Generate valid NLP model id from file path (#541)

The eland_import_hub_model script supports uploading a local file where
the --hub-model-id argument is a file path. If the --es-model-id option is
not used the model Id is generated from the hub model id and when that 
is a file path the path must be converted to a valid elasticsearch model id.

eland/ml/pytorch/transformers.py

@@ -22,6 +22,7 @@ libraries such as sentence-transformers.
 
 import json
 import os.path
+import re
 from abc import ABC, abstractmethod
 from typing import Any, Dict, List, Optional, Set, Tuple, Union
 
@@ -740,8 +741,7 @@ class TransformerModel:
             )
 
     def elasticsearch_model_id(self) -> str:
-        # Elasticsearch model IDs need to be a specific format: no special chars, all lowercase, max 64 chars
-        return self._model_id.replace("/", "__").lower()[:64]
+        return elasticsearch_model_id(self._model_id)
 
     def save(self, path: str) -> Tuple[str, NlpTrainedModelConfig, str]:
         # save traced model
@@ -753,3 +753,21 @@ class TransformerModel:
             json.dump(self._vocab, outfile)
 
         return model_path, self._config, vocab_path
+
+
+def elasticsearch_model_id(model_id: str) -> str:
+    """
+    Elasticsearch model IDs need to be a specific format:
+    no special chars, all lowercase, max 64 chars. If the
+    Id is longer than 64 charaters take the last 64- in the
+    case where the id is long file path this captures the
+    model name.
+
+    Ids starting with __ are not valid elasticsearch Ids,
+    # this might be the case if model_id is a file path
+    """
+
+    id = re.sub(r"[\s\\/]", "__", model_id).lower()[-64:]
+    if id.startswith("__"):
+        id = id.removeprefix("__")
+    return id

tests/ml/pytorch/test_transformer_pytorch_model_pytest.py

@@ -34,7 +34,7 @@ except ImportError:
 try:
     import torch  # noqa: F401
     from torch import Tensor, nn  # noqa: F401
-    from transformers import PretrainedConfig  # noqa: F401
+    from transformers import PretrainedConfig, elasticsearch_model_id  # noqa: F401
 
     from eland.ml.pytorch import (  # noqa: F401
         NlpBertTokenizationConfig,
@@ -338,3 +338,21 @@ class TestPytorchModelUpload:
             )
         )
         assert task_type_from_model_config(model_config=config) == expected_task
+
+    def test_elasticsearch_model_id(self):
+        model_id_from_path = elasticsearch_model_id(r"/foo/bar")
+        assert model_id_from_path == "foo_bar"
+
+        model_id_from_path = elasticsearch_model_id(r"\BAZ\with space")
+        assert model_id_from_path == "baz__with__space"
+
+        model_id_from_path = elasticsearch_model_id(r"/foo/with tab\tback\slash")
+        assert model_id_from_path == "foo__with__space__back__slash"
+
+        long_id_left_truncated = elasticsearch_model_id(
+            "/foo/bar/64charactersoftext64charactersoftext64charactersoftext64charofte"
+        )
+        assert (
+            long_id_left_truncated
+            == "64charactersoftext64charactersoftext64charactersoftext64charofte"
+        )