Change XpcomTransport to use a single socket connection and the NDN PITTable.
diff --git a/js/XpcomTransport.js b/js/XpcomTransport.js
index 42273f2..57f9dd9 100644
--- a/js/XpcomTransport.js
+++ b/js/XpcomTransport.js
@@ -9,61 +9,183 @@
 // Components.utils.import("resource://gre/modules/XPCOMUtils.jsm");
 // Components.utils.import("resource://gre/modules/NetUtil.jsm");
 
-var XpcomTransport = function XpcomTransport() { 
+var XpcomTransport = function XpcomTransport() {
+    this.ndn = null;
+    this.socket = null; // nsISocketTransport
+    this.outStream = null;
+    this.connectedHost = null;
+    this.connectedPort = null;
+    
     this.defaultGetHostAndPort = NDN.makeShuffledGetHostAndPort
         (["A.hub.ndn.ucla.edu", "B.hub.ndn.ucla.edu", "C.hub.ndn.ucla.edu", "D.hub.ndn.ucla.edu", 
           "E.hub.ndn.ucla.edu", "F.hub.ndn.ucla.edu", "G.hub.ndn.ucla.edu", "H.hub.ndn.ucla.edu"],
          9695);
 };
 
-XpcomTransport.prototype.expressInterest = function(ndn, interest, closure) {
-    var binaryInterest = encodeToBinaryInterest(interest);
+/*
+ * Connect to the host and port in ndn.  This replaces a previous connection.
+ * Listen on the port to read an entire binary XML encoded response and call
+ *    listener.onReceivedData(data) where data is Uint8Array.
+ */
+XpcomTransport.prototype.connect = function(ndn, listener) {
+    if (this.socket != null) {
+        try {
+            this.socket.close(0);
+        } catch (ex) {
+			console.log("XpcomTransport socket.close exception: " + ex);
+		}
+        this.socket = null;
+    }
+    this.ndn = ndn;
+
+	var transportService = Components.classes["@mozilla.org/network/socket-transport-service;1"].getService
+        (Components.interfaces.nsISocketTransportService);
+	var pump = Components.classes["@mozilla.org/network/input-stream-pump;1"].createInstance
+        (Components.interfaces.nsIInputStreamPump);
+	this.socket = transportService.createTransport(null, 0, ndn.host, ndn.port, null);
+    this.connectedHost = ndn.host;
+    this.connectedPort = ndn.port;
+    this.outStream = this.socket.openOutputStream(1, 0, 0);
+
+    var inStream = this.socket.openInputStream(0, 0, 0);
+	var dataListener = {
+		dataParts: [],
+        structureDecoder: new BinaryXMLStructureDecoder(),
+		
+		onStartRequest: function (request, context) {
+		},
+		onStopRequest: function (request, context, status) {
+		},
+		onDataAvailable: function (request, context, _inputStream, offset, count) {
+			try {
+				// Use readInputStreamToString to handle binary data.
+                // TODO: Can we go directly from the stream to Uint8Array?
+				var rawData = DataUtils.toNumbersFromString
+                    (NetUtil.readInputStreamToString(inStream, count));
+				
+                // Process multiple objects in this packet.
+                while(true) {
+                    // Scan the input to check if a whole ccnb object has been read.
+                    this.structureDecoder.seek(0);
+                    if (this.structureDecoder.findElementEnd(rawData)) {
+                        // Got the remainder of an object.  Report to the caller.
+                        this.dataParts.push(rawData.subarray(0, this.structureDecoder.offset));
+                        listener.onReceivedData(DataUtils.concatArrays(this.dataParts));
+                    
+                        // Need to read a new object.
+                        rawData = rawData.subarray(this.structureDecoder.offset, rawData.length);
+                        this.dataParts = [];
+                        this.structureDecoder = new BinaryXMLStructureDecoder();
+                        if (rawData.length == 0)
+                            // No more data in the packet.
+                            return;
+                        
+                        // else loop back to decode.
+                    }
+                    else {
+                        // Save for a later call to concatArrays so that we only copy data once.
+                        this.dataParts.push(rawData);
+                        return;
+                    }
+                }
+			} catch (ex) {
+				console.log("XpcomTransport.onDataAvailable exception: " + ex);
+			}
+		}
+    };
+	
+	pump.init(inStream, -1, -1, 0, 0, true);
+    pump.asyncRead(dataListener, null);
+};
+
+/*
+ * Send the data over the connection created by connect.
+ */
+XpcomTransport.prototype.send = function(/* Uint8Array */ data) {
+    if (this.socket == null) {
+        console.log("XpcomTransport connection is not established.");
+        return;
+    }
     
