feat: port fastbin to casbin (#318)

* feat: port fastbin

* feat: implement FastEnforcer

* fix: remove redundant init code

Author: BustDot

casbin/__init__.py

@@ -15,6 +15,7 @@
 from .enforcer import *
 from .synced_enforcer import SyncedEnforcer
 from .distributed_enforcer import DistributedEnforcer
+from .fast_enforcer import FastEnforcer
 from .async_enforcer import AsyncEnforcer
 from . import util
 from .persist import *

casbin/core_enforcer.py

@@ -12,8 +12,8 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-import logging
 import copy
+import logging
 
 from casbin.effect import Effector, get_effector, effect_to_bool
 from casbin.model import Model, FunctionMap
@@ -202,7 +202,6 @@ def load_policy(self):
         new_model.clear_policy()
 
         try:
-
             self.adapter.load_policy(new_model)
 
             new_model.sort_policies_by_subject_hierarchy()
@@ -212,7 +211,6 @@ def load_policy(self):
             new_model.print_policy()
 
             if self.auto_build_role_links:
-
                 need_to_rebuild = True
                 for rm in self.rm_map.values():
                     rm.clear()
@@ -222,7 +220,6 @@ def load_policy(self):
             self.model = new_model
 
         except Exception as e:
-
             if self.auto_build_role_links and need_to_rebuild:
                 self.build_role_links()
 
@@ -315,7 +312,6 @@ def add_named_domain_matching_func(self, ptype, fn):
         return False
 
     def new_enforce_context(self, suffix: str) -> EnforceContext:
-
         return EnforceContext(
             rtype="r" + suffix,
             ptype="p" + suffix,

casbin/distributed_enforcer.py

@@ -12,12 +12,10 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-from casbin import SyncedEnforcer
-import logging
-
-from casbin.persist import batch_adapter
 from casbin.model.policy_op import PolicyOp
+from casbin.persist import batch_adapter
 from casbin.persist.adapters import update_adapter
+from casbin.synced_enforcer import SyncedEnforcer
 
 
 class DistributedEnforcer(SyncedEnforcer):

casbin/fast_enforcer.py

@@ -0,0 +1,41 @@
+import logging
+from typing import Sequence
+
+from casbin.enforcer import Enforcer
+from casbin.model import Model, FastModel, fast_policy_filter, FunctionMap
+from casbin.persist.adapters import FileAdapter
+from casbin.util.log import configure_logging
+
+
+class FastEnforcer(Enforcer):
+    _cache_key_order: Sequence[int] = None
+
+    def __init__(self, model=None, adapter=None, enable_log=False, cache_key_order: Sequence[int] = None):
+        self._cache_key_order = cache_key_order
+        super().__init__(model, adapter, enable_log)
+
+    def new_model(self, path="", text=""):
+        """creates a model."""
+        if self._cache_key_order is None:
+            m = Model()
+        else:
+            m = FastModel(self._cache_key_order)
+        if len(path) > 0:
+            m.load_model(path)
+        else:
+            m.load_model_from_text(text)
+
+        return m
+
+    def enforce(self, *rvals):
+        """decides whether a "subject" can access a "object" with the operation "action",
+        input parameters are usually: (sub, obj, act).
+        """
+        if FastEnforcer._cache_key_order is None:
+            result, _ = self.enforce_ex(*rvals)
+        else:
+            keys = [rvals[x] for x in self._cache_key_order]
+            with fast_policy_filter(self.model.model["p"]["p"].policy, *keys):
+                result, _ = self.enforce_ex(*rvals)
+
+        return result

casbin/model/__init__.py

@@ -13,6 +13,8 @@
 # limitations under the License.
 
