediately.  
+     */
+    protected synchronized void checkParse() {
+    	if (parsed || bytes == null)
+    		return;
+    	try {
+			parse();
+			parsed = true;
+			//if (!parseRetain)
+				//bytes = null;
+		} catch (ProtocolException e) {
+			throw new RuntimeException("Lazy parsing of message failed", e);
+		}
+    }
+    
+    /**
+     * To be called before any change of internal values including any setters.  This ensures any cached byte array is removed after performing
+     * a lazy parse if necessary to ensure the object is fully populated.
+     * 
+     * Child messages of this object(e.g. Transactions belonging to a Block) will not have their internal byte caches invalidated unless
+     * they are also modified internally.
+     */
+    protected void unCache() {
+    	
+    	/*
+    	 * 	   This is a NOP at the moment.  Will complete lazy parsing as a separate patch first.
+    	 *     safe retention of backing byte array is tricky in cases where a parent Message object
+    	 *     may have child message objects (e.g. block - tx).  There has to be a way to either
+    	 *     mark the cursor at the end of the parent portion of the array or a way the child can
+    	 *     invalidate the parent array. This might require a ByteArrayView class which implements List
+    	 *     and retains a reference to it's parent ByteArrayView so it can invalidate it.  
+    	 *     Alternately the child message can hold a reference to
+    	 *     it's parent and propagate a call to unCache up the chain to the parent.  This way only those children on the
+    	 *     invalidated branch lose their caching.  On the other hand this might introduce more overhead than it's worth
+    	 *     since this call has to made in every setter.
+    	 *     Perhaps a simpler approach where in the special cases where a cached array is wanted it is the callers responsibility
+    	 *     to keep track of whether the cache is valid or not.
+    	 */
+
+    	
+    	//if (!parseRetain)
+    	//	return;
+    	//checkParse();
+    	//bytes = null;
+    }
+    
+    /**
+     * Serialize this message to a byte array that conforms to the bitcoin wire protocol.
+     * <br/>
+     * This method may return the original byte array used to construct this message if the 
+     * following conditions are met:
+     * <ol>
+     * <li>1) The message was parsed from a byte array with parseRetain = true</li>
+     * <li>2) The message has not been modified</li>
+     * <li>3) The array had an offset of 0 and no surplus bytes</li>
+     * </ol>
+     * 
+     * If condition 3 is not met then an copy of the relevant portion of the array will be returned.
+     * Otherwise a full serialize will occur. 
+     * 
+     * @return 
+     */
     final public byte[] bitcoinSerialize() {
+    	
+    	//1st attempt to use a cached array
+    	if (bytes != null) {
+    		if (offset == 0 && cursor == bytes.length) {
+    			//cached byte array is the entire message with no extras
+    			//so we can return as is and avoid an array copy.
+    			return bytes;
+    		}
+    		int len = cursor - offset;
+    		byte[] buf = new byte[len];
+    		System.arraycopy(bytes, offset, buf, 0, len);
+    		return buf;
+    	}
+    	
+    	//no cached array available so serialize parts by stream.
     	ByteArrayOutputStream stream = new ByteArrayOutputStream();
         try {
             bitcoinSerializeToStream(stream);
@@ -101,6 +206,20 @@ public abstract class Message implements Serializable {
         return stream.toByteArray();
     }
     
+    /**
+     * Serialize this message to the provided OutputStream using the bitcoin wire format.
+     * @param stream
+     * @throws IOException
+     */
+    final public void bitcoinSerialize(OutputStream stream) throws IOException {
+    	//1st check for cached bytes
+    	if (bytes != null) {
+    		stream.write(bytes, offset, cursor - offset);
+    		return;
+    	}
+    	bitcoinSerializeToStream(stream);
+    }
+
     /**
      * Serializes this message to the provided stream. If you just want the raw bytes use bitcoinSerialize().
      */

src/com/google/bitcoin/core/PeerAddress.java

@@ -31,7 +31,7 @@ import static com.google.bitcoin.core.Utils.uint64ToByteStreamLE;
  * A PeerAddress holds an IP address and port number representing the network location of
  * a peer in the BitCoin P2P network. It exists primarily for serialization purposes.
  */
-public class PeerAddress extends Message {
+public class PeerAddress extends ChildMessage {
     private static final long serialVersionUID = 7501293709324197411L;
 
     InetAddress addr;
@@ -46,6 +46,17 @@ public class PeerAddress extends Message {
         super(params, payload, offset, protocolVersion);
     }
     
