platypush/platypush/message/__init__.py

267 lines
7.0 KiB
Python

from abc import ABC, abstractmethod
from dataclasses import asdict, is_dataclass
import decimal
import datetime
from enum import Enum
import io
import logging
import inspect
import json
import time
from typing import Union
from uuid import UUID
_logger = logging.getLogger('platypush')
class JSONAble(ABC):
"""
Generic interface for JSON-able objects.
"""
@abstractmethod
def to_json(self) -> Union[str, list, dict]:
raise NotImplementedError()
class Message:
"""
Message generic class
"""
class Encoder(json.JSONEncoder):
@staticmethod
def parse_numpy(obj):
try:
import numpy as np
if isinstance(obj, np.floating):
return float(obj)
if isinstance(obj, np.integer):
return int(obj)
if isinstance(obj, np.ndarray):
return obj.tolist()
if isinstance(obj, decimal.Decimal):
return float(obj)
if isinstance(obj, (bytes, bytearray)):
return '0x' + ''.join([f'{x:02x}' for x in obj])
if callable(obj):
return f'<function at {obj.__module__}.{obj.__name__}>'
except (AttributeError, ImportError, TypeError):
pass
return
@staticmethod
def parse_datetime(obj):
if isinstance(obj, (datetime.datetime, datetime.date, datetime.time)):
return obj.isoformat()
def default(self, obj):
from platypush.procedure import Procedure
value = self.parse_datetime(obj)
if value is not None:
return value
if isinstance(obj, set):
return list(obj)
if isinstance(obj, UUID):
return str(obj)
value = self.parse_numpy(obj)
if value is not None:
return value
if isinstance(obj, JSONAble):
return obj.to_json()
if isinstance(obj, Procedure):
return obj.to_dict()
if isinstance(obj, Enum):
return obj.value
if isinstance(obj, Exception):
return f'<{obj.__class__.__name__}>' + (f' {obj}' if obj else '')
if is_dataclass(obj):
return asdict(obj)
if isinstance(obj, Message):
return obj.to_dict(obj)
# Don't serialize I/O wrappers/objects
if isinstance(obj, io.IOBase):
return None
try:
return super().default(obj)
except Exception as e:
_logger.warning(
'Could not serialize object type %s: %s: %s', type(obj), e, obj
)
def __init__(self, *_, timestamp=None, logging_level=logging.INFO, **__):
self.timestamp = timestamp or time.time()
self.logging_level = logging_level
self._logger = _logger
self._default_log_prefix = ''
def log(self, prefix=''):
if self.logging_level is None:
return # Skip logging
log_func = self._logger.info
if self.logging_level == logging.DEBUG:
log_func = self._logger.debug
elif self.logging_level == logging.WARNING:
log_func = self._logger.warning
elif self.logging_level == logging.ERROR:
log_func = self._logger.error
elif self.logging_level == logging.FATAL:
log_func = self._logger.fatal
if not prefix:
prefix = self._default_log_prefix
log_func('%s%s', prefix, self)
def __str__(self):
"""
Overrides the str() operator and converts
the message into a UTF-8 JSON string
"""
return json.dumps(
{
attr: getattr(self, attr)
for attr in self.__dir__()
if (attr != '_timestamp' or not attr.startswith('_'))
and not inspect.ismethod(getattr(self, attr))
},
cls=self.Encoder,
).replace('\n', ' ')
def __bytes__(self):
"""
Overrides the bytes() operator, converts the message into
its JSON-serialized UTF-8-encoded representation
"""
return str(self).encode('utf-8')
@classmethod
def parse(cls, msg):
"""
Parse a generic message into a key-value dictionary
:param msg: Original message. It can be a dictionary, a Message,
or a string/bytearray, as long as it's valid UTF-8 JSON
"""
if isinstance(msg, cls):
msg = str(msg)
if isinstance(msg, (bytes, bytearray)):
msg = msg.decode('utf-8')
if isinstance(msg, str):
try:
msg = json.loads(msg.strip())
except (ValueError, TypeError):
_logger.warning('Invalid JSON message: %s', msg)
assert isinstance(msg, dict)
if '_timestamp' not in msg:
msg['_timestamp'] = time.time()
return msg
@classmethod
def to_dict(cls, msg):
"""
Converts a Message object into a dictionary
:param msg: Message object
"""
return {
k: v
for k, v in cls.parse(msg).items()
if k not in ('id', 'token', 'target', 'origin', '_timestamp')
}
@classmethod
def build(cls, msg):
"""
Builds a Message object from a dictionary.
:param msg: The message as a key-value dictionary, Message object or JSON string
"""
from platypush.utils import get_message_class_by_type
msg = cls.parse(msg)
msgtype = get_message_class_by_type(msg['type'])
if msgtype != cls:
return msgtype.build(msg)
class Mapping(dict):
def __init__(self, *args, **kwargs):
super().__init__(*args, **kwargs)
for k, v in kwargs.items():
self.__setattr__(k, v)
def __setitem__(self, key, item):
self.__dict__[key] = item
def __getitem__(self, key):
return self.__dict__[key]
def __repr__(self):
return repr(self.__dict__)
def __len__(self):
return len(self.__dict__)
def __delitem__(self, key):
del self.__dict__[key]
def clear(self):
return self.__dict__.clear()
def copy(self):
return self.__dict__.copy()
def has_key(self, k):
return k in self.__dict__
def update(self, *args, **kwargs):
return self.__dict__.update(*args, **kwargs)
def keys(self):
return self.__dict__.keys()
def values(self):
return self.__dict__.values()
def items(self):
return self.__dict__.items()
def pop(self, *args):
return self.__dict__.pop(*args)
def __cmp__(self, dict_):
return self.__cmp__(dict_)
def __contains__(self, item):
return item in self.__dict__
def __iter__(self):
return iter(self.__dict__)
def __str__(self):
return str(self.__dict__)
# vim:sw=4:ts=4:et: