GUACAMOLE-377: Merge client-side support for frame tracking, RemoteFX parameter, and performance tracking extension.

extensions/guacamole-display-statistics/.gitignore

@@ -0,0 +1 @@
+src/main/resources/generated/

extensions/guacamole-display-statistics/.ratignore

@@ -0,0 +1 @@
+src/main/resources/html/*.html

extensions/guacamole-display-statistics/pom.xml

@@ -0,0 +1,124 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<!--
+    Licensed to the Apache Software Foundation (ASF) under one
+    or more contributor license agreements.  See the NOTICE file
+    distributed with this work for additional information
+    regarding copyright ownership.  The ASF licenses this file
+    to you under the Apache License, Version 2.0 (the
+    "License"); you may not use this file except in compliance
+    with the License.  You may obtain a copy of the License at
+
+      http://www.apache.org/licenses/LICENSE-2.0
+
+    Unless required by applicable law or agreed to in writing,
+    software distributed under the License is distributed on an
+    "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+    KIND, either express or implied.  See the License for the
+    specific language governing permissions and limitations
+    under the License.
+-->
+<project xmlns="http://maven.apache.org/POM/4.0.0"
+    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+    xsi:schemaLocation="http://maven.apache.org/POM/4.0.0
+                        http://maven.apache.org/maven-v4_0_0.xsd">
+
+    <modelVersion>4.0.0</modelVersion>
+    <groupId>org.apache.guacamole</groupId>
+    <artifactId>guacamole-display-statistics</artifactId>
+    <packaging>jar</packaging>
+    <version>1.4.0</version>
+    <name>guacamole-display-statistics</name>
+    <url>http://guacamole.apache.org/</url>
+
+    <parent>
+        <groupId>org.apache.guacamole</groupId>
+        <artifactId>extensions</artifactId>
+        <version>1.4.0</version>
+        <relativePath>../</relativePath>
+    </parent>
+
+    <build>
+        <plugins>
+
+            <!-- Pre-cache Angular templates with maven-angular-plugin -->
+            <plugin>
+                <groupId>com.keithbranton.mojo</groupId>
+                <artifactId>angular-maven-plugin</artifactId>
+                <version>0.3.4</version>
+                <executions>
+                    <execution>
+                        <phase>generate-resources</phase>
+                        <goals>
+                            <goal>html2js</goal>
+                        </goals>
+                    </execution>
+                </executions>
+                <configuration>
+                    <sourceDir>${basedir}/src/main/resources</sourceDir>
+                    <include>**/*.html</include>
+                    <target>${basedir}/src/main/resources/generated/templates-main/templates.js</target>
+                    <prefix>app/ext/display-stats</prefix>
+                </configuration>
+            </plugin>
+
+            <!-- JS/CSS Minification Plugin -->
+            <plugin>
+                <groupId>com.github.buckelieg</groupId>
+                <artifactId>minify-maven-plugin</artifactId>
+                <executions>
+                    <execution>
+                        <id>default-cli</id>
+                        <configuration>
+                            <charset>UTF-8</charset>
+
+                            <webappSourceDir>${basedir}/src/main/resources</webappSourceDir>
+                            <webappTargetDir>${project.build.directory}/classes</webappTargetDir>
+
+                            <cssSourceDir>/</cssSourceDir>
+                            <cssTargetDir>/</cssTargetDir>
+                            <cssFinalFile>display-stats.css</cssFinalFile>
+
+                            <cssSourceFiles>
+                                <cssSourceFile>license.txt</cssSourceFile>
+                            </cssSourceFiles>
+
+                            <cssSourceIncludes>
+                                <cssSourceInclude>**/*.css</cssSourceInclude>
+                            </cssSourceIncludes>
+
+                            <jsSourceDir>/</jsSourceDir>
+                            <jsTargetDir>/</jsTargetDir>
+                            <jsFinalFile>display-stats.js</jsFinalFile>
+
+                            <jsSourceFiles>
+                                <jsSourceFile>license.txt</jsSourceFile>
+                            </jsSourceFiles>
+
+                            <jsSourceIncludes>
+                                <jsSourceInclude>**/*.js</jsSourceInclude>
+                            </jsSourceIncludes>
+
+                            <!-- Do not minify and include tests -->
+                            <jsSourceExcludes>
+                                <jsSourceExclude>**/*.test.js</jsSourceExclude>
+                            </jsSourceExcludes>
+                            <jsEngine>CLOSURE</jsEngine>
+
+                            <!-- Disable warnings for JSDoc annotations -->
+                            <closureWarningLevels>
+                                <misplacedTypeAnnotation>OFF</misplacedTypeAnnotation>
+                                <nonStandardJsDocs>OFF</nonStandardJsDocs>
+                            </closureWarningLevels>
+
+                        </configuration>
+                        <goals>
+                            <goal>minify</goal>
+                        </goals>
+                    </execution>
+                </executions>
+            </plugin>
+
+        </plugins>
+    </build>
+
+</project>

