Tembro/template/start.py

#! /usr/bin/env python3
# -*- coding: utf-8 -*-
"""
Copyright 2022, Nils Hilbricht, Germany ( https://www.hilbricht.net )

This file is part of the Laborejo Software Suite ( https://www.laborejo.org ),

This application is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.

This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU General Public License for more details.

You should have received a copy of the GNU General Public License
along with this program.  If not, see <http://www.gnu.org/licenses/>.
"""

#This is the first file in the program to be actually executed, after the executable which uses this as first instruction.

"""
We use a 'wrong' scheme of importing modules here because there are multiple exit conditions, good and bad.
We don't want to load all the libraries, including the big Qt one, only to end up displaying the --version and exit.
Same with the tests if jack or nsm are running.
"""

#Give at least some feedback when C libs crash.
#Will still not work for the common case that PyQt crashes and ends Python.
#But every bit helps when hunting bugs.
import faulthandler; faulthandler.enable()

from engine.config import METADATA #includes METADATA only. No other environmental setup is executed.
from template.qtgui.chooseSessionDirectory import ChooseSessionDirectory
from template.qtgui.helper import setPaletteAndFont #our error boxes shall look like the rest of the program

"""
Check parameters first. It is possible that we will just --help or --version and exit. In this case
nothing gets loaded.
"""
import argparse
parser = argparse.ArgumentParser(description=f"""{METADATA["name"]} - Version {METADATA["version"]} - Copyright {METADATA["year"]} by {METADATA["author"]} - {METADATA["url"]}""")
parser.add_argument("-v", "--version", action='version', version="{} {}".format(METADATA["name"], METADATA["version"]))
parser.add_argument("-s", "--save", action='store', dest="directory", help="Use this directory to save. Will be created or loaded from if already present. Deactivates Agordejo/New-Session-Manager support.")
parser.add_argument("-p", "--profiler", action='store_true', help="(Development) Run the python profiler and produce a .cprof file at quit. The name will appear in your STDOUT.")
parser.add_argument("-m", "--mute", action='store_true', help="(Development) Use a fake cbox module, effectively deactivating midi and audio.")
parser.add_argument("-V", "--verbose", action='store_true', help="(Development) Switch the logger to INFO and print out all kinds of information to get a high-level idea of what the program is doing.")
args = parser.parse_args()

import logging
if args.verbose: #development
    logging.basicConfig(level=logging.INFO, format='[' + METADATA["shortName"] + '] %(levelname)s %(asctime)s %(name)s: %(message)s',)
    #logging.getLogger().setLevel(logging.INFO) #development
else: #production
    logging.basicConfig(level=logging.ERROR, format='[' + METADATA["shortName"] + '] %(levelname)s %(asctime)s %(name)s: %(message)s',)
    #logging.getLogger().setLevel(logging.ERROR) #production

logger = logging.getLogger(__name__)
logger.info("import")


"""set up python search path before the program starts and cbox gets imported.
We need to be earliest, so let's put it here.
This is influence during compiling by creating a temporary file "compiledprefix.py".
pyzipapp archives that in, when make is finished we delete it.

#Default mode is a self-contained directory relative to the uncompiled patroneo python start script
"""

import sys
import os
import os.path
from PyQt5.QtWidgets import QApplication, QStyleFactory
from PyQt5 import QtGui


import inspect
def get_script_dir(follow_symlinks=True):
    if getattr(sys, 'frozen', False): # py2exe, PyInstaller, cx_Freeze
        path = os.path.abspath(sys.executable)
    else:
        path = inspect.getabsfile(get_script_dir)
    if follow_symlinks:
        path = os.path.realpath(path)
    return os.path.dirname(path)


logger.info(f"Script dir: {get_script_dir()}")

logger.info(f"Python Version {sys.version}")

try:
    from compiledprefix import prefix as prefix_import
    prefix:str = prefix_import
    compiledVersion = True
    logger.info("Compiled prefix found: {}".format(prefix))
except ModuleNotFoundError as e:
    compiledVersion = False

logger.info("Compiled version: {}".format(compiledVersion))


#ZippApp with compiledprefix.py
if compiledVersion:
    PATHS={  #this gets imported
        "root": "",
        "bin": os.path.join(prefix, "bin"), # type: ignore
        "doc": os.path.join(prefix, "share", "doc", METADATA["shortName"]), # type: ignore
        "desktopfile": os.path.join(prefix, "share", "applications", METADATA["shortName"] + ".desktop"), # type: ignore #not ~/Desktop  but our desktop file
        "share": os.path.join(prefix, "share", METADATA["shortName"]), # type: ignore
        "templateShare": os.path.join(prefix, "share", METADATA["shortName"], "template"), # type: ignore
        #"lib": os.path.join(prefix, "lib", METADATA["shortName"]), #cbox is found via the PYTHONPATH
    }