 from .assertion import Assertion
+from .function import FunctionMap
 from .model import Model
+from .model_fast import FastModel
 from .policy import Policy
-from .function import FunctionMap
+from .policy_fast import FastPolicy, fast_policy_filter

casbin/model/model_fast.py

@@ -0,0 +1,36 @@
+# Copyright 2023 The casbin Authors. All Rights Reserved.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#      http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+from typing import Any, Sequence
+
+from .model import Model
+from .policy_fast import FastPolicy
+
+
+class FastModel(Model):
+    _cache_key_order: Sequence[int]
+
+    def __init__(self, cache_key_order: Sequence[int]) -> None:
+        super().__init__()
+        self._cache_key_order = cache_key_order
+
+    def add_def(self, sec: str, key: str, value: Any) -> None:
+        super().add_def(sec, key, value)
+        if sec == "p" and key == "p":
+            self.model[sec][key].policy = FastPolicy(self._cache_key_order)
+
+    def clear_policy(self) -> None:
+        """clears all current policy."""
+        super().clear_policy()
+        self.model["p"]["p"].policy = FastPolicy(self._cache_key_order)

casbin/model/policy_fast.py

@@ -0,0 +1,101 @@
+# Copyright 2023 The casbin Authors. All Rights Reserved.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#      http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+from contextlib import contextmanager
+from typing import Any, Container, Dict, Iterable, Iterator, Optional, Sequence, Set, cast
+
+
+def in_cache(cache: Dict[str, Any], keys: Sequence[str]) -> Optional[Set[Sequence[str]]]:
+    if keys[0] in cache:
+        if len(keys) > 1:
+            return in_cache(cache[keys[-0]], keys[1:])
+        return cast(Set[Sequence[str]], cache[keys[0]])
+    else:
+        return None
+
+
+class FastPolicy(Container[Sequence[str]]):
+    _cache: Dict[str, Any]
+    _current_filter: Optional[Set[Sequence[str]]]
+    _cache_key_order: Sequence[int]
+
+    def __init__(self, cache_key_order: Sequence[int]) -> None:
+        self._cache = {}
+        self._current_filter = None
+        self._cache_key_order = cache_key_order
+
+    def __iter__(self) -> Iterator[Sequence[str]]:
+        yield from self.__get_policy()
+
+    def __len__(self) -> int:
+        return len(list(self.__get_policy()))
+
+    def __contains__(self, item: object) -> bool:
+        if not isinstance(item, (list, tuple)) or len(self._cache_key_order) >= len(item):
+            return False
+        keys = [item[x] for x in self._cache_key_order]
+        exists = in_cache(self._cache, keys)
+        if not exists:
+            return False
+        return tuple(item) in exists
+
+    def __getitem__(self, item: int) -> Sequence[str]:
+        for i, entry in enumerate(self):
+            if i == item:
+                return entry
+        raise KeyError("No such value exists")
+
+    def append(self, item: Sequence[str]) -> None:
+        cache = self._cache
+        keys = [item[x] for x in self._cache_key_order]
+
+        for key in keys[:-1]:
+            if key not in cache:
+                cache[key] = dict()
+            cache = cache[key]
+        if keys[-1] not in cache:
+            cache[keys[-1]] = set()
+
+        cache[keys[-1]].add(tuple(item))
+
+    def remove(self, policy: Sequence[str]) -> bool:
+        keys = [policy[x] for x in self._cache_key_order]
+        exists = in_cache(self._cache, keys)
+        if not exists:
+            return True
+
+        exists.remove(tuple(policy))
+        return True
+
+    def __get_policy(self) -> Iterable[Sequence[str]]:
+        if self._current_filter is not None:
+            return (list(x) for x in self._current_filter)
+        else:
+            return (list(v2) for v in self._cache.values() for v1 in v.values() for v2 in v1)
+
+    def apply_filter(self, *keys: str) -> None:
+        value = in_cache(self._cache, keys)
+        self._current_filter = value or set()
+
+    def clear_filter(self) -> None:
+        self._current_filter = None
+
+
+@contextmanager
+def fast_policy_filter(policy: FastPolicy, *keys: str) -> Iterator[None]:
+    try:
+        policy.apply_filter(*keys)
+        yield
+    finally:
+        policy.clear_filter()

