Added block expansion

The expansion process follows pointers and library links to construct
the full set of actually-used data blocks. This set consists of all data
blocks in the initial blend file, and all *actually linked-to* data
blocks in linked blend files.

I've also removed non-recursive dependency listing.

blender_asset_tracer/blendfile/__init__.py

@@ -300,7 +300,7 @@ class BlendFile:
         try:
             return self.block_from_addr[address]
         except KeyError:
-            raise exceptions.SegmentationFault('address does not exist', address)
+            raise exceptions.SegmentationFault('address does not exist', address) from None
 
 
 class BlendFileBlock:
@@ -375,6 +375,10 @@ class BlendFileBlock:
                 self.addr_old == other.addr_old and
                 self.bfile.filepath == other.bfile.filepath)
 
+    def __bool__(self) -> bool:
+        """Data blocks are always True."""
+        return True
+
     @property
     def dna_type(self) -> dna.Struct:
         return self.bfile.structs[self.sdna_index]
@@ -581,6 +585,8 @@ class BlendFileBlock:
             fileobj = self.bfile.fileobj
             fileobj.seek(file_offset + ps * i, os.SEEK_SET)
             address = endian.read_pointer(fileobj, ps)
+            if address == 0:
+                continue
             yield self.bfile.dereference_pointer(address)
 
     def iter_fixed_array_of_pointers(self, path: dna.FieldPath) \

blender_asset_tracer/blendfile/iterators.py

@@ -1,10 +1,39 @@
+import typing
+
+from blender_asset_tracer import cdefs
 from . import BlendFileBlock
 from .dna import FieldPath
 
 
-def listbase(block: BlendFileBlock, next_path: FieldPath=b'next') -> BlendFileBlock:
+def listbase(block: BlendFileBlock, next_path: FieldPath = b'next') \
+        -> typing.Iterator[BlendFileBlock]:
     """Generator, yields all blocks in the ListBase linked list."""
     while block:
         yield block
         next_ptr = block[next_path]
         block = block.bfile.find_block_from_address(next_ptr)
+
+
+def sequencer_strips(sequence_editor: BlendFileBlock) \
+        -> typing.Iterator[typing.Tuple[BlendFileBlock, int]]:
+    """Generator, yield all sequencer strip blocks with their type number.
+
+    Recurses into meta strips, yielding both the meta strip itself and the
+    strips contained within it.
+
+    See blender_asset_tracer.cdefs.SEQ_TYPE_xxx for the type numbers.
+    """
+
+    def iter_seqbase(seqbase) -> typing.Iterator[BlendFileBlock]:
+        for seq in listbase(seqbase):
+            seq.refine_type(b'Sequence')
+            seq_type = seq[b'type']
+            yield seq, seq_type
+
+            if seq_type == cdefs.SEQ_TYPE_META:
+                # Recurse into this meta-sequence.
+                subseq = seq.get_pointer((b'seqbase', b'first'))
+                yield from iter_seqbase(subseq)
+
+    sbase = sequence_editor.get_pointer((b'seqbase', b'first'))
+    yield from iter_seqbase(sbase)

blender_asset_tracer/cdefs.py

@@ -55,4 +55,5 @@ PTCACHE_EXT = b'.bphys'
 PTCACHE_PATH = b'blendcache_'
 
 # BKE_node.h
+SH_NODE_TEX_IMAGE = 143
 CMP_NODE_R_LAYERS = 221

blender_asset_tracer/cli/list_deps.py

@@ -4,8 +4,8 @@ import logging
 import pathlib
 import sys
 
-from . import common
 from blender_asset_tracer import tracer
+from . import common
 
 log = logging.getLogger(__name__)
 
@@ -16,8 +16,6 @@ def add_parser(subparsers):
     parser = subparsers.add_parser('list', help=__doc__)
     parser.set_defaults(func=cli_list)
     parser.add_argument('blendfile', type=pathlib.Path)
-    common.add_flag(parser, 'nonrecursive',
-                    help='Limit to direct dependencies of the named blend file')
     common.add_flag(parser, 'json', help='Output as JSON instead of human-readable text')
 
