/*

* Copyright (c) Steven P. Goldsmith. All rights reserved.

*/

package com.codeferm.periphery;

import static com.codeferm.periphery.Common.MAX_CHAR_ARRAY_LEN;

import static com.codeferm.periphery.Common.jString;

import static com.codeferm.periphery.Common.memMove;

import static org.fusesource.hawtjni.runtime.FieldFlag.CONSTANT;

import org.fusesource.hawtjni.runtime.JniClass;

import org.fusesource.hawtjni.runtime.JniField;

import org.fusesource.hawtjni.runtime.JniMethod;

import org.fusesource.hawtjni.runtime.Library;

import static org.fusesource.hawtjni.runtime.MethodFlag.CONSTANT_INITIALIZER;

/**

* c-periphery Serial wrapper functions for Linux userspace termios tty devices.

*

* @author Steven P. Goldsmith

* @version 1.0.0

* @since 1.0.0

*/

@JniClass

public class Serial implements AutoCloseable {

/**

* Function was successful.

*/

public static final int SERIAL_SUCCESS = 0;

/**

* java-periphery library.

*/

private static final Library LIBRARY = new Library("java-periphery", Serial.class);

/**

* Serial handle.

*/

final private long handle;

/**

* Load library.

*/

static {

LIBRARY.load();

init();

}

/**

* Load constants.

*/

@JniMethod(flags = {CONSTANT_INITIALIZER})

private static native void init();

/**

* Error constants.

*/

@JniField(flags = {CONSTANT})

public static int SERIAL_ERROR_ARG;

@JniField(flags = {CONSTANT})

public static int SERIAL_ERROR_OPEN;

@JniField(flags = {CONSTANT})

public static int SERIAL_ERROR_QUERY;

@JniField(flags = {CONSTANT})

public static int SERIAL_ERROR_CONFIGURE;

@JniField(flags = {CONSTANT})

public static int SERIAL_ERROR_IO;

@JniField(flags = {CONSTANT})

public static int SERIAL_ERROR_CLOSE;

/**

* Parity constants.

*/

@JniField(flags = {CONSTANT})

public static int PARITY_NONE;

@JniField(flags = {CONSTANT})

public static int PARITY_ODD;

@JniField(flags = {CONSTANT})

public static int PARITY_EVEN;

/**

* Open the tty device at the specified path (e.g. "/dev/ttyUSB0"), with the specified baudrate, and the defaults of 8 data

* bits, no parity, 1 stop bit, software flow control (xonxoff) off, hardware flow control (rtscts) off.

*

* @param path Serial device path.

* @param baudrate Baud rate.

*/

public Serial(final String path, final int baudrate) {

// Allocate handle

handle = serialNew();

if (handle == 0) {

throw new RuntimeException("Handle cannot be NULL");

}

// Open device

if (serialOpen(handle, path, baudrate) != SERIAL_SUCCESS) {

// Free handle before throwing exception

serialFree(handle);

throw new RuntimeException(serialErrMessage(handle));

}

}

/**

* Close and free handle.

*/

@Override

public void close() {

serialClose(handle);

serialFree(handle);

}

/**

* Handle accessor.

*

* @return Handle.

*/

public long getHandle() {

return handle;

}

/**

* Allocate a Serial handle. Returns a valid handle on success, or NULL on failure.

*

* @return A valid handle on success, or NULL on failure.

*/

@JniMethod(accessor = "serial_new")

public static final native long serialNew();

/**

* Open the tty device at the specified path (e.g. "/dev/ttyUSB0"), with the specified baudrate, and the defaults of 8 data

* bits, no parity, 1 stop bit, software flow control (xonxoff) off, hardware flow control (rtscts) off.

*

* @param serial Valid pointer to an allocated Serial handle structure.

* @param path Serial device path.

* @param baudrate Baud rate.

* @return 0 on success, or a negative Serial error code on failure.

*/

@JniMethod(accessor = "serial_open")

public static native int serialOpen(long serial, String path, int baudrate);

/**

* Open the tty device at the specified path (e.g. "/dev/ttyUSB0"), with the specified baudrate, data bits, parity, stop bits,

* software flow control (xonxoff), and hardware flow control (rtscts) settings.

*

* serial should be a valid pointer to an allocated Serial handle structure. databits can be 5, 6, 7, or 8. parity can be

* PARITY_NONE, PARITY_ODD, or PARITY_EVEN as defined above. stopbits can be 1 or 2.

*

* @param serial Valid pointer to an allocated Serial handle structure.

* @param path Serial device path.

* @param baudrate Baud rate.

* @param databits Data bits.

* @param parity Parity.