extensions/guacamole-display-statistics/src/main/assembly/dist.xml

@@ -0,0 +1,53 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<!--
+    Licensed to the Apache Software Foundation (ASF) under one
+    or more contributor license agreements.  See the NOTICE file
+    distributed with this work for additional information
+    regarding copyright ownership.  The ASF licenses this file
+    to you under the Apache License, Version 2.0 (the
+    "License"); you may not use this file except in compliance
+    with the License.  You may obtain a copy of the License at
+
+      http://www.apache.org/licenses/LICENSE-2.0
+
+    Unless required by applicable law or agreed to in writing,
+    software distributed under the License is distributed on an
+    "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+    KIND, either express or implied.  See the License for the
+    specific language governing permissions and limitations
+    under the License.
+-->
+<assembly
+    xmlns="http://maven.apache.org/plugins/maven-assembly-plugin/assembly/1.1.0"
+    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+    xsi:schemaLocation="http://maven.apache.org/plugins/maven-assembly-plugin/assembly/1.1.0 http://maven.apache.org/xsd/assembly-1.1.0.xsd">
+    
+    <id>dist</id>
+    <baseDirectory>${project.artifactId}-${project.version}</baseDirectory>
+
+    <!-- Output tar.gz -->
+    <formats>
+        <format>tar.gz</format>
+    </formats>
+
+    <!-- Include licenses and extension .jar -->
+    <fileSets>
+
+        <!-- Include licenses -->
+        <fileSet>
+            <outputDirectory></outputDirectory>
+            <directory>target/licenses</directory>
+        </fileSet>
+
+        <!-- Include extension .jar -->
+        <fileSet>
+            <directory>target</directory>
+            <outputDirectory></outputDirectory>
+            <includes>
+                <include>*.jar</include>
+            </includes>
+        </fileSet>
+
+    </fileSets>
+
+</assembly>

extensions/guacamole-display-statistics/src/main/resources/directives/guacClientStatistics.js