 
@@ -27,14 +25,13 @@ def cli_list(args):
         log.fatal('File %s does not exist', args.blendfile)
         return 3
 
-    recursive = not args.nonrecursive
     if args.json:
-        report_json(bpath, recursive)
+        report_json(bpath)
     else:
-        report_text(bpath, recursive)
+        report_text(bpath)
 
 
-def report_text(bpath, recursive):
+def report_text(bpath):
     reported_assets = set()
     last_reported_bfile = None
     cwd = pathlib.Path.cwd()
@@ -46,7 +43,7 @@ def report_text(bpath, recursive):
         except ValueError:
             return somepath
 
-    for usage in tracer.deps(bpath, recursive=recursive):
+    for usage in tracer.deps(bpath):
         filepath = usage.block.bfile.filepath.absolute()
         if filepath != last_reported_bfile:
             print(shorten(filepath))
@@ -71,13 +68,13 @@ class JSONSerialiser(json.JSONEncoder):
         return super().default(o)
 
 
-def report_json(bpath, recursive):
+def report_json(bpath):
     import collections
 
     # Mapping from blend file to its dependencies.
     report = collections.defaultdict(set)
 
-    for usage in tracer.deps(bpath, recursive=recursive):
+    for usage in tracer.deps(bpath):
         filepath = usage.block.bfile.filepath.absolute()
         for assetpath in usage.files():
             assetpath = assetpath.resolve()

blender_asset_tracer/tracer/__init__.py

@@ -3,7 +3,7 @@ import pathlib
 import typing
 
 from blender_asset_tracer import blendfile, bpathlib
-from . import result, blocks2assets
+from . import result, blocks2assets, file2blocks
 
 log = logging.getLogger(__name__)
 
@@ -17,77 +17,21 @@ codes_to_skip = {
 }
 
 
-class _Tracer:
+def deps(bfilepath: pathlib.Path) -> typing.Iterator[result.BlockUsage]:
-    """Trace dependencies with protection against infinite loops.
-
-    Don't use this directly, use the function deps(...) instead.
-    """
-    def __init__(self):
-        self.seen_files = set()
-
-    def deps(self, 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)
-        bfilepath = bfilepath.absolute().resolve()
-        self.seen_files.add(bfilepath)
 
-        recurse_into = []
     with blendfile.BlendFile(bfilepath) as bfile:
-            for block in asset_holding_blocks(bfile):
+        for block in asset_holding_blocks(file2blocks.iter_blocks(bfile)):
             yield from blocks2assets.iter_assets(block)
 
-                if recursive and block.code == b'LI':
-                    recurse_into.append(block)
 
-            # Deal with recursion after we've handled all dependencies of the
+def asset_holding_blocks(blocks: typing.Iterable[blendfile.BlendFileBlock]) \
-            # current file, so that file access isn't interleaved and all deps
+        -> typing.Iterator[blendfile.BlendFileBlock]:
-            # of one file are reported before moving to the next.
-            for block in recurse_into:
-                yield from self._recurse_deps(block)
-
-    def _recurse_deps(self, 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.
-        path = abspath.to_path()
-        try:
-            path = path.resolve()
-        except FileNotFoundError:
-            log.warning('Linked blend file %s (%s) does not exist; skipping.', relpath, path)
-            return
-
-        # Avoid infinite recursion.
-        if path in self.seen_files:
-            log.debug('ignoring file, already seen %s', path)
-            return
-
-        yield from self.deps(path, recursive=True)
-
-
-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.
-    """
-
-    tracer = _Tracer()
-    yield from tracer.deps(bfilepath, recursive=recursive)
-
-
-def asset_holding_blocks(bfile: blendfile.BlendFile) -> typing.Iterator[blendfile.BlendFileBlock]:
     """Generator, yield data blocks that could reference external assets."""
-    for block in bfile.blocks:
+    for block in blocks:
         assert isinstance(block, blendfile.BlendFileBlock)
         code = block.code
 

