diff options
Diffstat (limited to 'pylog/onaplogging/mdcformatter.py')
| -rw-r--r-- | pylog/onaplogging/mdcformatter.py | 245 |
1 files changed, 157 insertions, 88 deletions
diff --git a/pylog/onaplogging/mdcformatter.py b/pylog/onaplogging/mdcformatter.py index 545a4c1..442f0ad 100644 --- a/pylog/onaplogging/mdcformatter.py +++ b/pylog/onaplogging/mdcformatter.py @@ -12,145 +12,214 @@ # See the License for the specific language governing permissions and # limitations under the License. -import sys import logging +from logging import LogRecord +from typing import Mapping, List, Dict, Callable +from deprecated import deprecated + +from onaplogging.utils.system import is_above_python_2_7, is_above_python_3_2 +from onaplogging.utils.styles import MDC_OPTIONS + from .markerFormatter import MarkerFormatter class MDCFormatter(MarkerFormatter): - """ - A custom MDC formatter to prepare Mapped Diagnostic Context - to enrich log message. + """A custom MDC formatter. + + Prepares Mapped Diagnostic Context to enrich log message. If `fmt` is not + supplied, the `style` is used. + + Extends: + MarkerFormatter + Args: + fmt : Built-in format string containing standard Python + %-style mapping keys in human-readable format. + mdcFmt : MDC format with '{}'-style mapping keys. + datefmt : Date format. + colorfmt : colored output with an ANSI terminal escape code. + style : style mapping keys in Python 3.x. """ - def __init__(self, fmt=None, mdcfmt=None, - datefmt=None, colorfmt=None, style="%"): - """ - :param fmt: build-in format string contains standard - Python %-style mapping keys - :param mdcFmt: mdc format with '{}'-style mapping keys - :param datefmt: Date format to use - :param colorfmt: colored output with ANSI escape code on terminal - :param style: style mapping keys in python3 - """ - if sys.version_info > (3, 2): + @property + def mdc_tag(self): + # type: () -> str + return self._mdc_tag + + @property + def mdcfmt(self): + # type: () -> str + return self._mdcFmt + + @mdc_tag.setter + def mdc_tag(self, value): + # type: (str) -> str + self._mdc_tag = value + + @mdcfmt.setter + def mdcfmt(self, value): + # type: (str) -> str + self._mdc_tag = value + + def __init__(self, + fmt=None, # type: str + mdcfmt=None, # type: str + datefmt=None, # type: str + colorfmt=None, # type: str + style="%"): # type: str + + if is_above_python_3_2(): super(MDCFormatter, self).__init__(fmt=fmt, datefmt=datefmt, colorfmt=colorfmt, style=style) - elif sys.version_info > (2, 7): + elif is_above_python_2_7(): super(MDCFormatter, self).__init__(fmt=fmt, datefmt=datefmt, colorfmt=colorfmt) else: - MarkerFormatter.__init__(self, fmt, datefmt, colorfmt) - - self._mdc_tag = "%(mdc)s" - if self.style == "{": - self._mdc_tag = "{mdc}" - elif self.style == "$": - self._mdc_tag = "${mdc}" + MarkerFormatter.\ + __init__(self, fmt, datefmt, colorfmt) # noqa: E122 - if mdcfmt: - self._mdcFmt = mdcfmt - else: - self._mdcFmt = '{reqeustID}' + self._mdc_tag = MDC_OPTIONS[self.style] + self._mdcFmt = mdcfmt if mdcfmt else '{reqeustID}' - def _mdcfmtKey(self): + def format(self, record): + # type: (LogRecord) -> str """ - maximum barce match algorithm to find the mdc key - :return: key in brace and key not in brace,such as ({key}, key) + Find MDCs in a log record's extra field. If the key from mdcFmt + doesn't contain MDC, the values will be empty. + + For example: + The MDC dict in a logging record is {'key1':'value1','key2':'value2'}. + The mdcFmt is '{key1} {key3}'. + The output of MDC message is 'key1=value1 key3='. + + Args: + record : an instance of a logged event. + Returns: + str : "colored" text (formatted text). + """ + + mdc_index = self._fmt.find(self._mdc_tag) + if mdc_index == -1: + return self._parent_format(record) + + mdc_format_keys, mdc_format_words = self._mdc_format_key() + + if mdc_format_words is None: + self._fmt = self._replace_mdc_tag_str("") + self._apply_styling() + + return self._parent_format(record) + + res = self._apply_mdc(record, mdc_format_words) + + try: + mdc_string = self._replaceStr(keys=mdc_format_keys).format(**res) + self._fmt = self._replace_mdc_tag_str(mdc_string) + self._apply_styling() + + return