HistorySQLite.read_node_history() - Code Metrics - Inspection of "Events History with Tests" - FreeOpcUa/python-opcua - Measure and Improve Code Quality continuously with Scrutinizer

Completed

Pull Request — master (#180)

unknown

created 2016-05-10 00:49 UTC

HistorySQLite.read_node_history() F

↳ Parent: HistorySQLite

Complexity

Conditions

Size

Total Lines

Duplication

Lines	0
Ratio	0 %

Code Coverage

Tests	34
CRAP Score	12.0247

Importance

Changes	3
Bugs	0	Features	0

Metric	Value
cc	12
c	3
b	0
f	0
dl	0
loc	54
ccs	34
cts	36
cp	0.9444
crap	12.0247
rs	3.5428

How to fix Long Method Complexity

import logging
from datetime import timedelta
from datetime import datetime
from threading import Lock
from opcua import ua
from opcua.common.utils import Buffer
from opcua.server.history import HistoryStorageInterface
import sqlite3


class HistorySQLite(HistoryStorageInterface):
    """
    very minimal history backend storing data in SQLite database
    """

    def __init__(self, path="history.db"):
        self.logger = logging.getLogger(__name__)
        self._datachanges_period = {}
        self._db_file = path
        self._lock = Lock()
        self._event_fields = {}

        self._conn = sqlite3.connect(self._db_file, detect_types=sqlite3.PARSE_DECLTYPES, check_same_thread=False)

    def new_historized_node(self, node_id, period, count=0):

        with self._lock:
            _c_new = self._conn.cursor()

            table = self._get_table_name(node_id)

            self._datachanges_period[node_id] = period, count

            # create a table for the node which will store attributes of the DataValue object
            # note: Value/VariantType TEXT is only for human reading, the actual data is stored in VariantBinary column
            try:
                _c_new.execute('CREATE TABLE "{tn}" (_Id INTEGER PRIMARY KEY NOT NULL,'
                               ' ServerTimestamp TIMESTAMP,'
                               ' SourceTimestamp TIMESTAMP,'
                               ' StatusCode INTEGER,'
                               ' Value TEXT,'
                               ' VariantType TEXT,'
                               ' VariantBinary BLOB)'.format(tn=table))

            except sqlite3.Error as e:
                self.logger.info('Historizing SQL Table Creation Error for %s: %s', node_id, e)

            self._conn.commit()

    def save_node_value(self, node_id, datavalue):
        with self._lock:
            _c_sub = self._conn.cursor()

            table = self._get_table_name(node_id)

            # insert the data change into the database
            try:
                _c_sub.execute('INSERT INTO "{tn}" VALUES (NULL, ?, ?, ?, ?, ?, ?)'.format(tn=table),
                               (
                                   datavalue.ServerTimestamp,
                                   datavalue.SourceTimestamp,
                                   datavalue.StatusCode.value,
                                   str(datavalue.Value.Value),
                                   datavalue.Value.VariantType.name,
                                   datavalue.Value.to_binary()
                               )
                               )
            except sqlite3.Error as e:
                self.logger.error('Historizing SQL Insert Error for %s: %s', node_id, e)

            self._conn.commit()

            # get this node's period from the period dict and calculate the limit
            period, count = self._datachanges_period[node_id]

            if period:
                # after the insert, if a period was specified delete all records older than period
                date_limit = datetime.now() - period

                try:
                    _c_sub.execute('DELETE FROM "{tn}" WHERE ServerTimestamp < ?'.format(tn=table),
                                   (date_limit.isoformat(' '),))
                except sqlite3.Error as e:
                    self.logger.error('Historizing SQL Delete Old Data Error for %s: %s', node_id, e)

                self._conn.commit()

    def read_node_history(self, node_id, start, end, nb_values):
        with self._lock:
            _c_read = self._conn.cursor()

            order = "ASC"

            if start is None or start == ua.DateTimeMinValue:
                order = "DESC"
                start = ua.DateTimeMinValue

            if end is None or end == ua.DateTimeMinValue:
                end = datetime.utcnow() + timedelta(days=1)

            if start < end:
                start_time = start.isoformat(' ')
                end_time = end.isoformat(' ')
            else:
                order = "DESC"
                start_time = end.isoformat(' ')
                end_time = start.isoformat(' ')

            if nb_values:
                limit = nb_values + 1  # add 1 to the number of values for retrieving a continuation point
            else:
                limit = -1  # in SQLite a LIMIT of -1 returns all results

            table = self._get_table_name(node_id)

            cont = None
            results = []