* @param stopbits Stop bits.

* @param xonXoff Software flow control.

* @param rtsCts Hardware flow control.

* @return 0 on success, or a negative Serial error code on failure.

*/

@JniMethod(accessor = "serial_open_advanced")

public static native int serialOpenAdvanced(long serial, String path, int baudrate, int databits, int parity, int stopbits,

boolean xonXoff, boolean rtsCts);

/**

* Read up to len number of bytes from the serial port into the buf buffer with the specified millisecond timeout. A 0 timeout

* can be specified for a non-blocking read. A negative timeout can be specified for a blocking read that will read until all of

* the requested number of bytes are read. A positive timeout in milliseconds can be specified for a blocking read with timeout.

*

* @param serial Valid pointer to an allocated Serial handle structure.

* @param buf Read buffer.

* @param len Amount of data to read.

* @param timeoutMs can be positive for a timeout in milliseconds, 0 for a non-blocking read, or a negative number for a

* blocking read.

* @return number of bytes read on success, 0 on timeout, or a negative Serial error code on failure.

*/

@JniMethod(accessor = "serial_read")

public static native int serialRead(long serial, byte[] buf, int len, int timeoutMs);

/**

* Write len number of bytes from the buf buffer to the serial port.

*

* @param serial Valid pointer to an allocated Serial handle structure.

* @param buf Write buffer.

* @param len Amount of data to write.

* @return Number of bytes written on success, or a negative Serial error code on failure.

*/

@JniMethod(accessor = "serial_write")

public static native int serialWrite(long serial, byte[] buf, int len);

/**

* Flush the write buffer of the serial port (i.e. force its write immediately).

*

* @param serial Valid pointer to an allocated Serial handle structure.

* @return 0 on success, or a negative Serial error code on failure.

*/

@JniMethod(accessor = "serial_flush")

public static native int serialFlush(long serial);

/**

* Get the number of bytes waiting to be read from the serial port.

*

* @param serial Valid pointer to an allocated Serial handle structure.

* @param count Byte count.

* @return 0 on success, or a negative Serial error code on failure.

*/

@JniMethod(accessor = "serial_input_waiting")

public static native int serialInputWaiting(long serial, int[] count);

/**

* Get the number of bytes waiting to be written to the serial port.

*

* @param serial Valid pointer to an allocated Serial handle structure.

* @param count Byte count.

* @return 0 on success, or a negative Serial error code on failure.

*/

@JniMethod(accessor = "serial_output_waiting")

public static native int serialOutputWaiting(long serial, int[] count);

/**

* Poll for data available for reading from the serial port.

*

* @param serial Valid pointer to an allocated Serial handle structure.

* @param timeoutMs can be positive for a timeout in milliseconds, 0 for a non-blocking poll, or a negative number for a

* blocking poll.

* @return 1 on success (data available for reading), 0 on timeout, or a negative Serial error code on failure.

*/

@JniMethod(accessor = "serial_poll")

public static native int serialPoll(long serial, int timeoutMs);

/**

* Close the tty device.

*

* @param serial Valid pointer to an allocated Serial handle structure.

* @return 0 on success, or a negative Serial error code on failure.

*/

@JniMethod(accessor = "serial_close")

public static native int serialClose(long serial);

/**

* Free a GPIO handle.

*

* @param serial Valid pointer to an allocated Serial handle structure.

*/

@JniMethod(accessor = "serial_free")

public static native void serialFree(long serial);

/**

* Get baud rate.

*

* @param serial Valid pointer to an allocated Serial handle structure.

* @param baudRate Baud rate.

* @return 0 on success, or a negative Serial error code on failure.

*/

@JniMethod(accessor = "serial_get_baudrate")

public static native int serialGetBaudRate(long serial, int[] baudRate);

/**

* Get data bits.

*

* @param serial Valid pointer to an allocated Serial handle structure.

* @param dataBits Data bits.

* @return 0 on success, or a negative Serial error code on failure.

*/

@JniMethod(accessor = "serial_get_databits")

public static native int serialGetDataBits(long serial, int[] dataBits);

/**

* Get parity.

*

* @param serial Valid pointer to an allocated Serial handle structure.

* @param parity Parity.

* @return 0 on success, or a negative Serial error code on failure.

*/

@JniMethod(accessor = "serial_get_parity")

public static native int serialGetParity(long serial, int[] parity);

/**

* Get stop bits.

*

* @param serial Valid pointer to an allocated Serial handle structure.

* @param stopBits Stop bits.

* @return 0 on success, or a negative Serial error code on failure.

*/

@JniMethod(accessor = "serial_get_stopbits")

public static native int serialGetStopBits(long serial, int[] stopBits);

/**

* Get Xon/Xoff.

