mirror of
https://git.anonymousland.org/anonymousland/synapse.git
synced 2025-05-02 14:56:42 -04:00
Add type hints to DictionaryCache and TTLCache. (#9442)
This commit is contained in:
Patrick Cloke
GitHub
parent
7dcf3fd221
commit
01dd90b0f0
7 changed files with 96 additions and 67 deletions
|
|
@ -15,26 +15,38 @@
|
|||
import enum
|
||||
import logging
|
||||
import threading
|
||||
from collections import namedtuple
|
||||
from typing import Any
|
||||
from typing import Any, Dict, Generic, Iterable, Optional, Set, TypeVar
|
||||
|
||||
import attr
|
||||
|
||||
from synapse.util.caches.lrucache import LruCache
|
||||
|
||||
logger = logging.getLogger(__name__)
|
||||
|
||||
|
||||
class DictionaryEntry(namedtuple("DictionaryEntry", ("full", "known_absent", "value"))):
|
||||
# The type of the cache keys.
|
||||
KT = TypeVar("KT")
|
||||
# The type of the dictionary keys.
|
||||
DKT = TypeVar("DKT")
|
||||
|
||||
|
||||
@attr.s(slots=True)
|
||||
class DictionaryEntry:
|
||||
"""Returned when getting an entry from the cache
|
||||
|
||||
Attributes:
|
||||
full (bool): Whether the cache has the full or dict or just some keys.
|
||||
full: Whether the cache has the full or dict or just some keys.
|
||||
If not full then not all requested keys will necessarily be present
|
||||
in `value`
|
||||
known_absent (set): Keys that were looked up in the dict and were not
|
||||
known_absent: Keys that were looked up in the dict and were not
|
||||
there.
|
||||
value (dict): The full or partial dict value
|
||||
value: The full or partial dict value
|
||||
"""
|
||||
|
||||
full = attr.ib(type=bool)
|
||||
known_absent = attr.ib()
|
||||
value = attr.ib()
|
||||
|
||||
def __len__(self):
|
||||
return len(self.value)
|
||||
|
||||
|
|
@ -45,21 +57,21 @@ class _Sentinel(enum.Enum):
|
|||
sentinel = object()
|
||||
|
||||
|
||||
class DictionaryCache:
|
||||
class DictionaryCache(Generic[KT, DKT]):
|
||||
"""Caches key -> dictionary lookups, supporting caching partial dicts, i.e.
|
||||
fetching a subset of dictionary keys for a particular key.
|
||||
"""
|
||||
|
||||
def __init__(self, name, max_entries=1000):
|
||||
def __init__(self, name: str, max_entries: int = 1000):
|
||||
self.cache = LruCache(
|
||||
max_size=max_entries, cache_name=name, size_callback=len
|
||||
) # type: LruCache[Any, DictionaryEntry]
|
||||
) # type: LruCache[KT, DictionaryEntry]
|
||||
|
||||
self.name = name
|
||||
self.sequence = 0
|
||||
self.thread = None
|
||||
self.thread = None # type: Optional[threading.Thread]
|
||||
|
||||
def check_thread(self):
|
||||
def check_thread(self) -> None:
|
||||
expected_thread = self.thread
|
||||
if expected_thread is None:
|
||||
self.thread = threading.current_thread()
|
||||
|
|
@ -69,12 +81,14 @@ class DictionaryCache:
|
|||
"Cache objects can only be accessed from the main thread"
|
||||
)
|
||||
|
||||
def get(self, key, dict_keys=None):
|
||||
def get(
|
||||
self, key: KT, dict_keys: Optional[Iterable[DKT]] = None
|
||||
) -> DictionaryEntry:
|
||||
"""Fetch an entry out of the cache
|
||||
|
||||
Args:
|
||||
key
|
||||
dict_key(list): If given a set of keys then return only those keys
|
||||
dict_key: If given a set of keys then return only those keys
|
||||
that exist in the cache.