    _root = os.path.dirname(__file__)
    _root = os.path.abspath(os.path.join(_root, ".."))

    import zipfile
    import tempfile
    logger.info("Extracting shared library to temporary directory")
    zipfilePath = get_script_dir().rstrip("/template")
    assert zipfile.is_zipfile(zipfilePath), (zipfilePath) #in our tests this worked. but in lss this results not in a zip file header. linux file also says it is no zip. However, unzip works.
    #Extract included .so to tmp dir, tmp dir gets garbage collected at the end of our program.
    libsharedDir = tempfile.TemporaryDirectory()

#Not compiled, not installed. Running pure python directly in the source tree.
else:
    _root = os.path.dirname(__file__)
    _root = os.path.abspath(os.path.join(_root, ".."))
    PATHS={  #this gets imported
        "root": _root,
        "bin": _root,
        "doc": os.path.join(_root, "documentation", "out"),
        "desktopfile": os.path.join(_root, "desktop", "desktop.desktop"),  #not ~/Desktop  but our desktop file
        "share": os.path.join(_root, "engine", "resources"),
        "templateShare": os.path.join(_root, "template", "engine", "resources"),
        #"lib": "", #use only system paths
    }

logger.info("PATHS: {}".format(PATHS))

#Construct QAppliction before constantsAndCOnfigs, which has the fontDB
#QtGui.QGuiApplication.setDesktopSettingsAware(False) #This will crash with new Qt!
qtApp = QApplication(sys.argv)
setPaletteAndFont(qtApp)
QApplication.setStyle(QStyleFactory.create("Fusion"))
setPaletteAndFont(qtApp)

def exitWithMessage(message:str):
    title = f"""{METADATA["name"]} Error"""
    if sys.stdout.isatty():
        sys.exit(title + ": " + message)
    else:
        from PyQt5.QtWidgets import QMessageBox
        #This is the start file for the Qt client so we know at least that Qt is installed and use that for a warning.
        QMessageBox.critical(qtApp.desktop(), title, message)
        sys.exit(title + ": " + message)

def setProcessName(executableName):
    """From
    https://stackoverflow.com/questions/31132342/change-process-name-while-executing-a-python-script
    """
    import ctypes, ctypes.util
    lib = ctypes.cdll.LoadLibrary(None)
    prctl = lib.prctl
    prctl.restype = ctypes.c_int
    prctl.argtypes = [ctypes.c_int, ctypes.c_char_p, ctypes.c_ulong,
                      ctypes.c_ulong, ctypes.c_ulong]
    def set_proctitle(new_title):
        result = prctl(15, new_title, 0, 0, 0)
        if result != 0:
            raise OSError("prctl result: %d" % result)
    set_proctitle(executableName.encode())


    libpthread_path = ctypes.util.find_library("pthread")
    if not libpthread_path:
        return

    libpthread = ctypes.CDLL(libpthread_path)
    if hasattr(libpthread, "pthread_setname_np"):
        _pthread_setname_np = libpthread.pthread_setname_np

        _pthread_self = libpthread.pthread_self
        _pthread_self.argtypes = []
        _pthread_self.restype = ctypes.c_void_p

        _pthread_setname_np.argtypes = [ctypes.c_void_p, ctypes.c_char_p]
        _pthread_setname_np.restype = ctypes.c_int

        if _pthread_setname_np is None:
            return

        _pthread_setname_np(_pthread_self(), executableName.encode())

def checkNsmOrExit(prettyName):
    """Check for NSM"""
    #NSM changes our cwd to whereever we started new-session-manager from.
    #print (os.getcwd())
    import sys
    from os import getenv
    if not getenv("NSM_URL"): #NSMClient checks for this itself but we can anticipate an error and inform the user.

        path = ChooseSessionDirectory(qtApp).path #ChooseSessionDirectory is calling exec. We can't call qtapp.exec_ because that blocks forever, even after quitting the window.
        #qSessionDirApp.quit()
        #del qSessionDirApp
        #path = "/tmp"

        if path:
            startPseudoNSMServer(path)
        else:
            sys.exit()

        #message = f"""Please start {prettyName} only through the New Session Manager (NSM) or use the --save command line parameter."""
        #exitWithMessage(message)

def _is_jack_running():
    """Check for JACK"""
    import ctypes
    import os
    silent = os.open(os.devnull, os.O_WRONLY)
    stdout = os.dup(1)
    stderr = os.dup(2)
    os.dup2(silent, 1) #stdout
    os.dup2(silent, 2) #stderr
    cjack = ctypes.cdll.LoadLibrary("libjack.so.0")
    class jack_client_t(ctypes.Structure):
        _fields_ = []
    cjack.jack_client_open.argtypes = [ctypes.c_char_p, ctypes.c_int, ctypes.POINTER(ctypes.c_int)]  #the two ints are enum and pointer to enum. #http://jackaudio.org/files/docs/html/group__ClientFunctions.html#gab8b16ee616207532d0585d04a0bd1d60
    cjack.jack_client_open.restype = ctypes.POINTER(jack_client_t)
    ctypesJackClient = cjack.jack_client_open("probe".encode("ascii"), 0x01, None) #0x01 is the bit set for do not autostart JackNoStartServer
    try:
        ret = bool(ctypesJackClient.contents)
    except ValueError: #NULL pointer access
        ret = False
    cjack.jack_client_close(ctypesJackClient)
    os.dup2(stdout, 1) #stdout
    os.dup2(stderr, 2) #stderr
    return ret

