[FSSDK-11166] update: implement CMAB service (#455)

FarhanAnjum-opti · web-flow · commit 82ec019c1089 · 2025-05-27T22:03:49.000+06:00
* update: Implement DefaultCmabService

* update: Add tests for DefaultCmabService

* update: Fix formatting in DefaultCmabService and test cases

* update: Fix key mapping in ProjectConfig to use 'id' instead of empty string

* update: Refactor cache decision logic and enhance test cases for DefaultCmabService

* update: Refactor attribute handling in get_decision and add test for CMAB attribute filtering
diff --git a/optimizely/cmab/cmab_service.py b/optimizely/cmab/cmab_service.py
@@ -0,0 +1,106 @@
+# Copyright 2025 Optimizely
+# 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.
+import uuid
+import json
+import hashlib
+
+from typing import Optional, List, TypedDict
+from optimizely.cmab.cmab_client import DefaultCmabClient
+from optimizely.odp.lru_cache import LRUCache
+from optimizely.optimizely_user_context import OptimizelyUserContext, UserAttributes
+from optimizely.project_config import ProjectConfig
+from optimizely.decision.optimizely_decide_option import OptimizelyDecideOption
+from optimizely import logger as _logging
+
+
+class CmabDecision(TypedDict):
+    variation_id: str
+    cmab_uuid: str
+
+
+class CmabCacheValue(TypedDict):
+    attributes_hash: str
+    variation_id: str
+    cmab_uuid: str
+
+
+class DefaultCmabService:
+    def __init__(self, cmab_cache: LRUCache[str, CmabCacheValue],
+                 cmab_client: DefaultCmabClient, logger: Optional[_logging.Logger] = None):
+        self.cmab_cache = cmab_cache
+        self.cmab_client = cmab_client
+        self.logger = logger
+
+    def get_decision(self, project_config: ProjectConfig, user_context: OptimizelyUserContext,
+                     rule_id: str, options: List[str]) -> CmabDecision:
+
+        filtered_attributes = self._filter_attributes(project_config, user_context, rule_id)
+
+        if OptimizelyDecideOption.IGNORE_CMAB_CACHE in options:
+            return self._fetch_decision(rule_id, user_context.user_id, filtered_attributes)
+
+        if OptimizelyDecideOption.RESET_CMAB_CACHE in options:
+            self.cmab_cache.reset()
+
+        cache_key = self._get_cache_key(user_context.user_id, rule_id)
+
+        if OptimizelyDecideOption.INVALIDATE_USER_CMAB_CACHE in options:
+            self.cmab_cache.remove(cache_key)
+
+        cached_value = self.cmab_cache.lookup(cache_key)
+
+        attributes_hash = self._hash_attributes(filtered_attributes)
+
+        if cached_value:
+            if cached_value['attributes_hash'] == attributes_hash:
+                return CmabDecision(variation_id=cached_value['variation_id'], cmab_uuid=cached_value['cmab_uuid'])
+            else:
+                self.cmab_cache.remove(cache_key)
+
+        cmab_decision = self._fetch_decision(rule_id, user_context.user_id, filtered_attributes)
+        self.cmab_cache.save(cache_key, {
+            'attributes_hash': attributes_hash,
+            'variation_id': cmab_decision['variation_id'],
+            'cmab_uuid': cmab_decision['cmab_uuid'],
+        })
+        return cmab_decision
+
+    def _fetch_decision(self, rule_id: str, user_id: str, attributes: UserAttributes) -> CmabDecision:
+        cmab_uuid = str(uuid.uuid4())
+        variation_id = self.cmab_client.fetch_decision(rule_id, user_id, attributes, cmab_uuid)
+        cmab_decision = CmabDecision(variation_id=variation_id, cmab_uuid=cmab_uuid)
+        return cmab_decision
+
+    def _filter_attributes(self, project_config: ProjectConfig,
+                           user_context: OptimizelyUserContext, rule_id: str) -> UserAttributes:
+        user_attributes = user_context.get_user_attributes()
+        filtered_user_attributes = UserAttributes({})
+
+        experiment = project_config.experiment_id_map.get(rule_id)
+        if not experiment or not experiment.cmab:
+            return filtered_user_attributes
+
+        cmab_attribute_ids = experiment.cmab['attributeIds']
+        for attribute_id in cmab_attribute_ids:
+            attribute = project_config.attribute_id_map.get(attribute_id)
+            if attribute and attribute.key in user_attributes:
+                filtered_user_attributes[attribute.key] = user_attributes[attribute.key]
+
+        return filtered_user_attributes
+
+    def _get_cache_key(self, user_id: str, rule_id: str) -> str:
+        return f"{len(user_id)}-{user_id}-{rule_id}"
+
+    def _hash_attributes(self, attributes: UserAttributes) -> str:
+        sorted_attrs = json.dumps(attributes, sort_keys=True)
+        return hashlib.md5(sorted_attrs.encode()).hexdigest()
diff --git a/optimizely/decision/optimizely_decide_option.py b/optimizely/decision/optimizely_decide_option.py
@@ -25,3 +25,6 @@ class OptimizelyDecideOption:
     IGNORE_USER_PROFILE_SERVICE: Final = 'IGNORE_USER_PROFILE_SERVICE'
     INCLUDE_REASONS: Final = 'INCLUDE_REASONS'
     EXCLUDE_VARIABLES: Final = 'EXCLUDE_VARIABLES'
+    IGNORE_CMAB_CACHE: Final = "IGNORE_CMAB_CACHE"
+    RESET_CMAB_CACHE: Final = "RESET_CMAB_CACHE"
+    INVALIDATE_USER_CMAB_CACHE: Final = "INVALIDATE_USER_CMAB_CACHE"
diff --git a/optimizely/project_config.py b/optimizely/project_config.py
@@ -97,6 +97,9 @@ def __init__(self, datafile: str | bytes, logger: Logger, error_handler: Any):
         self.attribute_id_to_key_map: dict[str, str] = {}
         for attribute in self.attributes:
             self.attribute_id_to_key_map[attribute['id']] = attribute['key']
+        self.attribute_id_map: dict[str, entities.Attribute] = self._generate_key_map(
+            self.attributes, 'id', entities.Attribute
+        )
         self.audience_id_map: dict[str, entities.Audience] = self._generate_key_map(
             self.audiences, 'id', entities.Audience
         )
diff --git a/tests/test_cmab_client.py b/tests/test_cmab_client.py
@@ -1,3 +1,15 @@
+# Copyright 2025, Optimizely
+# 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.
 import unittest
 import json
 from unittest.mock import MagicMock, patch, call
diff --git a/tests/test_cmab_service.py b/tests/test_cmab_service.py
@@ -0,0 +1,187 @@
+# Copyright 2025, Optimizely
+# 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.
+import unittest
+from unittest.mock import MagicMock
+from optimizely.cmab.cmab_service import DefaultCmabService
+from optimizely.optimizely_user_context import OptimizelyUserContext
+from optimizely.decision.optimizely_decide_option import OptimizelyDecideOption
+from optimizely.odp.lru_cache import LRUCache
+from optimizely.cmab.cmab_client import DefaultCmabClient
+from optimizely.project_config import ProjectConfig
+from optimizely.entities import Attribute
+
+
+class TestDefaultCmabService(unittest.TestCase):
+    def setUp(self):
+        self.mock_cmab_cache = MagicMock(spec=LRUCache)
+        self.mock_cmab_client = MagicMock(spec=DefaultCmabClient)
+        self.mock_logger = MagicMock()
+
+        self.cmab_service = DefaultCmabService(
+            cmab_cache=self.mock_cmab_cache,
+            cmab_client=self.mock_cmab_client,
+            logger=self.mock_logger
+        )
+
+        self.mock_project_config = MagicMock(spec=ProjectConfig)
+        self.mock_user_context = MagicMock(spec=OptimizelyUserContext)
+        self.mock_user_context.user_id = 'user123'
+        self.mock_user_context.get_user_attributes.return_value = {'age': 25, 'location': 'USA'}
+
+        # Setup mock experiment and attribute mapping
+        self.mock_project_config.experiment_id_map = {
+            'exp1': MagicMock(cmab={'attributeIds': ['66', '77']})
+        }
+        attr1 = Attribute(id="66", key="age")
+        attr2 = Attribute(id="77", key="location")
+        self.mock_project_config.attribute_id_map = {
+            "66": attr1,
+            "77": attr2
+        }
+
+    def test_returns_decision_from_cache_when_valid(self):
+        expected_key = self.cmab_service._get_cache_key("user123", "exp1")
+        expected_attributes = {"age": 25, "location": "USA"}
+        expected_hash = self.cmab_service._hash_attributes(expected_attributes)
+
+        self.mock_cmab_cache.lookup.return_value = {
+            "attributes_hash": expected_hash,
+            "variation_id": "varA",
+            "cmab_uuid": "uuid-123"
+        }
+
+        decision = self.cmab_service.get_decision(
+            self.mock_project_config, self.mock_user_context, "exp1", []
+        )
+
+        self.mock_cmab_cache.lookup.assert_called_once_with(expected_key)
+        self.assertEqual(decision["variation_id"], "varA")
+        self.assertEqual(decision["cmab_uuid"], "uuid-123")
+
+    def test_ignores_cache_when_option_given(self):
+        self.mock_cmab_client.fetch_decision.return_value = "varB"
+        expected_attributes = {"age": 25, "location": "USA"}
+
+        decision = self.cmab_service.get_decision(
+            self.mock_project_config,
+            self.mock_user_context,
+            "exp1",
+            [OptimizelyDecideOption.IGNORE_CMAB_CACHE]
