static async Task <byte[]> readExactAsync
(int count, Func <byte[], int, int, object> readFunc, ReadExactInfo info)
{
var timeouter = new Timeouter(info.MethodTimeout);
var buffer = new byte[count];
var offset = 0;
var totalBytesRead = 0;
var remain = count;
while (totalBytesRead != count)
{
var bytesRead = 0;
var readInfo = readFunc(buffer, offset, remain);
if (readInfo is Task <int> task)
{
bytesRead = await task;
}
else if (readInfo is int read)
{
bytesRead = read;
}
else
{
throw new NotSupportedException();
}
totalBytesRead += bytesRead;
offset = totalBytesRead;
remain = count - totalBytesRead;
if (bytesRead == 0 && info.ThrowIfZeroReceived)
{
throw new ReadExactZeroReceivedException();
}
if (info.RetryDelay != 0)
{
await Task.Delay(info.RetryDelay).ConfigureAwait(false);
}
if ((info.TimeoutOnlyIfNothingWasRead && totalBytesRead == 0) ||
(!info.TimeoutOnlyIfNothingWasRead))
{
timeouter.ThrowIfTimeout(() => new ReadExactTimeoutException(buffer.Take(totalBytesRead), count));
}
}
return(buffer);
}
public static async Task <byte[]> ReadExactAsync(this Stream stream, int count, ReadExactInfo info,
CancellationToken cancellation)
{
return(await readExactAsync(count, (a, b, c) => stream.ReadAsync(a, b, c, cancellation), info));
}