Remove unused code

kitty/utils.py

@@ -2,7 +2,6 @@
 # License: GPL v3 Copyright: 2016, Kovid Goyal <kovid at kovidgoyal.net>
 
 import atexit
-import errno
 import fcntl
 import math
 import os
@@ -25,7 +24,6 @@ from typing import (
 )
 
 from .constants import (
-    appname,
     clear_handled_signals,
     config_dir,
     is_macos,
@@ -410,71 +408,6 @@ def random_unix_socket() -> 'Socket':
     return ans
 
 
-def single_instance_unix(name: str) -> bool:
-    import socket
-    for path in unix_socket_paths(name):
-        socket_path = path.rpartition('.')[0] + '.sock'
-        fd = os.open(path, os.O_CREAT | os.O_WRONLY | os.O_TRUNC | os.O_CLOEXEC)
-        try:
-            fcntl.lockf(fd, fcntl.LOCK_EX | fcntl.LOCK_NB)
-        except OSError as err:
-            if err.errno in (errno.EAGAIN, errno.EACCES):
-                # Client
-                s = socket.socket(family=socket.AF_UNIX)
-                s.connect(socket_path)
-                single_instance.socket = s
-                return False
-            raise
-        s = socket.socket(family=socket.AF_UNIX)
-        try:
-            s.bind(socket_path)
-        except OSError as err:
-            if err.errno in (errno.EADDRINUSE, errno.EEXIST):
-                os.unlink(socket_path)
-                s.bind(socket_path)
-            else:
-                raise
-        single_instance.socket = s  # prevent garbage collection from closing the socket
-        atexit.register(remove_socket_file, s, socket_path)
-        s.listen()
-        s.set_inheritable(False)
-        return True
-    return False
-
-
-class SingleInstance:
-
-    socket: Optional['Socket'] = None
-
-    def __call__(self, group_id: Optional[str] = None) -> bool:
-        import socket
-        name = f'{appname}-ipc-{os.geteuid()}'
-        if group_id:
-            name += f'-{group_id}'
-
-        s = socket.socket(family=socket.AF_UNIX)
-        # First try with abstract UDS
-        addr = '\0' + name
-        try:
-            s.bind(addr)
-        except OSError as err:
-            if err.errno == errno.ENOENT:
-                return single_instance_unix(name)
-            if err.errno == errno.EADDRINUSE:
-                s.connect(addr)
-                self.socket = s
-                return False
-            raise
-        s.listen()
-        self.socket = s  # prevent garbage collection from closing the socket
-        s.set_inheritable(False)
-        atexit.register(remove_socket_file, s)
-        return True
-
-
-single_instance = SingleInstance()
-
-
 def parse_address_spec(spec: str) -> tuple[AddressFamily, Union[tuple[str, int], str], Optional[str]]:
     import socket
     try:
@@ -1240,12 +1173,10 @@ def timed_debug_print(*a: Any, sep: str = ' ', end: str = '\n') -> None:
 def lock_file(f: BinaryIO) -> None:
     if not f.writable():
         raise ValueError('Cannot lock files not opened in writable mode')
-    import fcntl
     fcntl.lockf(f, fcntl.LOCK_EX)
 
 
 def unlock_file(f: BinaryIO) -> None:
     if not f.writable():
         raise ValueError('Cannot unlock files not opened in writable mode')
-    import fcntl
     fcntl.lockf(f, fcntl.LOCK_UN)