Feature/fix fdb stream (#175)

* Fix fdb stream

earthkit/data/readers/grib/__init__.py

@@ -36,7 +36,8 @@ def memory_reader(source, buf, magic=None, deeper_check=False):
 
 
 def stream_reader(source, stream, magic=None, deeper_check=False):
-    if _match_magic(magic, deeper_check):
+    # by default we assume the stream is grib data
+    if magic is None or _match_magic(magic, deeper_check):
         from .memory import GribFieldListInMemory, GribStreamReader
 
         r = GribStreamReader(stream)

earthkit/data/testing.py

@@ -88,6 +88,14 @@ def modules_installed(*modules):
 except Exception:
     NO_EOD = True
 
+try:
+    import pyfdb  # noqa
+
+    fdb_home = os.environ.get("FDB_HOME", None)
+    NO_FDB = fdb_home is None
+except Exception:
+    NO_FDB = True
+
 
 def MISSING(*modules):
     return not modules_installed(*modules)

tests/sources/test_fdb.py

@@ -0,0 +1,68 @@
+#!/usr/bin/env python3
+
+# (C) Copyright 2020 ECMWF.
+#
+# This software is licensed under the terms of the Apache Licence Version 2.0
+# which can be obtained at http://www.apache.org/licenses/LICENSE-2.0.
+# In applying this licence, ECMWF does not waive the privileges and immunities
+# granted to it by virtue of its status as an intergovernmental organisation
+# nor does it submit to any jurisdiction.
+#
+
+import datetime
+
+import pytest
+
+from earthkit.data import from_source
+from earthkit.data.testing import NO_FDB
+
+
+@pytest.mark.long_test
+@pytest.mark.download
+@pytest.mark.skipif(NO_FDB, reason="No access to FDB")
+def test_fdb_grib_stream():
+    d = datetime.datetime.now() - datetime.timedelta(days=2)
+    request = {
+        "class": "od",
+        "expver": "0001",
+        "stream": "oper",
+        "date": d.strftime("%Y%m%d"),
+        "time": [0, 12],
+        "domain": "g",
+        "type": "an",
+        "levtype": "sfc",
+        "step": 0,
+        "param": [151, 167],
+    }
+
+    ds = from_source("fdb", request)
+    cnt = sum([1 for f in ds])
+    assert cnt == 4
+
+
+@pytest.mark.long_test
+@pytest.mark.download
+@pytest.mark.skipif(NO_FDB, reason="No access to FDB")
+def test_fdb_grib_file():
+    d = datetime.datetime.now() - datetime.timedelta(days=2)
+    request = {
+        "class": "od",
+        "expver": "0001",
+        "stream": "oper",
+        "date": d.strftime("%Y%m%d"),
+        "time": [0, 12],
+        "domain": "g",
+        "type": "an",
+        "levtype": "sfc",
+        "step": 0,
+        "param": [151, 167],
+    }
+
+    ds = from_source("fdb", request, stream=False)
+    assert len(ds) == 4
+
+
+if __name__ == "__main__":
+    from earthkit.data.testing import main
+
+    main(__file__)