            # select values from the database; recreate UA Variant from binary
            try:
                for row in _c_read.execute('SELECT * FROM "{tn}" WHERE "ServerTimestamp" BETWEEN ? AND ? '
                                           'ORDER BY "_Id" {dir} LIMIT ?'.format(tn=table, dir=order), (start_time, end_time, limit,)):

                    # rebuild the data value object
                    dv = ua.DataValue(ua.Variant.from_binary(Buffer(row[6])))
                    dv.ServerTimestamp = row[1]
                    dv.SourceTimestamp = row[2]
                    dv.StatusCode = ua.StatusCode(row[3])

                    results.append(dv)

            except sqlite3.Error as e:
                self.logger.error('Historizing SQL Read Error for %s: %s', node_id, e)

            if nb_values:
                if len(results) > nb_values:
                    cont = results[nb_values].ServerTimestamp

                results = results[:nb_values]

            return results, cont

    def new_historized_event(self, source_id, ev_fields, period):

        with self._lock:
            _c_new = self._conn.cursor()

            self._datachanges_period[source_id] = period
            self._event_fields[source_id] = ev_fields

            table = self._get_table_name(source_id)
            columns = self._get_event_columns(ev_fields)

            # create a table for the event which will store fields generated by the source object's events
            # note that _Timestamp is for SQL query, _EventTypeName is for debugging, be careful not to create event
            # properties with these names
            try:
                _c_new.execute('CREATE TABLE "{tn}" (_Id INTEGER PRIMARY KEY NOT NULL, '
                               '_Timestamp TIMESTAMP, '
                               '_EventTypeName TEXT, '
                               '{co})'.format(tn=table, co=columns))

            except sqlite3.Error as e:
                self.logger.info('Historizing SQL Table Creation Error for events from %s: %s', source_id, e)

            self._conn.commit()

    def save_event(self, event):
        with self._lock:
            _c_sub = self._conn.cursor()

            table = self._get_table_name(event.SourceNode)
            columns, placeholders, evtup = self._format_event(event)
            event_type = event.EventType  # useful for troubleshooting database

            # insert the event into the database
            try:
                _c_sub.execute('INSERT INTO "{tn}" ("_Id", "_Timestamp", "_EventTypeName", {co}) '
                               'VALUES (NULL, "{ts}", "{et}", {pl})'.format(tn=table, co=columns, ts=event.Time, et=event_type, pl=placeholders), evtup)

            except sqlite3.Error as e:
                self.logger.error('Historizing SQL Insert Error for events from %s: %s', event.SourceNode, e)

            self._conn.commit()

            # get this node's period from the period dict and calculate the limit
            period = self._datachanges_period[event.SourceNode]

            if period:
                # after the insert, if a period was specified delete all records older than period
                date_limit = datetime.now() - period

                try:
                    _c_sub.execute('DELETE FROM "{tn}" WHERE Time < ?'.format(tn=table),
                                   (date_limit.isoformat(' '),))
                except sqlite3.Error as e:
                    self.logger.error('Historizing SQL Delete Old Data Error for events from %s: %s', event.SourceNode, e)

                self._conn.commit()

    def read_event_history(self, source_id, start, end, nb_values, evfilter):
        with self._lock:

            _c_read = self._conn.cursor()

            order = "ASC"

            if start is None or start == ua.DateTimeMinValue:
                order = "DESC"
                start = ua.DateTimeMinValue

            if end is None or end == ua.DateTimeMinValue:
                end = datetime.utcnow() + timedelta(days=1)

            if start < end:
                start_time = start.isoformat(' ')
                end_time = end.isoformat(' ')
            else:
                order = "DESC"
                start_time = end.isoformat(' ')
                end_time = start.isoformat(' ')

            if nb_values:
                limit = nb_values + 1  # add 1 to the number of values for retrieving a continuation point
            else:
                limit = -1  # in SQLite a LIMIT of -1 returns all results

            table = self._get_table_name(source_id)
            clauses = self._get_select_clauses(source_id, evfilter)

            cont = None
            cont_timestamps = []
            results = []