-    var dataListener = {
+    var rawDataString = DataUtils.toString(data);
+	this.outStream.write(rawDataString, rawDataString.length);
+	this.outStream.flush();
+};
+
+XpcomTransport.prototype.expressInterest = function(ndn, interest, closure) {
+    var thisXpcomTransport = this;
+    
+    if (this.socket == null || this.connectedHost != ndn.host || this.connectedPort != ndn.port) {
+      var dataListener = {
 		onReceivedData : function(data) {
 			if (data == null || data == undefined || data.length == 0)
-				dump("NDN.expressInterest: received empty data from socket.\n");
+				console.log("XpcomTransport: received empty data from socket.");
 			else {
                 var decoder = new BinaryXMLDecoder(data);
                 if (decoder.peekStartElement(CCNProtocolDTags.Interest)) {
-                    // TODO: handle interest
-                    if (closure.upcall(Closure.UPCALL_INTEREST, null) == Closure.RESULT_OK)
-                        // success
-                        return true;
+                    // TODO: handle interest properly.  For now, assume the only use in getting
+                    //   an interest is knowing that the host is alive from NDN.ccndIdFetcher.
+					var pitEntry = NDN.getEntryForExpressedInterest(NDN.ccndIdFetcher);
+					if (pitEntry != null) {
+						// Remove PIT entry from NDN.PITTable.
+						var index = NDN.PITTable.indexOf(pitEntry);
+						if (index >= 0)
+							NDN.PITTable.splice(index, 1);
+                        
+                        pitEntry.closure.upcall(Closure.UPCALL_INTEREST, null);
+                    }
                 }
                 else if (decoder.peekStartElement(CCNProtocolDTags.ContentObject)) {
                     var co = new ContentObject();
                     co.from_ccnb(decoder);
                    					
-                    // TODO: verify the content object and set kind to UPCALL_CONTENT.
-                    var result = closure.upcall(Closure.UPCALL_CONTENT_UNVERIFIED,
-                               new UpcallInfo(ndn, interest, 0, co));
-                    if (result == Closure.RESULT_OK)
-                        // success
-                        return true;
-                    else if (result == Closure.RESULT_ERR)
-                        dump("NDN.expressInterest: upcall returned RESULT_ERR.\n");
-                    else if (result == Closure.RESULT_REEXPRESS) {
-                        XpcomTransport.readAllFromSocket(ndn.host, ndn.port, binaryInterest, dataListener);
-                        return true;
+					var pitEntry = NDN.getEntryForExpressedInterest(co.name);
+					if (pitEntry != null) {
+						// Remove PIT entry from NDN.PITTable.
+                        // TODO: This needs to be a single thread-safe transaction.
+						var index = NDN.PITTable.indexOf(pitEntry);
+						if (index >= 0)
+							NDN.PITTable.splice(index, 1);
                     }
-                    else if (result == Closure.RESULT_VERIFY) {
-                        // TODO: force verification of content.
-                    }
-                    else if (result == Closure.RESULT_FETCHKEY) {
-                        // TODO: get the key in the key locator and re-call the interest
-                        //   with the key available in the local storage.
+   					if (pitEntry != null) {
+						var currentClosure = pitEntry.closure;
+                        
+                        // TODO: verify the content object and set kind to UPCALL_CONTENT.
+                        var result = currentClosure.upcall(Closure.UPCALL_CONTENT_UNVERIFIED,
+                                    new UpcallInfo(thisXpcomTransport.ndn, null, 0, co));
+                        if (result == Closure.RESULT_OK) {
+                            // success
+                        }
+                        else if (result == Closure.RESULT_ERR)
+                            console.log("XpcomTransport: upcall returned RESULT_ERR.");
+                        else if (result == Closure.RESULT_REEXPRESS) {
+                            // TODO: Handl re-express interest.
+                        }
+                        else if (result == Closure.RESULT_VERIFY) {
+                            // TODO: force verification of content.
+                        }
+                        else if (result == Closure.RESULT_FETCHKEY) {
+                            // TODO: get the key in the key locator and re-call the interest
+                            //   with the key available in the local storage.
+                        }
                     }
                 }
                 else
                     console.log('Incoming packet is not Interest or ContentObject. Discard now.');
 			}
-            
-            return false;
 		}
-	}    
+	  }
+      
+      this.connect(ndn, dataListener);
+    }
     
