connectionSpeed = 0;
// The variable where connection speed information
// will be stored when it is available.
function drawCSImageTag( fileLocation, fileSize, imgTagProperties ) {
// This function draws the image tag required to run this process.
// It needs to be passed:
// 1. (String) The location of the file to be loaded
// 2. (Integer) The size of the image file in bytes
// 3. (String) The tag properties to be included in the ![]()
tag
// Place a call to this function inside the of your file
// in place of a static ![]()
tag.
start = (new Date()).getTime();
// Record Start time of ![]()
load.
loc = fileLocation + '?t=' + escape(start);
// Append the Start time to the image url
// to ensure the image is not in disk cache.
document.writeln('
');
// Write out the ![]()
tag.
return;
}
function connectionType(speed) {
// This function returns a string describing the connection type
// being used by the user-agent hitting the page.
SLOW_MODEM = 15;
FAST_MODEM = 57;
ISDN_MODEM = 120;
// These are constants which define the base speeds
// for a number of different connections. They are
// measured in units of kbps.
if (speed) {
if (speed < SLOW_MODEM) {
return "Slow Modem";
} else if (speed < FAST_MODEM) {
return "Fast Modem";
} else if (speed < ISDN_MODEM) {
return "ISDN Modem";
} else {
return "partial T1 or greater connection";
}
} else {
return "Undetermined Connection";
}
}
function computeConnectionSpeed( start, fileSize ) {
// This function returns the speed in kbps of the user's connection,
// based upon the loading of a single image. It is called via onload
// by the image drawn by drawCSImageTag() and is not meant to be called
// in any other way. You shouldn't ever need to call it explicitly.
end = (new Date()).getTime();
connectSpeed = (Math.floor((((fileSize * 8) / ((end - start) / 1000)) / 1024) * 10) / 10);
return connectSpeed;
}