Make VALID_EC_TYPES a runtime/dynamic property

... this is needed for compatibility with older versions
liberasurecode where a few EC types/backends were not
available

3 files changed, 46 insertions, 43 deletions

diff --git a/pyeclib/ec_iface.py b/pyeclib/ec_iface.py
index fc8ff03..2b459d6 100644
--- a/pyeclib/ec_iface.py
+++ b/pyeclib/ec_iface.py
@@ -41,14 +41,6 @@ PYECLIB_VERSION = PyECLibVersion(PYECLIB_MAJOR, PYECLIB_MINOR,
 PYECLIB_MAX_DATA = 32
 PYECLIB_MAX_PARITY = 32
 
-VALID_EC_TYPES = ['jerasure_rs_vand',
-                  'jerasure_rs_cauchy',
-                  'flat_xor_hd_3',
-                  'flat_xor_hd_4',
-                  'isa_l_rs_vand',
-                  'shss',
-                  'liberasurecode_rs_vand']
-
 
 @unique
 class PyECLibEnum(Enum):
@@ -460,3 +452,32 @@ class ECInsufficientFragments(ECDriverError):
 # Out of memory
 class ECOutOfMemory(ECDriverError):
     pass
+
+
+# PyECLib helper for "available" EC types
+ALL_EC_TYPES = [
+    'jerasure_rs_vand',
+    'jerasure_rs_cauchy',
+    'flat_xor_hd_3',
+    'flat_xor_hd_4',
+    'isa_l_rs_vand',
+    'shss',
+    'liberasurecode_rs_vand',
+]
+
+
+def _PyECLibValidECTypes():
+    available_ec_types = []
+    for _type in ALL_EC_TYPES:
+        try:
+            if _type is 'shss':
+                ECDriver(k=10, m=4, ec_type=_type)
+            else:
+                ECDriver(k=10, m=5, ec_type=_type)
+            available_ec_types.append(_type)
+        except Exception:
+            pass
+    return available_ec_types
+
+
+VALID_EC_TYPES = _PyECLibValidECTypes()
diff --git a/test/test_pyeclib_api.py b/test/test_pyeclib_api.py
index 985d88d..6d11076 100644
--- a/test/test_pyeclib_api.py
+++ b/test/test_pyeclib_api.py
@@ -27,14 +27,11 @@ import sys
 import tempfile
 import unittest
 from pyeclib.ec_iface import ECBackendNotSupported
+from pyeclib.ec_iface import ECDriver
 from pyeclib.ec_iface import ECDriverError
 from pyeclib.ec_iface import ECInsufficientFragments
-
-from pyeclib.ec_iface import ECDriver, PyECLib_EC_Types
-if sys.version < '3':
-    from test_pyeclib_c import _available_backends
-else:
-    from .test_pyeclib_c import _available_backends
+from pyeclib.ec_iface import PyECLib_EC_Types
+from pyeclib.ec_iface import VALID_EC_TYPES
 
 if sys.version < '3':
     def b2i(b):
@@ -114,7 +111,7 @@ class TestPyECLibDriver(unittest.TestCase):
         print("")
         for _type in PyECLib_EC_Types.names():
             # Check if this algo works
-            if _type not in _available_backends:
+            if _type not in VALID_EC_TYPES:
                 print("Skipping test for %s backend" % _type)
                 continue
             try:
@@ -131,7 +128,7 @@ class TestPyECLibDriver(unittest.TestCase):
     def get_pyeclib_testspec(self, csum="none"):
         pyeclib_drivers = []
         _type1 = 'jerasure_rs_vand'
-        if _type1 in _available_backends:
+        if _type1 in VALID_EC_TYPES:
             pyeclib_drivers.append(ECDriver(k=12, m=2, ec_type=_type1,
                                    chksum_type=csum))
             pyeclib_drivers.append(ECDriver(k=11, m=2, ec_type=_type1,
@@ -141,7 +138,7 @@ class TestPyECLibDriver(unittest.TestCase):
             pyeclib_drivers.append(ECDriver(k=8, m=4, ec_type=_type1,
                                    chksum_type=csum))
         _type2 = 'liberasurecode_rs_vand'
-        if _type2 in _available_backends:
+        if _type2 in VALID_EC_TYPES:
             pyeclib_drivers.append(ECDriver(k=12, m=2, ec_type=_type2,
                                    chksum_type=csum))
             pyeclib_drivers.append(ECDriver(k=11, m=2, ec_type=_type2,
@@ -151,19 +148,19 @@ class TestPyECLibDriver(unittest.TestCase):
             pyeclib_drivers.append(ECDriver(k=8, m=4, ec_type=_type2,
                                    chksum_type=csum))
         _type3_1 = 'flat_xor_hd'
-        if _type3_1 in _available_backends:
+        if _type3_1 in VALID_EC_TYPES:
             pyeclib_drivers.append(ECDriver(k=12, m=6, ec_type=_type3_1,
                                    chksum_type=csum))
             pyeclib_drivers.append(ECDriver(k=10, m=5, ec_type=_type3_1,
                                    chksum_type=csum))
         _type3_2 = 'flat_xor_hd_4'
-        if _type3_2 in _available_backends:
+        if _type3_2 in VALID_EC_TYPES:
             pyeclib_drivers.append(ECDriver(k=12, m=6, ec_type=_type3_2,
                                    chksum_type=csum))
             pyeclib_drivers.append(ECDriver(k=10, m=5, ec_type=_type3_2,
                                    chksum_type=csum))
         _type4 = 'shss'
-        if _type4 in _available_backends:
+        if _type4 in VALID_EC_TYPES:
             pyeclib_drivers.append(ECDriver(k=10, m=4, ec_type=_type4,
                                    chksum_type=csum))
             pyeclib_drivers.append(ECDriver(k=20, m=4, ec_type=_type4,
@@ -247,7 +244,7 @@ class TestPyECLibDriver(unittest.TestCase):
 