blender_asset_tracer/tracer/blocks2assets.py

@@ -140,19 +140,7 @@ def scene(block: blendfile.BlendFileBlock) -> typing.Iterator[result.BlockUsage]
     single_asset_types = {cdefs.SEQ_TYPE_MOVIE, cdefs.SEQ_TYPE_SOUND_RAM, cdefs.SEQ_TYPE_SOUND_HD}
     asset_types = single_asset_types.union({cdefs.SEQ_TYPE_IMAGE})
 
-    def iter_seqbase(seqbase) -> typing.Iterator[result.BlockUsage]:
+    for seq, seq_type in iterators.sequencer_strips(block_ed):
-        """Generate results from a ListBase of sequencer strips."""
-
-        for seq in iterators.listbase(seqbase):
-            seq.refine_type(b'Sequence')
-            seq_type = seq[b'type']
-
-            if seq_type == cdefs.SEQ_TYPE_META:
-                # Recurse into this meta-sequence.
-                subseq = seq.get_pointer((b'seqbase', b'first'))
-                yield from iter_seqbase(subseq)
-                continue
-
         if seq_type not in asset_types:
             continue
 
@@ -173,9 +161,6 @@ def scene(block: blendfile.BlendFileBlock) -> typing.Iterator[result.BlockUsage]
                                 path_dir_field=dn_field,
                                 path_base_field=bn_field)
 
-    sbase = block_ed.get_pointer((b'seqbase', b'first'))
-    yield from iter_seqbase(sbase)
-
 
