Add size constraint on RPC cache

tryton/tryton/cache.py

@@ -0,0 +1,34 @@
+# This file is part of Tryton.  The COPYRIGHT file at the top level of
+# this repository contains the full copyright notices and license terms.
+
+from collections import OrderedDict
+
+
+class CacheDict(OrderedDict):
+
+    def __init__(self, *args, cache_len=10, default_factory=None, **kwargs):
+        assert cache_len > 0
+        self.cache_len = cache_len
+        self.default_factory = default_factory
+
+        super().__init__(*args, **kwargs)
+
+    def __setitem__(self, key, value):
+        super().__setitem__(key, value)
+        self.move_to_end(key)
+
+        while len(self) > self.cache_len:
+            oldkey = next(iter(self))
+            self.__delitem__(oldkey)
+
+    def __getitem__(self, key):
+        value = super().__getitem__(key)
+        self.move_to_end(key)
+        return value
+
+    def __missing__(self, key):
+        if self.default_factory is None:
+            raise KeyError(key)
+        value = self.default_factory()
+        self[key] = value
+        return value

tryton/tryton/common/common.py

@@ -37,6 +37,7 @@ from string import Template
 from threading import Lock, Thread
 
 import tryton.rpc as rpc
+from tryton.cache import CacheDict
 from tryton.config import CONFIG, PIXMAPS_DIR, SOUNDS_DIR, TRYTON_ICON
 
 try:
@@ -59,28 +60,6 @@ _ = gettext.gettext
 logger = logging.getLogger(__name__)
 
 
-class CacheDict(OrderedDict):
-
-    def __init__(self, *args, cache_len=10, **kwargs):
-        assert cache_len > 0
-        self.cache_len = cache_len
-
-        super().__init__(*args, **kwargs)
-
-    def __setitem__(self, key, value):
-        super().__setitem__(key, value)
-        self.move_to_end(key)
-
-        while len(self) > self.cache_len:
-            oldkey = next(iter(self))
-            self.__delitem__(oldkey)
-
-    def __getitem__(self, key):
-        value = super().__getitem__(key)
-        self.move_to_end(key)
-        return value
-
-
 class IconFactory:
 
     batchnum = 10

tryton/tryton/config.py

@@ -81,6 +81,7 @@ class ConfigManager(object):
             'login.db': demo_database,
             'login.expanded': False,
             'client.title': 'Tryton',
+            'rpc.cache_size': 1024,
             'client.modepda': False,
             'client.toolbar': 'default',
             'client.save_tree_width': True,

tryton/tryton/jsonrpc.py

@@ -12,12 +12,14 @@ import socket
 import ssl
 import threading
 import xmlrpc.client
-from collections import defaultdict
 from contextlib import contextmanager
 from decimal import Decimal
 from functools import partial, reduce
 from urllib.parse import quote, urljoin
 
+from .cache import CacheDict
+from .config import CONFIG
+
 __all__ = ["ResponseError", "Fault", "ProtocolError", "Transport",
     "ServerProxy", "ServerPool"]
 CONNECT_TIMEOUT = 5
@@ -401,7 +403,10 @@ class ServerPool(object):
 class _Cache:
 
     def __init__(self):
-        self.store = defaultdict(dict)
+        cache_size = CONFIG['rpc.cache_size']
+        self.store = CacheDict(
+            cache_len=cache_size,
+            default_factory=lambda: CacheDict(cache_len=cache_size))
 
     def cached(self, prefix):
         return prefix in self.store