|
1
|
|
|
""" |
|
2
|
|
|
MyEMS Normalization Service - Virtual Point Processing Module |
|
3
|
|
|
|
|
4
|
|
|
This module handles the calculation of virtual point values using mathematical expressions. |
|
5
|
|
|
Virtual points are computed points that derive their values from combinations of other points |
|
6
|
|
|
(analog points, digital points, and other virtual points) using algebraic equations and piecewise functions. |
|
7
|
|
|
|
|
8
|
|
|
The virtual point processing performs the following functions: |
|
9
|
|
|
1. Retrieves all virtual points and their mathematical expressions from the system database |
|
10
|
|
|
2. Uses multiprocessing to process virtual points in parallel for efficiency |
|
11
|
|
|
3. Parses mathematical expressions and identifies dependent points |
|
12
|
|
|
4. Retrieves latest values from dependent points in the historical database |
|
13
|
|
|
5. Evaluates mathematical expressions using SymPy library |
|
14
|
|
|
6. Stores calculated virtual point values in the historical database |
|
15
|
|
|
|
|
16
|
|
|
Key features: |
|
17
|
|
|
- Supports complex mathematical expressions with multiple variables |
|
18
|
|
|
- Handles different point types (analog, digital, virtual) in expressions |
|
19
|
|
|
- Uses SymPy for robust mathematical expression evaluation including piecewise functions |
|
20
|
|
|
- Maintains data integrity through comprehensive error handling |
|
21
|
|
|
- Processes virtual points continuously to provide real-time calculated values |
|
22
|
|
|
""" |
|
23
|
|
|
|
|
24
|
|
|
import json |
|
25
|
|
|
import random |
|
26
|
|
|
import re |
|
27
|
|
|
import time |
|
28
|
|
|
from datetime import datetime |
|
29
|
|
|
from decimal import Decimal |
|
30
|
|
|
from multiprocessing import Pool |
|
31
|
|
|
import mysql.connector |
|
32
|
|
|
from sympy import sympify, Piecewise, symbols, parse_expr |
|
33
|
|
|
import config |
|
34
|
|
|
|
|
35
|
|
|
# Security configuration: Maximum number of datetime points to process in one batch |
|
36
|
|
|
MAX_DATETIME_POINTS = 100000 |
|
37
|
|
|
|
|
38
|
|
|
# Maximum expression length to prevent DoS attacks |
|
39
|
|
|
MAX_EXPRESSION_LENGTH = 10000 |
|
40
|
|
|
|
|
41
|
|
|
# Maximum number of substitutions to prevent DoS attacks |
|
42
|
|
|
MAX_SUBSTITUTIONS = 100 |
|
43
|
|
|
|
|
44
|
|
|
|
|
45
|
|
|
######################################################################################################################## |
|
46
|
|
|
# Security Validation Functions |
|
47
|
|
|
######################################################################################################################## |
|
48
|
|
|
|
|
49
|
|
|
def validate_variable_name(name): |
|
50
|
|
|
""" |
|
51
|
|
|
Validate variable name to ensure it follows safe identifier rules. |
|
52
|
|
|
|
|
53
|
|
|
Args: |
|
54
|
|
|
name: Variable name to validate |
|
55
|
|
|
|
|
56
|
|
|
Raises: |
|
57
|
|
|
ValueError: If variable name is invalid |
|
58
|
|
|
""" |
|
59
|
|
|
if not isinstance(name, str): |
|
60
|
|
|
raise ValueError(f"Variable name must be a string, got {type(name)}") |
|
61
|
|
|
if not re.match(r'^[a-zA-Z_][a-zA-Z0-9_]*$', name): |
|
62
|
|
|
raise ValueError(f"Invalid variable name: {name}. Must start with letter or underscore and contain only alphanumeric characters and underscores.") |
|
63
|
|
|
|
|
64
|
|
|
|
|
65
|
|
|
def validate_point_id(point_id): |
|
66
|
|
|
""" |
|
67
|
|
|
Validate point_id to ensure it is a positive integer. |
|
68
|
|
|
|
|
69
|
|
|
Args: |
|
70
|
|
|
point_id: Point ID to validate |
|
71
|
|
|
|
|
72
|
|
|
Raises: |
|
73
|
|
|
ValueError: If point_id is invalid |
|
74
|
|
|
""" |
|
75
|
|
|
if not isinstance(point_id, int): |
|
76
|
|
|
# Try to convert if it's a numeric string |
|
77
|
|