-	XpcomTransport.readAllFromSocket(ndn.host, ndn.port, binaryInterest, dataListener);
+    var binaryInterest = encodeToBinaryInterest(interest);
+    
+                        // TODO: This needs to be a single thread-safe transaction.
+	var pitEntry = new PITEntry(interest, closure);
+	NDN.PITTable.push(pitEntry);
+
+    this.send(binaryInterest);
 };
 
 /** Send outputData (Uint8Array) to host:port, read the entire response and call 
@@ -71,16 +193,16 @@
  *    false if need to keep reading.
  *  Code derived from http://stackoverflow.com/questions/7816386/why-nsiscriptableinputstream-is-not-working .
  */
+ /*
 XpcomTransport.readAllFromSocket = function(host, port, outputData, listener) {
 	var transportService = Components.classes["@mozilla.org/network/socket-transport-service;1"].getService
         (Components.interfaces.nsISocketTransportService);
-	var pump = Components.classes["@mozilla.org/network/input-stream-pump;1"].createInstance
-        (Components.interfaces.nsIInputStreamPump);
 	var transport = transportService.createTransport(null, 0, host, port, null);
 	var outStream = transport.openOutputStream(1, 0, 0);
     var rawDataString = DataUtils.toString(outputData);
 	outStream.write(rawDataString, rawDataString.length);
 	outStream.flush();
+    outStream.close();
 	var inStream = transport.openInputStream(0, 0, 0);
 	var dataListener = {
 		dataParts: [],
@@ -91,7 +213,6 @@
 		},
 		onStopRequest: function (request, context, status) {
 			inStream.close();
-			outStream.close();
 		},
 		onDataAvailable: function (request, context, _inputStream, offset, count) {
             if (this.dataIsConsumed)
@@ -134,12 +255,15 @@
                     }
                 }
 			} catch (ex) {
-				dump("readAllFromSocket.onDataAvailable exception: " + ex + "\n");
+				console.log("readAllFromSocket.onDataAvailable exception: " + ex);
 			}
 		}
     };
 	
+	var pump = Components.classes["@mozilla.org/network/input-stream-pump;1"].createInstance
+        (Components.interfaces.nsIInputStreamPump);
 	pump.init(inStream, -1, -1, 0, 0, true);
     pump.asyncRead(dataListener, null);
 }
+*/
 
diff --git a/js/ndnProtocol.xpi b/js/ndnProtocol.xpi
index 5449945..2b880b0 100644
--- a/js/ndnProtocol.xpi
+++ b/js/ndnProtocol.xpi
Binary files differ
diff --git a/js/ndnProtocol/modules/ndn-js.jsm b/js/ndnProtocol/modules/ndn-js.jsm
index ab41f5e..32705a3 100644
--- a/js/ndnProtocol/modules/ndn-js.jsm
+++ b/js/ndnProtocol/modules/ndn-js.jsm
@@ -317,61 +317,183 @@
 // Components.utils.import("resource://gre/modules/XPCOMUtils.jsm");
 // Components.utils.import("resource://gre/modules/NetUtil.jsm");
 
-var XpcomTransport = function XpcomTransport() { 
+var XpcomTransport = function XpcomTransport() {
+    this.ndn = null;
+    this.socket = null; // nsISocketTransport
+    this.outStream = null;
+    this.connectedHost = null;
+    this.connectedPort = null;
+    
     this.defaultGetHostAndPort = NDN.makeShuffledGetHostAndPort
         (["A.hub.ndn.ucla.edu", "B.hub.ndn.ucla.edu", "C.hub.ndn.ucla.edu", "D.hub.ndn.ucla.edu", 
           "E.hub.ndn.ucla.edu", "F.hub.ndn.ucla.edu", "G.hub.ndn.ucla.edu", "H.hub.ndn.ucla.edu"],
          9695);
 };
 
