logging.py

"""
    sphinx.util.logging
    ~~~~~~~~~~~~~~~~~~~

    Logging utility functions for Sphinx.

    :copyright: Copyright 2007-2020 by the Sphinx team, see AUTHORS.
    :license: BSD, see LICENSE for details.
"""

import logging
import logging.handlers
from collections import defaultdict
from contextlib import contextmanager
from typing import Any, Dict, Generator, IO, List, Tuple, Union

from docutils import nodes
from docutils.nodes import Node
from docutils.utils import get_source_line

from sphinx.errors import SphinxWarning
from sphinx.util.console import colorize

if False:
    # For type annotation
    from typing import Type  # for python3.5.1
    from sphinx.application import Sphinx


NAMESPACE = 'sphinx'
VERBOSE = 15

LEVEL_NAMES = defaultdict(lambda: logging.WARNING)  # type: Dict[str, int]
LEVEL_NAMES.update({
    'CRITICAL': logging.CRITICAL,
    'SEVERE': logging.CRITICAL,
    'ERROR': logging.ERROR,
    'WARNING': logging.WARNING,
    'INFO': logging.INFO,
    'VERBOSE': VERBOSE,
    'DEBUG': logging.DEBUG,
})

VERBOSITY_MAP = defaultdict(lambda: 0)  # type: Dict[int, int]
VERBOSITY_MAP.update({
    0: logging.INFO,
    1: VERBOSE,
    2: logging.DEBUG,
})

COLOR_MAP = defaultdict(lambda: 'blue',
                        {
                            logging.ERROR: 'darkred',
                            logging.WARNING: 'red',
                            logging.DEBUG: 'darkgray'
                        })


def getLogger(name: str) -> "SphinxLoggerAdapter":
    """Get logger wrapped by :class:`sphinx.util.logging.SphinxLoggerAdapter`.

    Sphinx logger always uses ``sphinx.*`` namespace to be independent from
    settings of root logger.  It ensures logging is consistent even if a
    third-party extension or imported application resets logger settings.

    Example usage::

        >>> from sphinx.util import logging
        >>> logger = logging.getLogger(__name__)
        >>> logger.info('Hello, this is an extension!')
        Hello, this is an extension!
    """
    # add sphinx prefix to name forcely
    logger = logging.getLogger(NAMESPACE + '.' + name)
    # Forcely enable logger
    logger.disabled = False
    # wrap logger by SphinxLoggerAdapter
    return SphinxLoggerAdapter(logger, {})


def convert_serializable(records: List[logging.LogRecord]) -> None:
    """Convert LogRecord serializable."""
    for r in records:
        # extract arguments to a message and clear them
        r.msg = r.getMessage()
        r.args = ()

        location = getattr(r, 'location', None)
        if isinstance(location, nodes.Node):
            r.location = get_node_location(location)  # type: ignore


class SphinxLogRecord(logging.LogRecord):
    """Log record class supporting location"""
    prefix = ''
    location = None  # type: Any

    def getMessage(self) -> str:
        message = super().getMessage()
        location = getattr(self, 'location', None)
        if location:
            message = '%s: %s%s' % (location, self.prefix, message)
        elif self.prefix not in message:
            message = self.prefix + message

        return message


class SphinxInfoLogRecord(SphinxLogRecord):
    """Info log record class supporting location"""
    prefix = ''  # do not show any prefix for INFO messages


class SphinxWarningLogRecord(SphinxLogRecord):
    """Warning log record class supporting location"""
    prefix = 'WARNING: '


class SphinxLoggerAdapter(logging.LoggerAdapter):
    """LoggerAdapter allowing ``type`` and ``subtype`` keywords."""
    KEYWORDS = ['type', 'subtype', 'location', 'nonl', 'color', 'once']

    def log(self, level: Union[int, str], msg: str, *args: Any, **kwargs: Any) -> None:
        if isinstance(level, int):
            super().log(level, msg, *args, **kwargs)
        else:
            levelno = LEVEL_NAMES[level]
            super().log(levelno, msg, *args, **kwargs)

    def verbose(self, msg: str, *args: Any, **kwargs: Any) -> None:
        self.log(VERBOSE, msg, *args, **kwargs)

    def process(self, msg: str, kwargs: Dict) -> Tuple[str, Dict]:  # type: ignore
        extra = kwargs.setdefault('extra', {})
        for keyword in self.KEYWORDS:
            if keyword in kwargs:
                extra[keyword] = kwargs.pop(keyword)

        return msg, kwargs

    def handle(self, record: logging.LogRecord) -> None:
        self.logger.handle(record)


class WarningStreamHandler(logging.StreamHandler):
    """StreamHandler for warnings."""
    pass


class NewLineStreamHandler(logging.StreamHandler):
    """StreamHandler which switches line terminator by record.nonl flag."""