+
+    /**
+     * Construct a peer address from a serialized payload.
+     */
+	public PeerAddress(NetworkParameters params, byte[] msg, int offset, int protocolVersion, Message parent, boolean parseLazy,
+			boolean parseRetain) throws ProtocolException {
+		super(params, msg, offset, protocolVersion, parent, parseLazy, parseRetain);
+	}
+
+
+
 	/**
      * Construct a peer address from a memorized or hardcoded address.
      */
@@ -69,7 +80,7 @@ public class PeerAddress extends Message {
     }
 
 	@Override
-    public void bitcoinSerializeToStream(OutputStream stream) throws IOException {
+	protected void bitcoinSerializeToStream(OutputStream stream) throws IOException {
         if (protocolVersion >= 31402) {
             int secs = (int)(Utils.now().getTime() / 1000);
             uint32ToByteStreamLE(secs, stream);

src/com/google/bitcoin/core/Transaction.java

@@ -18,6 +18,7 @@ package com.google.bitcoin.core;
 
 import java.io.ByteArrayOutputStream;
 import java.io.IOException;
+import java.io.ObjectOutputStream;
 import java.io.OutputStream;
 import java.io.Serializable;
 import java.math.BigInteger;
@@ -37,7 +38,7 @@ import static com.google.bitcoin.core.Utils.*;
  * serialization which is used for the wallet. This allows us to easily add extra fields used for our own accounting
  * or UI purposes.
  */
-public class Transaction extends Message implements Serializable {
+public class Transaction extends ChildMessage implements Serializable {
     private static final Logger log = LoggerFactory.getLogger(Transaction.class);
     private static final long serialVersionUID = -8567546957352643140L;
 
@@ -89,6 +90,22 @@ public class Transaction extends Message implements Serializable {
         // inputs/outputs will be created in parse()
     }
     
+    /**
+     * Creates a transaction by reading payload starting from offset bytes in. Length of a transaction is fixed.
+     */
+    public Transaction(NetworkParameters params, byte[] msg, int offset, Message parent, boolean parseLazy, boolean parseRetain)
+			throws ProtocolException {
+		super(params, msg, offset, parent, parseLazy, parseRetain);
+	}
+    
+    /**
+     * Creates a transaction by reading payload starting from offset bytes in. Length of a transaction is fixed.
+     */
+    public Transaction(NetworkParameters params, byte[] msg, Message parent, boolean parseLazy, boolean parseRetain)
+			throws ProtocolException {
+		super(params, msg, 0, parent, parseLazy, parseRetain);
+	}
+
 	/**
      * Returns a read-only list of the inputs of this transaction.
      */
@@ -272,7 +289,7 @@ public class Transaction extends Message implements Serializable {
         long numInputs = readVarInt();
         inputs = new ArrayList<TransactionInput>((int)numInputs);
         for (long i = 0; i < numInputs; i++) {
-            TransactionInput input = new TransactionInput(params, this, bytes, cursor);
+            TransactionInput input = new TransactionInput(params, this, bytes, cursor, parseLazy, parseRetain);
             inputs.add(input);
             cursor += input.getMessageSize();
         }
@@ -280,7 +297,7 @@ public class Transaction extends Message implements Serializable {
         long numOutputs = readVarInt();
         outputs = new ArrayList<TransactionOutput>((int)numOutputs);
         for (long i = 0; i < numOutputs; i++) {
-            TransactionOutput output = new TransactionOutput(params, this, bytes, cursor);
+            TransactionOutput output = new TransactionOutput(params, this, bytes, cursor, parseLazy, parseRetain);
             outputs.add(output);
             cursor += output.getMessageSize();
         }
@@ -457,14 +474,14 @@ public class Transaction extends Message implements Serializable {
     }
     
     @Override
-    public void bitcoinSerializeToStream(OutputStream stream) throws IOException {
+    protected void bitcoinSerializeToStream(OutputStream stream) throws IOException {
         uint32ToByteStreamLE(version, stream);
         stream.write(new VarInt(inputs.size()).encode());
         for (TransactionInput in : inputs)
-            in.bitcoinSerializeToStream(stream);
+            in.bitcoinSerialize(stream);
         stream.write(new VarInt(outputs.size()).encode());
         for (TransactionOutput out : outputs)
-            out.bitcoinSerializeToStream(stream);
+            out.bitcoinSerialize(stream);
         uint32ToByteStreamLE(lockTime, stream);
     }
 
