* i2psnark:

- Defer piece loading until required
      - Stub out Extension message support

apps/i2psnark/java/src/org/klomp/snark/DataLoader.java

@@ -0,0 +1,14 @@
+package org.klomp.snark;
+
+/**
+ * Callback used to fetch data
+ * @since 0.8.2
+ */
+interface DataLoader
+{
+  /**
+   *  This is the callback that PeerConnectionOut calls to get the data from disk
+   *  @return bytes or null for errors
+   */
+    public byte[] loadData(int piece, int begin, int length);
+}

apps/i2psnark/java/src/org/klomp/snark/Message.java

@@ -39,23 +39,28 @@ class Message
   final static byte REQUEST      = 6;
   final static byte PIECE        = 7;
   final static byte CANCEL       = 8;
+  final static byte EXTENSION    = 20;
   
   // Not all fields are used for every message.
   // KEEP_ALIVE doesn't have a real wire representation
   byte type;
 
   // Used for HAVE, REQUEST, PIECE and CANCEL messages.
+  // low byte used for EXTENSION message
   int piece;
 
   // Used for REQUEST, PIECE and CANCEL messages.
   int begin;
   int length;
 
-  // Used for PIECE and BITFIELD messages
+  // Used for PIECE and BITFIELD and EXTENSION messages
   byte[] data;
   int off;
   int len;
 
+  // Used to do deferred fetch of data
+  DataLoader dataLoader;
+
   SimpleTimer.TimedEvent expireEvent;
   
   /** Utility method for sending a message through a DataStream. */
@@ -68,6 +73,13 @@ class Message
         return;
       }
 
+    // Get deferred data
+    if (data == null && dataLoader != null) {
+        data = dataLoader.loadData(piece, begin, length);
+        if (data == null)
+            return;  // hmm will get retried, but shouldn't happen
+    }
+
     // Calculate the total length in bytes
 
     // Type is one byte.
@@ -85,8 +97,12 @@ class Message
     if (type == REQUEST || type == CANCEL)
       datalen += 4;
 
+    // length is 1 byte
+    if (type == EXTENSION)
+      datalen += 1;
+
     // add length of data for piece or bitfield array.
-    if (type == BITFIELD || type == PIECE)
+    if (type == BITFIELD || type == PIECE || type == EXTENSION)
       datalen += len;
 
     // Send length
@@ -105,8 +121,11 @@ class Message
     if (type == REQUEST || type == CANCEL)
         dos.writeInt(length);
 
+    if (type == EXTENSION)
+        dos.writeByte((byte) piece & 0xff);
+
     // Send actual data
-    if (type == BITFIELD || type == PIECE)
+    if (type == BITFIELD || type == PIECE || type == EXTENSION)
       dos.write(data, off, len);
   }
 
@@ -135,6 +154,8 @@ class Message
         return "PIECE(" + piece + "," + begin + "," + length + ")";
       case CANCEL:
         return "CANCEL(" + piece + "," + begin + "," + length + ")";
+      case EXTENSION:
+        return "EXTENSION(" + piece + ',' + data.length + ')';
       default:
         return "<UNKNOWN>";
       }

apps/i2psnark/java/src/org/klomp/snark/Peer.java

@@ -59,6 +59,11 @@ public class Peer implements Comparable
   private long uploaded_old[] = {-1,-1,-1};
   private long downloaded_old[] = {-1,-1,-1};
 
+  //  bytes per bt spec:                 0011223344556677
+  static final long OPTION_EXTENSION = 0x0000000000100000l;
+  static final long OPTION_FAST      = 0x0000000000000004l;
+  private long options;
+
   /**
    * Creates a disconnected peer given a PeerID, your own id and the
    * relevant MetaInfo.
@@ -285,9 +290,8 @@ public class Peer implements Comparable
     // Handshake write - header
     dout.write(19);
     dout.write("BitTorrent protocol".getBytes("UTF-8"));
-    // Handshake write - zeros
+    // Handshake write - options
-    byte[] zeros = new byte[8];
+    dout.writeLong(OPTION_EXTENSION);
-    dout.write(zeros);
     // Handshake write - metainfo hash
     byte[] shared_hash = metainfo.getInfoHash();
     dout.write(shared_hash);
@@ -312,8 +316,8 @@ public class Peer implements Comparable
                             + "'Bittorrent protocol', got '"
                             + bittorrentProtocol + "'");
     
-    // Handshake read - zeros
+    // Handshake read - options
-    din.readFully(zeros);
+    options = din.readLong();
     
