DoubleBufferedStreamReader.Read.cs

[MethodImpl(MethodImplOptions.AggressiveInlining)]
public int ReadByte()
{
    if (this.position >= this.Length)
    {
        return -1;
    }

    if (this.position == 0 || this.bytesRead >= ChunkLength)
    {
        return ReadByteSlow();
    }
    else
    {
        this.position++;
        return this.chunk[this.bytesRead++];
    }

}

[MethodImpl(MethodImplOptions.NoInlining)]
private int ReadByteSlow()
{
    this.stream.Seek(this.position, SeekOrigin.Begin);
    this.stream.Read(this.chunk, 0, ChunkLength);
    this.bytesRead = 0;

    this.position++;
    return this.chunk[this.bytesRead++];
}