gpsfake

#!/usr/bin/env python
#
# gpsfake -- test harness for gpsd
#
# Simulates one or more GPSes, playing back logfiles.
# Most of the logic for this now lives in gps.fake,
# factored out so we can write other test programs with it.
#
# This file is Copyright (c) 2010 by the GPSD project
# BSD terms apply: see the file COPYING in the distribution root for details.

import sys, os, time, getopt, socket, random, pty
import gps, gps.fake as gpsfake   # The "as" pacifies pychecker

class Baton:
    "Ship progress indications to stderr."
    # By setting this > 1 we reduce the frequency of the twirl
    # and speed up test runs.  Should be relatively prime to the
    # nunber of baton states, otherwise it will cause beat artifacts
    # in the twirling.
    SPINNER_INTERVAL = 11
    def __init__(self, prompt, endmsg=None):
        self.stream = sys.stderr
        self.stream.write(prompt + "...")
        if os.isatty(self.stream.fileno()):
            self.stream.write(" \b")
        self.stream.flush()
        self.count = 0
        self.endmsg = endmsg
        self.time = time.time()
        return

    def twirl(self, ch=None):
        if self.stream is None:
            return
        if os.isatty(self.stream.fileno()):
            if ch:
                self.stream.write(ch)
                self.stream.flush()
            elif self.count % Baton.SPINNER_INTERVAL == 0:
                self.stream.write("-/|\\"[self.count % 4])
                self.stream.write("\b")
                self.stream.flush()
        self.count = self.count + 1
        return

    def end(self, msg=None):
        if msg == None:
            msg = self.endmsg
        if self.stream:
            self.stream.write("...(%2.2f sec) %s.\n" % (time.time() - self.time, msg))
        return

def fakeport():
    "Find a port that isn't in use to bind to."
    # Grab a random port from IANA's unassigned/private range. Not perfect,
    # but at least less than in 16000 chance of a pair collision. It would
    # be very hard to get this deterministically correct, since there would
    # always be a window between port allocation and when the daemon picked
    # it up.  We'd need to do some kind of semaphore, etc., and even that
    # wouldn't prevent collisions with other apps using the range.
    return random.randint(49152, 65535)

def hexdump(s):
    rep = ""
    for c in s:
        rep += "%02x" % ord(c)
    return rep

def fakehook(linenumber, fakegps):
    if len(fakegps.testload.sentences) == 0:
        print >>sys.stderr, "fakegps: no sentences in test load."
        raise SystemExit, 1
    if linenumber % len(fakegps.testload.sentences) == 0:
        if singleshot and linenumber > 0:
            return False
        if progress:
            baton.twirl('*\b')
        elif not singleshot:
            sys.stderr.write("gpsfake: log cycle of %s begins.\n" % fakegps.testload.name)
    time.sleep(cycle)
    if linedump and fakegps.testload.legend:
        ml = fakegps.testload.sentences[linenumber % len(fakegps.testload.sentences)].strip()
        if not fakegps.testload.textual:
            ml = hexdump(ml)
        announce = fakegps.testload.legend % (linenumber % len(fakegps.testload.sentences) + 1) + ml
        if promptme:
            raw_input(announce + "? ")
        else:
            print announce
    if progress:
        baton.twirl()
    return True

if __name__ == '__main__':
    try:
        (options, arguments) = getopt.getopt(sys.argv[1:], "1bc:D:fghilm:no:pP:r:s:Stuvx")
    except getopt.GetoptError, msg:
        print "gpsfake: " + str(msg)
        raise SystemExit, 1