self._parent_format(record) + + except KeyError as e: + # is there a need for print? + print("The mdc key %s format is wrong" % str(e)) + + except Exception: + raise + + def _mdc_format_key(self): + # type: () -> (List, Mapping[str, str]) + """Maximum (balanced) parantehses matching algorithm for MDC keys. + + Extracts and strips keys and words from a MDC format string. Use this + method to find the MDC key. + + Returns: + list : list of keys. + map object : keys with and without brace, such as ({key}, key). """ left = '{' right = '}' target = self._mdcFmt - st = [] + stack = [] keys = [] + for index, v in enumerate(target): if v == left: - st.append(index) + stack.append(index) elif v == right: - if len(st) == 0: + if len(stack) == 0: continue - elif len(st) == 1: - start = st.pop() + elif len(stack) == 1: + start = stack.pop() end = index keys.append(target[start:end + 1]) - elif len(st) > 0: - st.pop() + elif len(stack) > 0: + stack.pop() keys = list(filter(lambda x: x[1:-1].strip('\n \t ') != "", keys)) words = None + if keys: words = map(lambda x: x[1:-1], keys) return keys, words - def _replaceStr(self, keys): - - fmt = self._mdcFmt - for i in keys: - fmt = fmt.replace(i, i[1:-1] + "=" + i) - - return fmt - - def format(self, record): + def _replace_string(self, keys): + # type: (List[str]) -> str """ - Find mdcs in log record extra field, if key form mdcFmt dosen't - contains mdcs, the values will be empty. - :param record: the logging record instance - :return: string - for example: - the mdcs dict in logging record is - {'key1':'value1','key2':'value2'} - the mdcFmt is" '{key1} {key3}' - the output of mdc message: 'key1=value1 key3=' - + Removes the first and last characters from each key and assigns not + stripped keys. """ - mdcIndex = self._fmt.find(self._mdc_tag) - if mdcIndex == -1: - if sys.version_info > (2, 7): - return super(MDCFormatter, self).format(record) - else: - return MarkerFormatter.format(self, record) - - mdcFmtkeys, mdcFmtWords = self._mdcfmtKey() - - if mdcFmtWords is None: - self._fmt = self._fmt.replace(self._mdc_tag, "") - if sys.version_info > (3, 2): - self._style = logging._STYLES[self.style][0](self._fmt) + fmt = self._mdcFmt + for key in keys: + fmt = fmt.replace(key, key[1:-1] + "=" + key) + return fmt - if sys.version_info > (2, 7): - return super(MDCFormatter, self).format(record) - else: - return MarkerFormatter.format(self, record) + def _parent_format(self, record): + # type: (LogRecord) -> str + """Call super class's format based on Python version.""" + if is_above_python_2_7(): + return super(MDCFormatter, self).format(record) + else: + return MarkerFormatter.format(self, record) + def _apply_mdc(self, record, mdc_format_words): + # type: (LogRecord, Mapping[Callable[[str], str], List]) -> Dict + """Apply MDC pamming to the LogRecord record.""" mdc = record.__dict__.get('mdc', None) res = {} - for i in mdcFmtWords: + + for i in mdc_format_words: if mdc and i in mdc: res[i] = mdc[i] else: res[i] = "" - del mdc - try: - mdcstr = self._replaceStr(keys=mdcFmtkeys).format(**res) - self._fmt = self._fmt.replace(self._mdc_tag, mdcstr) + return res - if sys.version_info > (3, 2): - self._style = logging._STYLES[self.style][0](self._fmt) + def _apply_styling(self): + # type: () -> None + """Apply styling to the formatter if using Python 3.2+""" + if is_above_python_3_2(): + StylingClass = logging._STYLES[self.style][0](self._fmt) + self._style = StylingClass - if sys.version_info > (2, 7): - return super(MDCFormatter, self).format(record) - else: - return MarkerFormatter.format(self, record) + def _replace_mdc_tag_str(self, replacement): + # type: (str) -> str + """Replace MDC tag in the format string.""" + return self._fmt.replace(self._mdc_tag, replacement) - except KeyError as e: - print("The mdc key %s format is wrong" % str(e)) - except Exception: - raise + @deprecated(reason="Will be replaced. Use _mdc_format_key() instead.") + def _mdcfmtKey(self): + """See _mdc_format_key().""" + return self._mdc_format_key() + + @deprecated(reason="Will be replaced. Use _replace_string(keys) instead.") + def _replaceStr(self, keys): + """See _replace_string(keys).""" + return self._replace_string(keys) |