|
||||
|
||||
Returns:
|
||||
|
|
@ -95,7 +109,7 @@ class DictionaryCache:
|
|||
|
||||
return DictionaryEntry(False, set(), {})
|
||||
|
||||
def invalidate(self, key):
|
||||
def invalidate(self, key: KT) -> None:
|
||||
self.check_thread()
|
||||
|
||||
# Increment the sequence number so that any SELECT statements that
|
||||
|
|
@ -103,19 +117,25 @@ class DictionaryCache:
|
|||
self.sequence += 1
|
||||
self.cache.pop(key, None)
|
||||
|
||||
def invalidate_all(self):
|
||||
def invalidate_all(self) -> None:
|
||||
self.check_thread()
|
||||
self.sequence += 1
|
||||
self.cache.clear()
|
||||
|
||||
def update(self, sequence, key, value, fetched_keys=None):
|
||||
def update(
|
||||
self,
|
||||
sequence: int,
|
||||
key: KT,
|
||||
value: Dict[DKT, Any],
|
||||
fetched_keys: Optional[Set[DKT]] = None,
|
||||
) -> None:
|
||||
"""Updates the entry in the cache
|
||||
|
||||
Args:
|
||||
sequence
|
||||
key (K)
|
||||
value (dict[X,Y]): The value to update the cache with.
|
||||
fetched_keys (None|set[X]): All of the dictionary keys which were
|
||||
key
|
||||
value: The value to update the cache with.
|
||||
fetched_keys: All of the dictionary keys which were
|
||||
fetched from the database.
|
||||
|
||||
If None, this is the complete value for key K. Otherwise, it
|
||||
|
|
@ -131,7 +151,9 @@ class DictionaryCache:
|
|||
else:
|
||||
self._update_or_insert(key, value, fetched_keys)
|
||||
|
||||
def _update_or_insert(self, key, value, known_absent):
|
||||
def _update_or_insert(
|
||||
self, key: KT, value: Dict[DKT, Any], known_absent: Set[DKT]
|
||||
) -> None:
|
||||
# We pop and reinsert as we need to tell the cache the size may have
|
||||
# changed
|
||||
|
||||
|
|
@ -140,5 +162,5 @@ class DictionaryCache:
|
|||
entry.known_absent.update(known_absent)
|
||||
self.cache[key] = entry
|
||||
|
||||
def _insert(self, key, value, known_absent):
|
||||
def _insert(self, key: KT, value: Dict[DKT, Any], known_absent: Set[DKT]) -> None:
|
||||
self.cache[key] = DictionaryEntry(True, known_absent, value)
|
||||
|
|
|
|||
|
|
@ -15,6 +15,7 @@
|
|||
|
||||
import logging
|
||||
import time
|
||||
from typing import Any, Callable, Dict, Generic, Tuple, TypeVar, Union
|
||||
|
||||
import attr
|
||||
from sortedcontainers import SortedList
|
||||
|
|
@ -23,15 +24,19 @@ from synapse.util.caches import register_cache
|
|||
|
||||
logger = logging.getLogger(__name__)
|
||||
|
||||
SENTINEL = object()
|
||||
SENTINEL = object() # type: Any
|
||||
|
||||
T = TypeVar("T")
|
||||
KT = TypeVar("KT")
|
||||
VT = TypeVar("VT")
|
||||
|
||||
|
||||
class TTLCache:
|
||||
class TTLCache(Generic[KT, VT]):
|
||||
"""A key/value cache implementation where each entry has its own TTL"""
|
||||
|
||||
def __init__(self, cache_name, timer=time.time):
|
||||
def __init__(self, cache_name: str, timer: Callable[[], float] = time.time):
|
||||
# map from key to _CacheEntry
|
||||
self._data = {}
|
||||
self._data = {} # type: Dict[KT, _CacheEntry]
|
||||
|
||||
# the _CacheEntries, sorted by expiry time
|
||||
self._expiry_list = SortedList() # type: SortedList[_CacheEntry]
|
||||
|
|
@ -40,26 +45,27 @@ class TTLCache:
|
|||
|
||||
self._metrics = register_cache("ttl", cache_name, self, resizable=False)
|
||||
|
||||
def set(self, key, value, ttl):
|
||||
def set(self, key: KT, value: VT, ttl: float) -> None:
|
||||
"""Add/update an entry in the cache
|
||||
|
||||
Args:
|
||||
key: key for this entry
|
||||
