feat: 增加redis KV存储，增加openai+neo4j+milvus+redis的demo测试，新增lightrag.py: RedisKVStorage，新增requirements.txt:aioredis依赖

lightrag/kg/redis_impl.py

@@ -0,0 +1,64 @@
+import os
+from tqdm.asyncio import tqdm as tqdm_async
+from dataclasses import dataclass
+import aioredis
+from lightrag.utils import logger
+from lightrag.base import BaseKVStorage
+import json
+
+
+@dataclass
+class RedisKVStorage(BaseKVStorage):
+    def __post_init__(self):
+        redis_url = os.environ.get("REDIS_URI", "redis://localhost:6379")
+        self._redis = aioredis.from_url(redis_url, decode_responses=True)
+        logger.info(f"Use Redis as KV {self.namespace}")
+
+    async def all_keys(self) -> list[str]:
+        keys = await self._redis.keys(f"{self.namespace}:*")
+        return [key.split(":", 1)[-1] for key in keys]
+
+    async def get_by_id(self, id):
+        data = await self._redis.get(f"{self.namespace}:{id}")
+        return json.loads(data) if data else None
+
+    async def get_by_ids(self, ids, fields=None):
+        pipe = self._redis.pipeline()
+        for id in ids:
+            pipe.get(f"{self.namespace}:{id}")
+        results = await pipe.execute()
+
+        if fields:
+            # Filter fields if specified
+            return [
+                {field: value.get(field) for field in fields if field in value}
+                if (value := json.loads(result))
+                else None
+                for result in results
+            ]
+
+        return [json.loads(result) if result else None for result in results]
+
+    async def filter_keys(self, data: list[str]) -> set[str]:
+        pipe = self._redis.pipeline()
+        for key in data:
+            pipe.exists(f"{self.namespace}:{key}")
+        results = await pipe.execute()
+
+        existing_ids = {data[i] for i, exists in enumerate(results) if exists}
+        return set(data) - existing_ids
+
+    async def upsert(self, data: dict[str, dict]):
+        pipe = self._redis.pipeline()
+        for k, v in tqdm_async(data.items(), desc="Upserting"):
+            pipe.set(f"{self.namespace}:{k}", json.dumps(v))
+        await pipe.execute()
+
+        for k in data:
+            data[k]["_id"] = k
+        return data
+
+    async def drop(self):
+        keys = await self._redis.keys(f"{self.namespace}:*")
+        if keys:
+            await self._redis.delete(*keys)