Fix EWA resampling tests not properly testing caching

satpy/resample.py

@@ -621,6 +621,11 @@ def _call_ll2cr(self, lons, lats, target_geo_def, swath_usage=0):
 
     def precompute(self, cache_dir=None, swath_usage=0, **kwargs):
         """Generate row and column arrays and store it for later use."""
+        if self.cache:
+            # this resampler should be used for one SwathDefinition
+            # no need to recompute ll2cr output again
+            return None
+
         if kwargs.get('mask') is not None:
             LOG.warning("'mask' parameter has no affect during EWA "
                         "resampling")
@@ -950,7 +955,7 @@ def prepare_resampler(source_area, destination_area, resampler=None, **resample_
 
     key = (resampler_class,
            source_area, destination_area,
-           hash_dict(resample_kwargs))
+           hash_dict(resample_kwargs).hexdigest())
     try:
         resampler_instance = resamplers_cache[key]
     except KeyError:
@@ -962,12 +967,6 @@ def prepare_resampler(source_area, destination_area, resampler=None, **resample_
 def resample(source_area, data, destination_area,
              resampler=None, **kwargs):
     """Do the resampling."""
-    if 'resampler_class' in kwargs:
-        import warnings
-        warnings.warn("'resampler_class' is deprecated, use 'resampler'",
-                      DeprecationWarning)
-        resampler = kwargs.pop('resampler_class')
-
     if not isinstance(resampler, BaseResampler):
         # we don't use the first argument (cache key)
         _, resampler_instance = prepare_resampler(source_area,

satpy/tests/test_resample.py

@@ -212,7 +212,8 @@ class TestEWAResampler(unittest.TestCase):
 
     @mock.patch('satpy.resample.fornav')
     @mock.patch('satpy.resample.ll2cr')
-    def test_2d_ewa(self, ll2cr, fornav):
+    @mock.patch('satpy.resample.SwathDefinition.get_lonlats')
+    def test_2d_ewa(self, get_lonlats, ll2cr, fornav):
         """Test EWA with a 2D dataset."""
         import numpy as np
         import xarray as xr
@@ -223,7 +224,9 @@ def test_2d_ewa(self, ll2cr, fornav):
         fornav.return_value = (100 * 200,
                                np.zeros((200, 100), dtype=np.float32))
         _, _, swath_data, source_swath, target_area = get_test_data()
+        get_lonlats.return_value = (source_swath.lons, source_swath.lats)
         swath_data.data = swath_data.data.astype(np.float32)
+        num_chunks = len(source_swath.lons.chunks[0]) * len(source_swath.lons.chunks[1])
 
         new_data = resample_dataset(swath_data, target_area, resampler='ewa')
         self.assertTupleEqual(new_data.shape, (200, 100))
@@ -232,16 +235,20 @@ def test_2d_ewa(self, ll2cr, fornav):
         self.assertIs(new_data.attrs['area'], target_area)
         # make sure we can actually compute everything
         new_data.compute()
-        previous_calls = ll2cr.call_count
+        lonlat_calls = get_lonlats.call_count
+        ll2cr_calls = ll2cr.call_count
 
         # resample a different dataset and make sure cache is used
         data = xr.DataArray(
             swath_data.data,
             dims=('y', 'x'), attrs={'area': source_swath, 'test': 'test2',
                                     'name': 'test2'})
         new_data = resample_dataset(data, target_area, resampler='ewa')
-        self.assertEqual(ll2cr.call_count, previous_calls)
         new_data.compute()
+        # ll2cr will be called once more because of the computation
+        self.assertEqual(ll2cr.call_count, ll2cr_calls + num_chunks)
+        # but we should already have taken the lonlats from the SwathDefinition
+        self.assertEqual(get_lonlats.call_count, lonlat_calls)
         self.assertIn('y', new_data.coords)
         self.assertIn('x', new_data.coords)
         if CRS is not None:
@@ -253,7 +260,8 @@ def test_2d_ewa(self, ll2cr, fornav):
 
     @mock.patch('satpy.resample.fornav')
     @mock.patch('satpy.resample.ll2cr')
-    def test_3d_ewa(self, ll2cr, fornav):
+    @mock.patch('satpy.resample.SwathDefinition.get_lonlats')
+    def test_3d_ewa(self, get_lonlats, ll2cr, fornav):
         """Test EWA with a 3D dataset."""
         import numpy as np
         import xarray as xr
@@ -266,6 +274,8 @@ def test_3d_ewa(self, ll2cr, fornav):
                               np.zeros((10, 10), dtype=np.float32))
         fornav.return_value = ([100 * 200] * 3,
                                [np.zeros((200, 100), dtype=np.float32)] * 3)
+        get_lonlats.return_value = (source_swath.lons, source_swath.lats)
+        num_chunks = len(source_swath.lons.chunks[0]) * len(source_swath.lons.chunks[1])
 
         new_data = resample_dataset(swath_data, target_area, resampler='ewa')
         self.assertTupleEqual(new_data.shape, (3, 200, 100))
@@ -274,16 +284,20 @@ def test_3d_ewa(self, ll2cr, fornav):
         self.assertIs(new_data.attrs['area'], target_area)
         # make sure we can actually compute everything
         new_data.compute()
-        previous_calls = ll2cr.call_count
+        lonlat_calls = get_lonlats.call_count
+        ll2cr_calls = ll2cr.call_count
 
         # resample a different dataset and make sure cache is used
         swath_data = xr.DataArray(
             swath_data.data,
             dims=('bands', 'y', 'x'), coords={'bands': ['R', 'G', 'B']},
             attrs={'area': source_swath, 'test': 'test'})
         new_data = resample_dataset(swath_data, target_area, resampler='ewa')
-        self.assertEqual(ll2cr.call_count, previous_calls)
         new_data.compute()
+        # ll2cr will be called once more because of the computation
+        self.assertEqual(ll2cr.call_count, ll2cr_calls + num_chunks)
+        # but we should already have taken the lonlats from the SwathDefinition
+        self.assertEqual(get_lonlats.call_count, lonlat_calls)
         self.assertIn('y', new_data.coords)
         self.assertIn('x', new_data.coords)
         self.assertIn('bands', new_data.coords)