     def check_metadata_formatted(self, k, m, ec_type, chksum_type):
 
-        if ec_type not in _available_backends:
+        if ec_type not in VALID_EC_TYPES:
             return
 
         filesize = 1024 * 1024 * 3
@@ -529,7 +526,7 @@ class TestPyECLibDriver(unittest.TestCase):
         if ec_type[:11] == "flat_xor_hd":
             return ECDriver(k=k, m=m, ec_type="flat_xor_hd",
                             chksum_type=chksum_type)
-        elif ec_type in _available_backends:
+        elif ec_type in VALID_EC_TYPES:
             return ECDriver(k=k, m=m, ec_type=ec_type, chksum_type=chksum_type)
         else:
             return None
@@ -540,7 +537,7 @@ class TestPyECLibDriver(unittest.TestCase):
         tmp_file.seek(0)
         whole_file_bytes = tmp_file.read()
         for ec_type in ['flat_xor_hd_3', 'liberasurecode_rs_vand']:
-            if ec_type in _available_backends:
+            if ec_type in VALID_EC_TYPES:
                 pyeclib_driver = self.get_available_backend(
                     k=10, m=5, ec_type=ec_type)
                 fragments = pyeclib_driver.encode(whole_file_bytes)
@@ -551,7 +548,7 @@ class TestPyECLibDriver(unittest.TestCase):
     def test_min_parity_fragments_needed(self):
         pyeclib_drivers = []
         for ec_type in ['flat_xor_hd_3', 'liberasurecode_rs_vand']:
-            if ec_type in _available_backends:
+            if ec_type in VALID_EC_TYPES:
                 pyeclib_drivers.append(ECDriver(k=10, m=5, ec_type=ec_type))
                 self.assertTrue(
                     pyeclib_drivers[0].min_parity_fragments_needed() == 1)
diff --git a/test/test_pyeclib_c.py b/test/test_pyeclib_c.py
index 26831b1..4975840 100644
--- a/test/test_pyeclib_c.py
+++ b/test/test_pyeclib_c.py
@@ -30,24 +30,9 @@ import unittest
 
 import pyeclib_c
 from pyeclib.ec_iface import PyECLib_EC_Types
+from pyeclib.ec_iface import VALID_EC_TYPES
 
 
-def collect_available_backends():
-    available_backends = []
-    for ec_type in PyECLib_EC_Types:
-        try:
-           if ec_type == PyECLib_EC_Types.flat_xor_hd:
-                handle = pyeclib_c.init(10, 5, ec_type.value, 3)
-           else:
-                handle = pyeclib_c.init(10, 4, ec_type.value)
-           available_backends.append(ec_type.name)
-           print(ec_type.name)
-        except:
-            pass
-    return available_backends
-
-_available_backends = collect_available_backends()
-
 class Timer:
 
     def __init__(self):
@@ -293,7 +278,7 @@ class TestPyECLib(unittest.TestCase):
         return format(throughput, '.10g')
 
     def test_xor_code(self):
-        if "flat_xor_hd" not in _available_backends:
+        if "flat_xor_hd" not in VALID_EC_TYPES:
             print("xor backend is not available in your enviromnet, skipping test")
             return
 
@@ -324,7 +309,7 @@ class TestPyECLib(unittest.TestCase):
                       (size_str, self.get_throughput(avg_time, size_str)))
 
     def test_shss(self):
-        if "shss" not in _available_backends:
+        if "shss" not in VALID_EC_TYPES:
             print("shss backend is not available in your enviromnet, skipping test")
             return
 
@@ -395,7 +380,7 @@ class TestPyECLib(unittest.TestCase):
 
     def test_codes(self):
         for ec_type in self.rs_types:
-            if ec_type.name not in _available_backends:
+            if ec_type.name not in VALID_EC_TYPES:
                 print("%s backend is not available in your enviromnet, skipping test" % ec_type.name)
                 continue