/// <summary>
/// Parse a multipart/mixed response body into several responses.
/// </summary>
/// <param name="batchContent">The response content.</param>
/// <param name="batchContentType">The response content type.</param>
/// <param name="async">
/// Whether to invoke the operation asynchronously.
/// </param>
/// <param name="cancellationToken">
/// Optional <see cref="CancellationToken"/> to propagate notifications
/// that the operation should be cancelled.
/// </param>
/// <returns>The parsed <see cref="Response"/>s.</returns>
public static async Task <Response[]> ParseAsync(
Stream batchContent,
string batchContentType,
bool async,
CancellationToken cancellationToken)
{
// Get the batch boundary
if (batchContentType == null ||
!batchContentType.StartsWith(BatchConstants.MultipartContentTypePrefix, StringComparison.Ordinal))
{
throw BatchErrors.InvalidBatchContentType(batchContentType);
}
string batchBoundary = batchContentType.Substring(BatchConstants.MultipartContentTypePrefix.Length);
// Collect the responses in a dictionary (in case the Content-ID
// values come back out of order)
Dictionary <int, Response> responses = new Dictionary <int, Response>();
// Read through the batch body one section at a time until the
// reader returns null
MultipartReader reader = new MultipartReader(batchBoundary, batchContent);
for (MultipartSection section = await reader.GetNextSectionAsync(async, cancellationToken).ConfigureAwait(false);
section != null;
section = await reader.GetNextSectionAsync(async, cancellationToken).ConfigureAwait(false))
{
// Get the Content-ID header
if (!section.Headers.TryGetValue(BatchConstants.ContentIdName, out StringValues contentIdValues) ||
contentIdValues.Count != 1 ||
!int.TryParse(contentIdValues[0], out int contentId))
{
// If the header wasn't found, this is a failed request
// with the details being sent as the first sub-operation
// so we default the Content-ID to 0
contentId = 0;
}
// Build a response
MemoryResponse response = new MemoryResponse();
responses[contentId] = response;
// We're going to read the section's response body line by line
using var body = new BufferedReadStream(section.Body, BatchConstants.ResponseLineSize);
// The first line is the status like "HTTP/1.1 202 Accepted"
string line = await body.ReadLineAsync(async, cancellationToken).ConfigureAwait(false);
string[] status = line.Split(new char[] { ' ' }, 3, StringSplitOptions.RemoveEmptyEntries);
if (status.Length != 3)
{
throw BatchErrors.InvalidHttpStatusLine(line);
}
response.SetStatus(int.Parse(status[1], CultureInfo.InvariantCulture));
response.SetReasonPhrase(status[2]);
// Continue reading headers until we reach a blank line
line = await body.ReadLineAsync(async, cancellationToken).ConfigureAwait(false);
while (!string.IsNullOrEmpty(line))
{
// Split the header into the name and value
int splitIndex = line.IndexOf(':');
if (splitIndex <= 0)
{
throw BatchErrors.InvalidHttpHeaderLine(line);
}
var name = line.Substring(0, splitIndex);
var value = line.Substring(splitIndex + 1, line.Length - splitIndex - 1).Trim();
response.AddHeader(name, value);
line = await body.ReadLineAsync(async, cancellationToken).ConfigureAwait(false);
}
// Copy the rest of the body as the response content
var responseContent = new MemoryStream();
if (async)
{
await body.CopyToAsync(responseContent).ConfigureAwait(false);
}
else
{
body.CopyTo(responseContent);
}
responseContent.Seek(0, SeekOrigin.Begin);
response.ContentStream = responseContent;
}
// Collect the responses and order by Content-ID
Response[] ordered = new Response[responses.Count];
for (int i = 0; i < ordered.Length; i++)
{
ordered[i] = responses[i];
}
return(ordered);
}
