VOL-1395: Common shared libraries needed for Python based device adapters.

This is an initial check-in of code from the master branch.  Additional work
is expected on a few items to work with the new go-core and will be covered
by separate JIRAs and commits.

Change-Id: I0856ec6b79b8d3e49082c609eb9c7eedd75b1708
diff --git a/python/adapters/extensions/omci/database/mib_db_dict.py b/python/adapters/extensions/omci/database/mib_db_dict.py
new file mode 100644
index 0000000..6a7de8f
--- /dev/null
+++ b/python/adapters/extensions/omci/database/mib_db_dict.py
@@ -0,0 +1,524 @@
+#
+# Copyright 2017 the original author or authors.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#      http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+#
+import copy
+from mib_db_api import *
+import json
+
+
+class MibDbVolatileDict(MibDbApi):
+    """
+    A very simple in-memory database for ME storage. Data is not persistent
+    across reboots.
+
+    In Phase 2, this DB will be instantiated on a per-ONU basis but act as if
+    it is shared for all ONUs. This class will be updated with and external
+    key-value store (or other appropriate database) in Voltha 1.3 Sprint 3
+
+    This class can be used for unit tests
+    """
+    CURRENT_VERSION = 1
+
+    def __init__(self, omci_agent):
+        """
+        Class initializer
+        :param omci_agent: (OpenOMCIAgent) OpenOMCI Agent
+        """
+        super(MibDbVolatileDict, self).__init__(omci_agent)
+        self._data = dict()   # device_id -> ME ID -> Inst ID -> Attr Name -> Values
+
+    def start(self):
+        """
+        Start up/restore the database. For in-memory, will be a nop. For external
+        DB, may need to create the DB and fetch create/modified values
+        """
+        super(MibDbVolatileDict, self).start()
+        # TODO: Delete this method if nothing else is done except calling the base class
+
+    def stop(self):
+        """
+        Start up the database. For in-memory, will be a nop. For external
+        DB, may need to create the DB and fetch create/modified values
+        """
+        super(MibDbVolatileDict, self).stop()
+        # TODO: Delete this method if nothing else is done except calling the base class
+
+    def add(self, device_id, overwrite=False):
+        """
+        Add a new ONU to database
+
+        :param device_id: (str) Device ID of ONU to add
+        :param overwrite: (bool) Overwrite existing entry if found.
+
+        :raises KeyError: If device already exist and 'overwrite' is False
+        """
+        self.log.debug('add-device', device_id=device_id, overwrite=overwrite)
+
+        if not isinstance(device_id, basestring):
+            raise TypeError('Device ID should be an string')
+
+        if not self._started:
+            raise DatabaseStateError('The Database is not currently active')
+
+        if not overwrite and device_id in self._data:
+            raise KeyError('Device {} already exists in the database'
+                           .format(device_id))
+
+        now = datetime.utcnow()
+        self._data[device_id] = {
+            DEVICE_ID_KEY: device_id,
+            CREATED_KEY: now,
+            LAST_SYNC_KEY: None,
+            MDS_KEY: 0,
+            VERSION_KEY: MibDbVolatileDict.CURRENT_VERSION,
+            ME_KEY: dict(),
+            MSG_TYPE_KEY: set()
+        }
+
+    def remove(self, device_id):
+        """
+        Remove an ONU from the database
+
+        :param device_id: (str) Device ID of ONU to remove from database
+        """
+        self.log.debug('remove-device', device_id=device_id)
+
+        if not isinstance(device_id, basestring):
+            raise TypeError('Device ID should be an string')
+
+        if not self._started:
+            raise DatabaseStateError('The Database is not currently active')
+
+        if device_id in self._data:
+            del self._data[device_id]
+            self._modified = datetime.utcnow()
+
+    def on_mib_reset(self, device_id):
+        """
+        Reset/clear the database for a specific Device
+
+        :param device_id: (str) ONU Device ID
+        :raises DatabaseStateError: If the database is not enabled
+        :raises KeyError: If the device does not exist in the database
+        """
+        if not self._started:
+            raise DatabaseStateError('The Database is not currently active')
+
+        if not isinstance(device_id, basestring):
+            raise TypeError('Device ID should be an string')
+
+        device_db = self._data[device_id]
+        self._modified = datetime.utcnow()
+
+        self._data[device_id] = {
+            DEVICE_ID_KEY: device_id,
+            CREATED_KEY: device_db[CREATED_KEY],
+            LAST_SYNC_KEY: device_db[LAST_SYNC_KEY],
+            MDS_KEY: 0,
+            VERSION_KEY: MibDbVolatileDict.CURRENT_VERSION,
+            ME_KEY: device_db[ME_KEY],
+            MSG_TYPE_KEY: device_db[MSG_TYPE_KEY]
+        }
+
+    def save_mib_data_sync(self, device_id, value):
+        """
+        Save the MIB Data Sync to the database in an easy location to access
+
+        :param device_id: (str) ONU Device ID
+        :param value: (int) Value to save
+        """
+        if not isinstance(device_id, basestring):
+            raise TypeError('Device ID should be an string')
+
+        if not isinstance(value, int):
+            raise TypeError('MIB Data Sync is an integer')
+
+        if not 0 <= value <= 255:
+            raise ValueError('Invalid MIB-data-sync value {}.  Must be 0..255'.
