New storage APIs

streaming/storage/__init__.py

@@ -7,8 +7,9 @@
                                         download_from_azure_datalake,
                                         download_from_databricks_unity_catalog, download_from_dbfs,
                                         download_from_gcs, download_from_local, download_from_oci,
-                                        download_from_s3, download_from_sftp,
-                                        wait_for_file_to_exist)
+                                        download_from_s3, download_from_sftp)
+from streaming.storage.extra import (file_exists, list_dataset_files, smart_download_file,
+                                     wait_for_file_to_exist, walk_dir, walk_prefix)
 from streaming.storage.upload import (AzureDataLakeUploader, AzureUploader, CloudUploader,
                                       GCSUploader, LocalUploader, OCIUploader, S3Uploader)
 
@@ -31,4 +32,9 @@
     'download_from_dbfs',
     'download_from_local',
     'wait_for_file_to_exist',
+    'walk_prefix',
+    'walk_dir',
+    'list_dataset_files',
+    'smart_download_file',
+    'file_exists',
 ]

streaming/storage/download.py

@@ -7,7 +7,6 @@
 import pathlib
 import shutil
 import urllib.parse
-from time import sleep, time
 from typing import Any, Dict, Optional
 
 from streaming.util import get_import_exception_message
@@ -22,7 +21,6 @@
     'download_from_databricks_unity_catalog',
     'download_from_dbfs',
     'download_from_local',
-    'wait_for_file_to_exist',
 ]
 
 BOTOCORE_CLIENT_ERROR_CODES = {'403', '404', 'NoSuchKey'}
@@ -473,29 +471,3 @@ def download_file(remote: Optional[str], local: str, timeout: float):
         download_from_dbfs(remote, local)
     else:
         download_from_local(remote, local)
-
-
-def wait_for_file_to_exist(filename: str, poll_interval: float, timeout: float,
-                           err_msg: str) -> None:
-    """Wait for the file to exist till timeout seconds. Raise an Exception after that.
-
-    Args:
-        filename (str): A file name
-        poll_interval (float): Number of seconds to wait before next polling
-        timeout (float): Number of seconds to wait for a file to exist before raising an exception
-        err_msg (str): Error message description for an exception
-
-    Raises:
-        RuntimeError: Raise an Exception if file does not exist after timeout
-    """
-    start_time = time()
-    while True:
-        sleep(poll_interval)
-        if os.path.exists(filename):
-            sleep(poll_interval)
-            break
-        dt = time() - start_time
-        if dt > timeout:
-            raise RuntimeError(
-                f'{err_msg} due to timeout. Waited {dt:.3f} sec, which is longer than the ' +
-                f'timeout limit of {timeout:.3f} sec.')