js/ccnxProtocol/components/ccnxProtocolService.js - ndn-js - Gitiles

 /*
  * @author: ucla-cs
  * See COPYING for copyright and distribution information.
  * This is the ccnx protocol handler for NDN.
  * Protocol handling code derived from http://mike.kaply.com/2011/01/18/writing-a-firefox-protocol-handler/
  */

 const Cc = Components.classes;
 const Ci = Components.interfaces;
 const Cr = Components.results;

 const nsIProtocolHandler = Ci.nsIProtocolHandler;

 Components.utils.import("resource://gre/modules/XPCOMUtils.jsm");
 Components.utils.import("chrome://modules/content/ndn-js.jsm");
 Components.utils.import("chrome://modules/content/ContentChannel.jsm");

 function CcnxProtocol() {
 }

 CcnxProtocol.prototype = {
     scheme: "ccnx",
     protocolFlags: nsIProtocolHandler.URI_NORELATIVE |
                    nsIProtocolHandler.URI_NOAUTH |
                    nsIProtocolHandler.URI_LOADABLE_BY_ANYONE,

     newURI: function(aSpec, aOriginCharset, aBaseURI)
     {
         var uri = Cc["@mozilla.org/network/simple-uri;1"].createInstance(Ci.nsIURI);
         uri.spec = aSpec;
         return uri;
     },

     newChannel: function(aURI)
     {
         try {
             var trimmedSpec = aURI.spec.trim();

             var contentChannel;
             var requestContent = function(contentListener) {
                 // Set nameString to the URI without the protocol.
                 var nameString = trimmedSpec;
                 var colonIndex = nameString.indexOf(':');
                 if (colonIndex >= 0)
                     nameString = nameString.substr
                         (colonIndex + 1, nameString.length - colonIndex - 1).trim();

                 var name = new Name(nameString);
                 // TODO: Strip off an ending implicit digest before checking the last component?
                 var uriEndsWithSegmentNumber = endsWithSegmentNumber(name);

                 var ndn = new NDN("lioncub.metwi.ucla.edu");
                 ndn.expressInterest(name, new ContentClosure
                     (ndn, contentListener, uriEndsWithSegmentNumber, aURI.originCharset));
             };

             contentChannel = new ContentChannel(aURI, requestContent);
             return contentChannel;
         } catch (ex) {
             dump("CcnxProtocol.newChannel exception: " + ex + "\n");
         }
     },

     classDescription: "ccnx Protocol Handler",
     contractID: "@mozilla.org/network/protocol;1?name=" + "ccnx",
     classID: Components.ID('{8122e660-1012-11e2-892e-0800200c9a66}'),
     QueryInterface: XPCOMUtils.generateQI([Ci.nsIProtocolHandler])
 }

 if (XPCOMUtils.generateNSGetFactory)
     var NSGetFactory = XPCOMUtils.generateNSGetFactory([CcnxProtocol]);
 else
     var NSGetModule = XPCOMUtils.generateNSGetModule([CcnxProtocol]);

 /*
  * Create a closure for calling expressInterest.
  * contentListener is from the call to requestContent.
  * uriEndsWithSegmentNumber is true if the URI passed to newChannel has a segment number
  *    (used to determine whether to request only that segment number and for updating the URL bar).
  * uriOriginCharset is the charset of the URI passed to newChannel (used for making a new URI)
  */
 var ContentClosure = function ContentClosure
         (ndn, contentListener, uriEndsWithSegmentNumber, uriOriginCharset) {
     // Inherit from Closure.
     Closure.call(this);

     this.ndn = ndn;
     this.contentListener = contentListener;
     this.uriEndsWithSegmentNumber = uriEndsWithSegmentNumber;
     this.uriOriginCharset = uriOriginCharset;
     this.firstReceivedSegmentNumber = null;
     this.firstReceivedContentObject = null;
 }

 ContentClosure.prototype.upcall = function(kind, upcallInfo) {
     if (!(kind == Closure.UPCALL_CONTENT ||
           kind == Closure.UPCALL_CONTENT_UNVERIFIED))
         // The upcall is not for us.
         return Closure.RESULT_ERR;

     var contentObject = upcallInfo.contentObject;
     if (contentObject.content == null) {
         dump("CcnxProtocol.ContentClosure: contentObject.content is null\n");
         return Closure.RESULT_ERR;
     }

