Add training metadata to output LoRA model

library/train_util.py

@@ -747,6 +747,20 @@ def exists(val):
 def default(val, d):
   return val if exists(val) else d
 
+
+def model_hash(filename):
+    try:
+        with open(filename, "rb") as file:
+            import hashlib
+            m = hashlib.sha256()
+
+            file.seek(0x100000)
+            m.update(file.read(0x10000))
+            return m.hexdigest()[0:8]
+    except FileNotFoundError:
+        return 'NOFILE'
+
+
 # flash attention forwards and backwards
 
 # https://arxiv.org/abs/2205.14135