🚦 f_limit

Dart concurrency limiter for async operations.

中文文档

---

📦 Install

dependencies:
  f_limit: ^1.0.0

dart pub get

---

⚡ Quick Start

import 'package:f_limit/f_limit.dart';

void main() async {
  final limit = fLimit(2); // Max 2 concurrent operations

  final tasks = List.generate(5, (i) => () async {
    await Future.delayed(Duration(seconds: 1));
    return i;
  });

  final results = await Future.wait(tasks.map((task) => limit(task)));
  print('Done: $results');
}

---

📋 Queue Strategies

Strategy	Description	Use Case
fifo	First In, First Out	Default, fair execution
lifo	Last In, First Out	Stack-like, newest first
priority	Priority-based	Important tasks first
alternating	Head → Tail → Head...	Two-way fair scheduling
random	Random selection	Load balancing

final limit = fLimit(2, queueStrategy: QueueStrategy.priority);

---

📖 API

Constructor

Method	Description
fLimit(concurrency, {queueStrategy})	Create limiter

Properties

Property	Type	Description
activeCount	int	Currently executing
pendingCount	int	In queue
concurrency	int	Max concurrent (get/set)
queueStrategy	QueueStrategy	Current strategy

Methods

Method	Description
call(fn, {priority})	Execute with limit
clearQueue()	Clear pending tasks
isolate(fn, {priority})	Run in isolate
map(items, mapper)	Concurrent mapping
onIdle	Wait for completion

---

🎯 Examples

Priority Queue

final limit = fLimit(1, queueStrategy: QueueStrategy.priority);

limit(() => print('🔴 Critical'), priority: 10);
limit(() => print('🟡 Normal'), priority: 5);
limit(() => print('🟢 Background'), priority: 1);

// Output: 🔴 🟡 🟢

Dynamic Concurrency

final limit = fLimit(1);

limit.concurrency = 5; // Increase at runtime
print('Max concurrent: ${limit.concurrency}');

Clear Queue

final limit = fLimit(1);

// Add many tasks...
for (int i = 0; i < 100; i++) {
  limit(() async => i);
}

print('Pending: ${limit.pendingCount}'); // 99
limit.clearQueue();
print('Pending: ${limit.pendingCount}'); // 0

---

📄 License

MIT © FlutterCandies