     // If !this.uriEndsWithSegmentNumber, we use the segmentNumber to load multiple segments.
     var segmentNumber = null;
     if (!this.uriEndsWithSegmentNumber && endsWithSegmentNumber(contentObject.name)) {
         segmentNumber = DataUtils.bigEndianToUnsignedInt
             (contentObject.name.components[contentObject.name.components.length - 1]);
         if (this.firstReceivedSegmentNumber == null) {
             // This is the first call.
             this.firstReceivedSegmentNumber = segmentNumber;
             if (segmentNumber != 0) {
                 // Special case: Save this content object for later and request segment zero.
                 this.firstReceivedContentObject = contentObject;
                 var componentsForZero = contentObject.name.components.slice
                     (0, contentObject.name.components.length - 1);
                 componentsForZero.push([0]);
                 this.ndn.expressInterest(new Name(componentsForZero), this);
                 return Closure.RESULT_OK;
             }
         }
     }

     if (this.uriEndsWithSegmentNumber || segmentNumber == null || segmentNumber == 0) {
         // This is the first or only segment, so start.
         // Get the URI from the ContentObject including the version.
         var contentUriSpec;
         if (!this.uriEndsWithSegmentNumber && endsWithSegmentNumber(contentObject.name)) {
             var nameWithoutSegmentNumber = new Name
                 (contentObject.name.components.slice
                  (0, contentObject.name.components.length - 1));
             contentUriSpec = "ccnx:" + nameWithoutSegmentNumber.to_uri();
         }
         else
             contentUriSpec = "ccnx:" + contentObject.name.to_uri();

         var contentTypeEtc = getNameContentTypeAndCharset(contentObject.name);
         var ioService = Cc["@mozilla.org/network/io-service;1"].getService(Ci.nsIIOService);
         this.contentListener.onStart(contentTypeEtc.contentType, contentTypeEtc.contentCharset,
             ioService.newURI(contentUriSpec, this.uriOriginCharset, null));
     }

     this.contentListener.onReceivedContent(DataUtils.toString(contentObject.content));

     // Check for the special case if the saved content is for the next segment that we need.
     if (this.firstReceivedContentObject != null &&
         this.firstReceivedSegmentNumber == segmentNumber + 1) {
         // Substitute the saved contentObject send its content and keep going.
         contentObject = this.firstReceivedContentObject;
         segmentNumber = segmentNumber + 1;
         // Clear firstReceivedContentObject to save memory.
         this.firstReceivedContentObject = null;

         this.contentListener.onReceivedContent(DataUtils.toString(contentObject.content));
     }

     var finalSegmentNumber = null;
     if (contentObject.signedInfo != null && contentObject.signedInfo.finalBlockID != null)
         finalSegmentNumber = DataUtils.bigEndianToUnsignedInt(contentObject.signedInfo.finalBlockID);

     if (!this.uriEndsWithSegmentNumber &&
         segmentNumber != null &&
         (finalSegmentNumber == null || segmentNumber != finalSegmentNumber)) {
         // Make a name for the next segment and get it.
         var segmentNumberPlus1 = DataUtils.nonNegativeIntToBigEndian(segmentNumber + 1);
         // Put a 0 byte in front.
         var nextSegmentNumber = new Uint8Array(segmentNumberPlus1.length + 1);
         nextSegmentNumber.set(segmentNumberPlus1, 1);

         // TODO: When Name uses Uint8Array, we don't need a byte array.
         var nextSegmentNumberByteArray = [];
         for (var i = 0; i < nextSegmentNumber.length; ++i)
             nextSegmentNumberByteArray.push(nextSegmentNumber[i]);

         var components = contentObject.name.components.slice
             (0, contentObject.name.components.length - 1);
         components.push(nextSegmentNumberByteArray);
         this.ndn.expressInterest(new Name(components), this);
     }
     else
         // Finished.
         this.contentListener.onStop();

     return Closure.RESULT_OK;
 };


 /*
  * Scan the name from the last component to the first (skipping special CCNx components)
  *   for a recognized file name extension, and return an object with properties contentType and charset.
  */
 function getNameContentTypeAndCharset(name) {
     var filename = "";
     for (var i = name.components.length - 1; i >= 0; --i) {
         var component = name.components[i];
         if (component.length <= 0)
             continue;

         // Skip special components which just may have ".gif", etc.
         if (component[0] == 0 || component[0] == 0xC0 || component[0] == 0xC1 ||
             (component[0] >= 0xF5 && component[0] <= 0xFF))
             continue;

         filename = DataUtils.toString(component).toLowerCase();
         break;
     }

     return MimeTypes.getContentTypeAndCharset(filename);
 }

 /*
  * Return true if the last component in the name is a segment number..
  */
 function endsWithSegmentNumber(name) {
     return name.components != null && name.components.length >= 1 &&
         name.components[name.components.length - 1].length >= 1 &&
         name.components[name.components.length - 1][0] == 0;
 }
	/*
	* @author: ucla-cs
	* See COPYING for copyright and distribution information.
	* This is the ccnx protocol handler for NDN.
	* Protocol handling code derived from http://mike.kaply.com/2011/01/18/writing-a-firefox-protocol-handler/
	*/

	const Cc = Components.classes;
	const Ci = Components.interfaces;
	const Cr = Components.results;

	const nsIProtocolHandler = Ci.nsIProtocolHandler;