-XpcomTransport.prototype.expressInterest = function(ndn, interest, closure) {
-    var binaryInterest = encodeToBinaryInterest(interest);
+/*
+ * Connect to the host and port in ndn.  This replaces a previous connection.
+ * Listen on the port to read an entire binary XML encoded response and call
+ *    listener.onReceivedData(data) where data is Uint8Array.
+ */
+XpcomTransport.prototype.connect = function(ndn, listener) {
+    if (this.socket != null) {
+        try {
+            this.socket.close(0);
+        } catch (ex) {
+			console.log("XpcomTransport socket.close exception: " + ex);
+		}
+        this.socket = null;
+    }
+    this.ndn = ndn;
+
+	var transportService = Components.classes["@mozilla.org/network/socket-transport-service;1"].getService
+        (Components.interfaces.nsISocketTransportService);
+	var pump = Components.classes["@mozilla.org/network/input-stream-pump;1"].createInstance
+        (Components.interfaces.nsIInputStreamPump);
+	this.socket = transportService.createTransport(null, 0, ndn.host, ndn.port, null);
+    this.connectedHost = ndn.host;
+    this.connectedPort = ndn.port;
+    this.outStream = this.socket.openOutputStream(1, 0, 0);
+
+    var inStream = this.socket.openInputStream(0, 0, 0);
+	var dataListener = {
+		dataParts: [],
+        structureDecoder: new BinaryXMLStructureDecoder(),
+		
+		onStartRequest: function (request, context) {
+		},
+		onStopRequest: function (request, context, status) {
+		},
+		onDataAvailable: function (request, context, _inputStream, offset, count) {
+			try {
+				// Use readInputStreamToString to handle binary data.
+                // TODO: Can we go directly from the stream to Uint8Array?
+				var rawData = DataUtils.toNumbersFromString
+                    (NetUtil.readInputStreamToString(inStream, count));
+				
+                // Process multiple objects in this packet.
+                while(true) {
+                    // Scan the input to check if a whole ccnb object has been read.
+                    this.structureDecoder.seek(0);
+                    if (this.structureDecoder.findElementEnd(rawData)) {
+                        // Got the remainder of an object.  Report to the caller.
+                        this.dataParts.push(rawData.subarray(0, this.structureDecoder.offset));
+                        listener.onReceivedData(DataUtils.concatArrays(this.dataParts));
+                    
+                        // Need to read a new object.
+                        rawData = rawData.subarray(this.structureDecoder.offset, rawData.length);
+                        this.dataParts = [];
+                        this.structureDecoder = new BinaryXMLStructureDecoder();
+                        if (rawData.length == 0)
+                            // No more data in the packet.
+                            return;
+                        
+                        // else loop back to decode.
+                    }
+                    else {
+                        // Save for a later call to concatArrays so that we only copy data once.
+                        this.dataParts.push(rawData);
+                        return;
+                    }
+                }
+			} catch (ex) {
+				console.log("XpcomTransport.onDataAvailable exception: " + ex);
+			}
+		}
+    };
+	
+	pump.init(inStream, -1, -1, 0, 0, true);
+    pump.asyncRead(dataListener, null);
+};
+
+/*
+ * Send the data over the connection created by connect.
+ */
+XpcomTransport.prototype.send = function(/* Uint8Array */ data) {
+    if (this.socket == null) {
+        console.log("XpcomTransport connection is not established.");
+        return;
+    }
     
-    var dataListener = {
+    var rawDataString = DataUtils.toString(data);
+	this.outStream.write(rawDataString, rawDataString.length);
+	this.outStream.flush();
+};
+
+XpcomTransport.prototype.expressInterest = function(ndn, interest, closure) {
+    var thisXpcomTransport = this;
+    
+    if (this.socket == null || this.connectedHost != ndn.host || this.connectedPort != ndn.port) {
+      var dataListener = {
 		onReceivedData : function(data) {
 			if (data == null || data == undefined || data.length == 0)
-				dump("NDN.expressInterest: received empty data from socket.\n");
+				console.log("XpcomTransport: received empty data from socket.");
 			else {
                 var decoder = new BinaryXMLDecoder(data);
                 if (decoder.peekStartElement(CCNProtocolDTags.Interest)) {
-                    // TODO: handle interest
-                    if (closure.upcall(Closure.UPCALL_INTEREST, null) == Closure.RESULT_OK)
-                        // success
-                        return true;
+                    // TODO: handle interest properly.  For now, assume the only use in getting
+                    //   an interest is knowing that the host is alive from NDN.ccndIdFetcher.
+					var pitEntry = NDN.getEntryForExpressedInterest(NDN.ccndIdFetcher);
+					if (pitEntry != null) {
+						// Remove PIT entry from NDN.PITTable.
+						var index = NDN.PITTable.indexOf(pitEntry);
+						if (index >= 0)
+							NDN.PITTable.splice(index, 1);
+                        
+                        pitEntry.closure.upcall(Closure.UPCALL_INTEREST, null);
+                    }
                 }
                 else if (decoder.peekStartElement(CCNProtocolDTags.ContentObject)) {
                     var co = new ContentObject();
                     co.from_ccnb(decoder);
                    					
