core: re-use metadata files if found in directory (#11)

Signed-off-by: tarilabs <[email protected]>

omlmd/helpers.py

@@ -1,5 +1,6 @@
 from __future__ import annotations
 
+import logging
 import os
 import urllib.request
 from collections.abc import Sequence
@@ -11,6 +12,9 @@
 from omlmd.provider import OMLMDRegistry
 
 
+logger = logging.getLogger(__name__)
+
+
 def download_file(uri: str):
     file_name = os.path.basename(uri)
     urllib.request.urlretrieve(uri, file_name)
@@ -57,17 +61,25 @@ def push(
             model_format_name=model_format_name,
             model_format_version=model_format_version,
         )
+        owns_meta_files = True
         if isinstance(path, str):
             path = Path(path)
 
         json_meta = path.parent / "model_metadata.omlmd.json"
         yaml_meta = path.parent / "model_metadata.omlmd.yaml"
-        if (p := json_meta).exists() or (p := yaml_meta).exists():
+        if model_metadata.is_empty() and json_meta.exists() and yaml_meta.exists():
+            owns_meta_files = False
+            logger.warning("No metadata supplied, but reusing md files found in path.")
+            logger.debug(f"{json_meta}, {yaml_meta}")
+            with open(json_meta, "r") as f:
+                model_metadata = ModelMetadata.from_json(f.read())
+        elif (p := json_meta).exists() or (p := yaml_meta).exists():
             raise RuntimeError(
                 f"File '{p}' already exists. Aborting TODO: demonstrator."
             )
-        json_meta.write_text(model_metadata.to_json())
-        yaml_meta.write_text(model_metadata.to_yaml())
+        else:
+            json_meta.write_text(model_metadata.to_json())
+            yaml_meta.write_text(model_metadata.to_yaml())
 
         manifest_cfg = f"{json_meta}:application/x-config"
         files = [
@@ -86,8 +98,9 @@ def push(
             self.notify_listeners(PushEvent(target, model_metadata))
             return result
         finally:
-            json_meta.unlink()
-            yaml_meta.unlink()
+            if owns_meta_files:
+                json_meta.unlink()
+                yaml_meta.unlink()
 
     def pull(
         self, target: str, outdir: Path | str, media_types: Sequence[str] | None = None

omlmd/model_metadata.py

@@ -37,6 +37,9 @@ def to_annotations_dict(self) -> dict[str, str]:
                     v
                 )  # post-fix "+json" for OCI annotation which is a str representing a json
         return result
+
+    def is_empty(self) -> bool:
+        return all(getattr(self, f.name) is None for f in fields(ModelMetadata) if f.name != "customProperties") and not self.customProperties
 
     @staticmethod
     def from_json(json_str: str) -> "ModelMetadata":

tests/test_omlmd.py

@@ -72,3 +72,26 @@ def test_from_dict():
         customProperties={"accuracy": 0.987},
     )
     assert ModelMetadata.from_dict(data) == md
+
+
+def test_is_empty():
+    md = ModelMetadata(
+        name="mnist",
+        description="Lorem ipsum",
+        author="John Doe",
+        customProperties={"accuracy": 0.987},
+    )
+    assert not md.is_empty()
+
+    md = ModelMetadata()
+    assert md.is_empty()
+
+    md = ModelMetadata(
+        customProperties={"accuracy": 0.987},
+    )
+    assert not md.is_empty()
+
+    md = ModelMetadata(
+        name="mnist",
+    )
+    assert not md.is_empty()