Request pieces in rarest-first order, instead of randomly.

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

@@ -0,0 +1,35 @@
+package org.klomp.snark;
+
+import java.util.Set;
+import java.util.HashSet;
+
+public class Piece implements Comparable {
+
+    private int id;
+    private Set peers;
+    private boolean requested;
+    
+    public Piece(int id) {
+        this.id = id;
+        this.peers = new HashSet();
+    }
+    
+    public int compareTo(Object o) throws ClassCastException {
+        return this.peers.size() - ((Piece)o).peers.size();
+    }
+    
+    public boolean equals(Object o) {
+        if (o == null) return false;
+        try {
+            return this.id == ((Piece)o).id;
+        } catch (ClassCastException cce) {
+            return false;
+        }
+    }
+    
+    public int getId() { return this.id; }
+    public Set getPeers() { return this.peers; }
+    public boolean addPeer(Peer peer) { return this.peers.add(peer.getPeerID()); }
+    public boolean isRequested() { return this.requested; }
+    public void setRequested(boolean requested) { this.requested = requested; } 
+}