Add lifo cache to new module; drop "utils", bleh

piker/_async_utils.py

@@ -1,66 +0,0 @@
-# piker: trading gear for hackers
-# Copyright (C) 2018-present  Tyler Goodlet (in stewardship of piker0)
-
-# This program is free software: you can redistribute it and/or modify
-# it under the terms of the GNU Affero General Public License as published by
-# the Free Software Foundation, either version 3 of the License, or
-# (at your option) any later version.
-
-# This program is distributed in the hope that it will be useful,
-# but WITHOUT ANY WARRANTY; without even the implied warranty of
-# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-# GNU Affero General Public License for more details.
-
-# You should have received a copy of the GNU Affero General Public License
-# along with this program.  If not, see <https://www.gnu.org/licenses/>.
-
-"""
-Async utils no one seems to have built into a core lib (yet).
-"""
-from typing import AsyncContextManager
-from collections import OrderedDict
-from contextlib import asynccontextmanager
-
-
-def async_lifo_cache(maxsize=128):
-    """Async ``cache`` with a LIFO policy.
-
-    Implemented my own since no one else seems to have
-    a standard. I'll wait for the smarter people to come
-    up with one, but until then...
-    """
-    cache = OrderedDict()
-
-    def decorator(fn):
-
-        async def wrapper(*args):
-            key = args
-            try:
-                return cache[key]
-            except KeyError:
-                if len(cache) >= maxsize:
-                    # discard last added new entry
-                    cache.popitem()
-
-                # do it
-                cache[key] = await fn(*args)
-                return cache[key]
-
-        return wrapper
-
-    return decorator
-
-
-@asynccontextmanager
-async def _just_none():
-    # noop -> skip entering context
-    yield None
-
-
-@asynccontextmanager
-async def maybe_with_if(
-    predicate: bool,
-    context: AsyncContextManager,
-) -> AsyncContextManager:
-    async with context if predicate else _just_none() as output:
-        yield output

piker/_cacheables.py

@@ -18,6 +18,7 @@
 Cacheing apis and toolz.
 
 """
+from collections import OrderedDict
 from typing import Optional
 from contextlib import (
     asynccontextmanager,
@@ -36,6 +37,35 @@ from .data.feed import Feed
 log = get_logger(__name__)
 
 
+def async_lifo_cache(maxsize=128):
+    """Async ``cache`` with a LIFO policy.
+
+    Implemented my own since no one else seems to have
+    a standard. I'll wait for the smarter people to come
+    up with one, but until then...
+    """
+    cache = OrderedDict()
+
+    def decorator(fn):
+
+        async def wrapper(*args):
+            key = args
+            try:
+                return cache[key]
+            except KeyError:
+                if len(cache) >= maxsize:
+                    # discard last added new entry
+                    cache.popitem()
+
+                # do it
+                cache[key] = await fn(*args)
+                return cache[key]
+
+        return wrapper
+
+    return decorator
+
+
 _cache: dict[str, 'Client'] = {}  # noqa
 
 

piker/brokers/questrade.py

@@ -42,11 +42,10 @@ import wrapt
 import asks
 
 from ..calc import humanize, percent_change
-from .._cacheables import open_cached_client
+from .._cacheables import open_cached_client, async_lifo_cache
 from . import config
 from ._util import resproc, BrokerError, SymbolNotFound
 from ..log import get_logger, colorize_json, get_console_log
-from .._async_utils import async_lifo_cache
 from . import get_brokermod
 from . import api