Websites/webkit.org/blog/wp-includes/js/swfupload/plugins/swfupload.speed.js

/*
	Speed Plug-in
	
	Features:
		*Adds several properties to the 'file' object indicated upload speed, time left, upload time, etc.
			- currentSpeed -- String indicating the upload speed, bytes per second
			- averageSpeed -- Overall average upload speed, bytes per second
			- movingAverageSpeed -- Speed over averaged over the last several measurements, bytes per second
			- timeRemaining -- Estimated remaining upload time in seconds
			- timeElapsed -- Number of seconds passed for this upload
			- percentUploaded -- Percentage of the file uploaded (0 to 100)
			- sizeUploaded -- Formatted size uploaded so far, bytes
		
		*Adds setting 'moving_average_history_size' for defining the window size used to calculate the moving average speed.
		
		*Adds several Formatting functions for formatting that values provided on the file object.
			- SWFUpload.speed.formatBPS(bps) -- outputs string formatted in the best units (Gbps, Mbps, Kbps, bps)
			- SWFUpload.speed.formatTime(seconds) -- outputs string formatted in the best units (x Hr y M z S)
			- SWFUpload.speed.formatSize(bytes) -- outputs string formatted in the best units (w GB x MB y KB z B )
			- SWFUpload.speed.formatPercent(percent) -- outputs string formatted with a percent sign (x.xx %)
			- SWFUpload.speed.formatUnits(baseNumber, divisionArray, unitLabelArray, fractionalBoolean)
				- Formats a number using the division array to determine how to apply the labels in the Label Array
				- factionalBoolean indicates whether the number should be returned as a single fractional number with a unit (speed)
				    or as several numbers labeled with units (time)
	*/

var SWFUpload;
if (typeof(SWFUpload) === "function") {
	SWFUpload.speed = {};
	
	SWFUpload.prototype.initSettings = (function (oldInitSettings) {
		return function () {
			if (typeof(oldInitSettings) === "function") {
				oldInitSettings.call(this);
			}
			
			this.ensureDefault = function (settingName, defaultValue) {
				this.settings[settingName] = (this.settings[settingName] == undefined) ? defaultValue : this.settings[settingName];
			};

			// List used to keep the speed stats for the files we are tracking
			this.fileSpeedStats = {};
			this.speedSettings = {};

			this.ensureDefault("moving_average_history_size", "10");
			
			this.speedSettings.user_file_queued_handler = this.settings.file_queued_handler;
			this.speedSettings.user_file_queue_error_handler = this.settings.file_queue_error_handler;
			this.speedSettings.user_upload_start_handler = this.settings.upload_start_handler;
			this.speedSettings.user_upload_error_handler = this.settings.upload_error_handler;
			this.speedSettings.user_upload_progress_handler = this.settings.upload_progress_handler;
			this.speedSettings.user_upload_success_handler = this.settings.upload_success_handler;
			this.speedSettings.user_upload_complete_handler = this.settings.upload_complete_handler;
			
			this.settings.file_queued_handler = SWFUpload.speed.fileQueuedHandler;
			this.settings.file_queue_error_handler = SWFUpload.speed.fileQueueErrorHandler;
			this.settings.upload_start_handler = SWFUpload.speed.uploadStartHandler;
			this.settings.upload_error_handler = SWFUpload.speed.uploadErrorHandler;
			this.settings.upload_progress_handler = SWFUpload.speed.uploadProgressHandler;
			this.settings.upload_success_handler = SWFUpload.speed.uploadSuccessHandler;
			this.settings.upload_complete_handler = SWFUpload.speed.uploadCompleteHandler;
			
			delete this.ensureDefault;
		};
	})(SWFUpload.prototype.initSettings);

	
	SWFUpload.speed.fileQueuedHandler = function (file) {
		if (typeof this.speedSettings.user_file_queued_handler === "function") {
			file = SWFUpload.speed.extendFile(file);
			
			return this.speedSettings.user_file_queued_handler.call(this, file);
		}
	};
	
	SWFUpload.speed.fileQueueErrorHandler = function (file, errorCode, message) {
		if (typeof this.speedSettings.user_file_queue_error_handler === "function") {
			file = SWFUpload.speed.extendFile(file);
			
			return this.speedSettings.user_file_queue_error_handler.call(this, file, errorCode, message);
		}
	};

	SWFUpload.speed.uploadStartHandler = function (file) {
		if (typeof this.speedSettings.user_upload_start_handler === "function") {
			file = SWFUpload.speed.extendFile(file, this.fileSpeedStats);
			return this.speedSettings.user_upload_start_handler.call(this, file);
		}
	};
	
