data.oci_model: init with app methods

data/oci_model/blob.py

@@ -0,0 +1,54 @@
+from peewee import IntegrityError
+
+from data.model import db_transaction
+from data.database import Blob, BlobPlacementLocation, BlobPlacement
+
+
+def get_blob(digest):
+  """ Find a blob by its digest. """
+  return Blob.select().where(Blob.digest == digest).get()
+
+
+def get_or_create_blob(digest, size, media_type_name, locations):
+  """ Try to find a blob by its digest or create it. """
+  with db_transaction():
+    try:
+      blob = get_blob(digest)
+    except Blob.DoesNotExist:
+      blob = Blob.create(digest=digest,
+                         media_type_id=Blob.media_type.get_id(media_type_name),
+                         size=size)
+    for location_name in locations:
+      location_id = BlobPlacement.location.get_id(location_name)
+      try:
+        BlobPlacement.create(blob=blob, location=location_id)
+      except IntegrityError:
+        pass
+
+    return blob
+
+
+def get_blob_locations(digest):
+  """ Find all locations names for a blob. """
+  return [x.name for x in
+          BlobPlacementLocation
+          .select()
+          .join(BlobPlacement)
+          .join(Blob)
+          .where(Blob.digest == digest)]
+
+
+def ensure_blob_locations(*names):
+  with db_transaction():
+    locations = BlobPlacementLocation.select().where(BlobPlacementLocation.name << names)
+
+    insert_names = list(names)
+
+    for location in locations:
+      insert_names.remove(location.name)
+
+    if not insert_names:
+      return
+
+    data = [{'name': name} for name in insert_names]
+    BlobPlacementLocation.insert_many(data).execute()