rejiggering file pointers

src/grung/types.py

@@ -295,13 +295,28 @@ class BinaryFilePointer(Field):
     def relpath(self, record):
         return Path(record._metadata.table) / record[record._metadata.primary_key] / f"{self.name}{self.extension}"
 
+    def reference(self, record):
+        return f"/::{self.relpath(record)}"
+
+    def dereference(self, reference, db):
+        relpath = reference.replace("/::", "", 1)
+        try:
+            return (db.path / relpath).read_bytes()
+        except FileNotFoundError:
+            return None
+
+    def serialize(self, value: value_type | str, record: Record | None = None) -> str:
+        return self.reference(record)
+
     def deserialize(self, value: str, db: TinyDB, recurse: bool = True) -> value_type:
         if not value:
             return None
-        _, relpath = value.split("::")
-        return self.value_type((db.path / relpath).read_bytes())
+        return self.dereference(value, db)
 
     def prepare(self, data: value_type):
+        """
+        Return bytes to be written to disk
+        """
         if not data:
             return
         if not isinstance(data, self.value_type):
@@ -315,7 +330,6 @@ class BinaryFilePointer(Field):
         path = db.path / relpath
         path.parent.mkdir(parents=True, exist_ok=True)
         path.write_bytes(self.prepare(value))
-        record[self.name] = f"File::{self.relpath(record)}"
 
 
 @dataclass
@@ -335,8 +349,8 @@ class TextFilePointer(BinaryFilePointer):
     def deserialize(self, value: str, db: TinyDB, recurse: bool = True) -> value_type:
         if not value:
             return None
-        _, relpath = value.split("::")
-        return (db.path / relpath).read_text()
+        buf = super().deserialize(value, db)
+        return buf.decode() if buf else None
 
 
 @dataclass