Files
sm-emby-share/lib/features/player/services/network_speed_monitor.dart
T
2026-07-14 11:11:36 +08:00

104 lines
2.6 KiB
Dart

import 'dart:async';
import 'package:flutter/foundation.dart';
class NetworkSpeedMonitor {
NetworkSpeedMonitor({required this._totalRxBytes, DateTime Function()? now})
: _now = now ?? DateTime.now;
final Future<int?> Function() _totalRxBytes;
final DateTime Function() _now;
final ValueNotifier<double> speed = ValueNotifier<double>(0);
final ValueNotifier<bool> available = ValueNotifier<bool>(false);
Timer? _timer;
int _lastBytes = 0;
int? _latestTotalBytes;
int? get latestTotalBytes => _latestTotalBytes;
DateTime? _lastSampleAt;
int _sampleSessionId = 0;
bool _disposed = false;
bool _sampleInFlight = false;
void start() {
if (_disposed) return;
_stopActiveSampling(resetValue: true);
final sessionId = _sampleSessionId;
_timer = Timer.periodic(const Duration(seconds: 1), (_) {
if (_disposed || sessionId != _sampleSessionId || _sampleInFlight) {
return;
}
_sampleInFlight = true;
unawaited(_sample(sessionId));
});
}
void stop() {
_stopActiveSampling(resetValue: true);
}
Future<void> _sample(int sessionId) async {
try {
final totalBytes = await _totalRxBytes();
if (_disposed || sessionId != _sampleSessionId) return;
if (totalBytes == null) {
available.value = false;
speed.value = 0.0;
return;
}
available.value = true;
final sampled = _sampleSpeedFromTotalBytes(totalBytes);
if (sampled != null) {
speed.value = sampled;
}
} finally {
if (!_disposed && sessionId == _sampleSessionId) {
_sampleInFlight = false;
}
}
}
double? _sampleSpeedFromTotalBytes(int totalBytes) {
final now = _now();
final lastSampleAt = _lastSampleAt;
final lastBytes = _lastBytes;
_lastBytes = totalBytes;
_latestTotalBytes = totalBytes;
_lastSampleAt = now;
if (lastSampleAt == null) return null;
if (totalBytes < lastBytes) return 0.0;
final elapsedMs = now.difference(lastSampleAt).inMilliseconds;
final deltaBytes = totalBytes - lastBytes;
if (elapsedMs <= 0 || deltaBytes <= 0) return 0.0;
return deltaBytes * 1000.0 / elapsedMs;
}
void _stopActiveSampling({required bool resetValue}) {
_timer?.cancel();
_timer = null;
_sampleSessionId++;
_sampleInFlight = false;
_lastBytes = 0;
_latestTotalBytes = null;
_lastSampleAt = null;
if (resetValue && !_disposed) {
available.value = false;
speed.value = 0;
}
}
void dispose() {
if (_disposed) return;
_stopActiveSampling(resetValue: false);
_disposed = true;
speed.dispose();
available.dispose();
}
}