@@ -0,0 +1,108 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+
+/**
+ * A directive which displays frame rendering performance statistics for a
+ * Guacamole client.
+ */
+angular.module('client').directive('guacClientStatistics', [function guacClientStatistics() {
+
+    const directive = {
+        restrict: 'E',
+        templateUrl: 'app/ext/display-stats/templates/guacClientStatistics.html',
+    };
+
+    directive.scope = {
+
+        /**
+         * The Guacamole client to display frame rendering statistics for.
+         *
+         * @type ManagedClient
+         */
+        client : '='
+
+    };
+
+    directive.controller = ['$scope', function guacClientStatisticsController($scope) {
+
+        /**
+         * Updates the displayed frame rendering statistics to the values
+         * within the given statistics object.
+         *
+         * @param {!Guacamole.Display.Statistics} stats
+         *     An object containing general rendering performance statistics for
+         *     the remote desktop, Guacamole server, and Guacamole client.
+         */
+        var updateStatistics = function updateStatistics(stats) {
+            $scope.$apply(function statisticsChanged() {
+                $scope.statistics = stats;
+            });
+        };
+
+        /**
+         * Returns whether the given value is a defined value that should be
+         * rendered within the statistics toolbar.
+         *
+         * @param {number} value
+         *     The value to test.
+         *
+         * @returns {!boolean}
+         *     true if the given value should be rendered within the statistics
+         *     toolbar, false otherwise.
+         */
+        $scope.hasValue = function hasValue(value) {
+            return value || value === 0;
+        };
+
+        /**
+         * Rounds the given numeric value to the nearest hundredth (two decimal places).
+         *
+         * @param {!number} value
+         *     The value to round.
+         *
+         * @param {!number}
+         *     The given value, rounded to the nearest hundredth.
+         */
+        $scope.round = function round(value) {
+            return Math.round(value * 100) / 100;
+        };
+
+        // Assign/remove onstatistics handlers to track the statistics of the
+        // current client
+        $scope.$watch('client', function clientChanged(client, oldClient) {
+
+            if (oldClient)
+                oldClient.managedDisplay.display.onstatistics = null;
+
+            client.managedDisplay.display.statisticWindow = 1000;
+            client.managedDisplay.display.onstatistics = updateStatistics;
+
+        });
+
+        // Clear onstatistics handler when directive is being unloaded
+        $scope.$on('$destroy', function scopeDestroyed() {
+            if ($scope.client)
+                $scope.client.managedDisplay.display.onstatistics = null;
+        });
+
+    }];
+
+    return directive;
+
+}]);

extensions/guacamole-display-statistics/src/main/resources/guac-manifest.json

@@ -0,0 +1,28 @@
+{
+
+    "guacamoleVersion" : "1.4.0",
+
+    "name"      : "Display Statistic Toolbar",
+    "namespace" : "display-stats",
+
+    "translations" : [
+        "translations/en.json"
+    ],
+
+    "js" : [
+        "display-stats.min.js"
+    ],
+
+    "css" : [
+        "display-stats.min.css"
+    ],
+
+    "html" : [
+        "html/add-statistics.html"
+    ],
+
+    "resources" : {
+        "templates/guacClientStatistics.html" : "text/html"
+    }
+
+}

extensions/guacamole-display-statistics/src/main/resources/html/add-statistics.html

@@ -0,0 +1,4 @@
+<meta name="after" content=".client-tile guac-client">
+
+<!-- Guacamole display statistics -->
+<guac-client-statistics client="client"></guac-client-statistics>

extensions/guacamole-display-statistics/src/main/resources/license.txt

@@ -0,0 +1,18 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */

extensions/guacamole-display-statistics/src/main/resources/styles/clientStatistics.css

@@ -0,0 +1,57 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+
+guac-client-statistics {
+    font-size: 13px;
+    color: white;
+    background: #111;
+}
+
+guac-client-statistics dl.client-statistics {
+    display: table;
+    margin: 0;
+    padding: 0.25em;
+}
+
+guac-client-statistics dl.client-statistics dt,
+guac-client-statistics dl.client-statistics dd {
+    display: table-cell;
+    padding: 0.25em;
+}
+
+guac-client-statistics dl.client-statistics dt {
+    padding-right: 0.5em;
+    padding-left: 1em;
+}
+
+guac-client-statistics dl.client-statistics dt:first-child {
+    padding-left: 0.5em;
+}
+
+guac-client-statistics dl.client-statistics dd {
+    min-width: 6em;
+    border: 1px solid rgba(255, 255, 255, 0.125);
+    border-radius: 3px;
+    background: black;
+}
+
+guac-client-statistics dl.client-statistics dd.no-value::before {
+    color: #888;
+    content: '-';
+}

extensions/guacamole-display-statistics/src/main/resources/templates/guacClientStatistics.html

