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#
# Copyright 2012 Facebook
#
# Licensed under the Apache License, Version 2.0 (the "License"); you may
# not use this file except in compliance with the License. You may obtain
# a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
# WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
# License for the specific language governing permissions and limitations
# under the License.
"""Logging support for Tornado.
Tornado uses three logger streams:
* ``tornado.access``: Per-request logging for Tornado's HTTP servers (and
potentially other servers in the future)
* ``tornado.application``: Logging of errors from application code (i.e.
uncaught exceptions from callbacks)
* ``tornado.general``: General-purpose logging, including any errors
or warnings from Tornado itself.
These streams may be configured independently using the standard library's
`logging` module. For example, you may wish to send ``tornado.access`` logs
to a separate file for analysis.
"""
import logging
import logging.handlers
import sys
from tornado.escape import _unicode
from tornado.util import unicode_type, basestring_type
try:
import colorama # type: ignore
except ImportError:
colorama = None
try:
import curses
except ImportError:
curses = None # type: ignore
from typing import Dict, Any, cast
# Logger objects for internal tornado use
access_log = logging.getLogger("tornado.access")
app_log = logging.getLogger("tornado.application")
gen_log = logging.getLogger("tornado.general")
def _stderr_supports_color() -> bool:
try:
if hasattr(sys.stderr, "isatty") and sys.stderr.isatty():
if curses:
curses.setupterm()
if curses.tigetnum("colors") > 0:
return True
elif colorama:
if sys.stderr is getattr(
colorama.initialise, "wrapped_stderr", object()
):
return True
except Exception:
# Very broad exception handling because it's always better to
# fall back to non-colored logs than to break at startup.
pass
return False
def _safe_unicode(s: Any) -> str:
try:
return _unicode(s)
except UnicodeDecodeError:
return repr(s)
class LogFormatter(logging.Formatter):
"""Log formatter used in Tornado.
Key features of this formatter are:
* Color support when logging to a terminal that supports it.
* Timestamps on every log line.
* Robust against str/bytes encoding problems.
This formatter is enabled automatically by
`tornado.options.parse_command_line` or `tornado.options.parse_config_file`
(unless ``--logging=none`` is used).
Color support on Windows versions that do not support ANSI color codes is
enabled by use of the colorama__ library. Applications that wish to use
this must first initialize colorama with a call to ``colorama.init``.
See the colorama documentation for details.
__ https://pypi.python.org/pypi/colorama
.. versionchanged:: 4.5
Added support for ``colorama``. Changed the constructor
signature to be compatible with `logging.config.dictConfig`.
"""
DEFAULT_FORMAT = "%(color)s[%(levelname)1.1s %(asctime)s %(module)s:%(lineno)d]%(end_color)s %(message)s" # noqa: E501
DEFAULT_DATE_FORMAT = "%y%m%d %H:%M:%S"
DEFAULT_COLORS = {
logging.DEBUG: 4, # Blue
logging.INFO: 2, # Green
logging.WARNING: 3, # Yellow
logging.ERROR: 1, # Red
}
def __init__(
self,
fmt: str = DEFAULT_FORMAT,
datefmt: str = DEFAULT_DATE_FORMAT,
style: str = "%",
color: bool = True,
colors: Dict[int, int] = DEFAULT_COLORS,
) -> None:
r"""
:arg bool color: Enables color support.
:arg str fmt: Log message format.
It will be applied to the attributes dict of log records. The
text between ``%(color)s`` and ``%(end_color)s`` will be colored
depending on the level if color support is on.
:arg dict colors: color mappings from logging level to terminal color
code
:arg str datefmt: Datetime format.
Used for formatting ``(asctime)`` placeholder in ``prefix_fmt``.
.. versionchanged:: 3.2
Added ``fmt`` and ``datefmt`` arguments.
"""
logging.Formatter.__init__(self, datefmt=datefmt)
self._fmt = fmt
self._colors = {} # type: Dict[int, str]
if color and _stderr_supports_color():
if curses is not None:
fg_color = curses.tigetstr("setaf") or curses.tigetstr("setf") or b""
for levelno, code in colors.items():
# Convert the terminal control characters from
# bytes to unicode strings for easier use with the
# logging module.
self._colors[levelno] = unicode_type(
curses.tparm(fg_color, code), "ascii"
)
self._normal = unicode_type(curses.tigetstr("sgr0"), "ascii")
else:
# If curses is not present (currently we'll only get here for
# colorama on windows), assume hard-coded ANSI color codes.
for levelno, code in colors.items():
self._colors[levelno] = "\033[2;3%dm" % code
self._normal = "\033[0m"
else:
self._normal = ""
def format(self, record: Any) -> str:
try:
message = record.getMessage()
