Store rewrites in AssetAction

This is in preparation of interchanging copying and rewriting.

blender_asset_tracer/pack/__init__.py

@@ -21,8 +21,21 @@ class PathAction(enum.Enum):
 class AssetAction:
     def __init__(self):
         self.path_action = PathAction.KEEP_PATH
-        self.usages = []  # which data blocks are referring to this asset
+        self.usages = []
+        """BlockUsage objects referring to this asset.
+
+        Those BlockUsage objects could refer to data blocks in this blend file
+        (if the asset is a blend file) or in another blend file.
+        """
+
         self.new_path = None
+        """Absolute path to the asset in the BAT Pack."""
+
+        self.rewrites = []
+        """BlockUsage objects in this asset that may require rewriting.
+
+        Empty list if this AssetAction is not for a blend file.
+        """
 
 
 class Packer:
@@ -43,7 +56,6 @@ class Packer:
 
         # Filled by strategise()
         self._actions = collections.defaultdict(AssetAction)
-        self._rewrites = collections.defaultdict(list)
 
         # Number of files we would copy, if not for --noop
         self._file_count = 0
@@ -116,7 +128,7 @@ class Packer:
 
             for usage in action.usages:
                 bfile_path = usage.block.bfile.filepath.absolute().resolve()
-                self._rewrites[bfile_path].append(usage)
+                self._actions[bfile_path].rewrites.append(usage)
 
     def _path_in_project(self, path: pathlib.Path) -> bool:
         try:
@@ -157,7 +169,10 @@ class Packer:
     def _rewrite_paths(self):
         """Rewrite paths to the new location of the assets."""
 
-        for bfile_path, rewrites in self._rewrites.items():
+        for bfile_path, action in self._actions.items():
+            if not action.rewrites:
+                continue
+
             assert isinstance(bfile_path, pathlib.Path)
             bfile_pp = self._actions[bfile_path].new_path
 
@@ -168,7 +183,7 @@ class Packer:
             bfile = blendfile.open_cached(bfile_path, assert_cached=True)
             bfile.rebind(bfile_pp, mode='rb+')
 
-            for usage in rewrites:
+            for usage in action.rewrites:
                 assert isinstance(usage, result.BlockUsage)
                 asset_pp = self._actions[usage.abspath].new_path
                 assert isinstance(asset_pp, pathlib.Path)

tests/test_pack.py

@@ -24,6 +24,12 @@ class AbstractPackTest(AbstractBlendFileTest):
     def tearDown(self):
         self.tdir.cleanup()
 
+    @staticmethod
+    def rewrites(packer: pack.Packer):
+        return {path: action.rewrites
+                for path, action in packer._actions.items()
+                if action.rewrites}
+
     def test_strategise_no_rewrite_required(self):
         infile = self.blendfiles / 'doubly_linked.blend'
 
@@ -44,7 +50,7 @@ class AbstractPackTest(AbstractBlendFileTest):
             self.assertEqual(pack.PathAction.KEEP_PATH, act.path_action, 'for %s' % pf)
             self.assertEqual(self.tpath / pf, act.new_path, 'for %s' % pf)
 
-        self.assertEqual({}, packer._rewrites)
+        self.assertEqual({}, self.rewrites(packer))
 
     def test_strategise_rewrite(self):
         ppath = self.blendfiles / 'subdir'
@@ -78,17 +84,18 @@ class AbstractPackTest(AbstractBlendFileTest):
             'material_textures.blend',
             'subdir/doubly_linked_up.blend',
         )
+        rewrites = self.rewrites(packer)
         self.assertEqual([self.blendfiles / fn for fn in to_rewrite],
-                         sorted(packer._rewrites.keys()))
+                         sorted(rewrites.keys()))
 
         # Library link referencing basic_file.blend should (maybe) be rewritten.
-        rw_linked_cube = packer._rewrites[self.blendfiles / 'linked_cube.blend']
+        rw_linked_cube = rewrites[self.blendfiles / 'linked_cube.blend']
         self.assertEqual(1, len(rw_linked_cube))
         self.assertEqual(b'LILib', rw_linked_cube[0].block_name)
         self.assertEqual(b'//basic_file.blend', rw_linked_cube[0].asset_path)
 
         # Texture links to image assets should (maybe) be rewritten.
-        rw_mattex = packer._rewrites[self.blendfiles / 'material_textures.blend']
+        rw_mattex = rewrites[self.blendfiles / 'material_textures.blend']
         self.assertEqual(2, len(rw_mattex))
         rw_mattex.sort()  # for repeatable tests
         self.assertEqual(b'IMbrick_dotted_04-bump', rw_mattex[0].block_name)
@@ -97,7 +104,7 @@ class AbstractPackTest(AbstractBlendFileTest):
         self.assertEqual(b'//textures/Bricks/brick_dotted_04-color.jpg', rw_mattex[1].asset_path)
 
         # Library links from doubly_linked_up.blend to the above to blend files should be rewritten.
-        rw_dbllink = packer._rewrites[self.blendfiles / 'subdir/doubly_linked_up.blend']
+        rw_dbllink = rewrites[self.blendfiles / 'subdir/doubly_linked_up.blend']
         self.assertEqual(2, len(rw_dbllink))
         rw_dbllink.sort()  # for repeatable tests
         self.assertEqual(b'LILib', rw_dbllink[0].block_name)