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yggdrasil.pickle.ser.logging

logging

logging.py – Serializers for Python :mod:logging objects.

Wire tags (all in the system range 200–299):

LOGGING_LOGGER      (216) – :class:`logging.Logger` / :class:`logging.RootLogger`
LOGGING_HANDLER     (217) – :class:`logging.Handler` and concrete subclasses
LOGGING_FORMATTER   (218) – :class:`logging.Formatter`
LOGGING_LOG_RECORD  (219) – :class:`logging.LogRecord`

Design notes

  • Loggers are reference-serialised by name: they are singletons managed by :func:logging.getLogger, so we only store the name + effective level and re-bind on load.
  • Handlers are reconstructed from their class reference plus the subset of state that is safe and portable (level, formatter, filters by name). Handler-specific init args (filename, stream, host/port, …) are stored via __getstate__ when available; otherwise we fall back to a dict extracted from __dict__.
  • Formatters store their format strings (fmt, datefmt, style, defaults).
  • LogRecords store all their public fields as a plain tuple payload.

The payload format uses :func:yggdrasil.pickle.ser.serialized.Serialized round-tripped msgpack-like nested bytes so that each sub-object goes through the normal serializer stack.

LoggingSerialized dataclass 

LoggingSerialized(head: Header, data: IO)

Bases: Serialized[object]

Abstract base for all logging-related serializers.

Concrete subclasses override :meth:as_python and :meth:from_python_object.

module_and_name staticmethod 

module_and_name(obj: Any, *, fallback: str = '') -> tuple[str, str]

Return (module, qualname) for obj.

Robust across Python objects, including many C-extension / PyArrow objects where module may be missing or misleading.

LoggerSerialized dataclass 

LoggerSerialized(head: Header, data: IO)

Bases: LoggingSerialized

Serializer for :class:logging.Logger.

Loggers are singletons: we persist the name and effective level only. On deserialisation we call :func:logging.getLogger to obtain the canonical instance, and (optionally) set the level when the logger has not been explicitly configured yet.

module_and_name staticmethod 

module_and_name(obj: Any, *, fallback: str = '') -> tuple[str, str]

Return (module, qualname) for obj.

Robust across Python objects, including many C-extension / PyArrow objects where module may be missing or misleading.

HandlerSerialized dataclass 

HandlerSerialized(head: Header, data: IO)

Bases: LoggingSerialized

Serializer for :class:logging.Handler and its subclasses.

Only portable state is captured:

  • Handler class (module + qualname)
  • Level
  • Formatter (if set)
  • Filter names
  • Handler-specific extra state (__getstate__ or __dict__ subset)

The handler is reconstructed via :func:_handler_try_reconstruct; if reconstruction fails, a plain :class:logging.NullHandler is returned instead.

module_and_name staticmethod 

module_and_name(obj: Any, *, fallback: str = '') -> tuple[str, str]

Return (module, qualname) for obj.

Robust across Python objects, including many C-extension / PyArrow objects where module may be missing or misleading.

FormatterSerialized dataclass 

FormatterSerialized(head: Header, data: IO)

Bases: LoggingSerialized

Serializer for :class:logging.Formatter.

Stores format string, date format, style, validation flag, and any extra defaults mapping. Custom :class:logging.Formatter subclasses that do not require special construction args will round-trip faithfully; more exotic subclasses are reconstructed as plain :class:logging.Formatter.

module_and_name staticmethod 

module_and_name(obj: Any, *, fallback: str = '') -> tuple[str, str]

Return (module, qualname) for obj.

Robust across Python objects, including many C-extension / PyArrow objects where module may be missing or misleading.

LogRecordSerialized dataclass 

LogRecordSerialized(head: Header, data: IO)

Bases: LoggingSerialized

Serializer for :class:logging.LogRecord.

All public fields are persisted. Exception info (exc_info) is serialised as a pickled bytes blob when the exception object is available; otherwise it is dropped.

module_and_name staticmethod 

module_and_name(obj: Any, *, fallback: str = '') -> tuple[str, str]

Return (module, qualname) for obj.

Robust across Python objects, including many C-extension / PyArrow objects where module may be missing or misleading.