	SWFUpload.speed.uploadErrorHandler = function (file, errorCode, message) {
		file = SWFUpload.speed.extendFile(file, this.fileSpeedStats);
		SWFUpload.speed.removeTracking(file, this.fileSpeedStats);

		if (typeof this.speedSettings.user_upload_error_handler === "function") {
			return this.speedSettings.user_upload_error_handler.call(this, file, errorCode, message);
		}
	};
	SWFUpload.speed.uploadProgressHandler = function (file, bytesComplete, bytesTotal) {
		this.updateTracking(file, bytesComplete);
		file = SWFUpload.speed.extendFile(file, this.fileSpeedStats);

		if (typeof this.speedSettings.user_upload_progress_handler === "function") {
			return this.speedSettings.user_upload_progress_handler.call(this, file, bytesComplete, bytesTotal);
		}
	};
	
	SWFUpload.speed.uploadSuccessHandler = function (file, serverData) {
		if (typeof this.speedSettings.user_upload_success_handler === "function") {
			file = SWFUpload.speed.extendFile(file, this.fileSpeedStats);
			return this.speedSettings.user_upload_success_handler.call(this, file, serverData);
		}
	};
	SWFUpload.speed.uploadCompleteHandler = function (file) {
		file = SWFUpload.speed.extendFile(file, this.fileSpeedStats);
		SWFUpload.speed.removeTracking(file, this.fileSpeedStats);

		if (typeof this.speedSettings.user_upload_complete_handler === "function") {
			return this.speedSettings.user_upload_complete_handler.call(this, file);
		}
	};
	
	// Private: extends the file object with the speed plugin values
	SWFUpload.speed.extendFile = function (file, trackingList) {
		var tracking;
		
		if (trackingList) {
			tracking = trackingList[file.id];
		}
		
		if (tracking) {
			file.currentSpeed = tracking.currentSpeed;
			file.averageSpeed = tracking.averageSpeed;
			file.movingAverageSpeed = tracking.movingAverageSpeed;
			file.timeRemaining = tracking.timeRemaining;
			file.timeElapsed = tracking.timeElapsed;
			file.percentUploaded = tracking.percentUploaded;
			file.sizeUploaded = tracking.bytesUploaded;

		} else {
			file.currentSpeed = 0;
			file.averageSpeed = 0;
			file.movingAverageSpeed = 0;
			file.timeRemaining = 0;
			file.timeElapsed = 0;
			file.percentUploaded = 0;
			file.sizeUploaded = 0;
		}
		
		return file;
	};
	
	// Private: Updates the speed tracking object, or creates it if necessary
	SWFUpload.prototype.updateTracking = function (file, bytesUploaded) {
		var tracking = this.fileSpeedStats[file.id];
		if (!tracking) {
			this.fileSpeedStats[file.id] = tracking = {};
		}
		
		// Sanity check inputs
		bytesUploaded = bytesUploaded || tracking.bytesUploaded || 0;
		if (bytesUploaded < 0) {
			bytesUploaded = 0;
		}
		if (bytesUploaded > file.size) {
			bytesUploaded = file.size;
		}
		
		var tickTime = (new Date()).getTime();
		if (!tracking.startTime) {
			tracking.startTime = (new Date()).getTime();
			tracking.lastTime = tracking.startTime;
			tracking.currentSpeed = 0;
			tracking.averageSpeed = 0;
			tracking.movingAverageSpeed = 0;
			tracking.movingAverageHistory = [];
			tracking.timeRemaining = 0;
			tracking.timeElapsed = 0;
			tracking.percentUploaded = bytesUploaded / file.size;
			tracking.bytesUploaded = bytesUploaded;
		} else if (tracking.startTime > tickTime) {
			this.debug("When backwards in time");
		} else {
			// Get time and deltas
			var now = (new Date()).getTime();
			var lastTime = tracking.lastTime;
			var deltaTime = now - lastTime;
			var deltaBytes = bytesUploaded - tracking.bytesUploaded;
			
			if (deltaBytes === 0 || deltaTime === 0) {
				return tracking;
			}
			
			// Update tracking object
			tracking.lastTime = now;
			tracking.bytesUploaded = bytesUploaded;
			
			// Calculate speeds
			tracking.currentSpeed = (deltaBytes * 8 ) / (deltaTime / 1000);
			tracking.averageSpeed = (tracking.bytesUploaded * 8) / ((now - tracking.startTime) / 1000);

			// Calculate moving average
			tracking.movingAverageHistory.push(tracking.currentSpeed);
			if (tracking.movingAverageHistory.length > this.settings.moving_average_history_size) {
				tracking.movingAverageHistory.shift();
			}
			
			tracking.movingAverageSpeed = SWFUpload.speed.calculateMovingAverage(tracking.movingAverageHistory);
			
