Merge branch 'unstructured_scheme' into unstructured_scheme_new

* unstructured_scheme: (22 commits)
  Check mesh equality on MeshToGridESMFRegridder call (SciTools#138)
  Formalise regridder file format (SciTools#137)
  Fix issue 135 (mesh to grid chunking problems) (SciTools#136)
  Add load/save benchmarks (SciTools#132)
  Regridder load/saving (SciTools#130)
  Update dependencies (SciTools#128)
  Perform scalability for larger grids (SciTools#122)
  Add performance tests (SciTools#117)
  change iris source (SciTools#115)
  Unstructured scheme lazy regridding (with performance tests) (SciTools#111)
  Updating feature branch unstructured_scheme from 44d6048 to head of main, e528cbf
  Add grid to mesh scheme (SciTools#96)
  Unstructured scheme integration test (SciTools#66)
  Updated lockfiles according to branch requirement spec.
  Update Version to v0.1.dev2 (SciTools#59)
  Update version to v0.1.dev1 (SciTools#58)
  Unstructured Scheme - Extra Dims (SciTools#55)
  add __init__ to tests (SciTools#56)
  Unstructured Scheme - Additional Polish (docstrings and test coverage) (SciTools#53)
  Unstructured Scheme - Cube Creation 3D (SciTools#47)
  ...

# Conflicts:
#	benchmarks/benchmarks/ci/esmf_regridder.py
#	benchmarks/benchmarks/generate_data.py
#	requirements/nox.lock/py36-linux-64.lock
#	requirements/nox.lock/py37-linux-64.lock
#	requirements/nox.lock/py38-linux-64.lock
#	requirements/py36.yml

.cirrus.yml

@@ -22,15 +22,36 @@ env:
   # Maximum cache period (in weeks) before forcing a new cache upload.
   CACHE_PERIOD: "2"
   # Increment the build number to force new conda cache upload.
-  CONDA_CACHE_BUILD: "0"
+  CONDA_CACHE_BUILD: "1"
   # Increment the build number to force new nox cache upload.
-  NOX_CACHE_BUILD: "0"
+  NOX_CACHE_BUILD: "2"
   # Increment the build number to force new pip cache upload.
   PIP_CACHE_BUILD: "0"
   # Pip package to be installed.
   PIP_CACHE_PACKAGES: "pip setuptools wheel nox pyyaml"
   # Conda packages to be installed.
   CONDA_CACHE_PACKAGES: "nox pip pyyaml"
+  # Use specific custom iris source feature branch.
+  IRIS_SOURCE: "github:main"
+  # Git commit hash for iris test data.
+  IRIS_TEST_DATA_VERSION: "2.2"
+  # Base directory for the iris-test-data.
+  IRIS_TEST_DATA_DIR: ${HOME}/iris-test-data
+  OVERRIDE_TEST_DATA_REPOSITORY: ${IRIS_TEST_DATA_DIR}/test_data
+
+
+#
+# YAML alias for the iris-test-data cache.
+#
+iris_test_data_template: &IRIS_TEST_DATA_TEMPLATE
+  data_cache:
+    folder: ${IRIS_TEST_DATA_DIR}
+    fingerprint_script:
+      - echo "iris-test-data v${IRIS_TEST_DATA_VERSION}"
+    populate_script:
+      - wget --quiet https://github.com/SciTools/iris-test-data/archive/v${IRIS_TEST_DATA_VERSION}.zip -O iris-test-data.zip
+      - unzip -q iris-test-data.zip
+      - mv iris-test-data-${IRIS_TEST_DATA_VERSION} ${IRIS_TEST_DATA_DIR}
 
 
 #
@@ -88,8 +109,6 @@ test_task:
   only_if: ${SKIP_TEST_TASK} == ""
   auto_cancellation: true
   matrix:
-    env:
-      PY_VER: "3.6"
     env:
       PY_VER: "3.7"
     env:
@@ -104,6 +123,7 @@ test_task:
       - echo "${CIRRUS_TASK_NAME}"
       - echo "${NOX_CACHE_BUILD}"
       - if [ -n "${IRIS_SOURCE}" ]; then echo "${IRIS_SOURCE}"; fi
+  << : *IRIS_TEST_DATA_TEMPLATE
   test_script:
     - export CONDA_OVERRIDE_LINUX="$(uname -r | cut -d'+' -f1)"
     - nox --session tests -- --verbose

benchmarks/benchmarks/__init__.py

@@ -1 +1,44 @@
 """Benchmark tests for iris-esmf-regrid"""
+
+
+def disable_repeat_between_setup(benchmark_object):
+    """
+    Decorator for benchmarks where object persistence would be inappropriate.
+
+    E.g:
+        * Data is realised during testing.
+
+    Can be applied to benchmark classes/methods/functions.
+
+    https://asv.readthedocs.io/en/stable/benchmarks.html#timing-benchmarks
+
+    """
+    # Prevent repeat runs between setup() runs - object(s) will persist after 1st.
+    benchmark_object.number = 1
+    # Compensate for reduced certainty by increasing number of repeats.
+    #  (setup() is run between each repeat).
+    #  Minimum 5 repeats, run up to 30 repeats / 20 secs whichever comes first.
+    benchmark_object.repeat = (5, 30, 20.0)
+    # ASV uses warmup to estimate benchmark time before planning the real run.
+    #  Prevent this, since object(s) will persist after first warmup run,
+    #  which would give ASV misleading info (warmups ignore ``number``).
+    benchmark_object.warmup_time = 0.0
+
+    return benchmark_object
+
+
+def skip_benchmark(benchmark_object):
+    """
+    Decorator for benchmarks skipping benchmarks.
+    """
+
+    def setup_cache(self):
+        pass
+
+    def setup(*args):
+        raise NotImplementedError
+
+    benchmark_object.setup_cache = setup_cache
+    benchmark_object.setup = setup
+
+    return benchmark_object