[algorithm] Implement warning if prepare is present with api_version 1 property

beat/backend/python/algorithm.py

@@ -36,6 +36,7 @@ Validation for algorithms
 
 import os
 import sys
+import logging
 
 import six
 import numpy
@@ -47,6 +48,9 @@ from . import loader
 from . import utils
 
 
+logger = logging.getLogger(__name__)
+
+
 # ----------------------------------------------------------
 
 
@@ -116,7 +120,15 @@ class Runner(object):
         self.exc = exc
 
         self.ready = not hasattr(self.obj, 'setup')
-        self.prepared = (self.algorithm.api_version == 1) or not hasattr(self.obj, 'prepare')
+
+        has_api_v1 = self.algorithm.api_version == 1
+        has_prepare = hasattr(self.obj, 'prepare')
+
+        self.prepared = has_api_v1 or not has_prepare
+
+        if has_api_v1 and has_prepare:
+            logger.warning("Prepare is a reserved function name starting with API V2")
+
 
 
     def _check_parameters(self, parameters):

beat/backend/python/test/prefix/algorithms/legacy/prepare/1.json

+{
+    "language": "python",
+    "splittable": false,
+    "parameters": {
+        "sync": {
+            "default": "in1",
+            "type": "string"
+        }
+    },
+    "groups": [
+        {
+            "inputs": {
+                "in1": {
+                    "type": "user/single_integer/1"
+                },
+                "in2": {
+                    "type": "user/single_integer/1"
+                }
+            },
+            "outputs": {
+                "out": {
+                    "type": "user/single_integer/1"
+                }
+            }
+        }
+    ]
+}
\ No newline at end of file

beat/backend/python/test/prefix/algorithms/legacy/prepare/1.py

+#!/usr/bin/env python
+# vim: set fileencoding=utf-8 :
+
+###############################################################################
+#                                                                             #
+# Copyright (c) 2016 Idiap Research Institute, http://www.idiap.ch/           #
+# Contact: beat.support@idiap.ch                                              #
+#                                                                             #
+# This file is part of the beat.backend.python module of the BEAT platform.   #
+#                                                                             #
+# Commercial License Usage                                                    #
+# Licensees holding valid commercial BEAT licenses may use this file in       #
+# accordance with the terms contained in a written agreement between you      #
+# and Idiap. For further information contact tto@idiap.ch                     #
+#                                                                             #
+# Alternatively, this file may be used under the terms of the GNU Affero      #
+# Public License version 3 as published by the Free Software and appearing    #
+# in the file LICENSE.AGPL included in the packaging of this file.            #
+# The BEAT platform is distributed in the hope that it will be useful, but    #
+# WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY  #
+# or FITNESS FOR A PARTICULAR PURPOSE.                                        #
+#                                                                             #
+# You should have received a copy of the GNU Affero Public License along      #
+# with the BEAT platform. If not, see http://www.gnu.org/licenses/.           #
+#                                                                             #
+###############################################################################
+
+class Algorithm:
+
+    def setup(self, parameters):
+        self.sync = parameters['sync']
+        return True
+
+    def prepare(self):
+    	return True
+
+    def process(self, inputs, outputs):
+        if inputs[self.sync].isDataUnitDone():
+            outputs['out'].write({
+                'value': inputs['in1'].data.value + inputs['in2'].data.value,
+            })
+
+        return True

beat/backend/python/test/test_algorithm.py

@@ -31,6 +31,8 @@ import six
 import os
 import glob
 import tempfile
+import logging
+
 import numpy as np
 
 from ..algorithm import Algorithm
@@ -47,6 +49,8 @@ from ..outputs import OutputList
 from ..outputs import SynchronizationListener
 
 from .mocks import MockDataSink
+from .mocks import MockLoggingHandler
+
 from . import prefix
 
 
@@ -451,6 +455,23 @@ class TestLegacyAPI_Prepare(unittest.TestCase):
         self.assertTrue(runnable.prepared)
 
 
+    def test_prepare_warning(self):
+        log_handler = MockLoggingHandler(level='DEBUG')
+        logging.getLogger().addHandler(log_handler)
+        log_messages = log_handler.messages
+
+        algorithm = Algorithm(prefix, 'legacy/prepare/1')
+        self.assertTrue(algorithm.valid)
+
+        runnable = algorithm.runner()
+        self.assertTrue(runnable.prepared)
+        self.assertTrue(runnable.prepare(DataLoaderList()))
+        self.assertTrue(runnable.prepared)
+
+        info_len = len(log_messages['warning'])
+        self.assertEqual(info_len, 1)
+        self.assertEqual(log_messages['warning'][info_len - 1], 'Prepare is a reserved function name starting with API V2')
+
 #----------------------------------------------------------