zulip/zerver/lib/stream_recipient.py

101 lines
3.2 KiB
Python

from typing import (Dict, List)
from django.db import connection
from zerver.models import Recipient
class StreamRecipientMap(object):
'''
This class maps stream_id -> recipient_id and vice versa.
It is useful for bulk operations. Call the populate_* methods
to initialize the data structures. You should try to avoid
excessive queries by finding ids up front, but you can call
this repeatedly, and it will only look up new ids.
You should ONLY use this class for READ operations.
Note that this class uses raw SQL, because we want to highly
optimize page loads.
'''
def __init__(self):
# type: () -> None
self.recip_to_stream = dict() # type: Dict[int, int]
self.stream_to_recip = dict() # type: Dict[int, int]
def populate_for_stream_ids(self, stream_ids):
# type: (List[int]) -> None
stream_ids = sorted([
stream_id for stream_id in stream_ids
if stream_id not in self.stream_to_recip
])
if not stream_ids:
return
# see comment at the top of the class
id_list = ', '.join(str(stream_id) for stream_id in stream_ids)
query = '''
SELECT
zerver_recipient.id as recipient_id,
zerver_stream.id as stream_id
FROM
zerver_stream
INNER JOIN zerver_recipient ON
zerver_stream.id = zerver_recipient.type_id
WHERE
zerver_recipient.type = %d
AND
zerver_stream.id in (%s)
''' % (Recipient.STREAM, id_list)
self._process_query(query)
def populate_for_recipient_ids(self, recipient_ids):
# type: (List[int]) -> None
recipient_ids = sorted([
recip_id for recip_id in recipient_ids
if recip_id not in self.recip_to_stream
])
if not recipient_ids:
return
# see comment at the top of the class
id_list = ', '.join(str(recip_id) for recip_id in recipient_ids)
query = '''
SELECT
zerver_recipient.id as recipient_id,
zerver_stream.id as stream_id
FROM
zerver_recipient
INNER JOIN zerver_stream ON
zerver_stream.id = zerver_recipient.type_id
WHERE
zerver_recipient.type = %d
AND
zerver_recipient.id in (%s)
''' % (Recipient.STREAM, id_list)
self._process_query(query)
def _process_query(self, query):
# type: (str) -> None
cursor = connection.cursor()
cursor.execute(query)
rows = cursor.fetchall()
cursor.close()
for recip_id, stream_id in rows:
self.recip_to_stream[recip_id] = stream_id
self.stream_to_recip[stream_id] = recip_id
def recipient_id_for(self, stream_id):
# type: (int) -> int
return self.stream_to_recip[stream_id]
def stream_id_for(self, recip_id):
# type: (int) -> int
return self.recip_to_stream[recip_id]
def recipient_to_stream_id_dict(self):
# type: () -> Dict[int, int]
return self.recip_to_stream