    def emit(self, record: logging.LogRecord) -> None:
        try:
            self.acquire()
            if getattr(record, 'nonl', False):
                # skip appending terminator when nonl=True
                self.terminator = ''
            super().emit(record)
        finally:
            self.terminator = '\n'
            self.release()


class MemoryHandler(logging.handlers.BufferingHandler):
    """Handler buffering all logs."""

    def __init__(self) -> None:
        super().__init__(-1)

    def shouldFlush(self, record: logging.LogRecord) -> bool:
        return False  # never flush

    def flushTo(self, logger: logging.Logger) -> None:
        self.acquire()
        try:
            for record in self.buffer:
                logger.handle(record)
            self.buffer = []  # type: List[logging.LogRecord]
        finally:
            self.release()

    def clear(self) -> List[logging.LogRecord]:
        buffer, self.buffer = self.buffer, []
        return buffer


@contextmanager
def pending_warnings() -> Generator[logging.Handler, None, None]:
    """Contextmanager to pend logging warnings temporary.

    Similar to :func:`pending_logging`.
    """
    logger = logging.getLogger(NAMESPACE)
    memhandler = MemoryHandler()
    memhandler.setLevel(logging.WARNING)

    try:
        handlers = []
        for handler in logger.handlers[:]:
            if isinstance(handler, WarningStreamHandler):
                logger.removeHandler(handler)
                handlers.append(handler)

        logger.addHandler(memhandler)
        yield memhandler
    finally:
        logger.removeHandler(memhandler)

        for handler in handlers:
            logger.addHandler(handler)

        memhandler.flushTo(logger)


@contextmanager
def suppress_logging() -> Generator[MemoryHandler, None, None]:
    """Contextmanager to suppress logging all logs temporary.

    For example::

        >>> with suppress_logging():
        >>>     logger.warning('Warning message!')  # suppressed
        >>>     some_long_process()
        >>>
    """
    logger = logging.getLogger(NAMESPACE)
    memhandler = MemoryHandler()

    try:
        handlers = []
        for handler in logger.handlers[:]:
            logger.removeHandler(handler)
            handlers.append(handler)

        logger.addHandler(memhandler)
        yield memhandler
    finally:
        logger.removeHandler(memhandler)

        for handler in handlers:
            logger.addHandler(handler)


@contextmanager
def pending_logging() -> Generator[MemoryHandler, None, None]:
    """Contextmanager to pend logging all logs temporary.

    For example::

        >>> with pending_logging():
        >>>     logger.warning('Warning message!')  # not flushed yet
        >>>     some_long_process()
        >>>
        Warning message!  # the warning is flushed here
    """
    logger = logging.getLogger(NAMESPACE)
    try:
        with suppress_logging() as memhandler:
            yield memhandler
    finally:
        memhandler.flushTo(logger)


@contextmanager
def skip_warningiserror(skip: bool = True) -> Generator[None, None, None]:
    """contextmanager to skip WarningIsErrorFilter for a while."""
    logger = logging.getLogger(NAMESPACE)

    if skip is False:
        yield
    else:
        try:
            disabler = DisableWarningIsErrorFilter()
            for handler in logger.handlers:
                # use internal method; filters.insert() directly to install disabler
                # before WarningIsErrorFilter
                handler.filters.insert(0, disabler)
            yield
        finally:
            for handler in logger.handlers:
                handler.removeFilter(disabler)


@contextmanager
def prefixed_warnings(prefix: str) -> Generator[None, None, None]:
    """Prepend prefix to all records for a while.

    For example::

        >>> with prefixed_warnings("prefix:"):
        >>>     logger.warning('Warning message!')  # => prefix: Warning message!

