CachedNetworkImageWidget/lib/src/http_request.dart

import 'dart:isolate';
import 'dart:typed_data';
import 'package:http/http.dart' as http;

class HttpGetImage {
  final String url;
  final int count;
  final Map<String, String>? httpHeaders;
  HttpGetImage({
    required this.url,
    required this.count,
    required this.httpHeaders,
  });

  Future<Uint8List> getDataObjectIsolate() async {
    final ReceivePort receivePort = ReceivePort();

    var data = {'sendPort': receivePort.sendPort, 'url': url, 'count': count};

    if (httpHeaders != null) {
      data = {
        'sendPort': receivePort.sendPort,
        'url': url,
        'headers': httpHeaders!,
        'count': count,
      };
    }

    final Isolate isolate = await Isolate.spawn(_isolateFetchVideo, data);

    try {
      final dynamic result = await receivePort.first;
      isolate.kill();

      if (result is Uint8List) {
        return result;
      } else {
        throw Exception();
      }
    } catch (e) {
      isolate.kill();
      throw Exception();
    } finally {
      receivePort.close();
    }
  }

  Future<void> _isolateFetchVideo(Map<String, dynamic> message) async {
    final SendPort sendPort = message['sendPort'];
    final String url = message['url'];
    int count = message['count'];
    Map<String, String> headers = message.containsKey("headers")
        ? message['headers']
        : null;

    int time = 10;
    late http.Response response;

    do {
      if (time > count) {
        sendPort.send(null);
        break;
      }
      try {
        response = await http
            .get(Uri.parse(url), headers: headers)
            .timeout(Duration(seconds: time));
        if (response.statusCode == 200) {
          sendPort.send(response.bodyBytes);
          break;
        }
        time++;
      } catch (e) {
        sendPort.send(null);
      }
    } while (response.statusCode != 200);
  }
}