value: value for this entry
|
||||
ttl (float): TTL for this entry, in seconds
|
||||
ttl: TTL for this entry, in seconds
|
||||
"""
|
||||
expiry = self._timer() + ttl
|
||||
|
||||
self.expire()
|
||||
e = self._data.pop(key, SENTINEL)
|
||||
if e != SENTINEL:
|
||||
if e is not SENTINEL:
|
||||
assert isinstance(e, _CacheEntry)
|
||||
self._expiry_list.remove(e)
|
||||
|
||||
entry = _CacheEntry(expiry_time=expiry, ttl=ttl, key=key, value=value)
|
||||
self._data[key] = entry
|
||||
self._expiry_list.add(entry)
|
||||
|
||||
def get(self, key, default=SENTINEL):
|
||||
def get(self, key: KT, default: T = SENTINEL) -> Union[VT, T]:
|
||||
"""Get a value from the cache
|
||||
|
||||
Args:
|
||||
|
|
@ -72,23 +78,23 @@ class TTLCache:
|
|||
"""
|
||||
self.expire()
|
||||
e = self._data.get(key, SENTINEL)
|
||||
if e == SENTINEL:
|
||||
if e is SENTINEL:
|
||||
self._metrics.inc_misses()
|
||||
if default == SENTINEL:
|
||||
if default is SENTINEL:
|
||||
raise KeyError(key)
|
||||
return default
|
||||
assert isinstance(e, _CacheEntry)
|
||||
self._metrics.inc_hits()
|
||||
return e.value
|
||||
|
||||
def get_with_expiry(self, key):
|
||||
def get_with_expiry(self, key: KT) -> Tuple[VT, float, float]:
|
||||
"""Get a value, and its expiry time, from the cache
|
||||
|
||||
Args:
|
||||
key: key to look up
|
||||
|
||||
Returns:
|
||||
Tuple[Any, float, float]: the value from the cache, the expiry time
|
||||
and the TTL
|
||||
A tuple of the value from the cache, the expiry time and the TTL
|
||||
|
||||
Raises:
|
||||
KeyError if the entry is not found
|
||||
|
|
@ -102,7 +108,7 @@ class TTLCache:
|
|||
self._metrics.inc_hits()
|
||||
return e.value, e.expiry_time, e.ttl
|
||||
|
||||
def pop(self, key, default=SENTINEL):
|
||||
def pop(self, key: KT, default: T = SENTINEL) -> Union[VT, T]: # type: ignore
|
||||
"""Remove a value from the cache
|
||||
|
||||
If key is in the cache, remove it and return its value, else return default.
|
||||
|
|
@ -118,29 +124,30 @@ class TTLCache:
|
|||
"""
|
||||
self.expire()
|
||||
e = self._data.pop(key, SENTINEL)
|
||||
if e == SENTINEL:
|
||||
if e is SENTINEL:
|
||||
self._metrics.inc_misses()
|
||||
if default == SENTINEL:
|
||||
if default is SENTINEL:
|
||||
raise KeyError(key)
|
||||
return default
|
||||
assert isinstance(e, _CacheEntry)
|
||||
self._expiry_list.remove(e)
|
||||
self._metrics.inc_hits()
|
||||
return e.value
|
||||
|
||||
def __getitem__(self, key):
|
||||
def __getitem__(self, key: KT) -> VT:
|
||||
return self.get(key)
|
||||
|
||||
def __delitem__(self, key):
|
||||
def __delitem__(self, key: KT) -> None:
|
||||
self.pop(key)
|
||||
|
||||
def __contains__(self, key):
|
||||
def __contains__(self, key: KT) -> bool:
|
||||
return key in self._data
|
||||
|
||||
def __len__(self):
|
||||
def __len__(self) -> int:
|
||||
self.expire()
|
||||
return len(self._data)
|
||||
|
||||
def expire(self):
|
||||
def expire(self) -> None:
|
||||
"""Run the expiry on the cache. Any entries whose expiry times are due will
|
||||
be removed
|
||||
"""
|
||||
|
|
@ -158,7 +165,7 @@ class _CacheEntry:
|
|||
"""TTLCache entry"""
|
||||
|
||||
# expiry_time is the first attribute, so that entries are sorted by expiry.
|
||||
expiry_time = attr.ib()
|
||||
ttl = attr.ib()
|
||||
expiry_time = attr.ib(type=float)
|
||||
ttl = attr.ib(type=float)
|
||||
key = attr.ib()
|
||||
value = attr.ib()
|
||||
|
|
|
|||
Loading…
Add table
Add a link
Reference in a new issue