public static int computeMessageSetExtensionSize ( final int fieldNumber , final MessageLite value ) { return computeTagSize ( WireFormat . MESSAGE_SET_ITEM ) * 2 + computeUInt32Size ( WireFormat . MESSAGE_SET_TYPE_ID , fieldNumber ) + computeMessageSize ( WireFormat . MESSAGE_SET_MESSAGE , value ) ; }
Compute the number of bytes that would be needed to encode a MessageSet extension to the stream . For historical reasons the wire format differs from normal fields .