Class Netchannels.pipeSource

A pipe has two internal buffers (realized by Netbuffer). The * output methods of the class write to the incoming buffer. When * new data are appended to the incoming buffer, the conversion function * conv is called; the arguments are the incoming buffer and the outgoing * buffer. The conversion function must convert the data available in the * incoming buffer and append the result to the outgoing buffer. Finally, * the input methods of the class return the data found in the outgoing * buffer. * * The conversion function is called as follows: * conv incoming_buffer at_eof outgoing_buffer * * The conversion function is allowed to do nothing if the incoming data * are not complete enough to be converted. It is also allowed to convert * only the beginning of the incoming buffer. * * If the outgoing buffer is empty, the input methods will raise * Buffer_underrun. * * If close_out is invoked, the end of the data stream will be recorded. * In this case, the conversion function is called with at_eof = true, * and it is expected that this function converts the whole data found * in the incoming buffer. * * close_in implies close_out. * * The conversion function may raise exceptions. The exceptions will * fall through to the caller of the input methods. (The output methods * and close_in, close_out never fail because of such exceptions.) * * The default conversion function copies everything from the incoming * buffer to the outgoing buffer without modification.