            # select events from the database; SQL select clause is built from EventFilter and available fields
            try:
                for row in _c_read.execute('SELECT "_Timestamp", {cl} FROM "{tn}" WHERE "_Timestamp" BETWEEN ? AND ? '
                                           'ORDER BY "_Id" {dir} LIMIT ?'.format(cl=clauses, tn=table, dir=order),
                                           (start_time, end_time, limit,)):

                    # place all the variants in the event field list object
                    hist_ev_field_list = ua.HistoryEventFieldList()
                    i = 0
                    for field in row:
                        # if the field is the _Timestamp column store it in a list used for getting the continuation
                        if i == 0:
                            cont_timestamps.append(field)
                        else:
                            if field is not None:
                                hist_ev_field_list.EventFields.append(ua.Variant.from_binary(Buffer(field)))
                            else:
                                hist_ev_field_list.EventFields.append(ua.Variant(None))
                        i += 1

                    results.append(hist_ev_field_list)

            except sqlite3.Error as e:
                self.logger.error('Historizing SQL Read Error events for node %s: %s', source_id, e)

            if nb_values:
                if len(results) > nb_values:  # start > ua.DateTimeMinValue and
                    cont = cont_timestamps[nb_values]

                results = results[:nb_values]

            return results, cont

    def _get_table_name(self, node_id):
        return str(node_id.NamespaceIndex) + '_' + str(node_id.Identifier)

    def _format_event(self, event_result):
        placeholders = []
        ev_fields = []
        ev_variant_binaries = []

        ev_variant_dict = event_result.get_event_props_as_field_dict()

        # split dict into two synchronized lists which will be converted to SQL strings
        # note that the variants are converted to binary objects for storing in SQL BLOB format
        for field, variant in ev_variant_dict.items():
            placeholders.append('?')
            ev_fields.append(field)
            ev_variant_binaries.append(variant.to_binary())

        return self._list_to_sql_str(ev_fields), self._list_to_sql_str(placeholders, False), tuple(ev_variant_binaries)

    def _get_event_columns(self, ev_fields):
        fields = []
        for field in ev_fields:
                fields.append(field + ' BLOB')
        return self._list_to_sql_str(fields, False)

    def _get_select_clauses(self, source_id, evfilter):
        s_clauses = []
        for select_clause in evfilter.SelectClauses:
            try:
                if not select_clause.BrowsePath:
                    s_clauses.append(select_clause.Attribute.name)
                else:
                    name = select_clause.BrowsePath[0].Name
                    s_clauses.append(name)
            except AttributeError:
                self.logger.error('Historizing SQL OPC UA Select Clauses Error for node %s', source_id)

        # remove select clauses that the event type doesn't have; SQL will error because the column doesn't exist
        clauses = [x for x in s_clauses if self._check(source_id, x)]

        return self._list_to_sql_str(clauses)

    def _check(self, source_id, s_clause):
        if s_clause in self._event_fields[source_id]:
            return True
        else:
            return False

    def _list_to_sql_str(self, ls, quotes=True):
        sql_str = ''
        for item in ls:
            if quotes:
                sql_str += '"' + item + '", '
            else:
                sql_str += item + ', '
        return sql_str[:-2]  # remove trailing space and comma for SQL syntax

    def stop(self):
        with self._lock:
            self._conn.close()
            self.logger.info('Historizing SQL connection closed')


