From 784a46f8f403cf18572c22c8779dc1e3dca315ca Mon Sep 17 00:00:00 2001
From: BustDot <bust.dev@outlook.com>
Date: Mon, 10 Jul 2023 10:38:26 +0800
Subject: [PATCH] feat: add string adapter (#304)

---
 casbin/persist/adapters/string_adapter.py | 67 ++++++++++++++++++
 tests/persist/__init__.py                 |  0
 tests/persist/test_string_adapter.py      | 83 +++++++++++++++++++++++
 3 files changed, 150 insertions(+)
 create mode 100644 casbin/persist/adapters/string_adapter.py
 create mode 100644 tests/persist/__init__.py
 create mode 100644 tests/persist/test_string_adapter.py

diff --git a/casbin/persist/adapters/string_adapter.py b/casbin/persist/adapters/string_adapter.py
new file mode 100644
index 00000000..0076caee
--- /dev/null
+++ b/casbin/persist/adapters/string_adapter.py
@@ -0,0 +1,67 @@
+# 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 casbin import persist, load_policy_line
+import os
+
+from casbin.util import util
+
+
+class StringAdapter(persist.Adapter):
+    """the string adapter for Casbin.
+    It can load policy from string or save policy to string.
+    """
+
+    _file_path = ""
+
+    def __init__(self, line):
+        self.line = line
+
+    def load_policy(self, model):
+        """loads all policy rules from the storage."""
+        if self.line == "":
+            raise RuntimeError("invalid line, line cannot be empty")
+
+        strs = self.line.split("\n")
+        for s in strs:
+            if s == "":
+                continue
+            load_policy_line(s, model)
+
+    def save_policy(self, model):
+        """saves all policy rules to the storage."""
+        tmp = []
+        for ptype, ast in model["p"].items():
+            for rule in ast.policy:
+                tmp.append(ptype + ", " + util.array_to_string(rule) + "\n")
+
+        for ptype, ast in model["g"].items():
+            for rule in ast.policy:
+                tmp.append(ptype + ", " + util.array_to_string(rule) + "\n")
+
+        self.line = "".join(tmp).rstrip("\n")
+
+    def add_policy(self, sec, ptype, rule):
+        """adds a policy rule to the storage."""
+        raise RuntimeError("not implemented")
+
+    def remove_policy(self, sec, ptype, rule):
+        """removes a policy rule from the storage."""
+        raise RuntimeError("not implemented")
+
+    def remove_filtered_policy(self, sec, ptype, field_index, *field_values):
+        """removes policy rules that match the filter from the storage.
+        This is part of the Auto-Save feature.
+        """
+        raise RuntimeError("not implemented")
diff --git a/tests/persist/__init__.py b/tests/persist/__init__.py
new file mode 100644
index 00000000..e69de29b
diff --git a/tests/persist/test_string_adapter.py b/tests/persist/test_string_adapter.py
new file mode 100644
index 00000000..b0a4b8e9
--- /dev/null
+++ b/tests/persist/test_string_adapter.py
@@ -0,0 +1,83 @@
+# 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 casbin import Model
+from casbin.persist.adapters.string_adapter import StringAdapter
+from tests import TestCaseBase
+
+
+class TestStringAdapter(TestCaseBase):
+    def test_key_match_rbac(self):
+        conf = """
+[request_definition]
+r = sub, obj, act
+
+[policy_definition]
+p = sub, obj, act
+
+[role_definition]
+g = _ , _
+
+[policy_effect]
+e = some(where (p.eft == allow))
+
+[matchers]
+m = g(r.sub, p.sub)  && keyMatch(r.obj, p.obj) && regexMatch(r.act, p.act)
+"""
+        line = """
+p, alice, /alice_data/*, (GET)|(POST)
+p, alice, /alice_data/resource1, POST
+p, data_group_admin, /admin/*, POST
+p, data_group_admin, /bob_data/*, POST
+g, alice, data_group_admin
+"""
+        adapter = StringAdapter(line)
+        model = Model()
+        model.load_model_from_text(conf)
+        e = self.get_enforcer(model, adapter)
+        sub = "alice"
+        obj = "/alice_data/login"
+        act = "POST"
+        self.assertTrue(e.enforce(sub, obj, act))
+
+    def test_string_rbac(self):
+        conf = """
+[request_definition]
+r = sub, obj, act
+
+[policy_definition]
+p = sub, obj, act
+
+[role_definition]
+g = _ , _
+
+[policy_effect]
+e = some(where (p.eft == allow))
+
+[matchers]
+m = g(r.sub, p.sub) && r.obj == p.obj && r.act == p.act
+"""
+        line = """
+p, alice, data1, read
+p, data_group_admin, data3, read
+p, data_group_admin, data3, write
+g, alice, data_group_admin
+"""
+        adapter = StringAdapter(line)
+        model = Model()
+        model.load_model_from_text(conf)
+        e = self.get_enforcer(model, adapter)
+        sub = "alice"
+        obj = "data1"
+        act = "read"
+        self.assertTrue(e.enforce(sub, obj, act))