65 lines
1.7 KiB
Python
65 lines
1.7 KiB
Python
from typing import List, Optional
|
|
|
|
from ._models import ServerSentEvent
|
|
|
|
|
|
class SSEDecoder:
|
|
def __init__(self) -> None:
|
|
self._event = ""
|
|
self._data: List[str] = []
|
|
self._last_event_id = ""
|
|
self._retry: Optional[int] = None
|
|
|
|
def decode(self, line: str) -> Optional[ServerSentEvent]:
|
|
# See: https://html.spec.whatwg.org/multipage/server-sent-events.html#event-stream-interpretation # noqa: E501
|
|
|
|
if not line:
|
|
if (
|
|
not self._event
|
|
and not self._data
|
|
and not self._last_event_id
|
|
and self._retry is None
|
|
):
|
|
return None
|
|
|
|
sse = ServerSentEvent(
|
|
event=self._event,
|
|
data="\n".join(self._data),
|
|
id=self._last_event_id,
|
|
retry=self._retry,
|
|
)
|
|
|
|
# NOTE: as per the SSE spec, do not reset last_event_id.
|
|
self._event = ""
|
|
self._data = []
|
|
self._retry = None
|
|
|
|
return sse
|
|
|
|
if line.startswith(":"):
|
|
return None
|
|
|
|
fieldname, _, value = line.partition(":")
|
|
|
|
if value.startswith(" "):
|
|
value = value[1:]
|
|
|
|
if fieldname == "event":
|
|
self._event = value
|
|
elif fieldname == "data":
|
|
self._data.append(value)
|
|
elif fieldname == "id":
|
|
if "\0" in value:
|
|
pass
|
|
else:
|
|
self._last_event_id = value
|
|
elif fieldname == "retry":
|
|
try:
|
|
self._retry = int(value)
|
|
except (TypeError, ValueError):
|
|
pass
|
|
else:
|
|
pass # Field is ignored.
|
|
|
|
return None
|