private GridFSDownloadStream CreateDownloadStream(FileDocument fileInfo, GridFSDownloadOptions options, CancellationToken cancellationToken)
{
var checkMD5 = options.CheckMD5 ?? false;
var seekable = options.Seekable ?? false;
return(new GridFSForwardOnlyDownloadStream(this, fileInfo, checkMD5));
}
public async Task DownloadToStreamAsync(Guid fileId, Stream destination,
GridFSDownloadOptions options = null,
CancellationToken cancellationToken = default(CancellationToken))
{
options = options ?? new GridFSDownloadOptions();
var fileInfo = GetFileInfo(fileId, cancellationToken);
await DownloadToStreamHelperAsync(fileInfo, destination, options, cancellationToken).ConfigureAwait(false);
}
public GridFSDownloadStream OpenDownloadStream(Guid fileId,
GridFSDownloadOptions options = null,
CancellationToken cancellationToken = default(CancellationToken))
{
options = options ?? new GridFSDownloadOptions();
var fileInfo = GetFileInfo(fileId, cancellationToken);
return(CreateDownloadStream(fileInfo, options, cancellationToken));
}
private async Task DownloadToStreamHelperAsync(FileDocument fileInfo, Stream destination, GridFSDownloadOptions options, CancellationToken cancellationToken)
{
var checkMD5 = options.CheckMD5 ?? false;
using (var source = new GridFSForwardOnlyDownloadStream(this, fileInfo, checkMD5))
{
var count = source.Length;
var buffer = new byte[fileInfo.ChunkSize];
while (count > 0)
{
var partialCount = (int)Math.Min(buffer.Length, count);
source.Read(buffer, 0, partialCount);
await destination.WriteAsync(buffer, 0, partialCount, cancellationToken).ConfigureAwait(false);
count -= partialCount;
}
await source.CloseAsync(cancellationToken).ConfigureAwait(false);
}
}