@@ -0,0 +1,39 @@
+<dl class="client-statistics">
+
+    <dt class="client-statistic desktop-fps">
+        {{ 'CLIENT.FIELD_HEADER_DESKTOP_FRAMERATE' | translate }}
+    </dt>
+    <dd ng-class="{ 'no-value' : !hasValue(statistics.desktopFps) }">
+        <span ng-show="hasValue(statistics.desktopFps)"
+            translate="CLIENT.INFO_FRAMERATE"
+            translate-values="{ VALUE : round(statistics.desktopFps) }"></span>
+    </dd>
+
+    <dt class="client-statistic server-fps">
+        {{ 'CLIENT.FIELD_HEADER_SERVER_FRAMERATE' | translate }}
+    </dt>
+    <dd ng-class="{ 'no-value' : !hasValue(statistics.serverFps) }">
+        <span ng-show="hasValue(statistics.serverFps)"
+            translate="CLIENT.INFO_FRAMERATE"
+            translate-values="{ VALUE : round(statistics.serverFps) }"></span>
+    </dd>
+
+    <dt class="client-statistic client-fps">
+        {{ 'CLIENT.FIELD_HEADER_CLIENT_FRAMERATE' | translate }}
+    </dt>
+    <dd ng-class="{ 'no-value' : !hasValue(statistics.clientFps) }">
+        <span ng-show="hasValue(statistics.clientFps)"
+            translate="CLIENT.INFO_FRAMERATE"
+            translate-values="{ VALUE : round(statistics.clientFps) }"></span>
+    </dd>
+
+    <dt class="client-statistic drop-rate">
+        {{ 'CLIENT.FIELD_HEADER_DROP_FRAMERATE' | translate }}
+    </dt>
+    <dd ng-class="{ 'no-value' : !hasValue(statistics.dropRate) }">
+        <span ng-show="hasValue(statistics.dropRate)"
+            translate="CLIENT.INFO_FRAMERATE"
+            translate-values="{ VALUE : round(statistics.dropRate) }"></span>
+    </dd>
+
+</dl>

extensions/guacamole-display-statistics/src/main/resources/translations/en.json

@@ -0,0 +1,12 @@
+{
+    "CLIENT" : {
+
+        "FIELD_HEADER_CLIENT_FRAMERATE"  : "Guacamole (Client):",
+        "FIELD_HEADER_DESKTOP_FRAMERATE" : "Remote Desktop:",
+        "FIELD_HEADER_DROP_FRAMERATE"    : "Drop:",
+        "FIELD_HEADER_SERVER_FRAMERATE"  : "Guacamole (Server):",
+
+        "INFO_FRAMERATE" : "{VALUE} fps"
+
+    }
+}

extensions/pom.xml

@@ -53,6 +53,9 @@
         <module>guacamole-history-recording-storage</module>
         <module>guacamole-vault</module>
 
+        <!-- Utility extensions -->
+        <module>guacamole-display-statistics</module>
+
     </modules>
 
     <build>

guacamole-common-js/src/main/webapp/modules/Client.js

@@ -840,6 +840,12 @@ Guacamole.Client = function(tunnel) {
      * @event
      * @param {!number} timestamp
      *     The timestamp associated with the sync instruction.
+     *
+     * @param {!number} frames
+     *     The number of frames that were considered or combined to produce the
+     *     frame associated with this sync instruction, or zero if this value
+     *     is not known or the remote desktop server provides no concept of
+     *     frames.
      */
     this.onsync = null;
 
@@ -1530,6 +1536,7 @@ Guacamole.Client = function(tunnel) {
         "sync": function(parameters) {
 
             var timestamp = parseInt(parameters[0]);
+            var frames = parameters[1] ? parseInt(parameters[1]) : 0;
 
             // Flush display, send sync when done
             display.flush(function displaySyncComplete() {
@@ -1547,7 +1554,7 @@ Guacamole.Client = function(tunnel) {
                     currentTimestamp = timestamp;
                 }
 
-            });
+            }, timestamp, frames);
 
