def ensure_single_instance(args, open_at):
try:
from calibre.utils.lock import singleinstance
si = singleinstance(singleinstance_name)
except Exception:
import traceback
error_dialog(None, _('Cannot start viewer'), _(
'Failed to start viewer, could not insure only a single instance of the viewer is running. Click "Show Details" for more information'),
det_msg=traceback.format_exc(), show=True)
raise SystemExit(1)
if not si:
if len(args) > 1:
t = RC(print_error=True, socket_address=viewer_socket_address())
t.start()
t.join(3.0)
if t.is_alive() or t.conn is None:
error_dialog(None, _('Connect to viewer failed'), _(
'Unable to connect to existing viewer window, try restarting the viewer.'), show=True)
raise SystemExit(1)
t.conn.send((os.path.abspath(args[1]), open_at))
t.conn.close()
prints('Opened book in existing viewer instance')
raise SystemExit(0)
listener = create_listener()
return listener
def send_message_to_viewer_instance(args, open_at):
if len(args) > 1:
msg = json.dumps((os.path.abspath(args[1]), open_at))
try:
send_message_in_process(msg, address=viewer_socket_address())
except Exception as err:
error_dialog(None, _('Connecting to E-book viewer failed'), _(
'Unable to connect to existing E-book viewer window, try restarting the viewer.'), det_msg=str(err), show=True)
raise SystemExit(1)
print('Opened book in existing viewer instance')
def main(args=sys.argv):
# Ensure viewer can continue to function if GUI is closed
os.environ.pop('CALIBRE_WORKER_TEMP_DIR', None)
reset_base_dir()
scheme = QWebEngineUrlScheme(FAKE_PROTOCOL.encode('ascii'))
scheme.setSyntax(QWebEngineUrlScheme.Syntax.Host)
scheme.setFlags(QWebEngineUrlScheme.Flag.SecureScheme)
QWebEngineUrlScheme.registerScheme(scheme)
override = 'calibre-ebook-viewer' if islinux else None
processed_args = []
internal_book_data = internal_book_data_path = None
for arg in args:
if arg.startswith('--internal-book-data='):
internal_book_data_path = arg.split('=', 1)[1]
continue
processed_args.append(arg)
if internal_book_data_path:
try:
with lopen(internal_book_data_path, 'rb') as f:
internal_book_data = json.load(f)
finally:
try:
os.remove(internal_book_data_path)
except OSError:
pass
args = processed_args
app = Application(args, override_program_name=override, windows_app_uid=VIEWER_APP_UID)
parser = option_parser()
opts, args = parser.parse_args(args)
oat = opts.open_at
if oat and not (
oat.startswith('toc:') or oat.startswith('toc-href:') or oat.startswith('toc-href-contains:') or
oat.startswith('epubcfi(/') or is_float(oat) or oat.startswith('ref:')):
raise SystemExit('Not a valid --open-at value: {}'.format(opts.open_at))
if get_session_pref('singleinstance', False):
from calibre.utils.lock import SingleInstance
from calibre.gui2.listener import Listener
with SingleInstance(singleinstance_name) as si:
if si:
try:
listener = Listener(address=viewer_socket_address(), parent=app)
listener.start_listening()
except Exception as err:
error_dialog(None, _('Failed to start listener'), _(
'Could not start the listener used for single instance viewers. Try rebooting your computer.'),
det_msg=str(err), show=True)
else:
with closing(listener):
run_gui(app, opts, args, internal_book_data, listener=listener)
else:
send_message_to_viewer_instance(args, opts.open_at)
else:
run_gui(app, opts, args, internal_book_data)
def create_listener():
addr = viewer_socket_address()
if islinux:
from calibre.utils.ipc.server import LinuxListener as Listener
else:
from multiprocessing.connection import Listener
if not iswindows:
# On macOS (and BSDs, I am guessing), following a crash, the
# listener socket file sticks around and needs to be explicitly
# removed. It is safe to do this since we are already guaranteed to
# be the owner of the socket by singleinstance()
try:
os.remove(addr)
except Exception:
pass
return Listener(address=addr)
def create_listener():
if islinux:
from calibre.utils.ipc.server import LinuxListener as Listener
else:
from multiprocessing.connection import Listener
return Listener(address=viewer_socket_address())
