[test][prefix][algorithms] Add loop/loop user algorithms for input test

These two algorithm allow for better testing of a complete
experiment with a database used for input of both loop and
loop user algorithm.

beat/core/test/prefix/algorithms/user/db_input_loop/1.json

+{
+    "schema_version": 3,
+    "language": "python",
+    "api_version": 2,
+    "type": "loop",
+    "groups": [
+        {
+            "inputs": {
+                "in": {
+                    "type": "user/single_integer/1"
+                }
+            },
+            "loop": {
+                "request": {
+                    "type": "user/single_integer/1"
+                },
+                "answer": {
+                    "type": "user/single_integer/1"
+                }
+            }
+        }
+    ],
+    "parameters": {
+        "threshold": {
+            "default": "9",
+            "type": "int8",
+            "description": "Value that will change loop result"
+        }
+    }
+}

beat/core/test/prefix/algorithms/user/db_input_loop/1.py

+#!/usr/bin/env python
+# vim: set fileencoding=utf-8 :
+
+###############################################################################
+#                                                                             #
+# Copyright (c) 2018 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/.           #
+#                                                                             #
+###############################################################################
+
+import numpy as np
+
+class Algorithm:
+
+    def __init__(self):
+        self.threshold = None
+        self.max = 0
+
+    def setup(self, parameters):
+        self.threshold = parameters['threshold']
+        return True
+
+    def prepare(self, data_loaders):
+        data_loader = data_loaders.loaderOf('in')
+
+        for i in range(data_loader.count()):
+            view = data_loader.view('in', i)
+            (data, _, _) = view[view.count() - 1]
+            value = data['in'].value
+            self.max += value
+
+        return True
+
+    def validate(self, result):
+        value = result.value
+        result = value > self.threshold and value < self.max
+        delta = self.max - value
+        return (result, {'value': np.int32(delta)})

beat/core/test/prefix/algorithms/user/db_input_loop_user/1.json

+{
+    "schema_version": 3,
+    "language": "python",
+    "api_version": 2,
+    "type": "loop_user",
+    "splittable": false,
+    "parameters": {
+
+    },
+    "groups": [
+        {
+            "inputs": {
+                "in": {
+                    "type": "user/single_integer/1"
+                }
+            },
+            "outputs": {
+                "out": {
+                    "type": "user/single_integer/1"
+                }
+            },
+            "loop": {
+                "request": {
+                    "type": "user/single_integer/1"
+                },
+                "answer": {
+                    "type": "user/single_integer/1"
+                }
+            }
+        }
+    ]
+}

beat/core/test/prefix/algorithms/user/db_input_loop_user/1.py

+#!/usr/bin/env python
+# vim: set fileencoding=utf-8 :
+
+###############################################################################
+#                                                                             #
+# Copyright (c) 2018 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/.           #
+#                                                                             #
+###############################################################################
+import numpy as np
+
+class Algorithm:
+
+    def process(self, data_loaders, outputs, loop_channel):
+        cnt = 1
+        is_valid, delta = loop_channel.validate({'value': np.int32(cnt)})
+        while not is_valid:
+            cnt = cnt + 1
+            is_valid, delta = loop_channel.validate({'value': np.int32(cnt)})
+
+        delta = delta.value
+
+        data_loader = data_loaders.loaderOf('in')
+
+        for i in range(data_loader.count()):
+            view = data_loader.view('in', i)
+            (data, _, end) = view[view.count() - 1]
+            value = data['in'].value
+            new_value = (value + cnt) * delta
+            outputs['out'].write({
+                    'value': np.int32(new_value),
+                },
+                end
+            )
+
+        return True