load topic parents

orm/topic.py

@@ -3,6 +3,8 @@ from sqlalchemy import Table, Column, Integer, String, ForeignKey, DateTime, JSO
 from sqlalchemy.orm import relationship
 from orm.base import Base
 
+import asyncio
+
 class TopicSubscription(Base):
 	__tablename__ = "topic_subscription"
 	
@@ -22,3 +24,48 @@ class Topic(Base):
 	pic: str = Column(String, nullable=True, comment="Picture")
 	children = Column(JSONType, nullable=True, comment="list of children topics")
 	community = Column(ForeignKey("community.slug"), nullable=False, comment="Community")
+
+class TopicStorage:
+	topics = {}
+	lock = asyncio.Lock()
+
+	@staticmethod
+	def init(session):
+		self = TopicStorage
+		topics = session.query(Topic)
+		self.topics = dict([(topic.slug, topic) for topic in topics])
+		for topic in self.topics.values():
+			self.load_parents(topic)
+
+	@staticmethod
+	def load_parents(topic):
+		self = TopicStorage
+		parents = []
+		for parent in self.topics.values():
+			if topic.slug in parent.children:
+				parents.append(parent.slug)
+		topic.parents = parents
+		return topic
+
+	@staticmethod
+	async def get_topics(slugs):
+		self = TopicStorage
+		async with self.lock:
+			if not slugs:
+				return self.topics.values()
+			topics = filter(lambda topic: topic.slug in slugs, self.topics.values())
+			return list(topics)
+
+	@staticmethod
+	async def get_topics_by_community(community):
+		self = TopicStorage
+		async with self.lock:
+			topics = filter(lambda topic: topic.community == community, self.topics.values())
+			return list(topics)
+
+	@staticmethod
+	async def add_topic(topic):
+		self = TopicStorage
+		async with self.lock:
+			self.topics[topic.slug] = topic
+			self.load_parents(topic)