logger.py

"""
Copyright 2020 The Magma Authors.

This source code is licensed under the BSD-style license found in the
LICENSE file in the root directory of this source tree.

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.
"""

import logging
from logging.handlers import RotatingFileHandler

LOG_FILE = './enodebd.log'
MAX_BYTES = 1024 * 1024 * 10  # 10MB
BACKUP_COUNT = 5  # 10MB, 5 files, 50MB total


class EnodebdLogger:
    """
    EnodebdLogger backs up debug logs with a RotatingFileHandler.

    Debug logs will be propagated to root level if the root logger is set to
    debug level.
    """

    _LOGGER = logging.getLogger(__name__)  # type: logging.Logger

    @staticmethod
    def init() -> None:
        if logging.root.level is not logging.DEBUG:
            EnodebdLogger._LOGGER.propagate = False
        handler = RotatingFileHandler(
            LOG_FILE,
            maxBytes=MAX_BYTES,
            backupCount=BACKUP_COUNT,
        )
        formatter = logging.Formatter(fmt='%(asctime)s %(levelname)s %(message)s')
        handler.setFormatter(formatter)
        EnodebdLogger._LOGGER.addHandler(handler)
        EnodebdLogger._LOGGER.setLevel(logging.DEBUG)

    @staticmethod
    def debug(msg, *args, **kwargs):
        EnodebdLogger._LOGGER.debug(msg, *args, **kwargs)

    @staticmethod
    def info(msg, *args, **kwargs):
        if not EnodebdLogger._LOGGER.propagate:
            logging.info(msg, *args, **kwargs)
        EnodebdLogger._LOGGER.info(msg, *args, **kwargs)

    @staticmethod
    def warning(msg, *args, **kwargs):
        if not EnodebdLogger._LOGGER.propagate:
            logging.warning(msg, *args, **kwargs)
        EnodebdLogger._LOGGER.warning(msg, *args, **kwargs)

    @staticmethod
    def error(msg, *args, **kwargs):
        if not EnodebdLogger._LOGGER.propagate:
            logging.error(msg, *args, **kwargs)
        EnodebdLogger._LOGGER.error(msg, *args, **kwargs)

    @staticmethod
    def exception(msg, *args, **kwargs):
        if not EnodebdLogger._LOGGER.propagate:
            logging.exception(msg, *args, **kwargs)
        EnodebdLogger._LOGGER.exception(msg, *args, **kwargs)

    @staticmethod
    def critical(msg, *args, **kwargs):
        if not EnodebdLogger._LOGGER.propagate:
            logging.critical(msg, *args, **kwargs)
        EnodebdLogger._LOGGER.critical(msg, *args, **kwargs)