    .. versionadded:: 2.0
    """
    logger = logging.getLogger(NAMESPACE)
    warning_handler = None
    for handler in logger.handlers:
        if isinstance(handler, WarningStreamHandler):
            warning_handler = handler
            break
    else:
        # warning stream not found
        yield
        return

    prefix_filter = None
    for _filter in warning_handler.filters:
        if isinstance(_filter, MessagePrefixFilter):
            prefix_filter = _filter
            break

    if prefix_filter:
        # already prefixed
        try:
            previous = prefix_filter.prefix
            prefix_filter.prefix = prefix
            yield
        finally:
            prefix_filter.prefix = previous
    else:
        # not prefixed yet
        try:
            prefix_filter = MessagePrefixFilter(prefix)
            warning_handler.addFilter(prefix_filter)
            yield
        finally:
            warning_handler.removeFilter(prefix_filter)


class LogCollector:
    def __init__(self) -> None:
        self.logs = []  # type: List[logging.LogRecord]

    @contextmanager
    def collect(self) -> Generator[None, None, None]:
        with pending_logging() as memhandler:
            yield

            self.logs = memhandler.clear()


class InfoFilter(logging.Filter):
    """Filter error and warning messages."""

    def filter(self, record: logging.LogRecord) -> bool:
        if record.levelno < logging.WARNING:
            return True
        else:
            return False


def is_suppressed_warning(type: str, subtype: str, suppress_warnings: List[str]) -> bool:
    """Check the warning is suppressed or not."""
    if type is None:
        return False

    for warning_type in suppress_warnings:
        if '.' in warning_type:
            target, subtarget = warning_type.split('.', 1)
        else:
            target, subtarget = warning_type, None

        if target == type:
            if (subtype is None or subtarget is None or
               subtarget == subtype or subtarget == '*'):
                return True

    return False


class WarningSuppressor(logging.Filter):
    """Filter logs by `suppress_warnings`."""

    def __init__(self, app: "Sphinx") -> None:
        self.app = app
        super().__init__()

    def filter(self, record: logging.LogRecord) -> bool:
        type = getattr(record, 'type', None)
        subtype = getattr(record, 'subtype', None)

        try:
            suppress_warnings = self.app.config.suppress_warnings
        except AttributeError:
            # config is not initialized yet (ex. in conf.py)
            suppress_warnings = []

        if is_suppressed_warning(type, subtype, suppress_warnings):
            return False
        else:
            self.app._warncount += 1
            return True


class WarningIsErrorFilter(logging.Filter):
    """Raise exception if warning emitted."""

    def __init__(self, app: "Sphinx") -> None:
        self.app = app
        super().__init__()

    def filter(self, record: logging.LogRecord) -> bool:
        if getattr(record, 'skip_warningsiserror', False):
            # disabled by DisableWarningIsErrorFilter
            return True
        elif self.app.warningiserror:
            location = getattr(record, 'location', '')
            try:
                message = record.msg % record.args
            except (TypeError, ValueError):
                message = record.msg  # use record.msg itself

            if location:
                raise SphinxWarning(location + ":" + str(message))
            else:
                raise SphinxWarning(message)
        else:
            return True


class DisableWarningIsErrorFilter(logging.Filter):
    """Disable WarningIsErrorFilter if this filter installed."""

    def filter(self, record: logging.LogRecord) -> bool:
        record.skip_warningsiserror = True  # type: ignore
        return True


class MessagePrefixFilter(logging.Filter):
    """Prepend prefix to all records."""

    def __init__(self, prefix: str) -> None:
        self.prefix = prefix
        super().__init__()

    def filter(self, record: logging.LogRecord) -> bool:
        if self.prefix:
            record.msg = self.prefix + ' ' + record.msg
        return True


class OnceFilter(logging.Filter):
    """Show the message only once."""

    def __init__(self, name: str = '') -> None:
        super().__init__(name)
        self.messages = {}  # type: Dict[str, List]

    def filter(self, record: logging.LogRecord) -> bool:
        once = getattr(record, 'once', '')
        if not once:
            return True
        else:
            params = self.messages.setdefault(record.msg, [])
            if record.args in params:
                return False

            params.append(record.args)
            return True


class SphinxLogRecordTranslator(logging.Filter):
    """Converts a log record to one Sphinx expects

