refactor: implement tenant self queue for rag tasks (#27559)

Co-authored-by: autofix-ci[bot] <114827586+autofix-ci[bot]@users.noreply.github.com>
Co-authored-by: -LAN- <laipz8200@outlook.com>

api/core/rag/pipeline/queue.py

@@ -0,0 +1,79 @@
+import json
+from collections.abc import Sequence
+from typing import Any
+
+from pydantic import BaseModel, ValidationError
+
+from extensions.ext_redis import redis_client
+
+_DEFAULT_TASK_TTL = 60 * 60  # 1 hour
+
+
+class TaskWrapper(BaseModel):
+    data: Any
+
+    def serialize(self) -> str:
+        return self.model_dump_json()
+
+    @classmethod
+    def deserialize(cls, serialized_data: str) -> "TaskWrapper":
+        return cls.model_validate_json(serialized_data)
+
+
+class TenantIsolatedTaskQueue:
+    """
+    Simple queue for tenant isolated tasks, used for rag related tenant tasks isolation.
+    It uses Redis list to store tasks, and Redis key to store task waiting flag.
+    Support tasks that can be serialized by json.
+    """
+
+    def __init__(self, tenant_id: str, unique_key: str):
+        self._tenant_id = tenant_id
+        self._unique_key = unique_key
+        self._queue = f"tenant_self_{unique_key}_task_queue:{tenant_id}"
+        self._task_key = f"tenant_{unique_key}_task:{tenant_id}"
+
+    def get_task_key(self):
+        return redis_client.get(self._task_key)
+
+    def set_task_waiting_time(self, ttl: int = _DEFAULT_TASK_TTL):
+        redis_client.setex(self._task_key, ttl, 1)
+
+    def delete_task_key(self):
+        redis_client.delete(self._task_key)
+
+    def push_tasks(self, tasks: Sequence[Any]):
+        serialized_tasks = []
+        for task in tasks:
+            # Store str list directly, maintaining full compatibility for pipeline scenarios
+            if isinstance(task, str):
+                serialized_tasks.append(task)
+            else:
+                # Use TaskWrapper to do JSON serialization for non-string tasks
+                wrapper = TaskWrapper(data=task)
+                serialized_data = wrapper.serialize()
+                serialized_tasks.append(serialized_data)
+
+        redis_client.lpush(self._queue, *serialized_tasks)
+
+    def pull_tasks(self, count: int = 1) -> Sequence[Any]:
+        if count <= 0:
+            return []
+
+        tasks = []
+        for _ in range(count):
+            serialized_task = redis_client.rpop(self._queue)
+            if not serialized_task:
+                break
+
+            if isinstance(serialized_task, bytes):
+                serialized_task = serialized_task.decode("utf-8")
+
+            try:
+                wrapper = TaskWrapper.deserialize(serialized_task)
+                tasks.append(wrapper.data)
+            except (json.JSONDecodeError, ValidationError, TypeError, ValueError):
+                # Fall back to raw string for legacy format or invalid JSON
+                tasks.append(serialized_task)
+
+        return tasks