Added recursion into library blend files.

blender_asset_tracer/tracer/__init__.py

@@ -2,25 +2,53 @@ import logging
 import pathlib
 import typing
 
-from blender_asset_tracer import blendfile
+from blender_asset_tracer import blendfile, bpathlib
 from . import result, block_walkers
 
 log = logging.getLogger(__name__)
 
 codes_to_skip = {
-    b'ID', b'WM', b'SN',  # These blocks never have external assets.
+    # These blocks never have external assets:
+    b'ID', b'WM', b'SN',
+
+    # These blocks are skipped for now, until we have proof they point to
+    # assets otherwise missed:
+    b'GR', b'WO', b'BR', b'LS',
 }
 
 
-def deps(bfilepath: pathlib.Path) -> typing.Iterator[result.BlockUsage]:
-    """Open the blend file and report its dependencies."""
+def deps(bfilepath: pathlib.Path, recursive=False) -> typing.Iterator[result.BlockUsage]:
+    """Open the blend file and report its dependencies.
+
+    :param bfilepath: File to open.
+    :param recursive: Also report dependencies inside linked blend files.
+    """
     log.info('Tracing %s', bfilepath)
 
     with blendfile.BlendFile(bfilepath) as bfile:
         for block in asset_holding_blocks(bfile):
             yield from block_walkers.from_block(block)
 
-        # TODO: handle library blocks for recursion.
+            if recursive and block.code == b'LI':
+                yield from _recurse_deps(block)
+
+
+def _recurse_deps(lib_block: blendfile.BlendFileBlock) -> typing.Iterator[result.BlockUsage]:
+    """Call deps() on the file linked from the library block."""
+    if lib_block.code != b'LI':
+        raise ValueError('Expected LI block, not %r' % lib_block)
+
+    relpath = bpathlib.BlendPath(lib_block[b'name'])
+    abspath = lib_block.bfile.abspath(relpath)
+
+    # Convert bytes to pathlib.Path object so we have a nice interface to work with.
+    # This assumes the path is encoded in UTF-8.
+    path = pathlib.Path(abspath.decode())
+    if not path.exists():
+        log.warning('Linked blend file %s (%s) does not exist; skipping.', relpath, path)
+        return
+
+    yield from deps(path, recursive=True)
 
 
 def asset_holding_blocks(bfile: blendfile.BlendFile) -> typing.Iterator[blendfile.BlendFileBlock]: