doorgo/door/input_linux.go

package door

import (
	"bufio"
	"bytes"
	"log"
	"strings"
	"syscall"
	"time"
)

var ReaderInterval = time.Duration(200) * time.Millisecond
var ReaderTimeval syscall.Timeval = syscall.NsecToTimeval(int64(ReaderInterval))

// Output a nice string representation of the rune buffer.
func extended_output(buffer []rune) string {
	var output string = string(buffer)
	output = strings.Replace(output, "\x1b", "^[", -1)
	return output
}

// syscall.FdSet clear all
func clearAll(fdSetPtr *syscall.FdSet) {
	for index := range (*fdSetPtr).Bits {
		(*fdSetPtr).Bits[index] = 0
	}
}

// syscall.FdSet set fd
func set(fdSetPtr *syscall.FdSet, fd int) {
	(*fdSetPtr).Bits[fd/64] |= 1 << uint64(fd%64)
}

// go routine Reader for input
// This "times out" every ReaderTimeval
func Reader(d *Door) {
	// I need non-blocking reads here.
	/*
		ReaderTimeval = syscall.Timeval{Sec: int64(ReaderInterval.Seconds()),
			Usec: ReaderInterval.Microseconds() % time.Second.Microseconds()}
	*/

	log.Println(ReaderInterval, ReaderTimeval)

	readerBuffer = make([]rune, 0, READ_SIZE*2)

	defer func() {
		log.Printf("~Reader\n")
		//if d.ReaderCanClose {
		d.wg.Done()
		//}
	}()
	defer func() {
		if err := recover(); err != nil {
			log.Printf("Reader: %#v\n", err)
		}
	}()

	var fdset syscall.FdSet
	var readbuffer [READ_SIZE]byte
	var runebuffer bytes.Buffer
	var runeread = bufio.NewReaderSize(&runebuffer, 1)
	var selectTimeval syscall.Timeval

	for {
		clearAll(&fdset)
		set(&fdset, d.READFD)
		selectTimeval = ReaderTimeval
		v, err := syscall.Select(d.READFD+1, &fdset, nil, nil, &selectTimeval)

		if err == syscall.EINTR {
			continue
		}
		// log.Printf("Select: %#v / %#v\n", v, err)

		if v == -1 {
			log.Printf("Reader ERR: %#v\n", err)
			d.readerMutex.Lock()

			if !d.ReaderClosed {
				d.ReaderClosed = true
				close(d.readerChannel)
			}
			return
		}

		if v == 0 {
			// timeout
			ReadRune(d, runeread, true)
			// process(d, false)

			d.readerMutex.Lock()
			if d.ReaderEnd {
				if !d.ReaderClosed {
					d.ReaderClosed = true
					close(d.readerChannel)
				}
				d.readerMutex.Unlock()
				return
			}
			d.readerMutex.Unlock()
			continue
		}

		// The buffer used here must have len & cap to size you want to read.
		// use [BUFF_SIZE]byte for readone
		r, err := syscall.Read(d.READFD, readbuffer[:])
		if r == -1 {
			log.Println("syscall.Read -1 (closed)")
			d.readerMutex.Lock()
			defer d.readerMutex.Unlock()
			if !d.ReaderClosed {
				d.ReaderClosed = true
				d.Disconnected = true
				close(d.readerChannel)
			}
			return
		}
		if r == 0 {
			log.Printf("Select said ready, but: %#v %#v\n", r, err)
			d.readerMutex.Lock()
			defer d.readerMutex.Unlock()
			if !d.ReaderClosed {
				d.ReaderClosed = true
				d.Disconnected = true
				close(d.readerChannel)
			}
			return
		}

		if DEBUG_INPUT {
			log.Printf("Reader << %d, %#v\n", r, readbuffer[:r])
		}

		// write the received bytes into runebuffer.
		runebuffer.Write(readbuffer[:r])

		ReadRune(d, runeread, false)
		// process(d, true)

		// buffer = append(buffer, readone[0])

		/*
			Take2:
				input, size = utf8.DecodeRune(buffer)
				if input != utf8.RuneError {
					d.readerChannel <- input
					for size > 0 {
						ArrayDelete(&buffer, 0)
						size--
					}
					if len(buffer) > 0 {
						goto Take2
					}
					timeoutCount = 0
				} else {
					// Not a valid rune
					continue
				}
		*/
		// d.readerChannel <- rune(buffer[0])

	}
}