+                             format(value))
+
+        self._data[device_id][MDS_KEY] = value
+        self._modified = datetime.utcnow()
+
+    def get_mib_data_sync(self, device_id):
+        """
+        Get the MIB Data Sync value last saved to the database for a device
+
+        :param device_id: (str) ONU Device ID
+        :return: (int) The Value or None if not found
+        """
+        if not isinstance(device_id, basestring):
+            raise TypeError('Device ID should be an string')
+
+        if device_id not in self._data:
+            return None
+
+        return self._data[device_id].get(MDS_KEY)
+
+    def save_last_sync(self, device_id, value):
+        """
+        Save the Last Sync time to the database in an easy location to access
+
+        :param device_id: (str) ONU Device ID
+        :param value: (DateTime) Value to save
+        """
+        if not isinstance(device_id, basestring):
+            raise TypeError('Device ID should be an string')
+
+        if not isinstance(value, datetime):
+            raise TypeError('Expected a datetime object, got {}'.
+                            format(type(datetime)))
+
+        self._data[device_id][LAST_SYNC_KEY] = value
+        self._modified = datetime.utcnow()
+
+    def get_last_sync(self, device_id):
+        """
+        Get the Last SYnc Time saved to the database for a device
+
+        :param device_id: (str) ONU Device ID
+        :return: (int) The Value or None if not found
+        """
+        if not isinstance(device_id, basestring):
+            raise TypeError('Device ID should be an string')
+
+        if device_id not in self._data:
+            return None
+
+        return self._data[device_id].get(LAST_SYNC_KEY)
+
+    def set(self, device_id, class_id, instance_id, attributes):
+        """
+        Set a database value.  This should only be called by the MIB synchronizer
+        and its related tasks
+
+        :param device_id: (str) ONU Device ID
+        :param class_id: (int) ME Class ID
+        :param instance_id: (int) ME Entity ID
+        :param attributes: (dict) Attribute dictionary
+
+        :returns: (bool) True if the value was saved to the database. False if the
+                         value was identical to the current instance
+
+        :raises KeyError: If device does not exist
+        :raises DatabaseStateError: If the database is not enabled
+        """
+        if not isinstance(device_id, basestring):
+            raise TypeError('Device ID should be a string')
+
+        if not 0 <= class_id <= 0xFFFF:
+            raise ValueError("Invalid Class ID: {}, should be 0..65535".format(class_id))
+
+        if not 0 <= instance_id <= 0xFFFF:
+            raise ValueError("Invalid Instance ID: {}, should be 0..65535".format(instance_id))
+
+        if not isinstance(attributes, dict):
+            raise TypeError("Attributes should be a dictionary")
+
+        if not self._started:
+            raise DatabaseStateError('The Database is not currently active')
+
+        now = datetime.utcnow()
+        try:
+            device_db = self._data[device_id]
+            class_db = device_db.get(class_id)
+            created = False
+
+            if class_db is None:
+                device_db[class_id] = {CLASS_ID_KEY: class_id}
+
+                class_db = device_db[class_id]
+                self._modified = now
+                created = True
+
+            instance_db = class_db.get(instance_id)
+            if instance_db is None:
+                class_db[instance_id] = {
+                    INSTANCE_ID_KEY: instance_id,
+                    CREATED_KEY: now,
+                    MODIFIED_KEY: now,
+                    ATTRIBUTES_KEY: dict()
+                }
+                instance_db = class_db[instance_id]
+                self._modified = now
+                created = True
+
+            changed = False
+
+            me_map = self._omci_agent.get_device(device_id).me_map
+            entity = me_map.get(class_id)
+
+            for attribute, value in attributes.items():
+                assert isinstance(attribute, basestring)
+                assert value is not None, "Attribute '{}' value cannot be 'None'".\
+                    format(attribute)
+
+                db_value = instance_db[ATTRIBUTES_KEY].get(attribute) \
