62 lines
1.8 KiB
Dart
62 lines
1.8 KiB
Dart
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import 'dart:async';
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import 'package:http/http.dart' as http;
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class RateLimitStatus {
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int consecutiveCount = 0;
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Duration timeout = const Duration(seconds: 1);
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}
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class ApiManager {
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String baseUrl;
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Future<void> ongoingRequest = Future.value();
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int consecutiveRateLimitExceeded = 0;
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Duration rateLimitTimeout = Duration.zero;
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DateTime? lastRequest;
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ApiManager(this.baseUrl);
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Future<http.Response> get(String path) async {
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Future<void> waitingForRequest = ongoingRequest;
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Completer completer = Completer();
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try {
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ongoingRequest = completer.future;
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await waitingForRequest;
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DateTime? lastRequestLocal = lastRequest;
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if (consecutiveRateLimitExceeded > 0 &&
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lastRequestLocal != null &&
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DateTime.now().isBefore(lastRequestLocal.add(rateLimitTimeout))) {
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throw Exception("Too many requests");
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}
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http.Response response = await http.get(Uri.parse(baseUrl + path));
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lastRequest = DateTime.now();
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if (response.statusCode == 429) {
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consecutiveRateLimitExceeded++;
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if (consecutiveRateLimitExceeded == 1) {
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rateLimitTimeout = const Duration(seconds: 1);
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} else {
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rateLimitTimeout *= 2;
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}
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String? retryAfter = response.headers["Retry-After"];
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if (retryAfter != null) {
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int? retryAfterSeconds = int.tryParse(retryAfter);
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if (retryAfterSeconds != null) {
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Duration retryAfterDuration = Duration(seconds: retryAfterSeconds);
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if (retryAfterDuration > rateLimitTimeout) {
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rateLimitTimeout = retryAfterDuration;
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}
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}
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}
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throw Exception("Too many requests");
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} else {
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consecutiveRateLimitExceeded = 0;
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}
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return response;
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} finally {
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completer.complete();
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}
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}
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}
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