0x1949 Team - FAZEMRX - MANAGER
Edit File: _json.py
# -*- test-case-name: twisted.logger.test.test_json -*- # Copyright (c) Twisted Matrix Laboratories. # See LICENSE for details. """ Tools for saving and loading log events in a structured format. """ from json import dumps, loads from typing import IO, Any, AnyStr, Dict, Iterable, Optional, Union, cast from uuid import UUID from constantly import NamedConstant # type: ignore[import] from twisted.python.failure import Failure from ._file import FileLogObserver from ._flatten import flattenEvent from ._interfaces import LogEvent from ._levels import LogLevel from ._logger import Logger log = Logger() JSONDict = Dict[str, Any] def failureAsJSON(failure: Failure) -> JSONDict: """ Convert a failure to a JSON-serializable data structure. @param failure: A failure to serialize. @return: a mapping of strings to ... stuff, mostly reminiscent of L{Failure.__getstate__} """ return dict( failure.__getstate__(), type=dict( __module__=failure.type.__module__, __name__=failure.type.__name__, ), ) def failureFromJSON(failureDict: JSONDict) -> Failure: """ Load a L{Failure} from a dictionary deserialized from JSON. @param failureDict: a JSON-deserialized object like one previously returned by L{failureAsJSON}. @return: L{Failure} """ f = Failure.__new__(Failure) typeInfo = failureDict["type"] failureDict["type"] = type(typeInfo["__name__"], (), typeInfo) f.__dict__ = failureDict return f classInfo = [ ( lambda level: ( isinstance(level, NamedConstant) and getattr(LogLevel, level.name, None) is level ), UUID("02E59486-F24D-46AD-8224-3ACDF2A5732A"), lambda level: dict(name=level.name), lambda level: getattr(LogLevel, level["name"], None), ), ( lambda o: isinstance(o, Failure), UUID("E76887E2-20ED-49BF-A8F8-BA25CC586F2D"), failureAsJSON, failureFromJSON, ), ] uuidToLoader = {uuid: loader for (predicate, uuid, saver, loader) in classInfo} def objectLoadHook(aDict: JSONDict) -> object: """ Dictionary-to-object-translation hook for certain value types used within the logging system. @see: the C{object_hook} parameter to L{json.load} @param aDict: A dictionary loaded from a JSON object. @return: C{aDict} itself, or the object represented by C{aDict} """ if "__class_uuid__" in aDict: return uuidToLoader[UUID(aDict["__class_uuid__"])](aDict) return aDict def objectSaveHook(pythonObject: object) -> JSONDict: """ Object-to-serializable hook for certain value types used within the logging system. @see: the C{default} parameter to L{json.dump} @param pythonObject: Any object. @return: If the object is one of the special types the logging system supports, a specially-formatted dictionary; otherwise, a marker dictionary indicating that it could not be serialized. """ for (predicate, uuid, saver, loader) in classInfo: if predicate(pythonObject): result = saver(pythonObject) result["__class_uuid__"] = str(uuid) return result return {"unpersistable": True} def eventAsJSON(event: LogEvent) -> str: """ Encode an event as JSON, flattening it if necessary to preserve as much structure as possible. Not all structure from the log event will be preserved when it is serialized. @param event: A log event dictionary. @return: A string of the serialized JSON; note that this will contain no newline characters, and may thus safely be stored in a line-delimited file. """ def default(unencodable: object) -> Union[JSONDict, str]: """ Serialize an object not otherwise serializable by L{dumps}. @param unencodable: An unencodable object. @return: C{unencodable}, serialized """ if isinstance(unencodable, bytes): return unencodable.decode("charmap") return objectSaveHook(unencodable) flattenEvent(event) return dumps(event, default=default, skipkeys=True) def eventFromJSON(eventText: str) -> JSONDict: """ Decode a log event from JSON. @param eventText: The output of a previous call to L{eventAsJSON} @return: A reconstructed version of the log event. """ return cast(JSONDict, loads(eventText, object_hook=objectLoadHook)) def jsonFileLogObserver( outFile: IO[Any], recordSeparator: str = "\x1e" ) -> FileLogObserver: """ Create a L{FileLogObserver} that emits JSON-serialized events to a specified (writable) file-like object. Events are written in the following form:: RS + JSON + NL C{JSON} is the serialized event, which is JSON text. C{NL} is a newline (C{"\\n"}). C{RS} is a record separator. By default, this is a single RS character (C{"\\x1e"}), which makes the default output conform to the IETF draft document "draft-ietf-json-text-sequence-13". @param outFile: A file-like object. Ideally one should be passed which accepts L{str} data. Otherwise, UTF-8 L{bytes} will be used. @param recordSeparator: The record separator to use. @return: A file log observer. """ return FileLogObserver( outFile, lambda event: f"{recordSeparator}{eventAsJSON(event)}\n" ) def eventsFromJSONLogFile( inFile: IO[Any], recordSeparator: Optional[str] = None, bufferSize: int = 4096, ) -> Iterable[LogEvent]: """ Load events from a file previously saved with L{jsonFileLogObserver}. Event records that are truncated or otherwise unreadable are ignored. @param inFile: A (readable) file-like object. Data read from C{inFile} should be L{str} or UTF-8 L{bytes}. @param recordSeparator: The expected record separator. If L{None}, attempt to automatically detect the record separator from one of C{"\\x1e"} or C{""}. @param bufferSize: The size of the read buffer used while reading from C{inFile}. @return: Log events as read from C{inFile}. """ def asBytes(s: AnyStr) -> bytes: if isinstance(s, bytes): return s else: return s.encode("utf-8") def eventFromBytearray(record: bytearray) -> Optional[LogEvent]: try: text = bytes(record).decode("utf-8") except UnicodeDecodeError: log.error( "Unable to decode UTF-8 for JSON record: {record!r}", record=bytes(record), ) return None try: return eventFromJSON(text) except ValueError: log.error("Unable to read JSON record: {record!r}", record=bytes(record)) return None if recordSeparator is None: first = asBytes(inFile.read(1)) if first == b"\x1e": # This looks json-text-sequence compliant. recordSeparatorBytes = first else: # Default to simpler newline-separated stream, which does not use # a record separator. recordSeparatorBytes = b"" else: recordSeparatorBytes = asBytes(recordSeparator) first = b"" if recordSeparatorBytes == b"": recordSeparatorBytes = b"\n" # Split on newlines below eventFromRecord = eventFromBytearray else: def eventFromRecord(record: bytearray) -> Optional[LogEvent]: if record[-1] == ord("\n"): return eventFromBytearray(record) else: log.error( "Unable to read truncated JSON record: {record!r}", record=bytes(record), ) return None buffer = bytearray(first) while True: newData = inFile.read(bufferSize) if not newData: if len(buffer) > 0: event = eventFromRecord(buffer) if event is not None: yield event break buffer += asBytes(newData) records = buffer.split(recordSeparatorBytes) for record in records[:-1]: if len(record) > 0: event = eventFromRecord(record) if event is not None: yield event buffer = records[-1]