1	1		import logging
2	1		from datetime import timedelta
3	1		from datetime import datetime
4	1		from threading import Lock
5	1		from opcua import ua
6	1		from opcua.common.utils import Buffer
7	1		from opcua.server.history import HistoryStorageInterface
8	1		import sqlite3
9
10
11	1		class HistorySQLite(HistoryStorageInterface):
12			"""
13			very minimal history backend storing data in SQLite database
14			"""
15
16	1		def __init__(self, path="history.db"):
17	1		self.logger = logging.getLogger(__name__)
18	1		self._datachanges_period = {}
19	1		self._db_file = path
20	1		self._lock = Lock()
21	1		self._event_fields = {}
22
23	1		self._conn = sqlite3.connect(self._db_file, detect_types=sqlite3.PARSE_DECLTYPES, check_same_thread=False)
24
25	1	View Code Duplication	def new_historized_node(self, node_id, period, count=0):
			0 ignored issues – show Duplication introduced 2016-04-30 06:41 UTC by Report Bug Copy Issue Report This code seems to be duplicated in your project. Loading history...
26	1		with self._lock:
27	1		_c_new = self._conn.cursor()
28
29	1		table = self._get_table_name(node_id)
30
31	1		self._datachanges_period[node_id] = period, count
32
33			# create a table for the node which will store attributes of the DataValue object
34			# note: Value/VariantType TEXT is only for human reading, the actual data is stored in VariantBinary column
35	1		try:
36	1		_c_new.execute('CREATE TABLE "{tn}" (_Id INTEGER PRIMARY KEY NOT NULL,'
37			' ServerTimestamp TIMESTAMP,'
38			' SourceTimestamp TIMESTAMP,'
39			' StatusCode INTEGER,'
40			' Value TEXT,'
41			' VariantType TEXT,'
42			' VariantBinary BLOB)'.format(tn=table))
43
44			except sqlite3.Error as e:
45			self.logger.info('Historizing SQL Table Creation Error for %s: %s', node_id, e)
46
47	1		self._conn.commit()
48
49	1		def save_node_value(self, node_id, datavalue):
50	1		with self._lock:
51	1		_c_sub = self._conn.cursor()
52
53	1		table = self._get_table_name(node_id)
54
55			# insert the data change into the database
56	1		try:
57	1		_c_sub.execute('INSERT INTO "{tn}" VALUES (NULL, ?, ?, ?, ?, ?, ?)'.format(tn=table),
58			(
59			datavalue.ServerTimestamp,
60			datavalue.SourceTimestamp,
61			datavalue.StatusCode.value,
62			str(datavalue.Value.Value),
63			datavalue.Value.VariantType.name,
64			datavalue.Value.to_binary()
65			)
66			)
67			except sqlite3.Error as e:
68			self.logger.error('Historizing SQL Insert Error for %s: %s', node_id, e)
69
70	1		self._conn.commit()
71
72			# get this node's period from the period dict and calculate the limit
73	1		period, count = self._datachanges_period[node_id]
74
75	1		if period:
76			# after the insert, if a period was specified delete all records older than period
77			date_limit = datetime.now() - period
78
79			try:
80			_c_sub.execute('DELETE FROM "{tn}" WHERE ServerTimestamp < ?'.format(tn=table),
81			(date_limit.isoformat(' '),))
82			except sqlite3.Error as e:
83			self.logger.error('Historizing SQL Delete Old Data Error for %s: %s', node_id, e)
84
85			self._conn.commit()
86
87	1		def read_node_history(self, node_id, start, end, nb_values):
88	1		with self._lock:
89	1		_c_read = self._conn.cursor()
90
91	1		order = "ASC"
92
93	1		if start is None or start == ua.DateTimeMinValue:
94	1		order = "DESC"
95	1		start = ua.DateTimeMinValue
96
97	1		if end is None or end == ua.DateTimeMinValue:
98	1		end = datetime.utcnow() + timedelta(days=1)
99
100	1		if start < end:
101	1		start_time = start.isoformat(' ')
102	1		end_time = end.isoformat(' ')
103			else:
104	1		order = "DESC"
105	1		start_time = end.isoformat(' ')
106	1		end_time = start.isoformat(' ')
107
108	1		if nb_values:
109	1		limit = nb_values + 1 # add 1 to the number of values for retrieving a continuation point
110			else:
111	1		limit = -1 # in SQLite a LIMIT of -1 returns all results
112
113	1		table = self._get_table_name(node_id)
114
115	1		cont = None
116	1		results = []
117
