private void updateLoadControl() {
long now = SystemClock.elapsedRealtime();
long nextLoadPositionUs = getNextLoadPositionUs();
boolean isBackedOff = currentLoadableException != null;
boolean loadingOrBackedOff = loader.isLoading() || isBackedOff;
// If we're not loading or backed off, evaluate the operation if (a) we don't have the next
// chunk yet and we're not finished, or (b) if the last evaluation was over 2000ms ago.
if (!loadingOrBackedOff
&& ((currentLoadableHolder.chunk == null && nextLoadPositionUs != -1)
|| (now - lastPerformedBufferOperation > 2000))) {
// Perform the evaluation.
lastPerformedBufferOperation = now;
doChunkOperation();
boolean chunksDiscarded = discardUpstreamMediaChunks(currentLoadableHolder.queueSize);
// Update the next load position as appropriate.
if (currentLoadableHolder.chunk == null) {
// Set loadPosition to -1 to indicate that we don't have anything to load.
nextLoadPositionUs = -1;
} else if (chunksDiscarded) {
// Chunks were discarded, so we need to re-evaluate the load position.
nextLoadPositionUs = getNextLoadPositionUs();
}
}
// Update the control with our current state, and determine whether we're the next loader.
boolean nextLoader =
loadControl.update(this, downstreamPositionUs, nextLoadPositionUs, loadingOrBackedOff);
if (isBackedOff) {
long elapsedMillis = now - currentLoadableExceptionTimestamp;
if (elapsedMillis >= getRetryDelayMillis(currentLoadableExceptionCount)) {
resumeFromBackOff();
}
return;
}
if (!loader.isLoading() && nextLoader) {
maybeStartLoading();
}
}
private void restartFrom(long positionUs) {
pendingResetPositionUs = positionUs;
loadingFinished = false;
if (loader.isLoading()) {
loader.cancelLoading();
} else {
sampleQueue.clear();
mediaChunks.clear();
clearCurrentLoadable();
updateLoadControl();
}
}
@Override
public void disable(int track) {
Assertions.checkState(state == STATE_ENABLED);
Assertions.checkState(--enabledTrackCount == 0);
state = STATE_PREPARED;
try {
chunkSource.disable(mediaChunks);
} finally {
loadControl.unregister(this);
if (loader.isLoading()) {
loader.cancelLoading();
} else {
sampleQueue.clear();
mediaChunks.clear();
clearCurrentLoadable();
loadControl.trimAllocator();
}
}
}