feat: allow pointing directly at mesh and skeleton paths

cloudvolume/datasource/precomputed/__init__.py

@@ -1,5 +1,7 @@
 from typing import Optional, Union
 
+import os
+
 from .image import PrecomputedImageSource
 from .metadata import PrecomputedMetadata
 from .mesh import PrecomputedMeshSource
@@ -58,13 +60,29 @@ def create_precomputed(
       use_https=use_https # for parsing redirects
     )
 
+    readonly = bool(meta.redirected_from)
+
+    if meta.info.get("@type", "") == "neuroglancer_skeletons":
+      info = meta.info
+      meta = synthetic_meta(cloudpath, config, cache_service)
+      meta.info["skeletons"] = os.path.basename(cloudpath)
+      skeleton = PrecomputedSkeletonSource(meta, cache_service, config, readonly, info=info)
+    else:
+      skeleton = PrecomputedSkeletonSource(meta, cache_service, config, readonly)
+
+    if meta.info.get("@type", "") in ["neuroglancer_legacy_mesh", "neuroglancer_multilod_draco"]:
+      info = meta.info
+      meta = synthetic_meta(cloudpath, config, cache_service)
+      meta.info["mesh"] = os.path.basename(cloudpath)
+      mesh = PrecomputedMeshSource(meta, cache_service, config, readonly, info=info)
+    else:
+      mesh = PrecomputedMeshSource(meta, cache_service, config, readonly)
+
     if mesh_dir:
       meta.info['mesh'] = str(mesh_dir)
     if skel_dir:
       meta.info['skeletons'] = str(skel_dir)
 
-    readonly = bool(meta.redirected_from)
-
     if readonly:
       print(yellow("""
         Redirected 
@@ -99,9 +117,6 @@ def create_precomputed(
       lru_bytes=lru_bytes,
     )
 
-    mesh = PrecomputedMeshSource(meta, cache_service, config, readonly)
-    skeleton = PrecomputedSkeletonSource(meta, cache_service, config, readonly)
-
     cv = CloudVolumePrecomputed(
       meta, cache_service, config, 
       image, mesh, skeleton,
@@ -113,6 +128,25 @@ def create_precomputed(
 
     return cv
 
+def synthetic_meta(cloudpath, config, cache_service) -> PrecomputedMetadata:
+  info = PrecomputedMetadata.create_info(
+    num_channels=1, 
+    layer_type="segmentation", 
+    data_type='uint8', 
+    encoding="raw", 
+    resolution=[1,1,1], 
+    voxel_offset=[0,0,0], 
+    volume_size=[1,1,1],
+  )
+  return PrecomputedMetadata(
+      os.path.dirname(cloudpath),
+      config=config, 
+      cache=cache_service,
+      info=info, provenance=None,
+      max_redirects=0,
+      use_https=True # for parsing redirects
+  )
+
 
 def register():
   register_plugin('precomputed', create_precomputed)

cloudvolume/datasource/precomputed/metadata.py

@@ -189,6 +189,9 @@ def refresh_info(self, max_redirects=10, force_fetch=False):
 
   def parse_rois(self, info) -> List[Bbox]:
     """Parse ROIs from the info file at mip 0."""
+    if 'scales' not in info:
+      return None
+
     scale = info['scales'][0]
     if 'rois' not in scale:
       return None

cloudvolume/skeleton.py

@@ -1262,7 +1262,7 @@ def __str__(self):
         template.format(attr, buf.shape[0], buf.dtype)
       )
 
-    return "Skeleton(segid={}, vertices=(shape={}, {}), edges=(shape={}, {}), {}, space='{}' transform={})".format(
+    return "Skeleton(segid={}, vertices=(shape={}, {}), edges=(shape={}, {}), {}, space='{}', transform={})".format(
       self.id,
       self.vertices.shape[0], self.vertices.dtype,
       self.edges.shape[0], self.edges.dtype,