private async Task Save(Stream source, Stream dest, FileUploadStatus status, Action <FileUploadStatus> statusUpdate)
{
try
{
status.StartedAt = DateTime.UtcNow;
if (statusUpdate != null)
{
statusUpdate.Invoke(status);
}
byte[] buffer = new byte[4096];
int bytes = 0;
long totalBlocks = 0;
do
{
bytes = await source.ReadAsync(buffer, 0, buffer.Length);
await dest.WriteAsync(buffer, 0, bytes);
totalBlocks += 1;
status.Count += bytes;
if (totalBlocks % 1024 == 0 && statusUpdate != null)
{
statusUpdate.Invoke(status);
}
} while (bytes > 0);
status.Count = status.Size;
status.StoppedAt = DateTime.UtcNow;
_logger.LogInformation("File upload complete: {0} {1}b {2}s {3}b/s", status.Key, status.Count, status.Duration, status.Rate);
}
catch (Exception ex)
{
status.Error = ex;
_logger.LogError(0, ex, "File upload failed: {0}", status.Key);
throw ex;
}
finally
{
await dest.FlushAsync();
dest.Dispose();
statusUpdate.Invoke(status); //give caller chance to clean up
}
}
public async Task Process(
HttpRequest request,
Action <FormOptions> optionsAction,
Func <NameValueCollection, Stream> getDestinationStream,
Action <FileUploadStatus> statusUpdate,
Action <NameValueCollection> postProcess = null
)
{
if (!request.ContentType.IsMultipartContentType())
{
throw new InvalidOperationException($"Expected a multipart request, but got {request.ContentType}");
}
if (optionsAction != null)
{
optionsAction.Invoke(_formOptions);
}
string boundary = request.ContentType.GetBoundary();
NameValueCollection metadata = new NameValueCollection();
MultipartReader reader = new MultipartReader(boundary, request.Body);
MultipartSection section = await reader.ReadNextSectionAsync();
while (section != null)
{
bool hasContentDispositionHeader = ContentDispositionHeaderValue
.TryParse(section.ContentDisposition, out ContentDispositionHeaderValue contentDisposition);
if (hasContentDispositionHeader)
{
if (contentDisposition.HasFormDataContentDisposition())
{
//add form values to metadata collection
var encoding = section.GetEncoding();
using (var streamReader = new StreamReader(
section.Body,
encoding,
detectEncodingFromByteOrderMarks: true,
bufferSize: 1024,
leaveOpen: true))
{
// The value length limit is enforced by MultipartBodyLengthLimit
string value = await streamReader.ReadToEndAsync();
if (String.Equals(value, "undefined", StringComparison.OrdinalIgnoreCase))
{
value = String.Empty;
}
metadata = value.ParseFormValues();
}
}
if (contentDisposition.HasFileContentDisposition())
{
metadata.Add("filename", HeaderUtilities.RemoveQuotes(contentDisposition.FileName).Value);
if (!metadata["size"].HasValue())
{
metadata.Add("size", "1000000000");
}
if (!metadata["upload-key"].HasValue())
{
metadata.Add("upload-key", Guid.NewGuid().ToString());
}
Stream targetStream = getDestinationStream.Invoke(metadata);
FileUploadStatus status = new FileUploadStatus
{
Metadata = metadata,
Key = metadata["upload-key"],
Size = Int64.Parse(metadata["size"])
};
await Save(section.Body, targetStream, status, statusUpdate);
if (postProcess != null)
{
postProcess.Invoke(metadata);
}
}
}
// Drains any remaining section body that has not been consumed and
// reads the headers for the next section.
section = await reader.ReadNextSectionAsync();
}
}