ReadAsync() [2/3]

override Task< int > System.IO.BufferedStream.ReadAsync ( byte[] buffer, int offset, int count, CancellationToken cancellationToken )

inlinevirtual

Reimplemented from System.IO.Stream.

Definition at line 433 of file BufferedStream.cs.

    {
        Stream.ValidateBufferArguments(buffer, offset, count);
        if (cancellationToken.IsCancellationRequested)
        {
            return Task.FromCanceled<int>(cancellationToken);
        }
        EnsureNotClosed();
        EnsureCanRead();
        int num = 0;
        SemaphoreSlim semaphoreSlim = EnsureAsyncActiveSemaphoreInitialized();
        Task task = semaphoreSlim.WaitAsync(cancellationToken);
        if (task.IsCompletedSuccessfully)
        {
            bool flag = true;
            try
            {
                num = ReadFromBuffer(buffer, offset, count, out var error);
                flag = num == count || error != null;
                if (flag)
                {
                    return (error == null) ? LastSyncCompletedReadTask(num) : Task.FromException<int>(error);
                }
            }
            finally
            {
                if (flag)
                {
                    semaphoreSlim.Release();
                }
            }
        }
        return ReadFromUnderlyingStreamAsync(new Memory<byte>(buffer, offset + num, count - num), cancellationToken, num, task).AsTask();
    }

References System.Threading.Tasks.ValueTask< TResult >.AsTask(), System.buffer, System.cancellationToken, System.count, System.IO.Stream.EnsureAsyncActiveSemaphoreInitialized(), System.IO.BufferedStream.EnsureCanRead(), System.IO.BufferedStream.EnsureNotClosed(), System.Threading.Tasks.Task< TResult >.FromCanceled(), System.Threading.Tasks.Task< TResult >.FromException(), System.IO.BufferedStream.LastSyncCompletedReadTask(), System.offset, System.IO.BufferedStream.ReadFromBuffer(), System.IO.BufferedStream.ReadFromUnderlyingStreamAsync(), System.Threading.SemaphoreSlim.Release(), System.task, System.IO.Stream.ValidateBufferArguments(), and System.Threading.SemaphoreSlim.WaitAsync().

Referenced by System.IO.BufferedStream.BeginRead().