Cache X11 extensions

lib/xcore.js

@@ -114,6 +114,7 @@ XClient.prototype.init = function(stream)
     this.event_consumers = {}; // maps window id to eventemitter TODO: bad name
     this.eventParsers = {};
     this.errorParsers = {};
+    this._extensions = {};
 
     this.importRequestsFromTemplates(this, coreRequests);
 
@@ -553,9 +554,24 @@ XClient.prototype.startHandshake = function() {
 
 XClient.prototype.require = function(extName, callback)
 {
-   var ext = require('./ext/' + extName);
-   ext.requireExt(this.display, callback);
-}
+   var self = this;
+   var ext = this._extensions[extName];
+   if (ext) {
+       return process.nextTick(function() {
+           callback(null, ext);
+       });
+   }
+
+   ext = require('./ext/' + extName);
+   ext.requireExt(this.display, function(err, _ext) {
+       if (err) {
+           return callback(err);
+       }
+
+       self._extensions[extName] = _ext;
+       callback(null, _ext);
+   });
+};
 
 module.exports.createClient = function(options, initCb)
 {

test/cache-extensions.js

@@ -0,0 +1,34 @@
+var x11 = require('../lib');
+var should = require('should');
+
+describe('requiring an X11 extension on same connection', function() {
+    before(function(done) {
+        var self = this;
+        var client = x11.createClient(function(err, dpy) {
+            should.not.exist(err);
+            self.X = dpy.client;
+            done();
+        });
+
+        client.on('error', function (err) {
+            console.error('Error : ', err);
+        });
+    });
+
+    it('should be cached', function(done) {
+        var self = this;
+        this.X.require('xtest', function(err, randr) {
+            should.not.exist(err);
+            self.X.require('xtest', function(err, randr1) {
+                should.not.exist(err);
+                randr.should.equal(randr1);
+                done();
+            });
+        });
+    });
+
+    after(function(done) {
+        this.X.terminate();
+        this.X.on('end', done);
+    });
+});