 @dna_code('SO')
 @skip_packed

blender_asset_tracer/tracer/expanders.py

@@ -0,0 +1,230 @@
+"""Low-level functions called by file2block.
+
+Those can expand data blocks and yield their dependencies (e.g. other data
+blocks necessary to render/display/work with the given data block).
+"""
+import logging
+import typing
+
+from blender_asset_tracer import blendfile, cdefs
+from blender_asset_tracer.blendfile import iterators
+
+_warned_about_types = set()
+_funcs_for_code = {}
+log = logging.getLogger(__name__)
+
+
+def expand_block(block: blendfile.BlendFileBlock) -> typing.Iterator[blendfile.BlendFileBlock]:
+    """Generator, yield the data blocks used by this data block."""
+
+    try:
+        expander = _funcs_for_code[block.code]
+    except KeyError:
+        if block.code not in _warned_about_types:
+            log.info('No expander implemented for block type %r', block.code.decode())
+            _warned_about_types.add(block.code)
+        return
+
+    log.debug('Expanding block %r', block)
+    # Filter out falsy blocks, i.e. None values.
+    # Allowing expanders to yield None makes them more consise.
+    yield from filter(None, expander(block))
+
+
+def dna_code(block_code: str):
+    """Decorator, marks decorated func as expander for that DNA code."""
+
+    assert isinstance(block_code, str)
+
+    def decorator(wrapped):
+        _funcs_for_code[block_code.encode()] = wrapped
+        return wrapped
+
+    return decorator
+
+
+def _expand_generic_material(block: blendfile.BlendFileBlock):
+    array_len = block.get(b'totcol')
+    yield from block.iter_array_of_pointers(b'mat', array_len)
+
+
+def _expand_generic_mtex(block: blendfile.BlendFileBlock):
+    for mtex in block.iter_fixed_array_of_pointers(b'mtex'):
+        yield mtex.get_pointer(b'tex')
+        yield mtex.get_pointer(b'object')
+
+
+def _expand_generic_nodetree(block: blendfile.BlendFileBlock):
+    assert block.dna_type.dna_type_id == b'bNodeTree'
+
+    nodes = block.get_pointer((b'nodes', b'first'))
+    for node in iterators.listbase(nodes):
+        if node[b'type'] == cdefs.CMP_NODE_R_LAYERS:
+            continue
+        yield node
+
+        # The 'id' property points to whatever is used by the node
+        # (like the image in an image texture node).
+        yield node.get_pointer(b'id')
+
+
+def _expand_generic_nodetree_id(block: blendfile.BlendFileBlock):
+    block_ntree = block.get_pointer(b'nodetree', None)
+    if block_ntree is not None:
+        yield from _expand_generic_nodetree(block_ntree)
+
+
+def _expand_generic_animdata(block: blendfile.BlendFileBlock):
+    block_adt = block.get_pointer(b'adt')
+    if block_adt:
+        yield block_adt.get_pointer(b'action')
+    # TODO, NLA
+
+
+@dna_code('AR')
+def _expand_armature(block: blendfile.BlendFileBlock):
+    yield from _expand_generic_animdata(block)
+
+
+@dna_code('CU')
+def _expand_curve(block: blendfile.BlendFileBlock):
+    yield from _expand_generic_animdata(block)
+    yield from _expand_generic_material(block)
+
+    for fieldname in (b'vfont', b'vfontb', b'vfonti', b'vfontbi',
+                      b'bevobj', b'taperobj', b'textoncurve'):
+        yield block.get_pointer(fieldname)
+
+
+@dna_code('GR')
+def _expand_group(block: blendfile.BlendFileBlock):
+    objects = block.get_pointer((b'gobject', b'first'))
+    for item in iterators.listbase(objects):
+        yield item.get_pointer(b'ob')
+
+
+@dna_code('LA')
+def _expand_lamp(block: blendfile.BlendFileBlock):
+    yield from _expand_generic_animdata(block)
+    yield from _expand_generic_nodetree_id(block)
+    yield from _expand_generic_mtex(block)
+
+
+@dna_code('MA')
+def _expand_material(block: blendfile.BlendFileBlock):
+    yield from _expand_generic_animdata(block)
+    yield from _expand_generic_nodetree_id(block)
+    yield from _expand_generic_mtex(block)
+
+    yield block.get_pointer(b'group')
+
+