+        )
+
+        self.assertEqual(decision["variation_id"], "varB")
+        self.assertIn('cmab_uuid', decision)
+        self.mock_cmab_client.fetch_decision.assert_called_once_with(
+            "exp1",
+            self.mock_user_context.user_id,
+            expected_attributes,
+            decision["cmab_uuid"]
+        )
+
+    def test_invalidates_user_cache_when_option_given(self):
+        self.mock_cmab_client.fetch_decision.return_value = "varC"
+        self.mock_cmab_cache.lookup.return_value = None
+        self.cmab_service.get_decision(
+            self.mock_project_config,
+            self.mock_user_context,
+            "exp1",
+            [OptimizelyDecideOption.INVALIDATE_USER_CMAB_CACHE]
+        )
+
+        key = self.cmab_service._get_cache_key("user123", "exp1")
+        self.mock_cmab_cache.remove.assert_called_with(key)
+        self.mock_cmab_cache.remove.assert_called_once()
+
+    def test_resets_cache_when_option_given(self):
+        self.mock_cmab_client.fetch_decision.return_value = "varD"
+
+        decision = self.cmab_service.get_decision(
+            self.mock_project_config,
+            self.mock_user_context,
+            "exp1",
+            [OptimizelyDecideOption.RESET_CMAB_CACHE]
+        )
+
+        self.mock_cmab_cache.reset.assert_called_once()
+        self.assertEqual(decision["variation_id"], "varD")
+        self.assertIn('cmab_uuid', decision)
+
+    def test_new_decision_when_hash_changes(self):
+        self.mock_cmab_cache.lookup.return_value = {
+            "attributes_hash": "old_hash",
+            "variation_id": "varA",
+            "cmab_uuid": "uuid-123"
+        }
+        self.mock_cmab_client.fetch_decision.return_value = "varE"
+
+        expected_attribute = {"age": 25, "location": "USA"}
+        expected_hash = self.cmab_service._hash_attributes(expected_attribute)
+        expected_key = self.cmab_service._get_cache_key("user123", "exp1")
+
+        decision = self.cmab_service.get_decision(self.mock_project_config, self.mock_user_context, "exp1", [])
+        self.mock_cmab_cache.remove.assert_called_once_with(expected_key)
+        self.mock_cmab_cache.save.assert_called_once_with(
+            expected_key,
+            {
+                "cmab_uuid": decision["cmab_uuid"],
+                "variation_id": decision["variation_id"],
+                "attributes_hash": expected_hash
+            }
+        )
+        self.assertEqual(decision["variation_id"], "varE")
+        self.mock_cmab_client.fetch_decision.assert_called_once_with(
+            "exp1",
+            self.mock_user_context.user_id,
+            expected_attribute,
+            decision["cmab_uuid"]
+        )
+
+    def test_filter_attributes_returns_correct_subset(self):
+        filtered = self.cmab_service._filter_attributes(self.mock_project_config, self.mock_user_context, "exp1")
+        self.assertEqual(filtered["age"], 25)
+        self.assertEqual(filtered["location"], "USA")
+
+    def test_filter_attributes_empty_when_no_cmab(self):
+        self.mock_project_config.experiment_id_map["exp1"].cmab = None
+        filtered = self.cmab_service._filter_attributes(self.mock_project_config, self.mock_user_context, "exp1")
+        self.assertEqual(filtered, {})
+
+    def test_hash_attributes_produces_stable_output(self):
+        attrs = {"b": 2, "a": 1}
+        hash1 = self.cmab_service._hash_attributes(attrs)
+        hash2 = self.cmab_service._hash_attributes({"a": 1, "b": 2})
+        self.assertEqual(hash1, hash2)
+
+    def test_only_cmab_attributes_passed_to_client(self):
+        self.mock_user_context.get_user_attributes.return_value = {
+            'age': 25,
+            'location': 'USA',
+            'extra_attr': 'value',  # This shouldn't be passed to CMAB
+            'another_extra': 123    # This shouldn't be passed to CMAB
+        }
+        self.mock_cmab_client.fetch_decision.return_value = "varF"
+
+        decision = self.cmab_service.get_decision(
+            self.mock_project_config,
+            self.mock_user_context,
+            "exp1",
+            [OptimizelyDecideOption.IGNORE_CMAB_CACHE]
+        )
+
+        # Verify only age and location are passed (attributes configured in setUp)
+        self.mock_cmab_client.fetch_decision.assert_called_once_with(
+            "exp1",
+            self.mock_user_context.user_id,
+            {"age": 25, "location": "USA"},
+            decision["cmab_uuid"]
+        )
