Add allow_overwrite parameter to Layer.downsample() (#614)

* add only_setup_mag(s) parameter to downsample methods to allow parallel downsampling without writing outdated datasource-properties.json

* update changelog

* add test

* add allow_overwrite parameter to Layer.downsample()

* update changelog

Author: philippotto

webknossos/Changelog.md

@@ -12,6 +12,9 @@ For upgrade instructions, please check the respective *Breaking Changes* section
 ### Breaking Changes
 
 ### Added
+- Added `only_setup_mag` parameter to downsample-related methods in `Layer`. This parameter allows creating output magnifications before parallelizing downsampling invocations to avoid outdated writes to datasource-properties.json. [#610](https://github.com/scalableminds/webknossos-libs/pull/610)
+- Added `Task.create()` method to create tasks by prodiving a dataset name, location, and rotation. [#605](https://github.com/scalableminds/webknossos-libs/pull/605)
+- Added `allow_overwrite` parameter to `Layer.downsample()`. [#614](https://github.com/scalableminds/webknossos-libs/pull/614)
 
 ### Changed
 

webknossos/webknossos/dataset/layer.py

@@ -515,6 +515,7 @@ def downsample(
         buffer_edge_len: Optional[int] = None,
         force_sampling_scheme: bool = False,
         args: Optional[Namespace] = None,
+        allow_overwrite: bool = False,
         only_setup_mags: bool = False,
     ) -> None:
         """
@@ -603,6 +604,7 @@ def downsample(
                 compress=compress,
                 buffer_edge_len=buffer_edge_len,
                 args=args,
+                allow_overwrite=allow_overwrite,
                 only_setup_mag=only_setup_mags,
             )
 

wkcuber/tests/test_downsampling.py

@@ -364,6 +364,13 @@ def test_downsample_mag_list_with_only_setup_mags() -> None:
             layer.get_mag(m).read((0, 0, 0), (10, 20, 30)) == 0
         ), "The mags should be empty."
 
+    layer.downsample_mag_list(
+        from_mag=Mag(1), target_mags=target_mags, allow_overwrite=True
+    )
+
+    for m in target_mags:
+        assert m in layer.mags
+
 
 def test_downsample_with_invalid_mag_list() -> None:
     ds = Dataset(TESTOUTPUT_DIR / "downsample_mag_list", scale=(1, 1, 2))