    port = None
    progress = False
    cycle = 0
    monitor = ""
    speed = 4800
    linedump = False
    predump = False
    pipe = False
    singleshot = False
    promptme = False
    client_init = '?WATCH={"json":true,"nmea":true}'
    doptions = ""
    tcp = False
    udp = False
    verbose = 0
    slow = False
    for (switch, val) in options:
        if (switch == '-1'):
            singleshot = True
        elif (switch == '-f'):
            port = fakeport()
        elif (switch == '-b'):
            progress = True
        elif (switch == '-c'):
            cycle = float(val)
        elif (switch == '-D'):
            doptions += " -D " + val
        elif (switch == '-g'):
            monitor = "xterm -e gdb -tui --args "
        elif (switch == '-i'):
            linedump = promptme = True
        elif (switch == '-l'):
            linedump = True
        elif (switch == '-m'):
            monitor = val + " "
        elif (switch == '-n'):
            doptions += " -n"
        elif (switch == '-x'):
            predump = True
        elif (switch == '-o'):
            doptions = val
        elif (switch == '-p'):
            pipe = True
        elif (switch == '-P'):
            port = int(val)
        elif (switch == '-r'):
            client_init = val
        elif (switch == '-s'):
            speed = int(val)
        elif (switch == '-S'):
            slow = True
        elif (switch == '-t'):
            tcp = True
        elif (switch == '-u'):
            udp = True
        elif (switch == '-v'):
            verbose += 1
        elif (switch == '-h'):
            sys.stderr.write("usage: gpsfake [-h] [-l] [-m monitor] [--D debug] [-o options] [-p] [-s speed] [-S] [-c cycle] [-b] logfile\n")
            raise SystemExit,0

    try:
        pty.openpty()
    except Exception:
        print >>sys.stderr, "gpsfake: ptys not available, falling back to UDP."
        udp = True

    if not arguments:
        print >>sys.stderr, "gpsfake: requires at least one logfile argument."
        raise SystemExit, 1

    if progress:
        baton = Baton("Processing %s" % ",".join(arguments), "done")
    else:
        print >>sys.stderr, "Processing %s" % ",".join(arguments)

    test = gpsfake.TestSession(prefix=monitor, port=port, options=doptions,
                               tcp=tcp, udp=udp, verbose=verbose,
                               predump=predump, slow=slow)

    if pipe:
        test.reporter = sys.stdout.write
        if verbose:
            progress = False
            test.progress = sys.stdout.write
    test.spawn()
    try:
        for logfile in arguments:
            try:
                test.gps_add(logfile, speed=speed, pred=fakehook)
            except gpsfake.TestLoadError, e:
                sys.stderr.write("gpsfake: " + e.msg + "\n")
                raise SystemExit, 1
            except gpsfake.PacketError, e:
                sys.stderr.write("gpsfake: " + e.msg + "\n")
                raise SystemExit, 1
            except gpsfake.DaemonError, e:
                sys.stderr.write("gpsfake: " + e.msg + "\n")
                raise SystemExit, 1
            except IOError, e:
                if e.filename is None:
                    sys.stderr.write("gpsfake: unknown internal I/O error %s\n" % e)
                else:
                    sys.stderr.write("gpsfake: no such file as %s or file unreadable\n"%e.filename)
                raise SystemExit, 1
            except OSError:
                sys.stderr.write("gpsfake: can't open pty.\n")
                raise SystemExit, 1

        try:
            if pipe:
                test.client_add(client_init + "\n")
                # Give daemon time to get ready for the feeds.
                # Without a delay here there's a window for test
                # sentences to arrive before the watch takes effect.
                # This needs to increase if leading sentences in
                # test loads aren't being processed.
                time.sleep(1)
            test.run()
        except socket.error, msg:
            sys.stderr.write("gpsfake: socket error %s.\n" % msg)
            raise SystemExit, 1
        except gps.client.json_error, e:
            sys.stderr.write("gpsfake: JSON error on line %s is %s.\n" % (repr(e.data), e.explanation))
            raise SystemExit, 1
        except KeyboardInterrupt:
            sys.stderr.write("gpsfake: aborted\n")
            raise SystemExit, 1
    finally:
        test.cleanup()

    if progress:
        baton.end()

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