Move singleton to common directory (#10935)

### What problem does this PR solve?

As title

### Type of change

- [x] Refactoring

Signed-off-by: Jin Hai <haijin.chn@gmail.com>

rag/utils/__init__.py

@@ -15,23 +15,10 @@
 #
 
 import os
-
 import tiktoken
 
 from api.utils.file_utils import get_project_base_directory
 
-
-def singleton(cls, *args, **kw):
-    instances = {}
-
-    def _singleton():
-        key = str(cls) + str(os.getpid())
-        if key not in instances:
-            instances[key] = cls(*args, **kw)
-        return instances[key]
-
-    return _singleton
-
 tiktoken_cache_dir = get_project_base_directory()
 os.environ["TIKTOKEN_CACHE_DIR"] = tiktoken_cache_dir
 # encoder = tiktoken.encoding_for_model("gpt-3.5-turbo")

rag/utils/azure_sas_conn.py

@@ -19,7 +19,7 @@ import os
 import time
 from io import BytesIO
 from rag import settings
-from rag.utils import singleton
+from common.decorator import singleton
 from azure.storage.blob import ContainerClient
 
 

rag/utils/azure_spn_conn.py

@@ -18,7 +18,7 @@ import logging
 import os
 import time
 from rag import settings
-from rag.utils import singleton
+from common.decorator import singleton
 from azure.identity import ClientSecretCredential, AzureAuthorityHosts
 from azure.storage.filedatalake import FileSystemClient
 

rag/utils/es_conn.py

@@ -26,7 +26,7 @@ from elasticsearch_dsl import UpdateByQuery, Q, Search, Index
 from elastic_transport import ConnectionTimeout
 from rag import settings
 from rag.settings import TAG_FLD, PAGERANK_FLD
-from rag.utils import singleton
+from common.decorator import singleton
 from api.utils.file_utils import get_project_base_directory
 from api.utils.common import convert_bytes
 from rag.utils.doc_store_conn import DocStoreConnection, MatchExpr, OrderByExpr, MatchTextExpr, MatchDenseExpr, \

rag/utils/infinity_conn.py

@@ -27,7 +27,7 @@ from infinity.connection_pool import ConnectionPool
 from infinity.errors import ErrorCode
 from rag import settings
 from rag.settings import PAGERANK_FLD, TAG_FLD
-from rag.utils import singleton
+from common.decorator import singleton
 import pandas as pd
 from api.utils.file_utils import get_project_base_directory
 from rag.nlp import is_english

rag/utils/minio_conn.py

@@ -21,7 +21,7 @@ from minio.commonconfig import CopySource
 from minio.error import S3Error
 from io import BytesIO
 from rag import settings
-from rag.utils import singleton
+from common.decorator import singleton
 
 
 @singleton

rag/utils/opendal_conn.py

@@ -4,7 +4,7 @@ import pymysql
 from urllib.parse import quote_plus
 
 from api.utils.configs import get_base_config
-from rag.utils import singleton
+from common.decorator import singleton
 
 
 CREATE_TABLE_SQL = """

rag/utils/opensearch_conn.py

@@ -26,7 +26,7 @@ from opensearchpy import UpdateByQuery, Q, Search, Index
 from opensearchpy import ConnectionTimeout
 from rag import settings
 from rag.settings import TAG_FLD, PAGERANK_FLD
-from rag.utils import singleton
+from common.decorator import singleton
 from api.utils.file_utils import get_project_base_directory
 from rag.utils.doc_store_conn import DocStoreConnection, MatchExpr, OrderByExpr, MatchTextExpr, MatchDenseExpr, \
     FusionExpr

rag/utils/oss_conn.py

@@ -19,7 +19,7 @@ from botocore.exceptions import ClientError
 from botocore.config import Config
 import time
 from io import BytesIO
-from rag.utils import singleton
+from common.decorator import singleton
 from rag import settings
 
 

rag/utils/redis_conn.py

@@ -20,7 +20,7 @@ import uuid
 
 import valkey as redis
 from rag import settings
-from rag.utils import singleton
+from common.decorator import singleton
 from valkey.lock import Lock
 import trio
 

rag/utils/s3_conn.py

@@ -20,7 +20,7 @@ from botocore.exceptions import ClientError
 from botocore.config import Config
 import time
 from io import BytesIO
-from rag.utils import singleton
+from common.decorator import singleton
 from rag import settings
 
 @singleton