*

* @param serial Valid pointer to an allocated Serial handle structure.

* @param xonXoff Xon/Xoff.

* @return 0 on success, or a negative Serial error code on failure.

*/

@JniMethod(accessor = "serial_get_stopbits")

public static native int serialGetXonXoff(long serial, boolean[] xonXoff);

/**

* Get RTS/CTS.

*

* @param serial Valid pointer to an allocated Serial handle structure.

* @param rtsCts RTS/CTS.

* @return 0 on success, or a negative Serial error code on failure.

*/

@JniMethod(accessor = "serial_get_rtscts")

public static native int serialGetRtsCts(long serial, boolean[] rtsCts);

/**

* Set baud rate.

*

* @param serial Valid pointer to an allocated Serial handle structure.

* @param baudRate Baud rate.

* @return 0 on success, or a negative Serial error code on failure.

*/

@JniMethod(accessor = "serial_set_baudrate")

public static native int serialSetBaudRate(long serial, int baudRate);

/**

* Set data bits.

*

* @param serial Valid pointer to an allocated Serial handle structure.

* @param dataBits Data bits.

* @return 0 on success, or a negative Serial error code on failure.

*/

@JniMethod(accessor = "serial_set_databits")

public static native int serialSetDataBits(long serial, int dataBits);

/**

* Set parity.

*

* @param serial Valid pointer to an allocated Serial handle structure.

* @param parity Parity.

* @return 0 on success, or a negative Serial error code on failure.

*/

@JniMethod(accessor = "serial_set_parity")

public static native int serialSetParity(long serial, int parity);

/**

* Set stop bits.

*

* @param serial Valid pointer to an allocated Serial handle structure.

* @param stopBits Stop bits.

* @return 0 on success, or a negative Serial error code on failure.

*/

@JniMethod(accessor = "serial_set_stopbits")

public static native int serialSetStopBits(long serial, int stopBits);

/**

* Set Xon/Xoff.

*

* @param serial Valid pointer to an allocated Serial handle structure.

* @param xonXoff Xon/Xoff.

* @return 0 on success, or a negative Serial error code on failure.

*/

@JniMethod(accessor = "serial_set_stopbits")

public static native int serialSetXonXoff(long serial, boolean xonXoff);

/**

* Set RTS/CTS.

*

* @param serial Valid pointer to an allocated Serial handle structure.

* @param rtsCts RTS/CTS.

* @return 0 on success, or a negative Serial error code on failure.

*/

@JniMethod(accessor = "serial_set_rtscts")

public static native int serialSetRtsCts(long serial, boolean rtsCts);

/**

* Return the file descriptor (for the underlying tty device) of the Serial handle.

*

* @param serial Valid pointer to an allocated Serial handle structure.

* @return File descriptor (for the underlying tty device) of the Serial handle.

*/

@JniMethod(accessor = "serial_fd")

public static native int serialFd(long serial);

/**

* Return a string representation of the serial handle.

*

* @param serial Valid pointer to an allocated serial handle structure.

* @param str String representation of the serial handle.

* @param len Length of char array.

* @return 0 on success, or a negative serial error code on failure.

*/

@JniMethod(accessor = "serial_tostring")

public static native int serialToString(long serial, byte[] str, long len);

/**

* Return a string representation of the serial handle. Wraps native method and simplifies.

*

* @param serial Valid pointer to an allocated serial handle structure.

* @return Serial handle as String.

*/

public static String serialToString(long serial) {

var str = new byte[MAX_CHAR_ARRAY_LEN];

if (serialToString(serial, str, str.length) < 0) {

throw new RuntimeException(serialErrMessage(serial));

}

return jString(str);

}

/**

* Return the libc errno of the last failure that occurred.

*

* @param serial Valid pointer to an allocated serial handle structure.

* @return libc errno.

*/

@JniMethod(accessor = "serial_errno")

public static native int serialErrNo(long serial);

/**

* Return a human readable error message pointer of the last failure that occurred.

*

* @param serial Valid pointer to an allocated serial handle structure.

* @return Error message pointer.

*/

@JniMethod(accessor = "serial_errmsg")

public static native long serialErrMsg(long serial);

/**

* Return a human readable error message of the last failure that occurred. Converts const char * returned by serial_errmsg to a

* Java String.

*

* @param serial Valid pointer to an allocated serial handle structure.

* @return Error message.

*/

public static String serialErrMessage(long serial) {

var ptr = serialErrMsg(serial);

var str = new byte[MAX_CHAR_ARRAY_LEN];

memMove(str, ptr, str.length);

return jString(str);

}

}