    * Make a instance of SphinxLogRecord
    * docname to path if location given
    """
    LogRecordClass = None  # type: Type[logging.LogRecord]

    def __init__(self, app: "Sphinx") -> None:
        self.app = app
        super().__init__()

    def filter(self, record: SphinxWarningLogRecord) -> bool:  # type: ignore
        if isinstance(record, logging.LogRecord):
            # force subclassing to handle location
            record.__class__ = self.LogRecordClass  # type: ignore

        location = getattr(record, 'location', None)
        if isinstance(location, tuple):
            docname, lineno = location
            if docname and lineno:
                record.location = '%s:%s' % (self.app.env.doc2path(docname), lineno)
            elif docname:
                record.location = '%s' % self.app.env.doc2path(docname)
            else:
                record.location = None
        elif isinstance(location, nodes.Node):
            record.location = get_node_location(location)
        elif location and ':' not in location:
            record.location = '%s' % self.app.env.doc2path(location)

        return True


class InfoLogRecordTranslator(SphinxLogRecordTranslator):
    """LogRecordTranslator for INFO level log records."""
    LogRecordClass = SphinxInfoLogRecord


class WarningLogRecordTranslator(SphinxLogRecordTranslator):
    """LogRecordTranslator for WARNING level log records."""
    LogRecordClass = SphinxWarningLogRecord


def get_node_location(node: Node) -> str:
    (source, line) = get_source_line(node)
    if source and line:
        return "%s:%s" % (source, line)
    elif source:
        return "%s:" % source
    elif line:
        return "<unknown>:%s" % line
    else:
        return None


class ColorizeFormatter(logging.Formatter):
    def format(self, record: logging.LogRecord) -> str:
        message = super().format(record)
        color = getattr(record, 'color', None)
        if color is None:
            color = COLOR_MAP.get(record.levelno)

        if color:
            return colorize(color, message)
        else:
            return message


class SafeEncodingWriter:
    """Stream writer which ignores UnicodeEncodeError silently"""
    def __init__(self, stream: IO) -> None:
        self.stream = stream
        self.encoding = getattr(stream, 'encoding', 'ascii') or 'ascii'

    def write(self, data: str) -> None:
        try:
            self.stream.write(data)
        except UnicodeEncodeError:
            # stream accept only str, not bytes.  So, we encode and replace
            # non-encodable characters, then decode them.
            self.stream.write(data.encode(self.encoding, 'replace').decode(self.encoding))

    def flush(self) -> None:
        if hasattr(self.stream, 'flush'):
            self.stream.flush()


class LastMessagesWriter:
    """Stream writer which memories last 10 messages to save trackback"""
    def __init__(self, app: "Sphinx", stream: IO) -> None:
        self.app = app

    def write(self, data: str) -> None:
        self.app.messagelog.append(data)


def setup(app: "Sphinx", status: IO, warning: IO) -> None:
    """Setup root logger for Sphinx"""
    logger = logging.getLogger(NAMESPACE)
    logger.setLevel(logging.DEBUG)
    logger.propagate = False

    # clear all handlers
    for handler in logger.handlers[:]:
        logger.removeHandler(handler)

    info_handler = NewLineStreamHandler(SafeEncodingWriter(status))  # type: ignore
    info_handler.addFilter(InfoFilter())
    info_handler.addFilter(InfoLogRecordTranslator(app))
    info_handler.setLevel(VERBOSITY_MAP[app.verbosity])
    info_handler.setFormatter(ColorizeFormatter())

    warning_handler = WarningStreamHandler(SafeEncodingWriter(warning))  # type: ignore
    warning_handler.addFilter(WarningSuppressor(app))
    warning_handler.addFilter(WarningLogRecordTranslator(app))
    warning_handler.addFilter(WarningIsErrorFilter(app))
    warning_handler.addFilter(OnceFilter())
    warning_handler.setLevel(logging.WARNING)
    warning_handler.setFormatter(ColorizeFormatter())

    messagelog_handler = logging.StreamHandler(LastMessagesWriter(app, status))  # type: ignore
    messagelog_handler.addFilter(InfoFilter())
    messagelog_handler.setLevel(VERBOSITY_MAP[app.verbosity])
    messagelog_handler.setFormatter(ColorizeFormatter())

    logger.addHandler(info_handler)
    logger.addHandler(warning_handler)
    logger.addHandler(messagelog_handler)