public int getBlockLength(final DirectBuffer buffer, final int bufferOffset)
    {
        return Types.getInt(buffer, bufferOffset + blockLengthOffset, blockLengthType, blockLengthByteOrder);
    }
Get the block length of the root block in the message.

@param buffer       from which to read the value.
@param bufferOffset in the buffer at which the message header begins.
@return the length of the root block in the coming message.
sbe-tool/src/main/java/uk/co/real_logic/sbe/otf/OtfHeaderDecoder.java