+@dna_code('MB')
+def _expand_metaball(block: blendfile.BlendFileBlock):
+    yield from _expand_generic_animdata(block)
+    yield from _expand_generic_material(block)
+
+
+@dna_code('ME')
+def _expand_mesh(block: blendfile.BlendFileBlock):
+    yield from _expand_generic_animdata(block)
+    yield from _expand_generic_material(block)
+    yield block.get_pointer(b'texcomesh')
+    # TODO, TexFace? - it will be slow, we could simply ignore :S
+
+
+@dna_code('NT')
+def _expand_node_tree(block: blendfile.BlendFileBlock):
+    yield from _expand_generic_animdata(block)
+    yield from _expand_generic_nodetree(block)
+
+
+@dna_code('OB')
+def _expand_object(block: blendfile.BlendFileBlock):
+    yield from _expand_generic_animdata(block)
+    yield from _expand_generic_material(block)
+
+    yield block.get_pointer(b'data')
+
+    if block[b'transflag'] & cdefs.OB_DUPLIGROUP:
+        yield block.get_pointer(b'dup_group')
+
+    yield block.get_pointer(b'proxy')
+    yield block.get_pointer(b'proxy_group')
+
+    # 'ob->pose->chanbase[...].custom'
+    block_pose = block.get_pointer(b'pose')
+    if block_pose:
+        assert block_pose.dna_type.dna_type_id == b'bPose'
+        # sdna_index_bPoseChannel = block_pose.file.sdna_index_from_id[b'bPoseChannel']
+        channels = block_pose.get_pointer((b'chanbase', b'first'))
+        for pose_chan in iterators.listbase(channels):
+            yield pose_chan.get_pointer(b'custom')
+
+    # Expand the objects 'ParticleSettings' via 'ob->particlesystem[...].part'
+    # sdna_index_ParticleSystem = block.file.sdna_index_from_id.get(b'ParticleSystem')
+    # if sdna_index_ParticleSystem is not None:
+    psystems = block.get_pointer((b'particlesystem', b'first'))
+    for psystem in iterators.listbase(psystems):
+        yield psystem.get_pointer(b'part')
+
+
+@dna_code('PA')
+def _expand_particle_settings(block: blendfile.BlendFileBlock):
+    yield from _expand_generic_animdata(block)
+    yield from _expand_generic_mtex(block)
+
+    block_ren_as = block[b'ren_as']
+    if block_ren_as == cdefs.PART_DRAW_GR:
+        yield block.get_pointer(b'dup_group')
+    elif block_ren_as == cdefs.PART_DRAW_OB:
+        yield block.get_pointer(b'dup_ob')
+
+
+@dna_code('SC')
+def _expand_scene(block: blendfile.BlendFileBlock):
+    yield from _expand_generic_animdata(block)
+    yield from _expand_generic_nodetree_id(block)
+    yield block.get_pointer(b'camera')
+    yield block.get_pointer(b'world')
+    yield block.get_pointer(b'set', default=None)
+    yield block.get_pointer(b'clip', default=None)
+
+    # sdna_index_Base = block.file.sdna_index_from_id[b'Base']
+    # for item in bf_utils.iter_ListBase(block.get_pointer((b'base', b'first'))):
+    #     yield item.get_pointer(b'object', sdna_index_refine=sdna_index_Base)
+    bases = block.get_pointer((b'base', b'first'))
+    for base in iterators.listbase(bases):
+        yield base.get_pointer(b'object')
+
+    # Sequence Editor
+    block_ed = block.get_pointer(b'ed')
+    if not block_ed:
+        return
+
+    strip_type_to_field = {
+        cdefs.SEQ_TYPE_SCENE: b'scene',
+        cdefs.SEQ_TYPE_MOVIECLIP: b'clip',
+        cdefs.SEQ_TYPE_MASK: b'mask',
+        cdefs.SEQ_TYPE_SOUND_RAM: b'sound',
+    }
+    for strip, strip_type in iterators.sequencer_strips(block_ed):
+        try:
+            field_name = strip_type_to_field[strip_type]
+        except KeyError:
+            continue
+        yield strip.get_pointer(field_name)
+
+
+@dna_code('TE')
+def _expand_texture(block: blendfile.BlendFileBlock):
+    yield from _expand_generic_animdata(block)
+    yield from _expand_generic_nodetree_id(block)
+    yield block.get_pointer(b'ima')
+
+
+@dna_code('WO')
+def _expand_world(block: blendfile.BlendFileBlock):
+    yield from _expand_generic_animdata(block)
+    yield from _expand_generic_nodetree_id(block)
+    yield from _expand_generic_mtex(block)

