/**
* Adds bandwidth to the current filtered latency counter. Sends a broadcast to all {@link
* ConnectionClassStateChangeListener} if the counter moves from one bucket to another (i.e. poor
* bandwidth -> moderate bandwidth).
*/
public synchronized void addBandwidth(long bytes, long timeInMs) {
// Ignore garbage values.
if (timeInMs == 0 || (bytes) * 1.0 / (timeInMs) * BYTES_TO_BITS < BANDWIDTH_LOWER_BOUND) {
return;
}
double bandwidth = (bytes) * 1.0 / (timeInMs) * BYTES_TO_BITS;
mDownloadBandwidth.addMeasurement(bandwidth);
if (mInitiateStateChange) {
mSampleCounter += 1;
if (getCurrentBandwidthQuality() != mNextBandwidthConnectionQuality.get()) {
mInitiateStateChange = false;
mSampleCounter = 1;
}
if (mSampleCounter >= DEFAULT_SAMPLES_TO_QUALITY_CHANGE
&& significantlyOutsideCurrentBand()) {
mInitiateStateChange = false;
mSampleCounter = 1;
mCurrentBandwidthConnectionQuality.set(mNextBandwidthConnectionQuality.get());
notifyListeners();
}
return;
}
if (mCurrentBandwidthConnectionQuality.get() != getCurrentBandwidthQuality()) {
mInitiateStateChange = true;
mNextBandwidthConnectionQuality =
new AtomicReference<ConnectionQuality>(getCurrentBandwidthQuality());
}
}
private boolean significantlyOutsideCurrentBand() {
if (mDownloadBandwidth == null) {
// Make Infer happy. It wouldn't make any sense to call this while mDownloadBandwidth is null.
return false;
}
ConnectionQuality currentQuality = mCurrentBandwidthConnectionQuality.get();
double bottomOfBand;
double topOfBand;
switch (currentQuality) {
case POOR:
bottomOfBand = 0;
topOfBand = DEFAULT_POOR_BANDWIDTH;
break;
case MODERATE:
bottomOfBand = DEFAULT_POOR_BANDWIDTH;
topOfBand = DEFAULT_MODERATE_BANDWIDTH;
break;
case GOOD:
bottomOfBand = DEFAULT_MODERATE_BANDWIDTH;
topOfBand = DEFAULT_GOOD_BANDWIDTH;
break;
case EXCELLENT:
bottomOfBand = DEFAULT_GOOD_BANDWIDTH;
topOfBand = Float.MAX_VALUE;
break;
default: // If current quality is UNKNOWN, then changing is always valid.
return true;
}
double average = mDownloadBandwidth.getAverage();
if (average > topOfBand) {
if (average > topOfBand * HYSTERESIS_TOP_MULTIPLIER) {
return true;
}
} else if (average < bottomOfBand * HYSTERESIS_BOTTOM_MULTIPLIER) {
return true;
}
return false;
}
/**
* Accessor method for the current bandwidth average.
*
* @return The current bandwidth average, or -1 if no average has been recorded.
*/
public synchronized double getDownloadKBitsPerSecond() {
return mDownloadBandwidth == null ? -1.0 : mDownloadBandwidth.getAverage();
}
/**
* Get the ConnectionQuality that the moving bandwidth average currently represents.
*
* @return A ConnectionQuality representing the device's bandwidth at this exact moment.
*/
public synchronized ConnectionQuality getCurrentBandwidthQuality() {
if (mDownloadBandwidth == null) {
return ConnectionQuality.UNKNOWN;
}
return mapBandwidthQuality(mDownloadBandwidth.getAverage());
}
/** Resets the bandwidth average for this instance of the bandwidth manager. */
public void reset() {
if (mDownloadBandwidth != null) {
mDownloadBandwidth.reset();
}
mCurrentBandwidthConnectionQuality.set(ConnectionQuality.UNKNOWN);
}