             // If received first update, no longer waiting.
             if (currentState === STATE_WAITING)
@@ -1555,7 +1562,7 @@ Guacamole.Client = function(tunnel) {
 
             // Call sync handler if defined
             if (guac_client.onsync)
-                guac_client.onsync(timestamp);
+                guac_client.onsync(timestamp, frames);
 
         },
 

guacamole-common-js/src/main/webapp/modules/Display.js

@@ -112,6 +112,17 @@ Guacamole.Display = function() {
      */
     this.cursorY = 0;
 
+    /**
+     * The number of milliseconds over which display rendering statistics
+     * should be gathered, dispatching {@link #onstatistics} events as those
+     * statistics are available. If set to zero, no statistics will be
+     * gathered.
+     *
+     * @default 0
+     * @type {!number}
+     */
+    this.statisticWindow = 0;
+
     /**
      * Fired when the default layer (and thus the entire Guacamole display)
      * is resized.
@@ -142,6 +153,18 @@ Guacamole.Display = function() {
      */
     this.oncursor = null;
 
+    /**
+     * Fired whenever performance statistics are available for recently-
+     * rendered frames. This event will fire only if {@link #statisticWindow}
+     * is non-zero.
+     *
+     * @event
+     * @param {!Guacamole.Display.Statistics} stats
+     *     An object containing general rendering performance statistics for
+     *     the remote desktop, Guacamole server, and Guacamole client.
+     */
+    this.onstatistics = null;
+
     /**
      * The queue of all pending Tasks. Tasks will be run in order, with new
      * tasks added at the end of the queue and old tasks removed from the
@@ -163,11 +186,33 @@ Guacamole.Display = function() {
     var frames = [];
 
     /**
-     * Flushes all pending frames.
+     * The ID of the animation frame request returned by the last call to
+     * requestAnimationFrame(). This value will only be set if the browser
+     * supports requestAnimationFrame(), if a frame render is currently
+     * pending, and if the current browser tab is currently focused (likely to
+     * handle requests for animation frames). In all other cases, this will be
+     * null.
+     *
+     * @private
+     * @type {number}
+     */
+    var inProgressFrame = null;
+
+    /**
+     * Flushes all pending frames synchronously. This function will block until
+     * all pending frames have rendered. If a frame is currently blocked by an
+     * asynchronous operation like an image load, this function will return
+     * after reaching that operation and the flush operation will
+     * automamtically resume after that operation completes.
+     *
      * @private
      */
-    function __flush_frames() {
+    var syncFlush = function syncFlush() {
 
+        var localTimestamp = 0;
+        var remoteTimestamp = 0;
+
+        var renderedLogicalFrames = 0;
         var rendered_frames = 0;
 
         // Draw all pending frames, if ready
@@ -178,6 +223,10 @@ Guacamole.Display = function() {
                 break;
 
             frame.flush();
+
+            localTimestamp = frame.localTimestamp;
+            remoteTimestamp = frame.remoteTimestamp;
+            renderedLogicalFrames += frame.logicalFrames;
             rendered_frames++;
 
         } 
@@ -185,6 +234,172 @@ Guacamole.Display = function() {
         // Remove rendered frames from array
         frames.splice(0, rendered_frames);
 