+                    if ATTRIBUTES_KEY in instance_db else None
+
+                if entity is not None and isinstance(value, basestring):
+                    from scapy.fields import StrFixedLenField
+                    attr_index = entity.attribute_name_to_index_map[attribute]
+                    eca = entity.attributes[attr_index]
+                    field = eca.field
+
+                    if isinstance(field, StrFixedLenField):
+                        from scapy.base_classes import Packet_metaclass
+                        if isinstance(field.default, Packet_metaclass) \
+                                and hasattr(field.default, 'json_from_value'):
+                            # Value/hex of Packet Class to string
+                            value = field.default.json_from_value(value)
+
+                if entity is not None and attribute in entity.attribute_name_to_index_map:
+                    attr_index = entity.attribute_name_to_index_map[attribute]
+                    eca = entity.attributes[attr_index]
+                    field = eca.field
+
+                    if hasattr(field, 'to_json'):
+                        value = field.to_json(value, db_value)
+
+                # Complex packet types may have an attribute encoded as an object, this
+                # can be check by seeing if there is a to_json() conversion callable
+                # defined
+                if hasattr(value, 'to_json'):
+                    value = value.to_json()
+
+                # Other complex packet types may be a repeated list field (FieldListField)
+                elif isinstance(value, (list, dict)):
+                    value = json.dumps(value, separators=(',', ':'))
+
+                assert db_value is None or isinstance(value, type(db_value)), \
+                    "New value type for attribute '{}' type is changing from '{}' to '{}'".\
+                    format(attribute, type(db_value), type(value))
+
+                if db_value is None or db_value != value:
+                    instance_db[ATTRIBUTES_KEY][attribute] = value
+                    changed = True
+
+            if changed:
+                instance_db[MODIFIED_KEY] = now
+                self._modified = now
+
+            return changed or created
+
+        except Exception as e:
+            self.log.error('set-failure', e=e, class_id=class_id,
+                           instance_id=instance_id, attributes=attributes)
+            raise
+
+    def delete(self, device_id, class_id, instance_id):
+        """
+        Delete an entity from the database if it exists.  If all instances
+        of a class are deleted, the class is deleted as well.
+
+        :param device_id: (str) ONU Device ID
+        :param class_id: (int) ME Class ID
+        :param instance_id: (int) ME Entity ID
+
+        :returns: (bool) True if the instance was found and deleted. False
+                         if it did not exist.
+
+        :raises KeyError: If device does not exist
+        :raises DatabaseStateError: If the database is not enabled
+        """
+        if not self._started:
+            raise DatabaseStateError('The Database is not currently active')
+
+        if not isinstance(device_id, basestring):
+            raise TypeError('Device ID should be an string')
+
+        if not 0 <= class_id <= 0xFFFF:
+            raise ValueError('class-id is 0..0xFFFF')
+
+        if not 0 <= instance_id <= 0xFFFF:
+            raise ValueError('instance-id is 0..0xFFFF')
+
+        try:
+            device_db = self._data[device_id]
+            class_db = device_db.get(class_id)
+
+            if class_db is None:
+                return False
+
+            instance_db = class_db.get(instance_id)
+            if instance_db is None:
+                return False
+
+            now = datetime.utcnow()
+            del class_db[instance_id]
+
+            if len(class_db) == 1:      # Is only 'CLASS_ID_KEY' remaining
+                del device_db[class_id]
+
+            self._modified = now
+            return True
+
+        except Exception as e:
+            self.log.error('delete-failure', e=e)
+            raise
+
+    def query(self, device_id, class_id=None, instance_id=None, attributes=None):
+        """
+        Get database information.