blender_asset_tracer/tracer/file2blocks.py

@@ -0,0 +1,122 @@
+"""Expand data blocks.
+
+The expansion process follows pointers and library links to construct the full
+set of actually-used data blocks. This set consists of all data blocks in the
+initial blend file, and all *actually linked-to* data blocks in linked
+blend files.
+"""
+import collections
+import logging
+import typing
+
+from blender_asset_tracer import blendfile, bpathlib
+from . import expanders
+
+_funcs_for_code = {}
+log = logging.getLogger(__name__)
+
+
+class _BlockIterator:
+    """Expand blocks with dependencies from other libraries.
+
+    This class exists so that we have some context for the recursive expansion
+    without having to pass those variables to each recursive call.
+    """
+
+    def __init__(self):
+        # Set of (blend file Path, block address) of already-reported blocks.
+        self.blocks_yielded = set()
+
+        # Queue of blocks to visit
+        self.to_visit = collections.deque()
+
+    def iter_blocks(self,
+                    bfile: blendfile.BlendFile,
+                    limit_to: typing.Set[blendfile.BlendFileBlock] = frozenset(),
+                    ) -> typing.Iterator[blendfile.BlendFileBlock]:
+        """Expand blocks with dependencies from other libraries."""
+        bpath = bfile.filepath
+        root_dir = bpathlib.BlendPath(bpath.parent)
+
+        # Mapping from library path to data blocks to expand.
+        blocks_per_lib = collections.defaultdict(set)
+
+        if limit_to:
+            self._queue_named_blocks(bfile, limit_to)
+        else:
+            self._queue_all_blocks(bfile)
+
+        while self.to_visit:
+            block = self.to_visit.popleft()
+            assert isinstance(block, blendfile.BlendFileBlock)
+            if (bpath, block.addr_old) in self.blocks_yielded:
+                continue
+
+            if block.code == b'ID':
+                # ID blocks represent linked-in assets. Those are the ones that
+                # should be loaded from their own blend file and "expanded" to
+                # the entire set of data blocks required to render them. We
+                # defer the handling of those so that we can work with one
+                # blend file at a time.
+                lib = block.get_pointer(b'lib')
+                lib_bpath = bpathlib.BlendPath(lib[b'name']).absolute(root_dir)
+                blocks_per_lib[lib_bpath].add(block)
+
+                # The library block itself should also be reported, because it
+                # represents a blend file that is a dependency as well.
+                self.to_visit.append(lib)
+                continue
+
+            if limit_to:
+                # We're limiting the blocks, so we have to expand them to make
+                # sure we don't miss anything. Otherwise we're yielding the
+                # entire file anyway, and no expansion is necessary.
+                self._queue_dependencies(block)
+            self.blocks_yielded.add((bpath, block.addr_old))
+            yield block
+
+        # We've gone through all the blocks in this file, now open the libraries
+        # and iterate over the blocks referred there.
+        for lib_bpath, idblocks in blocks_per_lib.items():
+            lib_path = lib_bpath.to_path()
+            log.debug('Expanding %d blocks in %s', len(idblocks), lib_path)
+
+            with blendfile.BlendFile(lib_path) as libfile:
+                yield from self.iter_blocks(libfile, idblocks)
+
+    def _queue_all_blocks(self, bfile: blendfile.BlendFile):
+        log.debug('Queueing all blocks from file %s', bfile.filepath)
+        # Don't bother visiting DATA blocks, as we won't know what
+        # to do with them anyway.
+        self.to_visit.extend(block for block in bfile.blocks
+                             if block.code != b'DATA')
+
+    def _queue_named_blocks(self,
+                            bfile: blendfile.BlendFile,
+                            limit_to: typing.Set[blendfile.BlendFileBlock]):
+        """Queue only the blocks referred to in limit_to.
+
+        :param bfile:
+        :param limit_to: set of ID blocks that name the blocks to queue.
+            The queued blocks are loaded from the actual blend file, and
+            selected by name.
+        """
+        for to_find in limit_to:
+            assert to_find.code == b'ID'
+            name_to_find = to_find[b'name']
+            code = name_to_find[:2]
+            log.debug('Finding block %r with code %r', name_to_find, code)
+            same_code = bfile.find_blocks_from_code(code)
+            for block in same_code:
+                if block.id_name == name_to_find:
+                    log.debug('Queueing %r from file %s', block, bfile.filepath)
+                    self.to_visit.append(block)
+
+    def _queue_dependencies(self, block: blendfile.BlendFileBlock):
+        self.to_visit.extend(expanders.expand_block(block))
+
+
+def iter_blocks(bfile: blendfile.BlendFile) -> typing.Iterator[blendfile.BlendFileBlock]:
+    """Generator, yield all blocks in this file + required blocks in libs."""
+    bi = _BlockIterator()
+    yield from bi.iter_blocks(bfile)

tests/test_tracer.py

@@ -29,7 +29,7 @@ class AssetHoldingBlocksTest(AbstractTracerTest):
         blocks_seen = 0
         seen_scene = seen_ob = False
 
-        for block in tracer.asset_holding_blocks(self.bf):
+        for block in tracer.asset_holding_blocks(self.bf.blocks):
             assert isinstance(block, blendfile.BlendFileBlock)
             blocks_seen += 1
 
