Fix: load training data from all sub dirs (#396)

* Fix: load training data from all sub dirs

* fix flake8 formatting

* fix local integ test

* resolve some comments

Author: haixiw

src/sagemaker_xgboost_container/data_utils.py

@@ -38,6 +38,8 @@
 PARQUET = "parquet"
 RECORDIO_PROTOBUF = "recordio-protobuf"
 
+MAX_FOLDER_DEPTH = 3
+
 VALID_CONTENT_TYPES = [
     CSV,
     LIBSVM,
@@ -528,33 +530,74 @@ def _get_pipe_mode_files_path(data_path: Union[List[str], str]) -> List[str]:
     return files_path
 
 
+def _make_symlinks_from_a_folder(dest_path: str, data_path: str, depth: int):
+    if (depth > MAX_FOLDER_DEPTH):
+        raise exc.UserError(f"Folder depth exceed the limit: {MAX_FOLDER_DEPTH}.")
+
+    if os.path.isfile(data_path):
+        _make_symlink(data_path, dest_path, os.path.basename(data_path))
+        return
+    else:
+        logging.info(f"Making smlinks from folder {data_path} to folder {dest_path}")
+        for item in os.scandir(data_path):
+            if item.is_file():
+                _make_symlink(item.path, dest_path, item.name)
+            elif item.is_dir():
+                _make_symlinks_from_a_folder(dest_path, item.path, depth + 1)
+
+
+def _make_symlinks_from_a_folder_with_warning(dest_path: str, data_path: str):
+    """
+    :param dest_path: A dir
+    :param data_path: Either dir or file
+    :param depth: current folder depth, Integer
+    """
+
+    # If data_path is a single file A, create smylink A -> dest_path/A
+    # If data_path is a dir, create symlinks for files located within depth of MAX_FOLDER_DEPTH
+    # under this dir. Ignore the files in deeper sub dirs and log a warning if they exist.
+
+    if (not os.path.exists(dest_path)) or (not os.path.exists(data_path)):
+        raise exc.AlgorithmError(f"Unable to create symlinks as {data_path} or {dest_path} doesn't exist ")
+
+    if (not os.path.isdir(dest_path)):
+        raise exc.AlgorithmError(f"Unable to create symlinks as dest_path {dest_path} is not a dir")
+
+    try:
+        _make_symlinks_from_a_folder(dest_path, data_path, 1)
+    except exc.UserError as e:
+        if e.message == f"Folder depth exceed the limit: {MAX_FOLDER_DEPTH}.":
+            logging.warning(
+                f"The depth of folder {data_path} exceed the limit {MAX_FOLDER_DEPTH}."
+                f" Files in deeper sub dirs won't be loaded."
+                f" Please adjust the folder structure accordingly."
+                )
+
+
 def _get_file_mode_files_path(data_path: Union[List[str], str]) -> List[str]:
     """
     :param data_path: Either directory or file
     """
     # In file mode, we create a temp directory with symlink to all input files or
     # directories to meet XGB's assumption that all files are in the same directory.
 
+    logging.info("File path {} of input files".format(data_path))
+    # Create a directory with symlinks to input files.
+    files_path = "/tmp/sagemaker_xgboost_input_data"
+    shutil.rmtree(files_path, ignore_errors=True)
+    os.mkdir(files_path)
     if isinstance(data_path, list):
-        logging.info("File path {} of input files".format(data_path))
-        # Create a directory with symlinks to input files.
-        files_path = "/tmp/sagemaker_xgboost_input_data"
-        shutil.rmtree(files_path, ignore_errors=True)
-        os.mkdir(files_path)
-        for index, path in enumerate(data_path):
-            if not os.path.exists(path):
-                return None
-            if os.path.isfile(path):
-                _make_symlink(path, files_path, os.path.basename(path), index)
-            else:
-                for file in os.scandir(path):
-                    _make_symlink(file, files_path, file.name, index)
-
+        for path in data_path:
+            _make_symlinks_from_a_folder_with_warning(files_path, path)
     else:
         if not os.path.exists(data_path):
             logging.info("File path {} does not exist!".format(data_path))
             return None
-        files_path = get_files_path_from_string(data_path)
+        elif os.path.isdir(data_path) or os.path.isfile(data_path):
+            # traverse all sub-dirs to load all training data
+            _make_symlinks_from_a_folder_with_warning(files_path, data_path)
+        else:
+            exc.UserError("Unknown input files path: {}".format(data_path))
 
     return files_path
 
@@ -635,22 +678,11 @@ def get_size(data_path, is_pipe=False):
             return total_size
 
 
-def get_files_path_from_string(data_path: Union[List[str], str]) -> List[str]:
-    if os.path.isfile(data_path):
-        files_path = data_path
-    else:
-        for root, dirs, files in os.walk(data_path):
-            if dirs == []:
-                files_path = root
-                break
-
-    return files_path
-
-
-def _make_symlink(path, source_path, name, index):
-    base_name = os.path.join(source_path, f"{name}_{str(index)}")
-    logging.info(f"creating symlink between Path {source_path} and destination {base_name}")
-    os.symlink(path, base_name)
+def _make_symlink(path, source_path, name):
+    base_name = os.path.join(source_path, name)
+    file_name = base_name + str(hash(path))
+    logging.info(f"creating symlink between Path {path} and destination {file_name}")
+    os.symlink(path, file_name)
 
 
 def check_data_redundancy(train_path, validate_path):