@@ -480,4 +497,15 @@ public class Transaction extends Message implements Serializable {
     public int hashCode() {
         return getHash().hashCode();
     }
+    
+    /**
+     * Ensure object is fully parsed before invoking java serialization.  The backing byte array
+     * is transient so if the object has parseLazy = true and hasn't invoked checkParse yet
+     * then data will be lost during serialization.
+     */
+    private void writeObject(ObjectOutputStream out) throws IOException {
+    	checkParse();
+    	out.defaultWriteObject();
+    }
+    
 }

src/com/google/bitcoin/core/TransactionInput.java

@@ -17,6 +17,7 @@
 package com.google.bitcoin.core;
 
 import java.io.IOException;
+import java.io.ObjectOutputStream;
 import java.io.OutputStream;
 import java.io.Serializable;
 import java.util.Map;
@@ -27,7 +28,7 @@ import java.util.Map;
  * transaction as being a module which is wired up to others, the inputs of one have to be wired
  * to the outputs of another. The exceptions are coinbase transactions, which create new coins.
  */
-public class TransactionInput extends Message implements Serializable {
+public class TransactionInput extends ChildMessage implements Serializable {
     private static final long serialVersionUID = 2;
     public static final byte[] EMPTY_ARRAY = new byte[0];
 
@@ -73,8 +74,15 @@ public class TransactionInput extends Message implements Serializable {
         this.parentTransaction = parentTransaction;
     }
     
+    /** Deserializes an input message. This is usually part of a transaction message. */
+    public TransactionInput(NetworkParameters params, Transaction parentTransaction, byte[] msg, int offset, boolean parseLazy, boolean parseRetain)
+			throws ProtocolException {
+		super(params, msg, offset, parentTransaction, parseLazy, parseRetain);
+		this.parentTransaction = parentTransaction;
+	}
+
 	void parse() throws ProtocolException {
-        outpoint = new TransactionOutPoint(params, bytes, cursor);
+        outpoint = new TransactionOutPoint(params, bytes, cursor, this, parseLazy, parseRetain);
         cursor += outpoint.getMessageSize(); 
         int scriptLen = (int) readVarInt();
         scriptBytes = readBytes(scriptLen);
@@ -82,8 +90,8 @@ public class TransactionInput extends Message implements Serializable {
     }
     
     @Override
-    public void bitcoinSerializeToStream(OutputStream stream) throws IOException {
+    protected void bitcoinSerializeToStream(OutputStream stream) throws IOException {
-        outpoint.bitcoinSerializeToStream(stream);
+        outpoint.bitcoinSerialize(stream);
         stream.write(new VarInt(scriptBytes.length).encode());
         stream.write(scriptBytes);
         Utils.uint32ToByteStreamLE(sequence, stream);
@@ -187,4 +195,14 @@ public class TransactionInput extends Message implements Serializable {
         outpoint.fromTx = null;
         return true;
     }
+    
+    /**
+     * Ensure object is fully parsed before invoking java serialization.  The backing byte array
+     * is transient so if the object has parseLazy = true and hasn't invoked checkParse yet
+     * then data will be lost during serialization.
+     */
+    private void writeObject(ObjectOutputStream out) throws IOException {
+    	checkParse();
+    	out.defaultWriteObject();
+    }
 }

src/com/google/bitcoin/core/TransactionOutPoint.java

@@ -17,6 +17,7 @@
 package com.google.bitcoin.core;
 
 import java.io.IOException;
+import java.io.ObjectOutputStream;
 import java.io.OutputStream;
 import java.io.Serializable;
 
@@ -25,7 +26,7 @@ import java.io.Serializable;
 /**
  * This message is a reference or pointer to an output of a different transaction.
  */
-public class TransactionOutPoint extends Message implements Serializable {
+public class TransactionOutPoint extends ChildMessage implements Serializable {
     private static final long serialVersionUID = -6320880638344662579L;
 
     /** Hash of the transaction to which we refer. */
@@ -54,6 +55,11 @@ public class TransactionOutPoint extends Message implements Serializable {
         super(params, payload, offset);
     }
     
+    /** Deserializes the message. This is usually part of a transaction message. */
+    public TransactionOutPoint(NetworkParameters params, byte[] payload, int offset, Message parent, boolean parseLazy, boolean parseRetain) throws ProtocolException {
+        super(params, payload, offset, parent, parseLazy, parseRetain);
+    }
+    
     @Override
     void parse() throws ProtocolException {
         hash = readHash();
@@ -61,7 +67,7 @@ public class TransactionOutPoint extends Message implements Serializable {
     }
 
     @Override
-    public void bitcoinSerializeToStream(OutputStream stream) throws IOException {
+    protected void bitcoinSerializeToStream(OutputStream stream) throws IOException {
         stream.write(Utils.reverseBytes(hash.getBytes()));
         Utils.uint32ToByteStreamLE(index, stream);
     }
@@ -96,4 +102,14 @@ public class TransactionOutPoint extends Message implements Serializable {
     public String toString() {
         return "outpoint " + index + ":" + hash.toString();
     }
+    
+    /**
+     * Ensure object is fully parsed before invoking java serialization.  The backing byte array
+     * is transient so if the object has parseLazy = true and hasn't invoked checkParse yet
+     * then data will be lost during serialization.
+     */
+    private void writeObject(ObjectOutputStream out) throws IOException {
+    	checkParse();
+    	out.defaultWriteObject();
+    }
 }