assert isinstance(message, basestring_type) # guaranteed by logging
# Encoding notes: The logging module prefers to work with character
# strings, but only enforces that log messages are instances of
# basestring. In python 2, non-ascii bytestrings will make
# their way through the logging framework until they blow up with
# an unhelpful decoding error (with this formatter it happens
# when we attach the prefix, but there are other opportunities for
# exceptions further along in the framework).
#
# If a byte string makes it this far, convert it to unicode to
# ensure it will make it out to the logs. Use repr() as a fallback
# to ensure that all byte strings can be converted successfully,
# but don't do it by default so we don't add extra quotes to ascii
# bytestrings. This is a bit of a hacky place to do this, but
# it's worth it since the encoding errors that would otherwise
# result are so useless (and tornado is fond of using utf8-encoded
# byte strings wherever possible).
record.message = _safe_unicode(message)
except Exception as e:
record.message = "Bad message (%r): %r" % (e, record.__dict__)
record.asctime = self.formatTime(record, cast(str, self.datefmt))
if record.levelno in self._colors:
record.color = self._colors[record.levelno]
record.end_color = self._normal
else:
record.color = record.end_color = ""
formatted = self._fmt % record.__dict__
if record.exc_info:
if not record.exc_text:
record.exc_text = self.formatException(record.exc_info)
if record.exc_text:
# exc_text contains multiple lines. We need to _safe_unicode
# each line separately so that non-utf8 bytes don't cause
# all the newlines to turn into '\n'.
lines = [formatted.rstrip()]
lines.extend(_safe_unicode(ln) for ln in record.exc_text.split("\n"))
formatted = "\n".join(lines)
return formatted.replace("\n", "\n ")
def enable_pretty_logging(options: Any = None, logger: logging.Logger = None) -> None:
"""Turns on formatted logging output as configured.
This is called automatically by `tornado.options.parse_command_line`
and `tornado.options.parse_config_file`.
"""
if options is None:
import tornado.options
options = tornado.options.options
if options.logging is None or options.logging.lower() == "none":
return
if logger is None:
logger = logging.getLogger()
logger.setLevel(getattr(logging, options.logging.upper()))
if options.log_file_prefix:
rotate_mode = options.log_rotate_mode
if rotate_mode == "size":
channel = logging.handlers.RotatingFileHandler(
filename=options.log_file_prefix,
maxBytes=options.log_file_max_size,
backupCount=options.log_file_num_backups,
encoding="utf-8",
) # type: logging.Handler
elif rotate_mode == "time":
channel = logging.handlers.TimedRotatingFileHandler(
filename=options.log_file_prefix,
when=options.log_rotate_when,
interval=options.log_rotate_interval,
backupCount=options.log_file_num_backups,
encoding="utf-8",
)
else:
error_message = (
"The value of log_rotate_mode option should be "
+ '"size" or "time", not "%s".' % rotate_mode
)
raise ValueError(error_message)
channel.setFormatter(LogFormatter(color=False))
logger.addHandler(channel)
if options.log_to_stderr or (options.log_to_stderr is None and not logger.handlers):
# Set up color if we are in a tty and curses is installed
channel = logging.StreamHandler()
channel.setFormatter(LogFormatter())
logger.addHandler(channel)
def define_logging_options(options: Any = None) -> None:
"""Add logging-related flags to ``options``.
These options are present automatically on the default options instance;
this method is only necessary if you have created your own `.OptionParser`.
.. versionadded:: 4.2
This function existed in prior versions but was broken and undocumented until 4.2.
"""
if options is None:
# late import to prevent cycle
import tornado.options
options = tornado.options.options
options.define(
"logging",
default="info",
help=(
"Set the Python log level. If 'none', tornado won't touch the "
"logging configuration."
),
metavar="debug|info|warning|error|none",
)
options.define(
"log_to_stderr",
type=bool,
default=None,
help=(
"Send log output to stderr (colorized if possible). "
"By default use stderr if --log_file_prefix is not set and "
"no other logging is configured."
),
)
options.define(
"log_file_prefix",
type=str,
default=None,
metavar="PATH",
help=(
"Path prefix for log files. "
"Note that if you are running multiple tornado processes, "
"log_file_prefix must be different for each of them (e.g. "
"include the port number)"
),
)
options.define(
"log_file_max_size",
type=int,
default=100 * 1000 * 1000,
help="max size of log files before rollover",
)
options.define(
"log_file_num_backups", type=int, default=10, help="number of log files to keep"
)
options.define(
"log_rotate_when",
type=str,
default="midnight",
help=(
"specify the type of TimedRotatingFileHandler interval "
"other options:('S', 'M', 'H', 'D', 'W0'-'W6')"
),
)
options.define(
"log_rotate_interval",
type=int,
default=1,
help="The interval value of timed rotating",
)
options.define(
"log_rotate_mode",
type=str,
default="size",
help="The mode of rotating files(time or size)",
)
options.add_parse_callback(lambda: enable_pretty_logging(options))