+
+        This method can be used to request information from the database to the detailed
+        level requested
+
+        :param device_id: (str) ONU Device ID
+        :param class_id:  (int) Managed Entity class ID
+        :param instance_id: (int) Managed Entity instance
+        :param attributes: (list/set or str) Managed Entity instance's attributes
+
+        :return: (dict) The value(s) requested. If class/inst/attribute is
+                        not found, an empty dictionary is returned
+        :raises KeyError: If the requested device does not exist
+        :raises DatabaseStateError: If the database is not enabled
+        """
+        self.log.debug('query', device_id=device_id, class_id=class_id,
+                       instance_id=instance_id, attributes=attributes)
+
+        if not self._started:
+            raise DatabaseStateError('The Database is not currently active')
+
+        if not isinstance(device_id, basestring):
+            raise TypeError('Device ID is a string')
+
+        device_db = self._data[device_id]
+        if class_id is None:
+            return self._fix_dev_json_attributes(copy.copy(device_db), device_id)
+
+        if not isinstance(class_id, int):
+            raise TypeError('Class ID is an integer')
+
+        me_map = self._omci_agent.get_device(device_id).me_map
+        entity = me_map.get(class_id)
+
+        class_db = device_db.get(class_id, dict())
+        if instance_id is None or len(class_db) == 0:
+            return self._fix_cls_json_attributes(copy.copy(class_db), entity)
+
+        if not isinstance(instance_id, int):
+            raise TypeError('Instance ID is an integer')
+
+        instance_db = class_db.get(instance_id, dict())
+        if attributes is None or len(instance_db) == 0:
+            return self._fix_inst_json_attributes(copy.copy(instance_db), entity)
+
+        if not isinstance(attributes, (basestring, list, set)):
+            raise TypeError('Attributes should be a string or list/set of strings')
+
+        if not isinstance(attributes, (list, set)):
+            attributes = [attributes]
+
+        results = {attr: val for attr, val in instance_db[ATTRIBUTES_KEY].iteritems()
+                   if attr in attributes}
+
+        for attr, attr_data in results.items():
+            attr_index = entity.attribute_name_to_index_map[attr]
+            eca = entity.attributes[attr_index]
+            results[attr] = self._fix_attr_json_attribute(copy.copy(attr_data), eca)
+
+        return results
+
+    #########################################################################
+    # Following routines are used to fix-up JSON encoded complex data. A
+    # nice side effect is that the values returned will be a deep-copy of
+    # the class/instance/attribute data of what is in the database. Note
+    # That other database values (created, modified, ...) will still reference
+    # back to the original DB.
+
+    def _fix_dev_json_attributes(self, dev_data, device_id):
+        for cls_id, cls_data in dev_data.items():
+            if isinstance(cls_id, int):
+                me_map = self._omci_agent.get_device(device_id).me_map
+                entity = me_map.get(cls_id)
+                dev_data[cls_id] = self._fix_cls_json_attributes(copy.copy(cls_data), entity)
+        return dev_data
+
+    def _fix_cls_json_attributes(self, cls_data, entity):
+        for inst_id, inst_data in cls_data.items():
+            if isinstance(inst_id, int):
+                cls_data[inst_id] = self._fix_inst_json_attributes(copy.copy(inst_data), entity)
+        return cls_data
+
+    def _fix_inst_json_attributes(self, inst_data, entity):
+        if ATTRIBUTES_KEY in inst_data:
+            for attr, attr_data in inst_data[ATTRIBUTES_KEY].items():
+                attr_index = entity.attribute_name_to_index_map[attr] \
+                    if entity is not None and attr in entity.attribute_name_to_index_map else None
+                eca = entity.attributes[attr_index] if attr_index is not None else None
+                inst_data[ATTRIBUTES_KEY][attr] = self._fix_attr_json_attribute(copy.copy(attr_data), eca)
+        return inst_data
+
+    def _fix_attr_json_attribute(self, attr_data, eca):
+
+        try:
+            if eca is not None:
+                field = eca.field
+                if hasattr(field, 'load_json'):
+                    value = field.load_json(attr_data)
+                    return value
+
+            return json.loads(attr_data) if isinstance(attr_data, basestring) else attr_data
+
+        except ValueError:
+            return attr_data
+
+        except Exception as e:
+            pass
+
+    def update_supported_managed_entities(self, device_id, managed_entities):
+        """
+        Update the supported OMCI Managed Entities for this device
+
+        :param device_id: (str) ONU Device ID
+        :param managed_entities: (set) Managed Entity class IDs
+        """
+        now = datetime.utcnow()
+        try:
+            device_db = self._data[device_id]
+
+            entities = {class_id: self._managed_entity_to_name(device_id, class_id)
+                        for class_id in managed_entities}
+
+            device_db[ME_KEY] = entities
+            self._modified = now
+
+        except Exception as e:
+            self.log.error('set-me-failure', e=e)
+            raise
+
+    def _managed_entity_to_name(self, device_id, class_id):
+        me_map = self._omci_agent.get_device(device_id).me_map
+        entity = me_map.get(class_id)
+
+        return entity.__name__ if entity is not None else 'UnknownManagedEntity'
+
+    def update_supported_message_types(self, device_id, msg_types):
+        """
+        Update the supported OMCI Managed Entities for this device
+
+        :param device_id: (str) ONU Device ID
+        :param msg_types: (set) Message Type values (ints)
+        """
+        now = datetime.utcnow()
+        try:
+            msg_type_set = {msg_type.value for msg_type in msg_types}
+            self._data[device_id][MSG_TYPE_KEY] = msg_type_set
+            self._modified = now
+
+        except Exception as e:
+            self.log.error('set-me-failure', e=e)
+            raise