getObjectUrl method

String getObjectUrl({ required String bucket, required String key, String? region, bool? sign, bool cache = true, int? signValidity, })

获取对象访问 url 参考文档： https://cloud.tencent.com/document/product/436/57420 sign 链接是否需要带上签名 cache 获取的链接是否缓存，目前带签名的链接默认开启缓存，在签名有效期内不会重新生成 signValidity 签名有效期，单位 ms

Implementation

String getObjectUrl({
  required String bucket,
  required String key,
  String? region,
  bool? sign,
  bool cache = true,
  int? signValidity,
}) {
  region ??= config.region;

  final endPoint = config.getEndpoint(bucket, region);
  String url = '$endPoint$key';

  getCOSSign() {
    final startTimeMs = DateTimeHelper.now.millisecondsSinceEpoch;
    final expiredTimeMs = startTimeMs + (signValidity ?? config.signValidity);

    return COSSign(
        startTimeMs: startTimeMs,
        expiredTimeMs: expiredTimeMs,
        secretKey: config.secretKey,
        secretId: config.secretId,
        method: 'GET',
        uriPathname: key);
  }

  if (sign == true) {
    if (cache == true) {
      final cacheKey = '$region-$bucket-$key';
      final cacheValue = memoryCache.getValue(cacheKey);

      if (cacheValue != null) {
        return cacheValue;
      } else {
        final cosSign = getCOSSign();

        final result = '$url?${cosSign.getSignature()}';

        // let the expiration time earlier than the sign, to avoid
        // the sign expiring when arrived the server.
        final expired = cosSign.expiredTimeMs - 1000 * 60;

        memoryCache.addValue(cacheKey, result, expired);

        return result;
      }
    } else {
      final cosSign = getCOSSign();

      return '$url?${cosSign.getSignature()}';
    }
  } else {
    return url;
  }
}