@@ -70,8 +70,8 @@ class DepsTest(AbstractTracerTest):
             return None
         return field.name.name_full.decode()
 
-    def assert_deps(self, blend_fname, expects: dict, recursive=False):
+    def assert_deps(self, blend_fname, expects: dict):
-        for dep in tracer.deps(self.blendfiles / blend_fname, recursive=recursive):
+        for dep in tracer.deps(self.blendfiles / blend_fname):
             actual_type = dep.block.dna_type.dna_type_id.decode()
             actual_full_field = self.field_name(dep.path_full_field)
             actual_dirname = self.field_name(dep.path_dir_field)
@@ -92,7 +92,7 @@ class DepsTest(AbstractTracerTest):
                 del expects[dep.block_name]
 
         # All expected uses should have been seen.
-        self.assertEqual({}, expects, 'Expected results were not seen.')
+        self.assertEqual(expects, {}, 'Expected results were not seen.')
 
     def test_no_deps(self):
         self.assert_deps('basic_file.blend', {})
@@ -203,10 +203,14 @@ class DepsTest(AbstractTracerTest):
             b'IMbrick_dotted_04-color': Expect(
                 'Image', 'name[1024]', None, None,
                 b'//textures/Bricks/brick_dotted_04-color.jpg', False),
-            b'IMbuildings_roof_04-color': Expect(
+
-                'Image', 'name[1024]', None, None,
+            # This data block is in the basic_file.blend file, but not used by
-                b'//textures/Textures/Buildings/buildings_roof_04-color.png', False),
+            # any of the objects linked in from linked_cube.blend or
-        }, recursive=True)
+            # doubly_linked.blend, hence it should *not* be reported:
+            # b'IMbuildings_roof_04-color': Expect(
+            #     'Image', 'name[1024]', None, None,
+            #     b'//textures/Textures/Buildings/buildings_roof_04-color.png', False),
+        })
 
     def test_sim_data(self):
         self.assert_deps('T53562/bam_pack_bug.blend', {
@@ -222,7 +226,7 @@ class DepsTest(AbstractTracerTest):
         try:
             sys.setrecursionlimit(80)
             # This should finish without hitting the recursion limit.
-            for _ in tracer.deps(infinite_bfile, recursive=True):
+            for _ in tracer.deps(infinite_bfile):
                 pass
         finally:
             sys.setrecursionlimit(reclim)

tests/test_tracer_file2blocks.py

@@ -0,0 +1,36 @@
+from blender_asset_tracer import blendfile
+from blender_asset_tracer.tracer import file2blocks
+
+from test_tracer import AbstractTracerTest
+
+
+class File2BlocksTest(AbstractTracerTest):
+    def test_id_blocks(self):
+        self.bf = blendfile.BlendFile(self.blendfiles / 'doubly_linked.blend')
+
+        foreign_blocks = {}
+        for block in file2blocks.iter_blocks(self.bf):
+            # Only register blocks from libraries.
+            if block.bfile == self.bf:
+                continue
+            foreign_blocks[block.id_name] = block
+
+        self.assertNotEqual({}, foreign_blocks)
+        # It should find directly linked blocks (GRCubes and MABrick) as well
+        # as indirectly linked (MECube³).
+        self.assertIn(b'GRCubes', foreign_blocks)
+        self.assertIn(b'MABrick', foreign_blocks)
+        self.assertIn('MECube³'.encode(), foreign_blocks)
+        self.assertIn('OBümlaut'.encode(), foreign_blocks)
+
+    def test_circular_files(self):
+        self.bf = blendfile.BlendFile(self.blendfiles / 'recursive_dependency_1.blend')
+
+        blocks = {}
+        for block in file2blocks.iter_blocks(self.bf):
+            blocks[block.id_name] = block
+
+        self.assertNotEqual({}, blocks)
+        self.assertIn(b'MAMaterial', blocks)
+        self.assertIn(b'OBCube', blocks)
+        self.assertIn(b'MECube', blocks)