     // Handshake read - metainfo hash
     bs = new byte[20];
@@ -325,6 +329,15 @@ public class Peer implements Comparable
     din.readFully(bs);
     if (_log.shouldLog(Log.DEBUG))
         _log.debug("Read the remote side's hash and peerID fully from " + toString());
+
+//  if ((options & OPTION_EXTENSION) != 0) {
+    if (options != 0) {
+        // send them something
+        if (_log.shouldLog(Log.DEBUG))
+            //_log.debug("Peer supports extension message, what should we say? " + toString());
+            _log.debug("Peer supports options 0x" + Long.toString(options, 16) + ", what should we say? " + toString());
+    }
+
     return bs;
   }
 

apps/i2psnark/java/src/org/klomp/snark/PeerConnectionIn.java

@@ -171,6 +171,13 @@ class PeerConnectionIn implements Runnable
                 if (_log.shouldLog(Log.DEBUG)) 
                     _log.debug("Received cancel(" + piece + "," + begin + ") from " + peer + " on " + peer.metainfo.getName());
                 break;
+              case 20:  // Extension message
+                int id = din.readUnsignedByte();
+                byte[] payload = new byte[i-2];
+                din.readFully(payload);
+                ps.extensionMessage(id, payload);
+                if (_log.shouldLog(Log.DEBUG)) 
+                    _log.debug("Received extension message from " + peer + " on " + peer.metainfo.getName());
               default:
                 byte[] bs = new byte[i-1];
                 din.readFully(bs);

apps/i2psnark/java/src/org/klomp/snark/PeerConnectionOut.java

@@ -430,6 +430,33 @@ class PeerConnectionOut implements Runnable
     return total;
   }
 
+  /** @since 0.8.2 */
+  void sendPiece(int piece, int begin, int length, DataLoader loader)
+  {
+      boolean sendNow = false;
+      // are there any cases where we should?
+
+      if (sendNow) {
+        // queue the real thing
+        byte[] bytes = loader.loadData(piece, begin, length);
+        if (bytes != null)
+            sendPiece(piece, begin, length, bytes);
+        return;
+      }
+
+      // queue a fake message... set everything up,
+      // except save the PeerState instead of the bytes.
+      Message m = new Message();
+      m.type = Message.PIECE;
+      m.piece = piece;
+      m.begin = begin;
+      m.length = length;
+      m.dataLoader = loader;
+      m.off = 0;
+      m.len = length;
+      addMessage(m);
+  }
+
   void sendPiece(int piece, int begin, int length, byte[] bytes)
   {
     Message m = new Message();
@@ -488,4 +515,16 @@ class PeerConnectionOut implements Runnable
           }
       }
   }
+
+  /** @since 0.8.2 */
+  void sendExtension(int id, byte[] bytes) {
+    Message m = new Message();
+    m.type = Message.EXTENSION;
+    m.piece = id;
+    m.data = bytes;
+    m.begin = 0;
+    m.length = bytes.length;
+    addMessage(m);
+
+  }
 }

apps/i2psnark/java/src/org/klomp/snark/PeerState.java

@@ -20,14 +20,20 @@
 
 package org.klomp.snark;
 
+import java.io.ByteArrayInputStream;
+import java.io.InputStream;
 import java.util.ArrayList;
 import java.util.Iterator;
 import java.util.List;
+import java.util.Map;
 
 import net.i2p.I2PAppContext;
 import net.i2p.util.Log;
 
-class PeerState
+import org.klomp.snark.bencode.BDecoder;
+import org.klomp.snark.bencode.BEValue;
+
+class PeerState implements DataLoader
 {
   private final Log _log = I2PAppContext.getGlobalContext().logManager().getLog(PeerState.class);
   final Peer peer;
@@ -201,13 +207,28 @@ class PeerState
         return;
       }
 
+    if (_log.shouldLog(Log.INFO))
+      _log.info("Queueing (" + piece + ", " + begin + ", "
+                + length + ")" + " to " + peer);
+
+    // don't load the data into mem now, let PeerConnectionOut do it
+    out.sendPiece(piece, begin, length, this);
+  }
+
+  /**
+   *  This is the callback that PeerConnectionOut calls
+   *
+   *  @return bytes or null for errors
+   *  @since 0.8.2
+   */
+  public byte[] loadData(int piece, int begin, int length) {
     byte[] pieceBytes = listener.gotRequest(peer, piece, begin, length);
     if (pieceBytes == null)
       {
         // XXX - Protocol error-> diconnect?
         if (_log.shouldLog(Log.WARN))
           _log.warn("Got request for unknown piece: " + piece);
-        return;
+        return null;
       }
 
     // More sanity checks
@@ -219,13 +240,13 @@ class PeerState
                       + ", " + begin
                       + ", " + length
                       + "' message from " + peer);
-        return;
+        return null;
       }
 
     if (_log.shouldLog(Log.INFO))
       _log.info("Sending (" + piece + ", " + begin + ", "
                 + length + ")" + " to " + peer);
-    out.sendPiece(piece, begin, length, pieceBytes);
+    return pieceBytes;
   }
 
   /**
@@ -413,6 +434,24 @@ class PeerState
     out.cancelRequest(piece, begin, length);
   }
 
+  /** @since 0.8.2 */
+  void extensionMessage(int id, byte[] bs)
+  {
+      if (id == 0) {
+          InputStream is = new ByteArrayInputStream(bs);
+          try {
+              BDecoder dec = new BDecoder(is);
+              BEValue bev = dec.bdecodeMap();
+              Map map = bev.getMap();
+              if (_log.shouldLog(Log.DEBUG))
+                  _log.debug("Got extension handshake message " + bev.toString());
+          } catch (Exception e) {}
+      } else {
+          if (_log.shouldLog(Log.DEBUG))
+              _log.debug("Got extended message type: " + id + " length: " + bs.length);
+      }
+  }
+
   void unknownMessage(int type, byte[] bs)
   {
     if (_log.shouldLog(Log.WARN))