Latest eccodes + workaround seg fault when saving (#208)

environment.yml

@@ -2,5 +2,5 @@ channels:
     - conda-forge
 dependencies:
     - iris>=2.4
-    - python-eccodes>=0.9.1,<2
+    - python-eccodes
     - pep8

iris_grib/_save_rules.py

@@ -1489,6 +1489,13 @@ def data_section(cube, grib):
         # Enable missing values in the grib message.
         gribapi.grib_set(grib, "bitmapPresent", 1)
         gribapi.grib_set_double(grib, "missingValue", fill_value)
+
+    # A segmentation fault is raised by `gribapi.grib_set_double_array` if it
+    # tries to cast large data to float64. As a temporary fix we cast the data
+    # upfront
+    # TODO: remove the `astype` command once eccodes (gribapi) has been fixed.
+    if data.dtype != np.float64:
+        data = data.astype(np.float64)
     gribapi.grib_set_double_array(grib, "values", data.flatten())
 
     # todo: check packing accuracy?

iris_grib/tests/unit/save_rules/test_data_section.py

@@ -14,6 +14,7 @@
 
 from unittest import mock
 
+import gribapi
 import iris.cube
 import numpy as np
 
@@ -151,5 +152,27 @@ def test_scaled_with_nan_fill_value(self):
         self.assertValues(grib_api, [-1000, 2000, FILL, FILL])
 
 
+class TestNonDoubleData(tests.IrisGribTest):
+    # When saving to GRIB, data that is not float64 is cast to float64. This
+    # test checks that non-float64 data is saved without raising a segmentation
+    # fault.
+    def check(self, dtype):
+        data = np.random.random(1920 * 2560).astype(dtype)
+        cube = iris.cube.Cube(data,
+                              standard_name='geopotential_height', units='km')
+        grib_message = gribapi.grib_new_from_samples("GRIB2")
+        data_section(cube, grib_message)
+        gribapi.grib_release(grib_message)
+
+    def test_float32(self):
+        self.check(dtype=np.float32)
+
+    def test_int32(self):
+        self.check(dtype=np.int32)
+
+    def test_int64(self):
+        self.check(dtype=np.int64)
+
+
 if __name__ == "__main__":
     tests.main()

iris_grib/tests/unit/test_save_messages.py

@@ -23,22 +23,14 @@ def setUp(self):
     def test_save(self):
         m = mock.mock_open()
         with mock.patch('builtins.open', m, create=True):
-            # sending a MagicMock object to gribapi raises an AssertionError
-            # as the gribapi code does a type check
-            # this is deemed acceptable within the scope of this unit test
-            with self.assertRaises((AssertionError, TypeError)):
-                iris_grib.save_messages([self.grib_message], 'foo.grib2')
+            iris_grib.save_messages([self.grib_message], 'foo.grib2')
         self.assertTrue(mock.call('foo.grib2', 'wb') in m.mock_calls)
 
     def test_save_append(self):
         m = mock.mock_open()
         with mock.patch('builtins.open', m, create=True):
-            # sending a MagicMock object to gribapi raises an AssertionError
-            # as the gribapi code does a type check
-            # this is deemed acceptable within the scope of this unit test
-            with self.assertRaises((AssertionError, TypeError)):
-                iris_grib.save_messages([self.grib_message], 'foo.grib2',
-                                        append=True)
+            iris_grib.save_messages([self.grib_message], 'foo.grib2',
+                                    append=True)
         self.assertTrue(mock.call('foo.grib2', 'ab') in m.mock_calls)