internal virtual string BuildPresignedObjectCacheKey(string bucketName, string objectName, PresignedObjectType type)
{
return(Encrypt.MD5($"{this.GetType().FullName}_{bucketName}_{objectName}_{type.ToString().ToUpper()}"));
}
private async Task <string> PresignedObjectAsync(string bucketName, string objectName, int expiresInt, PresignedObjectType type)
{
if (string.IsNullOrEmpty(bucketName))
{
throw new ArgumentNullException(nameof(bucketName));
}
if (string.IsNullOrEmpty(objectName))
{
throw new ArgumentNullException(nameof(objectName));
}
if (expiresInt <= 0)
{
throw new Exception("ExpiresIn time can not less than 0.");
}
if (expiresInt > 7 * 24 * 3600)
{
throw new Exception("ExpiresIn time no more than 7 days.");
}
long nowTime = (DateTime.Now.ToUniversalTime().Ticks - 621355968000000000) / 10000000;
const int minExpiresInt = 600;
string key = Encrypt.MD5($"{bucketName}_{objectName}_{type.ToString().ToUpper()}");
string objectUrl = null;
//查找缓存
if (Options.IsEnableCache && (expiresInt > minExpiresInt))
{
var cacheResult = await _cache.GetAsync <PresignedUrlCache>(key);
PresignedUrlCache cache = cacheResult.HasValue ? cacheResult.Value : null;
//缓存中存在，且有效时间不低于10分钟
if (cache != null &&
cache.Type == type &&
cache.CreateTime > 0 &&
(cache.CreateTime + expiresInt - nowTime) > minExpiresInt &&
cache.Name == objectName &&
cache.BucketName == bucketName)
{
return(cache.Url);
}
}
if (type == PresignedObjectType.Get)
{
//生成URL
AccessMode accessMode = await this.GetObjectAclAsync(bucketName, objectName);
if (accessMode == AccessMode.PublicRead || accessMode == AccessMode.PublicReadWrite)
{
string bucketUrl = await this.GetBucketEndpointAsync(bucketName);
objectUrl = $"{bucketUrl}{(objectName.StartsWith("/") ? "" : "/")}{objectName}";
}
else
{
var req = new GeneratePresignedUriRequest(bucketName, objectName, SignHttpMethod.Get)
{
Expiration = DateTime.Now.AddSeconds(expiresInt)
};
var uri = _client.GeneratePresignedUri(req);
if (uri != null)
{
objectUrl = uri.ToString();
}
}
}
else
{
var req = new GeneratePresignedUriRequest(bucketName, objectName, SignHttpMethod.Put)
{
Expiration = DateTime.Now.AddSeconds(expiresInt)
};
var uri = _client.GeneratePresignedUri(req);
if (uri != null)
{
objectUrl = uri.ToString();
}
}
if (string.IsNullOrEmpty(objectUrl))
{
throw new Exception("Presigned get object url failed.");
}
//save cache
if (Options.IsEnableCache && expiresInt > minExpiresInt)
{
PresignedUrlCache urlCache = new PresignedUrlCache()
{
Url = objectUrl,
CreateTime = nowTime,
Name = objectName,
BucketName = bucketName,
Type = type
};
int randomSec = new Random().Next(5, 30);
await _cache.SetAsync(key, urlCache, TimeSpan.FromSeconds(expiresInt + randomSec));
}
return(objectUrl);
}
private async Task <string> PresignedObjectAsync(string bucketName, string objectName, int expiresInt, PresignedObjectType type)
{
if (string.IsNullOrEmpty(bucketName))
{
throw new ArgumentNullException(nameof(bucketName));
}
if (string.IsNullOrEmpty(objectName))
{
throw new ArgumentNullException(nameof(objectName));
}
if (expiresInt <= 0)
{
throw new Exception("ExpiresIn time can not less than 0.");
}
if (expiresInt > 7 * 24 * 3600)
{
throw new Exception("ExpiresIn time no more than 7 days.");
}
long nowTime = (DateTime.Now.ToUniversalTime().Ticks - 621355968000000000) / 10000000;
const int minExpiresInt = 600;
string key = Encrypt.MD5($"{bucketName}_{objectName}_{type.ToString().ToUpper()}");
string objectUrl = null;
string newBucketName = ConvertBucketName(bucketName);
PreSignatureStruct preSignatureStruct = new PreSignatureStruct()
{
appid = Options.Endpoint,
region = Options.Region,
bucket = newBucketName,
key = objectName,
httpMethod = type.ToString().ToUpper(),
isHttps = Options.IsEnableHttps,
signDurationSecond = expiresInt,
headers = null,
queryParameters = null,
};
//查找缓存
if (Options.IsEnableCache && (expiresInt > minExpiresInt))
{
var cacheResult = await _cache.GetAsync <PresignedUrlCache>(key);
PresignedUrlCache cache = cacheResult.HasValue ? cacheResult.Value : null;
//缓存中存在，且有效时间不低于10分钟
if (cache != null &&
cache.Type == type &&
cache.CreateTime > 0 &&
(cache.CreateTime + expiresInt - nowTime) > minExpiresInt &&
cache.Name == objectName &&
cache.BucketName == bucketName)
{
return(cache.Url);
}
}
if (type == PresignedObjectType.Get)
{
//生成URL
AccessMode accessMode = await this.GetObjectAclAsync(bucketName, objectName);
if (accessMode == AccessMode.PublicRead || accessMode == AccessMode.PublicReadWrite)
{
objectUrl = $"{(Options.IsEnableHttps ? "https" : "http")}://{newBucketName}.cos.{Options.Region}.myqcloud.com{(objectName.StartsWith("/") ? "" : "/")}{objectName}";
}
else
{
string uri = _client.GenerateSignURL(preSignatureStruct);
if (uri != null)
{
objectUrl = uri.ToString();
}
}
}
else
{
string uri = _client.GenerateSignURL(preSignatureStruct);
if (uri != null)
{
objectUrl = uri.ToString();
}
}
if (string.IsNullOrEmpty(objectUrl))
{
throw new Exception("Presigned get object url failed.");
}
//save cache
if (Options.IsEnableCache && expiresInt > minExpiresInt)
{
PresignedUrlCache urlCache = new PresignedUrlCache()
{
Url = objectUrl,
CreateTime = nowTime,
Name = objectName,
BucketName = bucketName,
Type = type
};
int randomSec = new Random().Next(5, 30);
await _cache.SetAsync(key, urlCache, TimeSpan.FromSeconds(expiresInt + randomSec));
}
return(objectUrl);
}