118			# select values from the database; recreate UA Variant from binary
119	1		try:
120	1		for row in _c_read.execute('SELECT * FROM "{tn}" WHERE "ServerTimestamp" BETWEEN ? AND ? '
121			'ORDER BY "_Id" {dir} LIMIT ?'.format(tn=table, dir=order), (start_time, end_time, limit,)):
122	1
123	1		# rebuild the data value object
124	1		dv = ua.DataValue(ua.Variant.from_binary(Buffer(row[6])))
125	1		dv.ServerTimestamp = row[1]
126			dv.SourceTimestamp = row[2]
127	1		dv.StatusCode = ua.StatusCode(row[3])
128
129			results.append(dv)
130
131			except sqlite3.Error as e:
132	1		self.logger.error('Historizing SQL Read Error for %s: %s', node_id, e)
133	1
134	1		if nb_values:
135			if len(results) > nb_values:
136	1		cont = results[nb_values].ServerTimestamp
137
138	1		results = results[:nb_values]
139
140	1		return results, cont
141
142		View Code Duplication	def new_historized_event(self, source_id, ev_fields, period):
			0 ignored issues – show Duplication introduced 2016-04-30 06:41 UTC by Report Bug Copy Issue Report This code seems to be duplicated in your project. Loading history...
143	1		with self._lock:
144			_c_new = self._conn.cursor()
145
146	1		self._datachanges_period[source_id] = period
147			self._event_fields[source_id] = ev_fields
148
149	1		table = self._get_table_name(source_id)
150	1		columns = self._get_event_columns(ev_fields)
151
152	1		# create a table for the event which will store fields generated by the source object's events
153	1		# note that _Timestamp is for SQL query, _EventTypeName is for debugging, be careful not to create event
154	1		# properties with these names
155			try:
156			_c_new.execute('CREATE TABLE "{tn}" (_Id INTEGER PRIMARY KEY NOT NULL, '
157			'_Timestamp TIMESTAMP, '
158			'_EventTypeName TEXT, '
159			'{co})'.format(tn=table, co=columns))
160
161			except sqlite3.Error as e:
162			self.logger.info('Historizing SQL Table Creation Error for events from %s: %s', source_id, e)
163
164			self._conn.commit()
165
166			def save_event(self, event):
167			with self._lock:
168			_c_sub = self._conn.cursor()
169
170			table = self._get_table_name(event.SourceNode)
171			columns, placeholders, evtup = self._format_event(event)
172			event_type = event.EventType # useful for troubleshooting database
173
174			# insert the event into the database
175			try:
176			_c_sub.execute('INSERT INTO "{tn}" ("_Id", "_Timestamp", "_EventTypeName", {co}) '
177			'VALUES (NULL, "{ts}", "{et}", {pl})'.format(tn=table, co=columns, ts=event.Time, et=event_type, pl=placeholders), evtup)
178
179			except sqlite3.Error as e:
180			self.logger.error('Historizing SQL Insert Error for events from %s: %s', event.SourceNode, e)
181
182			self._conn.commit()
183
184			# get this node's period from the period dict and calculate the limit
185			period = self._datachanges_period[event.SourceNode]
186
187			if period:
188			# after the insert, if a period was specified delete all records older than period
189			date_limit = datetime.now() - period
190
191			try:
192			_c_sub.execute('DELETE FROM "{tn}" WHERE Time < ?'.format(tn=table),
193			(date_limit.isoformat(' '),))
194			except sqlite3.Error as e:
195			self.logger.error('Historizing SQL Delete Old Data Error for events from %s: %s', event.SourceNode, e)
196
197			self._conn.commit()
198
199			def read_event_history(self, source_id, start, end, nb_values, evfilter):
200			with self._lock:
201
202			_c_read = self._conn.cursor()
203
204			order = "ASC"
205
206			if start is None or start == ua.DateTimeMinValue:
207			order = "DESC"
208			start = ua.DateTimeMinValue
209
210			if end is None or end == ua.DateTimeMinValue:
211			end = datetime.utcnow() + timedelta(days=1)
212
213			if start < end:
214			start_time = start.isoformat(' ')
215			end_time = end.isoformat(' ')
216			else:
217			order = "DESC"
218			start_time = end.isoformat(' ')
219			end_time = start.isoformat(' ')
220
221			if nb_values:
222			limit = nb_values + 1 # add 1 to the number of values for retrieving a continuation point
223			else:
224			limit = -1 # in SQLite a LIMIT of -1 returns all results
225
226			table = self._get_table_name(source_id)
227			clauses = self._get_select_clauses(source_id, evfilter)
228
229			cont = None
230			cont_timestamps = []
231			results = []
232
233			# select events from the database; SQL select clause is built from EventFilter and available fields
234			try:
235			for row in _c_read.execute('SELECT "_Timestamp", {cl} FROM "{tn}" WHERE "_Timestamp" BETWEEN ? AND ? '
236			'ORDER BY "_Id" {dir} LIMIT ?'.format(cl=clauses, tn=table, dir=order),
237			(start_time, end_time, limit,)):
238
239			# place all the variants in the event field list object
240			hist_ev_field_list = ua.HistoryEventFieldList()
241			i = 0
242			for field in row:
243			# if the field is the _Timestamp column store it in a list used for getting the continuation
244			if i == 0:
245			cont_timestamps.append(field)
246			else:
247			if field is not None:
248			hist_ev_field_list.EventFields.append(ua.Variant.from_binary(Buffer(field)))
249			else:
250			hist_ev_field_list.EventFields.append(ua.Variant(None))
251			i += 1
252
253			results.append(hist_ev_field_list)
254
255			except sqlite3.Error as e:
256			self.logger.error('Historizing SQL Read Error events for node %s: %s', source_id, e)
257
258			if nb_values:
259			if len(results) > nb_values: # start > ua.DateTimeMinValue and
260			cont = cont_timestamps[nb_values]
261
262			results = results[:nb_values]
263
264			return results, cont
265
266			def _get_table_name(self, node_id):
267			return str(node_id.NamespaceIndex) + '_' + str(node_id.Identifier)
268
269			def _format_event(self, event_result):
270			placeholders = []
271			ev_fields = []
272			ev_variant_binaries = []
273
274			ev_variant_dict = event_result.get_event_props_as_field_dict()
275
276			# split dict into two synchronized lists which will be converted to SQL strings
277			# note that the variants are converted to binary objects for storing in SQL BLOB format
278			for field, variant in ev_variant_dict.items():
279			placeholders.append('?')
280			ev_fields.append(field)
281			ev_variant_binaries.append(variant.to_binary())
282
283			return self._list_to_sql_str(ev_fields), self._list_to_sql_str(placeholders, False), tuple(ev_variant_binaries)
284
285			def _get_event_columns(self, ev_fields):
286			fields = []
287			for field in ev_fields:
288			fields.append(field + ' BLOB')
289			return self._list_to_sql_str(fields, False)
290
291			def _get_select_clauses(self, source_id, evfilter):
292			s_clauses = []
293			for select_clause in evfilter.SelectClauses:
294			try:
295			if not select_clause.BrowsePath:
296			s_clauses.append(select_clause.Attribute.name)
297			else:
298			name = select_clause.BrowsePath[0].Name
299			s_clauses.append(name)
300			except AttributeError:
301			self.logger.error('Historizing SQL OPC UA Select Clauses Error for node %s', source_id)
302
303			# remove select clauses that the event type doesn't have; SQL will error because the column doesn't exist
304			clauses = [x for x in s_clauses if self._check(source_id, x)]
305
306			return self._list_to_sql_str(clauses)
307
308			def _check(self, source_id, s_clause):
309			if s_clause in self._event_fields[source_id]:
310			return True
311			else:
312			return False
313
314			def _list_to_sql_str(self, ls, quotes=True):
315			sql_str = ''
316			for item in ls:
317			if quotes:
318			sql_str += '"' + item + '", '
319			else:
320			sql_str += item + ', '
321			return sql_str[:-2] # remove trailing space and comma for SQL syntax
322
323			def stop(self):
324			with self._lock:
325			self._conn.close()
326			self.logger.info('Historizing SQL connection closed')
327

FreeOpcUa / python-opcua

Pull Request — master (#180)

HistorySQLite.read_node_history() F

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