	Components.utils.import("resource://gre/modules/XPCOMUtils.jsm");
	Components.utils.import("chrome://modules/content/ndn-js.jsm");
	Components.utils.import("chrome://modules/content/ContentChannel.jsm");

	function CcnxProtocol() {
	}

	CcnxProtocol.prototype = {
	scheme: "ccnx",
	protocolFlags: nsIProtocolHandler.URI_NORELATIVE \|
	nsIProtocolHandler.URI_NOAUTH \|
	nsIProtocolHandler.URI_LOADABLE_BY_ANYONE,

	newURI: function(aSpec, aOriginCharset, aBaseURI)
	{
	var uri = Cc["@mozilla.org/network/simple-uri;1"].createInstance(Ci.nsIURI);
	uri.spec = aSpec;
	return uri;
	},

	newChannel: function(aURI)
	{
	try {
	var trimmedSpec = aURI.spec.trim();

	var contentChannel;
	var requestContent = function(contentListener) {
	// Set nameString to the URI without the protocol.
	var nameString = trimmedSpec;
	var colonIndex = nameString.indexOf(':');
	if (colonIndex >= 0)
	nameString = nameString.substr
	(colonIndex + 1, nameString.length - colonIndex - 1).trim();

	var name = new Name(nameString);
	// TODO: Strip off an ending implicit digest before checking the last component?
	var uriEndsWithSegmentNumber = endsWithSegmentNumber(name);

	var ndn = new NDN("lioncub.metwi.ucla.edu");
	ndn.expressInterest(name, new ContentClosure
	(ndn, contentListener, uriEndsWithSegmentNumber, aURI.originCharset));
	};

	contentChannel = new ContentChannel(aURI, requestContent);
	return contentChannel;
	} catch (ex) {
	dump("CcnxProtocol.newChannel exception: " + ex + "\n");
	}
	},

	classDescription: "ccnx Protocol Handler",
	contractID: "@mozilla.org/network/protocol;1?name=" + "ccnx",
	classID: Components.ID('{8122e660-1012-11e2-892e-0800200c9a66}'),
	QueryInterface: XPCOMUtils.generateQI([Ci.nsIProtocolHandler])
	}

	if (XPCOMUtils.generateNSGetFactory)
	var NSGetFactory = XPCOMUtils.generateNSGetFactory([CcnxProtocol]);
	else
	var NSGetModule = XPCOMUtils.generateNSGetModule([CcnxProtocol]);

	/*
	* Create a closure for calling expressInterest.
	* contentListener is from the call to requestContent.
	* uriEndsWithSegmentNumber is true if the URI passed to newChannel has a segment number
	* (used to determine whether to request only that segment number and for updating the URL bar).
	* uriOriginCharset is the charset of the URI passed to newChannel (used for making a new URI)
	*/
	var ContentClosure = function ContentClosure
	(ndn, contentListener, uriEndsWithSegmentNumber, uriOriginCharset) {
	// Inherit from Closure.
	Closure.call(this);

	this.ndn = ndn;
	this.contentListener = contentListener;
	this.uriEndsWithSegmentNumber = uriEndsWithSegmentNumber;
	this.uriOriginCharset = uriOriginCharset;
	this.firstReceivedSegmentNumber = null;
	this.firstReceivedContentObject = null;
	}

	ContentClosure.prototype.upcall = function(kind, upcallInfo) {
	if (!(kind == Closure.UPCALL_CONTENT \|\|
	kind == Closure.UPCALL_CONTENT_UNVERIFIED))
	// The upcall is not for us.
	return Closure.RESULT_ERR;

	var contentObject = upcallInfo.contentObject;
	if (contentObject.content == null) {
	dump("CcnxProtocol.ContentClosure: contentObject.content is null\n");
	return Closure.RESULT_ERR;
	}

