add delay to retrieval

- allow queue to be filled before being processed

slkspec/core.py

@@ -5,6 +5,7 @@
 import os
 import re
 import threading
+import time
 import warnings
 from collections import defaultdict
 from getpass import getuser
@@ -92,6 +93,7 @@ def __init__(
         mode: str = "rb",
         touch: bool = True,
         file_permissions: int = 0o3777,
+        sleep: int = 2,
         _lock: threading.Lock = _retrieval_lock,
         _file_queue: Queue[Tuple[str, str]] = FileQueue,
         **kwargs: Any,
@@ -113,6 +115,7 @@ def __init__(
         self.error = "strict"
         self.encoding = kwargs.get("encoding")
         self.write_through = False
+        self.sleep = sleep
         self._file_queue = _file_queue
         print(self._file)
         with _lock:
@@ -152,6 +155,7 @@ def _retrieve_items(self, retrieve_files: list[tuple[str, str]]) -> None:
                 (output_dir / out_file.name).chmod(self.file_permissions)
 
     def _cache_files(self) -> None:
+        time.sleep(self.sleep)
         with self._lock:
             items = []
             if self._file_queue.qsize() > 0: