private async Task WriteBlob(HttpContext httpContext, BlobInfo blobInfo)
{
if (await this.TryCached(httpContext, blobInfo))
{
return;
}
FileStream currentFile = null;
await this.WriteBlobHeaders(httpContext, blobInfo);
try
{
var blocks = await this.GetBlocks(blobInfo);
string?currentFilePath = null;
foreach (var block in blocks)
{
if (currentFilePath != block.FilePath)
{
if (currentFile != null)
{
await currentFile.DisposeAsync();
}
currentFile = File.Open(block.FilePath, FileMode.Open, FileAccess.Read, FileShare.Read);
}
if (currentFile == null)
{
throw new Exception("Error finding backing file for block");
}
var blockBuffer = blockCopyPool.Rent((int)block.Length);
currentFile.Position = block.StartOffset;
// Can't use Span overload since we're renting the buffer
await currentFile.ReadAsync(blockBuffer, 0, (int)block.Length);
await httpContext.Response.Body.WriteAsync(blockBuffer, 0, (int)block.Length);
}
await httpContext.Response.Body.FlushAsync();
return;
}
catch (FileNotFoundException)
{
}
catch (DirectoryNotFoundException)
{
}
finally
{
currentFile?.Dispose();
}
httpContext.Response.StatusCode = 500;
await this.WriteText(httpContext, $"File backing blocks were not found for '{blobInfo.BlobName}'");
}