	// If !this.uriEndsWithSegmentNumber, we use the segmentNumber to load multiple segments.
	var segmentNumber = null;
	if (!this.uriEndsWithSegmentNumber && endsWithSegmentNumber(contentObject.name)) {
	segmentNumber = DataUtils.bigEndianToUnsignedInt
	(contentObject.name.components[contentObject.name.components.length - 1]);
	if (this.firstReceivedSegmentNumber == null) {
	// This is the first call.
	this.firstReceivedSegmentNumber = segmentNumber;
	if (segmentNumber != 0) {
	// Special case: Save this content object for later and request segment zero.
	this.firstReceivedContentObject = contentObject;
	var componentsForZero = contentObject.name.components.slice
	(0, contentObject.name.components.length - 1);
	componentsForZero.push([0]);
	this.ndn.expressInterest(new Name(componentsForZero), this);
	return Closure.RESULT_OK;
	}
	}
	}

	if (this.uriEndsWithSegmentNumber \|\| segmentNumber == null \|\| segmentNumber == 0) {
	// This is the first or only segment, so start.
	// Get the URI from the ContentObject including the version.
	var contentUriSpec;
	if (!this.uriEndsWithSegmentNumber && endsWithSegmentNumber(contentObject.name)) {
	var nameWithoutSegmentNumber = new Name
	(contentObject.name.components.slice
	(0, contentObject.name.components.length - 1));
	contentUriSpec = "ccnx:" + nameWithoutSegmentNumber.to_uri();
	}
	else
	contentUriSpec = "ccnx:" + contentObject.name.to_uri();

	var contentTypeEtc = getNameContentTypeAndCharset(contentObject.name);
	var ioService = Cc["@mozilla.org/network/io-service;1"].getService(Ci.nsIIOService);
	this.contentListener.onStart(contentTypeEtc.contentType, contentTypeEtc.contentCharset,
	ioService.newURI(contentUriSpec, this.uriOriginCharset, null));
	}

	this.contentListener.onReceivedContent(DataUtils.toString(contentObject.content));

	// Check for the special case if the saved content is for the next segment that we need.
	if (this.firstReceivedContentObject != null &&
	this.firstReceivedSegmentNumber == segmentNumber + 1) {
	// Substitute the saved contentObject send its content and keep going.
	contentObject = this.firstReceivedContentObject;
	segmentNumber = segmentNumber + 1;
	// Clear firstReceivedContentObject to save memory.
	this.firstReceivedContentObject = null;

	this.contentListener.onReceivedContent(DataUtils.toString(contentObject.content));
	}

	var finalSegmentNumber = null;
	if (contentObject.signedInfo != null && contentObject.signedInfo.finalBlockID != null)
	finalSegmentNumber = DataUtils.bigEndianToUnsignedInt(contentObject.signedInfo.finalBlockID);

	if (!this.uriEndsWithSegmentNumber &&
	segmentNumber != null &&
	(finalSegmentNumber == null \|\| segmentNumber != finalSegmentNumber)) {
	// Make a name for the next segment and get it.
	var segmentNumberPlus1 = DataUtils.nonNegativeIntToBigEndian(segmentNumber + 1);
	// Put a 0 byte in front.
	var nextSegmentNumber = new Uint8Array(segmentNumberPlus1.length + 1);
	nextSegmentNumber.set(segmentNumberPlus1, 1);

	// TODO: When Name uses Uint8Array, we don't need a byte array.
	var nextSegmentNumberByteArray = [];
	for (var i = 0; i < nextSegmentNumber.length; ++i)
	nextSegmentNumberByteArray.push(nextSegmentNumber[i]);

	var components = contentObject.name.components.slice
	(0, contentObject.name.components.length - 1);
	components.push(nextSegmentNumberByteArray);
	this.ndn.expressInterest(new Name(components), this);
	}
	else
	// Finished.
	this.contentListener.onStop();

	return Closure.RESULT_OK;
	};


	/*
	* Scan the name from the last component to the first (skipping special CCNx components)
	* for a recognized file name extension, and return an object with properties contentType and charset.
	*/
	function getNameContentTypeAndCharset(name) {
	var filename = "";
	for (var i = name.components.length - 1; i >= 0; --i) {
	var component = name.components[i];
	if (component.length <= 0)
	continue;

	// Skip special components which just may have ".gif", etc.
	if (component[0] == 0 \|\| component[0] == 0xC0 \|\| component[0] == 0xC1 \|\|
	(component[0] >= 0xF5 && component[0] <= 0xFF))
	continue;

	filename = DataUtils.toString(component).toLowerCase();
	break;
	}

	return MimeTypes.getContentTypeAndCharset(filename);
	}

	/*
	* Return true if the last component in the name is a segment number..
	*/
	function endsWithSegmentNumber(name) {
	return name.components != null && name.components.length >= 1 &&
	name.components[name.components.length - 1].length >= 1 &&
	name.components[name.components.length - 1][0] == 0;
	}