public static async Task DownloadS3ObjectAsync(string downloadDir, string objectKey)
{
try
{
var settings = await GetSettingsAsync();
var downloadInfo = new DownloadObjectInfo {
DownloadDirectory = downloadDir, ObjectKey = objectKey
};
AmazonS3Client client = new AmazonS3Client(
settings.AWSAccessKeyID,
settings.AWSSecretAccessKey,
RegionEndpoint.GetBySystemName(settings.AWSS3Region.SystemName));
var request = new GetObjectRequest {
BucketName = settings.AWSS3Bucket, Key = objectKey
};
var response = await client.GetObjectAsync(request);
await SaveObjectAsync(response, downloadInfo);
}
catch (Exception ex)
{
Debug.WriteLine(ex.Message);
DownloadError?.Invoke("Error during download");
throw ex;
}
}
private static async Task SaveObjectAsync(GetObjectResponse response, DownloadObjectInfo info)
{
response.WriteObjectProgressEvent += Response_WriteObjectProgressEvent;
string checkedFilePath = CheckFilePath(info);
await response.WriteResponseStreamToFileAsync(checkedFilePath, false, new CancellationToken());
DownloadSuccess?.Invoke($"Backup downloaded {info.ObjectKey} to {Path.Combine(info.DownloadDirectory, checkedFilePath)}");
}
private static string CheckFilePath(DownloadObjectInfo info)
{
// start: does file already exist?
// yes: rename
// name contains '.'?
// yes: split and rename with n
// no: append n to name
// n++
// goto start
// no: download
var file = info.ObjectKey;
var splits = info.ObjectKey.Split('.');
string baseName = "";
for (int i = 0; i < splits.Count() - 1; i++)
{
baseName += splits[i] + '.';
}
baseName = baseName.TrimEnd('.');
int n = 0;
while (File.Exists(Path.Combine(info.DownloadDirectory, file)))
{
n++;
if (splits.Count() > 1)
{
file = $"{baseName} ({n})." + splits[splits.Count() - 1];
}
else
{
file = $"{info.ObjectKey} ({n})";
}
}
var checkedFilePath = Path.Combine(info.DownloadDirectory, file);
return(checkedFilePath);
}