			// Update times
			tracking.timeRemaining = (file.size - tracking.bytesUploaded) * 8 / tracking.movingAverageSpeed;
			tracking.timeElapsed = (now - tracking.startTime) / 1000;
			
			// Update percent
			tracking.percentUploaded = (tracking.bytesUploaded / file.size * 100);
		}
		
		return tracking;
	};
	SWFUpload.speed.removeTracking = function (file, trackingList) {
		try {
			trackingList[file.id] = null;
			delete trackingList[file.id];
		} catch (ex) {
		}
	};
	
	SWFUpload.speed.formatUnits = function (baseNumber, unitDivisors, unitLabels, singleFractional) {
		var i, unit, unitDivisor, unitLabel;

		if (baseNumber === 0) {
			return "0 " + unitLabels[unitLabels.length - 1];
		}
		
		if (singleFractional) {
			unit = baseNumber;
			unitLabel = unitLabels.length >= unitDivisors.length ? unitLabels[unitDivisors.length - 1] : "";
			for (i = 0; i < unitDivisors.length; i++) {
				if (baseNumber >= unitDivisors[i]) {
					unit = (baseNumber / unitDivisors[i]).toFixed(2);
					unitLabel = unitLabels.length >= i ? " " + unitLabels[i] : "";
					break;
				}
			}
			
			return unit + unitLabel;
		} else {
			var formattedStrings = [];
			var remainder = baseNumber;
			
			for (i = 0; i < unitDivisors.length; i++) {
				unitDivisor = unitDivisors[i];
				unitLabel = unitLabels.length > i ? " " + unitLabels[i] : "";
				
				unit = remainder / unitDivisor;
				if (i < unitDivisors.length -1) {
					unit = Math.floor(unit);
				} else {
					unit = unit.toFixed(2);
				}
				if (unit > 0) {
					remainder = remainder % unitDivisor;
					
					formattedStrings.push(unit + unitLabel);
				}
			}
			
			return formattedStrings.join(" ");
		}
	};
	
	SWFUpload.speed.formatBPS = function (baseNumber) {
		var bpsUnits = [1073741824, 1048576, 1024, 1], bpsUnitLabels = ["Gbps", "Mbps", "Kbps", "bps"];
		return SWFUpload.speed.formatUnits(baseNumber, bpsUnits, bpsUnitLabels, true);
	
	};
	SWFUpload.speed.formatTime = function (baseNumber) {
		var timeUnits = [86400, 3600, 60, 1], timeUnitLabels = ["d", "h", "m", "s"];
		return SWFUpload.speed.formatUnits(baseNumber, timeUnits, timeUnitLabels, false);
	
	};
	SWFUpload.speed.formatBytes = function (baseNumber) {
		var sizeUnits = [1073741824, 1048576, 1024, 1], sizeUnitLabels = ["GB", "MB", "KB", "bytes"];
		return SWFUpload.speed.formatUnits(baseNumber, sizeUnits, sizeUnitLabels, true);
	
	};
	SWFUpload.speed.formatPercent = function (baseNumber) {
		return baseNumber.toFixed(2) + " %";
	};
	
	SWFUpload.speed.calculateMovingAverage = function (history) {
		var vals = [], size, sum = 0.0, mean = 0.0, varianceTemp = 0.0, variance = 0.0, standardDev = 0.0;
		var i;
		var mSum = 0, mCount = 0;
		
		size = history.length;
		
		// Check for sufficient data
		if (size >= 8) {
			// Clone the array and Calculate sum of the values 
			for (i = 0; i < size; i++) {
				vals[i] = history[i];
				sum += vals[i];
			}

			mean = sum / size;

			// Calculate variance for the set
			for (i = 0; i < size; i++) {
				varianceTemp += Math.pow((vals[i] - mean), 2);
			}

			variance = varianceTemp / size;
			standardDev = Math.sqrt(variance);
			
			//Standardize the Data
			for (i = 0; i < size; i++) {
				vals[i] = (vals[i] - mean) / standardDev;
			}

			// Calculate the average excluding outliers
			var deviationRange = 2.0;
			for (i = 0; i < size; i++) {
				
				if (vals[i] <= deviationRange && vals[i] >= -deviationRange) {
					mCount++;
					mSum += history[i];
				}
			}
			
		} else {
			// Calculate the average (not enough data points to remove outliers)
			mCount = size;
			for (i = 0; i < size; i++) {
				mSum += history[i];
			}
		}

		return mSum / mCount;
	};
	
}