update: Implement DefaultCmabService

Author: FarhanAnjum-opti

optimizely/cmab/cmab_service.py

@@ -0,0 +1,94 @@
+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()

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"

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, '', entities.Attribute
+        )
         self.audience_id_map: dict[str, entities.Audience] = self._generate_key_map(
             self.audiences, 'id', entities.Audience
         )