src/com/google/bitcoin/core/TransactionOutput.java

@@ -20,6 +20,7 @@ import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
 import java.io.IOException;
+import java.io.ObjectOutputStream;
 import java.io.OutputStream;
 import java.io.Serializable;
 import java.math.BigInteger;
@@ -28,7 +29,7 @@ import java.math.BigInteger;
  * A TransactionOutput message contains a scriptPubKey that controls who is able to spend its value. It is a sub-part
  * of the Transaction message.
  */
-public class TransactionOutput extends Message implements Serializable {
+public class TransactionOutput extends ChildMessage implements Serializable {
     private static final Logger log = LoggerFactory.getLogger(TransactionOutput.class);
     private static final long serialVersionUID = -590332479859256824L;
 
@@ -58,6 +59,14 @@ public class TransactionOutput extends Message implements Serializable {
         availableForSpending = true;
     }
     
+    /** Deserializes a transaction output message. This is usually part of a transaction message. */
+    public TransactionOutput(NetworkParameters params, Transaction parent, byte[] msg, int offset, boolean parseLazy, boolean parseRetain)
+			throws ProtocolException {
+		super(params, msg, offset, parent, parseLazy, parseRetain);
+		parentTransaction = parent;
+        availableForSpending = true;
+	}
+
 	TransactionOutput(NetworkParameters params, Transaction parent, BigInteger value, Address to) {
         super(params);
         this.value = value;
@@ -88,7 +97,7 @@ public class TransactionOutput extends Message implements Serializable {
     }
     
     @Override
-    public void bitcoinSerializeToStream( OutputStream stream) throws IOException {
+    protected void bitcoinSerializeToStream( OutputStream stream) throws IOException {
         assert scriptBytes != null;
         Utils.uint64ToByteStreamLE(getValue(), stream);
         // TODO: Move script serialization into the Script class, where it belongs.
@@ -162,4 +171,14 @@ public class TransactionOutput extends Message implements Serializable {
     TransactionInput getSpentBy() {
         return spentBy;
     }
+    
+    /**
+     * Ensure object is fully parsed before invoking java serialization.  The backing byte array
+     * is transient so if the object has parseLazy = true and hasn't invoked checkParse yet
+     * then data will be lost during serialization.
+     */
+    private void writeObject(ObjectOutputStream out) throws IOException {
+    	checkParse();
+    	out.defaultWriteObject();
+    }
 }

src/com/google/bitcoin/core/VersionMessage.java

@@ -51,6 +51,15 @@ public class VersionMessage extends Message {
         super(params, msg, 0);
     }
     
+    /**
+     * It doesn't really make sense to ever lazily parse a version message or to retain the backing bytes.
+     * If you're receiving this on the wire you need to check the protocol version and it will never need to be sent
+     * back down the wire.
+     */
+//    public VersionMessage(NetworkParameters params, byte[] msg, boolean parseLazy, boolean parseRetain) throws ProtocolException {
+//        super(params, msg, 0, parseLazy, parseRetain);
+//    }
+
     public VersionMessage(NetworkParameters params, int newBestHeight) {
         super(params);
         clientVersion = NetworkParameters.PROTOCOL_VERSION;
@@ -96,9 +105,9 @@ public class VersionMessage extends Message {
         Utils.uint32ToByteStreamLE(time >> 32, buf);
         try {
             // My address.
-            myAddr.bitcoinSerializeToStream(buf);
+            myAddr.bitcoinSerialize(buf);
             // Their address.
-            theirAddr.bitcoinSerializeToStream(buf);
+            theirAddr.bitcoinSerialize(buf);
         } catch (UnknownHostException e) {
             throw new RuntimeException(e);  // Can't happen.
         } catch (IOException e) {
@@ -143,4 +152,17 @@ public class VersionMessage extends Message {
         return (int)bestHeight ^ clientVersion ^ (int)localServices ^ (int)time ^ subVer.hashCode() ^ myAddr.hashCode()
                 ^ theirAddr.hashCode();
     }
+    
+    public String toString() {
+    	StringBuilder sb = new StringBuilder();
+    	sb.append("\n");
+    	sb.append("client version: ").append(clientVersion).append("\n");
+    	sb.append("local services: ").append(localServices).append("\n");
+    	sb.append("time:           ").append(time).append("\n");
+    	sb.append("my addr:        ").append(myAddr).append("\n");
+    	sb.append("their addr:     ").append(theirAddr).append("\n");
+    	sb.append("sub version:    ").append(subVer).append("\n");
+    	sb.append("best height:    ").append(bestHeight).append("\n");
+    	return sb.toString();
+    }
 }