-                    // TODO: verify the content object and set kind to UPCALL_CONTENT.
-                    var result = closure.upcall(Closure.UPCALL_CONTENT_UNVERIFIED,
-                               new UpcallInfo(ndn, interest, 0, co));
-                    if (result == Closure.RESULT_OK)
-                        // success
-                        return true;
-                    else if (result == Closure.RESULT_ERR)
-                        dump("NDN.expressInterest: upcall returned RESULT_ERR.\n");
-                    else if (result == Closure.RESULT_REEXPRESS) {
-                        XpcomTransport.readAllFromSocket(ndn.host, ndn.port, binaryInterest, dataListener);
-                        return true;
+					var pitEntry = NDN.getEntryForExpressedInterest(co.name);
+					if (pitEntry != null) {
+						// Remove PIT entry from NDN.PITTable.
+                        // TODO: This needs to be a single thread-safe transaction.
+						var index = NDN.PITTable.indexOf(pitEntry);
+						if (index >= 0)
+							NDN.PITTable.splice(index, 1);
                     }
-                    else if (result == Closure.RESULT_VERIFY) {
-                        // TODO: force verification of content.
-                    }
-                    else if (result == Closure.RESULT_FETCHKEY) {
-                        // TODO: get the key in the key locator and re-call the interest
-                        //   with the key available in the local storage.
+   					if (pitEntry != null) {
+						var currentClosure = pitEntry.closure;
+                        
+                        // TODO: verify the content object and set kind to UPCALL_CONTENT.
+                        var result = currentClosure.upcall(Closure.UPCALL_CONTENT_UNVERIFIED,
+                                    new UpcallInfo(thisXpcomTransport.ndn, null, 0, co));
+                        if (result == Closure.RESULT_OK) {
+                            // success
+                        }
+                        else if (result == Closure.RESULT_ERR)
+                            console.log("XpcomTransport: upcall returned RESULT_ERR.");
+                        else if (result == Closure.RESULT_REEXPRESS) {
+                            // TODO: Handl re-express interest.
+                        }
+                        else if (result == Closure.RESULT_VERIFY) {
+                            // TODO: force verification of content.
+                        }
+                        else if (result == Closure.RESULT_FETCHKEY) {
+                            // TODO: get the key in the key locator and re-call the interest
+                            //   with the key available in the local storage.
+                        }
                     }
                 }
                 else
                     console.log('Incoming packet is not Interest or ContentObject. Discard now.');
 			}
-            
-            return false;
 		}
-	}    
+	  }
+      
+      this.connect(ndn, dataListener);
+    }
     
-	XpcomTransport.readAllFromSocket(ndn.host, ndn.port, binaryInterest, dataListener);
+    var binaryInterest = encodeToBinaryInterest(interest);
+    
+                        // TODO: This needs to be a single thread-safe transaction.
+	var pitEntry = new PITEntry(interest, closure);
+	NDN.PITTable.push(pitEntry);
+
+    this.send(binaryInterest);
 };
 
 /** Send outputData (Uint8Array) to host:port, read the entire response and call 
@@ -379,16 +501,16 @@
  *    false if need to keep reading.
  *  Code derived from http://stackoverflow.com/questions/7816386/why-nsiscriptableinputstream-is-not-working .
  */
+ /*
 XpcomTransport.readAllFromSocket = function(host, port, outputData, listener) {
 	var transportService = Components.classes["@mozilla.org/network/socket-transport-service;1"].getService
         (Components.interfaces.nsISocketTransportService);
-	var pump = Components.classes["@mozilla.org/network/input-stream-pump;1"].createInstance
-        (Components.interfaces.nsIInputStreamPump);
 	var transport = transportService.createTransport(null, 0, host, port, null);
 	var outStream = transport.openOutputStream(1, 0, 0);
     var rawDataString = DataUtils.toString(outputData);
 	outStream.write(rawDataString, rawDataString.length);
 	outStream.flush();
+    outStream.close();
 	var inStream = transport.openInputStream(0, 0, 0);
 	var dataListener = {
 		dataParts: [],
@@ -399,7 +521,6 @@
 		},
 		onStopRequest: function (request, context, status) {
 			inStream.close();
-			outStream.close();
 		},
 		onDataAvailable: function (request, context, _inputStream, offset, count) {
             if (this.dataIsConsumed)
@@ -442,14 +563,17 @@
                     }
                 }
 			} catch (ex) {
-				dump("readAllFromSocket.onDataAvailable exception: " + ex + "\n");
+				console.log("readAllFromSocket.onDataAvailable exception: " + ex);
 			}
 		}
     };
 	
+	var pump = Components.classes["@mozilla.org/network/input-stream-pump;1"].createInstance
+        (Components.interfaces.nsIInputStreamPump);
 	pump.init(inStream, -1, -1, 0, 0, true);
     pump.asyncRead(dataListener, null);
 }
+*/
 
 /*
  * This class defines MOME types based on the filename extension.