def checkJackOrExit(mute, prettyName):
    import sys
    if not mute and (not _is_jack_running()):
        exitWithMessage("JACK Audio Connection Kit is not running. Please start it.")

from contextlib import contextmanager
@contextmanager
def profiler(*pargs, **kwds):
    """Eventhough this is a context manager we never get past the yield statement because our
    program quits the moment we receive NSM quit signal. The only chance is to register a atexit
    handler which will be called no matter what"""
    if args.profiler:
        import tracemalloc
        import cProfile
        import atexit
        def profilerExit(pr):
            snapshot = tracemalloc.take_snapshot()
            top_stats = snapshot.statistics('lineno')
            print("[ Top 10 ]")
            for stat in top_stats[:10]:
                print(stat)

            from tempfile import NamedTemporaryFile
            cprofPath = NamedTemporaryFile().name + ".cprof"
            pr.dump_stats(cprofPath)
            logger.info("{}: write profiling data to {}".format(METADATA["name"], cprofPath))
            print (f"pyprof2calltree -k -i {cprofPath}")

        pr = cProfile.Profile()
        pr.enable()
        #Closing and file writing happens in guiMainWindow._nsmQuit
        tracemalloc.start()
        atexit.register(lambda: profilerExit(pr))

    #Program execution
    yield

#Catch Exceptions even if PyQt crashes.
import sys
sys._excepthook = sys.excepthook # type: ignore  #mypy thinks that doesn't exist, eventhough we set it ourselves right here.
def exception_hook(exctype, value, traceback):
    """This hook purely exists to call sys.exit(1) even on a Qt crash
    so that atexit gets triggered"""
    #print(exctype, value, traceback)
    logger.error("Caught crash in execpthook. Trying too execute atexit anyway")
    sys._excepthook(exctype, value, traceback)
    sys.exit(1)
sys.excepthook = exception_hook


def startPseudoNSMServer(path):
    from os import getenv
    assert not getenv("NSM_URL")
    from .qtgui.nsmsingleserver import startSingleNSMServer
    startSingleNSMServer(path) #provides NSM_URL environment variable and a limited drop-in replacement for NSM that will only answer to our application
    assert getenv("NSM_URL")
    sys.path.append("sitepackages") # If you compiled but did not install you can still run with the local build of cbox in our temp dir sitepackages. Add path to the last place, in case there is an installed or bundled version

if args.directory:
    #Switch to the mode without NSM.
    startPseudoNSMServer(args.directory)

checkNsmOrExit(METADATA["name"])
checkJackOrExit(args.mute, METADATA["name"])
try:
    #Only cosmetics
    setProcessName(METADATA["shortName"])
except:
    pass

if args.mute:
    """This uses the fact that imports are global and only triggered once.
    Inside nullbox it will overwrite the actual cbox functions,
    so that the rest of the program can naively import cbox directly.
    We only need this one line to change between the two cbox modes.

    There are four possible states:
    1) run program locally, system wide calfbox
    2) run program installed, calfbox bundled/installed
    both work fine with a simple import calfbox.nullbox because
    bundled has already changed the cbox/python search path

    3) run program locally, calfbox in local tree
    Needs adding of the local tree into python search path.

    4) impossible: run program installed, calfbox in local tree

    """
    #if not compiledVersion:
    #import template.calfbox.py
    #    sys.modules["calfbox"] = sys.modules["template.calfbox.py"]

    import template.calfbox.nullbox
else:
    import ctypes.util
    libname = ctypes.util.find_library("calfbox-lss") #returns something like 'libcalfbox-lss.so.1' without a path, but with "lib"
    if libname:
        logger.info(f"libcalfbox-lss name is {libname}")
        os.environ["CALFBOXLIBFILENAME"] = "calfbox-lss" #let _cbox2 use ctypes to find the name and path again. We just need to tell it that we are not the standard cbox file name.
    else:
        logger.error("libcalfbox-lss not installed on system")
        raise RuntimeError("libcalfbox-lss not installed on system")

#Capture Ctlr+C / SIGINT and let @atexit handle the rest.
import signal
import sys
def signal_handler(sig, frame):
    sys.exit(0) #atexit will trigger
signal.signal(signal.SIGINT, signal_handler)