+        if (rendered_frames)
+            notifyFlushed(localTimestamp, remoteTimestamp, renderedLogicalFrames);
+
+    };
+
+    /**
+     * Flushes all pending frames asynchronously. This function returns
+     * immediately, relying on requestAnimationFrame() to dictate when each
+     * frame should be flushed.
+     *
+     * @private
+     */
+    var asyncFlush = function asyncFlush() {
+
+        var continueFlush = function continueFlush() {
+
+            // We're no longer waiting to render a frame
+            inProgressFrame = null;
+
+            // Nothing to do if there are no frames remaining
+            if (!frames.length)
+                return;
+
+            // Flush the next frame only if it is ready (not awaiting
+            // completion of some asynchronous operation like an image load)
+            if (frames[0].isReady()) {
+                var frame = frames.shift();
+                frame.flush();
+                notifyFlushed(frame.localTimestamp, frame.remoteTimestamp, frame.logicalFrames);
+            }
+
+            // Request yet another animation frame if frames remain to be
+            // flushed
+            if (frames.length)
+                inProgressFrame = window.requestAnimationFrame(continueFlush);
+
+        };
+
+        // Begin flushing frames if not already waiting to render a frame
+        if (!inProgressFrame)
+            inProgressFrame = window.requestAnimationFrame(continueFlush);
+
+    };
+
+    /**
+     * Recently-gathered display render statistics, as made available by calls
+     * to notifyFlushed(). The contents of this array will be trimmed to
+     * contain only up to {@link #statisticWindow} milliseconds of statistics.
+     *
+     * @private
+     * @type {Guacamole.Display.Statistics[]}
+     */
+    var statistics = [];
+
+    /**
+     * Notifies that one or more frames have been successfully rendered
+     * (flushed) to the display.
+     *
+     * @private
+     * @param {!number} localTimestamp
+     *     The local timestamp of the point in time at which the most recent,
+     *     flushed frame was received by the display, in milliseconds since the
+     *     Unix Epoch.
+     *
+     * @param {!number} remoteTimestamp
+     *     The remote timestamp of sync instruction associated with the most
+     *     recent, flushed frame received by the display. This timestamp is in
+     *     milliseconds, but is arbitrary, having meaning only relative to
+     *     other timestamps in the same connection.
+     *
+     * @param {!number} logicalFrames
+     *     The number of remote desktop frames that were flushed.
+     */
+    var notifyFlushed = function notifyFlushed(localTimestamp, remoteTimestamp, logicalFrames) {
+
+        // Ignore if statistics are not being gathered
+        if (!guac_display.statisticWindow)
+            return;
+
+        var current = new Date().getTime();
+
+        // Find the first statistic that is still within the configured time
+        // window
+        for (var first = 0; first < statistics.length; first++) {
+            if (current - statistics[first].timestamp <= guac_display.statisticWindow)
+                break;
+        }
+
+        // Remove all statistics except those within the time window
+        statistics.splice(0, first - 1);
+
+        // Record statistics for latest frame
+        statistics.push({
+            localTimestamp : localTimestamp,
+            remoteTimestamp : remoteTimestamp,
+            timestamp : current,
+            frames : logicalFrames
+        });
+
+        // Determine the actual time interval of the available statistics (this
+        // will not perfectly match the configured interval, which is an upper
+        // bound)
+        var statDuration = (statistics[statistics.length - 1].timestamp - statistics[0].timestamp) / 1000;
+
+        // Determine the amount of time that elapsed remotely (within the
+        // remote desktop)
+        var remoteDuration = (statistics[statistics.length - 1].remoteTimestamp - statistics[0].remoteTimestamp) / 1000;
+
+        // Calculate the number of frames that have been rendered locally
+        // within the configured time interval
+        var localFrames = statistics.length;
+
+        // Calculate the number of frames actually received from the remote
+        // desktop by the Guacamole server
+        var remoteFrames = statistics.reduce(function sumFrames(prev, stat) {
+            return prev + stat.frames;
+        }, 0);
+
+        // Calculate the number of frames that the Guacamole server had to
+        // drop or combine with other frames
+        var drops = statistics.reduce(function sumDrops(prev, stat) {
+            return prev + Math.max(0, stat.frames - 1);
+        }, 0);
+
+        // Produce lag and FPS statistics from above raw measurements
+        var stats = new Guacamole.Display.Statistics({
+            processingLag : current - localTimestamp,
+            desktopFps : (remoteDuration && remoteFrames) ? remoteFrames / remoteDuration : null,
+            clientFps : statDuration ? localFrames / statDuration : null,
+            serverFps : remoteDuration ? localFrames / remoteDuration : null,
+            dropRate : remoteDuration ? drops / remoteDuration : null
+        });
+
+        // Notify of availability of new statistics
+        if (guac_display.onstatistics)
+            guac_display.onstatistics(stats);
+
+    };
+
+    // Switch from asynchronous frame handling to synchronous frame handling if
+    // requestAnimationFrame() is unlikely to be usable (browsers may not
+    // invoke the animation frame callback if the relevant tab is not focused)
+    window.addEventListener('blur', function switchToSyncFlush() {
+        if (inProgressFrame && !document.hasFocus()) {
+
+            // Cancel pending asynchronous processing of frame ...
+            window.cancelAnimationFrame(inProgressFrame);
+            inProgressFrame = null;
+
+            // ... and instead process it synchronously
+            syncFlush();
+
+        }
+    }, true);
+
+    /**
+     * Flushes all pending frames.
+     * @private
+     */
+    function __flush_frames() {
+
+        if (window.requestAnimationFrame && document.hasFocus())
+            asyncFlush();
+        else
+            syncFlush();
+
     }
 
