import io
import sys
def init_streams(log_write, stdout_level, stderr_level):
# Redirect stdout and stderr to the Apple system log. This method is
# invoked by init_apple_streams() (initconfig.c) if config->use_system_logger
# is enabled.
sys.stdout = SystemLog(log_write, stdout_level, errors=sys.stderr.errors)
sys.stderr = SystemLog(log_write, stderr_level, errors=sys.stderr.errors)
class SystemLog(io.TextIOWrapper):
def __init__(self, log_write, level, **kwargs):
kwargs.setdefault("encoding", "UTF-8")
kwargs.setdefault("line_buffering", True)
super().__init__(LogStream(log_write, level), **kwargs)
def __repr__(self):
return f"<SystemLog (level {self.buffer.level})>"
def write(self, s):
if not isinstance(s, str):
raise TypeError(
f"write() argument must be str, not {type(s).__name__}")
# In case `s` is a str subclass that writes itself to stdout or stderr
# when we call its methods, convert it to an actual str.
s = str.__str__(s)
# We want to emit one log message per line, so split
# the string before sending it to the superclass.
for line in s.splitlines(keepends=True):
super().write(line)
return len(s)
class LogStream(io.RawIOBase):
def __init__(self, log_write, level):
self.log_write = log_write
self.level = level
def __repr__(self):
return f"<LogStream (level {self.level!r})>"
def writable(self):
return True
def write(self, b):
if type(b) is not bytes:
try:
b = bytes(memoryview(b))
except TypeError:
raise TypeError(
f"write() argument must be bytes-like, not {type(b).__name__}"
) from None
# Writing an empty string to the stream should have no effect.
if b:
# Encode null bytes using "modified UTF-8" to avoid truncating the
# message. This should not affect the return value, as the caller
# may be expecting it to match the length of the input.
self.log_write(self.level, b.replace(b"\x00", b"\xc0\x80"))
return len(b)