tests/__init__.py

@@ -12,14 +12,15 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
+from . import benchmarks
+from . import config
+from . import model
+from . import rbac
+from . import util
 from .test_distributed_api import TestDistributedApi
 from .test_enforcer import *
+from .test_fast_enforcer import TestFastEnforcer
 from .test_filter import TestFilteredAdapter
 from .test_frontend import TestFrontend
 from .test_management_api import TestManagementApi, TestManagementApiSynced
 from .test_rbac_api import TestRbacApi, TestRbacApiSynced
-from . import benchmarks
-from . import config
-from . import model
-from . import rbac
-from . import util

tests/model/__init__.py

@@ -13,3 +13,4 @@
 # limitations under the License.
 
 from .test_policy import TestPolicy
+from .test_policy_fast import TestContextManager, TestFastPolicy

tests/model/test_policy_fast.py

@@ -0,0 +1,101 @@
+# Copyright 2023 The casbin Authors. All Rights Reserved.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#      http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+from unittest import TestCase
+
+from casbin.model import FastPolicy, fast_policy_filter
+
+
+class TestFastPolicy(TestCase):
+    def test_able_to_add_rules(self) -> None:
+        policy = FastPolicy([2, 1])
+
+        policy.append(["sub", "obj", "read"])
+
+        assert list(policy) == [["sub", "obj", "read"]]
+
+    def test_does_not_add_duplicates(self) -> None:
+        policy = FastPolicy([2, 1])
+
+        policy.append(["sub", "obj", "read"])
+        policy.append(["sub", "obj", "read"])
+
+        assert list(policy) == [["sub", "obj", "read"]]
+
+    def test_can_remove_rules(self) -> None:
+        policy = FastPolicy([2, 1])
+
+        policy.append(["sub", "obj", "read"])
+        policy.remove(["sub", "obj", "read"])
+
+        assert list(policy) == []
+
+    def test_returns_lengtt(self) -> None:
+        policy = FastPolicy([2, 1])
+
+        policy.append(["sub", "obj", "read"])
+
+        assert len(policy) == 1
+
+    def test_supports_in_keyword(self) -> None:
+        policy = FastPolicy([2, 1])
+
+        policy.append(["sub", "obj", "read"])
+
+        assert ["sub", "obj", "read"] in policy
+
+    def test_supports_filters(self) -> None:
+        policy = FastPolicy([2, 1])
+
+        policy.append(["sub", "obj", "read"])
+        policy.append(["sub", "obj", "read2"])
+        policy.append(["sub", "obj2", "read2"])
+
+        policy.apply_filter("read2", "obj2")
+
+        assert list(policy) == [["sub", "obj2", "read2"]]
+
+    def test_clears_filters(self) -> None:
+        policy = FastPolicy([2, 1])
+
+        policy.append(["sub", "obj", "read"])
+        policy.append(["sub", "obj", "read2"])
+        policy.append(["sub", "obj2", "read2"])
+
+        policy.apply_filter("read2", "obj2")
+        policy.clear_filter()
+
+        assert list(policy) == [
+            ["sub", "obj", "read"],
+            ["sub", "obj", "read2"],
+            ["sub", "obj2", "read2"],
+        ]
+
+
+class TestContextManager:
+    def test_fast_policy_filter(self) -> None:
+        policy = FastPolicy([2, 1])
+
+        policy.append(["sub", "obj", "read"])
+        policy.append(["sub", "obj", "read2"])
+        policy.append(["sub", "obj2", "read2"])
+
+        with fast_policy_filter(policy, "read2", "obj2"):
+            assert list(policy) == [["sub", "obj2", "read2"]]
+
+        assert list(policy) == [
+            ["sub", "obj", "read"],
+            ["sub", "obj", "read2"],
+            ["sub", "obj2", "read2"],
+        ]