     /**
@@ -198,8 +413,43 @@ Guacamole.Display = function() {
      *
      * @param {!Task[]} tasks
      *     The set of tasks which must be executed to render this frame.
+     *
+     * @param {number} [timestamp]
+     *     The remote timestamp of sync instruction associated with this frame.
+     *     This timestamp is in milliseconds, but is arbitrary, having meaning
+     *     only relative to other remote timestamps in the same connection. If
+     *     omitted, a compatible but local timestamp will be used instead.
+     *
+     * @param {number} [logicalFrames=0]
+     *     The number of remote desktop frames that were combined to produce
+     *     this frame, or zero if this value is unknown or inapplicable.
      */
-    function Frame(callback, tasks) {
+    var Frame = function Frame(callback, tasks, timestamp, logicalFrames) {
+
+        /**
+         * The local timestamp of the point in time at which this frame was
+         * received by the display, in milliseconds since the Unix Epoch.
+         *
+         * @type {!number}
+         */
+        this.localTimestamp = new Date().getTime();
+
+        /**
+         * The remote timestamp of sync instruction associated with this frame.
+         * This timestamp is in milliseconds, but is arbitrary, having meaning
+         * only relative to other remote timestamps in the same connection.
+         *
+         * @type {!number}
+         */
+        this.remoteTimestamp = timestamp || this.localTimestamp;
+
+        /**
+         * The number of remote desktop frames that were combined to produce
+         * this frame. If unknown or not applicable, this will be zero.
+         *
+         * @type {!number}
+         */
+        this.logicalFrames = logicalFrames || 0;
 
         /**
          * Cancels rendering of this frame and all associated tasks. The
@@ -254,7 +504,7 @@ Guacamole.Display = function() {
 
         };
 
-    }
+    };
 
     /**
      * A container for an task handler. Each operation which must be ordered
@@ -431,11 +681,20 @@ Guacamole.Display = function() {
      * @param {function} [callback]
      *     The function to call when this frame is flushed. This may happen
      *     immediately, or later when blocked tasks become unblocked.
+     *
+     * @param {number} timestamp
+     *     The remote timestamp of sync instruction associated with this frame.
+     *     This timestamp is in milliseconds, but is arbitrary, having meaning
+     *     only relative to other remote timestamps in the same connection.
+     *
+     * @param {number} logicalFrames
+     *     The number of remote desktop frames that were combined to produce
+     *     this frame.
      */
-    this.flush = function(callback) {
+    this.flush = function(callback, timestamp, logicalFrames) {
 
         // Add frame, reset tasks
-        frames.push(new Frame(callback, tasks));
+        frames.push(new Frame(callback, tasks, timestamp, logicalFrames));
         tasks = [];
 
         // Attempt flush
@@ -1855,3 +2114,79 @@ Guacamole.Display.VisibleLayer = function(width, height) {
  * @type {!number}
  */
 Guacamole.Display.VisibleLayer.__next_id = 0;
+
+/**
+ * A set of Guacamole display performance statistics, describing the speed at
+ * which the remote desktop, Guacamole server, and Guacamole client are
+ * rendering frames.
+ *
+ * @constructor
+ * @param {Guacamole.Display.Statistics|Object} [template={}]
+ *     The object whose properties should be copied within the new
+ *     Guacamole.Display.Statistics.
+ */
+Guacamole.Display.Statistics = function Statistics(template) {
+
+    template = template || {};
+
+    /**
+     * The amount of time that the Guacamole client is taking to render
+     * individual frames, in milliseconds, if known. If this value is unknown,
+     * such as if the there are insufficient frame statistics recorded to
+     * calculate this value, this will be null.
+     *
+     * @type {?number}
+     */
+    this.processingLag = template.processingLag;
+
+    /**
+     * The framerate of the remote desktop currently being viewed within the
+     * relevant Gucamole.Display, independent of Guacamole, in frames per
+     * second. This represents the speed at which the remote desktop is
+     * producing frame data for the Guacamole server to consume. If this
+     * value is unknown, such as if the remote desktop server does not actually
+     * define frame boundaries, this will be null.
+     *
+     * @type {?number}
+     */
+    this.desktopFps = template.desktopFps;
+
+    /**
+     * The rate at which the Guacamole server is generating frames for the
+     * Guacamole client to consume, in frames per second. If the Guacamole
+     * server is correctly adjusting for variance in client/browser processing
+     * power, this rate should closely match the client rate, and should remain
+     * independent of any network latency. If this value is unknown, such as if
+     * the there are insufficient frame statistics recorded to calculate this
+     * value, this will be null.
+     *
+     * @type {?number}
+     */
+    this.serverFps = template.serverFps;
+
+    /**
+     * The rate at which the Guacamole client is consuming frames generated by
+     * the Guacamole server, in frames per second. If the Guacamole server is
+     * correctly adjusting for variance in client/browser processing power,
+     * this rate should closely match the server rate, regardless of any
+     * latency on the network between the server and client. If this value is
+     * unknown, such as if the there are insufficient frame statistics recorded
+     * to calculate this value, this will be null.
+     *
+     * @type {?number}
+     */
+    this.clientFps = template.clientFps;
+
+    /**
+     * The rate at which the Guacamole server is dropping or combining frames
+     * received from the remote desktop server to compensate for variance in
+     * client/browser processing power, in frames per second. This value may
+     * also be non-zero if the server is compensating for variances in its own
+     * processing power, or relative slowness in image compression vs. the rate
+     * that inbound frames are received. If this value is unknown, such as if
+     * the remote desktop server does not actually define frame boundaries,
+     * this will be null.
+     */
+    this.dropRate = template.dropRate;
+
+};

guacamole-ext/src/main/resources/org/apache/guacamole/protocols/rdp.json

@@ -298,6 +298,11 @@
                     "name"    : "disable-glyph-caching",
                     "type"    : "BOOLEAN",
                     "options" : [ "true" ]
+                },
+                {
+                    "name"    : "disable-gfx",
+                    "type"    : "BOOLEAN",
+                    "options" : [ "true" ]
                 }
             ]
         },

guacamole/src/main/frontend/src/translations/en.json

@@ -494,6 +494,7 @@
         "FIELD_HEADER_DISABLE_BITMAP_CACHING"     : "Disable bitmap caching:",
         "FIELD_HEADER_DISABLE_OFFSCREEN_CACHING"  : "Disable off-screen caching:",
         "FIELD_HEADER_DISABLE_GLYPH_CACHING"      : "Disable glyph caching:",
+        "FIELD_HEADER_DISABLE_GFX"                : "Disable Graphics Pipeline Extension:",
         "FIELD_HEADER_ENABLE_PRINTING"            : "Enable printing:",
         "FIELD_HEADER_ENABLE_SFTP"     : "Enable SFTP:",
         "FIELD_HEADER_ENABLE_THEMING"             : "Enable theming:",