|
try: |
|
78
|
|
|
point_id = int(point_id) |
|
79
|
|
|
except (ValueError, TypeError): |
|
80
|
|
|
raise ValueError(f"Invalid point_id: {point_id}. Must be an integer.") |
|
81
|
|
|
if point_id <= 0: |
|
82
|
|
|
raise ValueError(f"Invalid point_id: {point_id}. Must be a positive integer.") |
|
83
|
|
|
|
|
84
|
|
|
|
|
85
|
|
|
def validate_expression_safe(expression): |
|
86
|
|
|
""" |
|
87
|
|
|
Validate expression to ensure it doesn't contain dangerous patterns. |
|
88
|
|
|
|
|
89
|
|
|
Args: |
|
90
|
|
|
expression: Expression string to validate |
|
91
|
|
|
|
|
92
|
|
|
Raises: |
|
93
|
|
|
ValueError: If expression contains dangerous patterns |
|
94
|
|
|
""" |
|
95
|
|
|
if not isinstance(expression, str): |
|
96
|
|
|
raise ValueError(f"Expression must be a string, got {type(expression)}") |
|
97
|
|
|
|
|
98
|
|
|
if len(expression) > MAX_EXPRESSION_LENGTH: |
|
99
|
|
|
raise ValueError(f"Expression too long: {len(expression)} characters. Maximum allowed: {MAX_EXPRESSION_LENGTH}") |
|
100
|
|
|
|
|
101
|
|
|
# Check for dangerous patterns that could lead to code execution |
|
102
|
|
|
dangerous_patterns = [ |
|
103
|
|
|
(r'__\w+__', 'Double underscore pattern (magic methods)'), |
|
104
|
|
|
(r'import\s+', 'Import statement'), |
|
105
|
|
|
(r'exec\s*\(', 'exec() call'), |
|
106
|
|
|
(r'eval\s*\(', 'eval() call'), |
|
107
|
|
|
(r'open\s*\(', 'File open operation'), |
|
108
|
|
|
(r'file\s*\(', 'File operation'), |
|
109
|
|
|
(r'__import__', 'Direct __import__ call'), |
|
110
|
|
|
(r'compile\s*\(', 'compile() call'), |
|
111
|
|
|
(r'globals\s*\(', 'globals() call'), |
|
112
|
|
|
(r'locals\s*\(', 'locals() call'), |
|
113
|
|
|
] |
|
114
|
|
|
|
|
115
|
|
|
for pattern, description in dangerous_patterns: |
|
116
|
|
|
if re.search(pattern, expression, re.IGNORECASE): |
|
117
|
|
|
raise ValueError(f"Dangerous pattern detected in expression: {description}") |
|
118
|
|
|
|
|
119
|
|
|
|
|
120
|
|
|
def parse_piecewise_safe(expression, substitutions): |
|
121
|
|
|
""" |
|
122
|
|
|
Safely parse a piecewise function expression without using eval(). |
|
123
|
|
|
|
|
124
|
|
|
Piecewise format: "(value1, condition1), (value2, condition2), (default_value, True)" |
|
125
|
|
|
|
|
126
|
|
|
Args: |
|
127
|
|
|
expression: Piecewise function expression string |
|
128
|
|
|
substitutions: Dictionary mapping variable names to point IDs |
|
129
|
|
|
|
|
130
|
|
|
Returns: |
|
131
|
|
|
List of tuples (value_expr, condition_expr) for Piecewise construction |
|
132
|
|
|
|
|
133
|
|
|
Raises: |
|
134
|
|
|
ValueError: If expression cannot be safely parsed |
|
135
|
|
|
""" |
|
136
|
|
|
# Validate expression first |
|
137
|
|
|
validate_expression_safe(expression) |
|
138
|
|
|
|
|
139
|
|
|
# Parse the piecewise expression manually |
|
140
|
|
|
# Format: "(value, condition), (value, condition), ..." |
|
141
|
|
|
try: |
|
142
|
|
|
# Use regex to find all tuples: (value, condition) |
|
143
|
|
|
# Pattern matches: ( ... , ... ) where we need to find the comma that separates value from condition |
|
144
|
|
|
# This is complex because conditions may contain parentheses and commas |
|
145
|
|
|
# Strategy: Find matching parentheses pairs and split on commas outside of them |
|
146
|
|
|
|
|
147
|
|
|
piecewise_parts = [] |
|
148
|
|
|
expr = expression.strip() |
|
149
|
|
|
|
|
150
|
|
|
# Remove outer parentheses if present |
|
151
|
|
|
if expr.startswith('(') and expr.endswith(')'): |
|
152
|
|
|
# Check if it's a single tuple or multiple tuples |
|
153
|
|
|
# Count opening and closing parentheses |
|
154
|
|
|
depth = 0 |
|
155
|
|
|
for i, char in enumerate(expr): |
|
156
|
|
|
if char == '(': |
|
157
|
|
|
depth += 1 |
|
158
|
|
|
elif char == ')': |
|
159
|
|
|
depth -= 1 |
|
160
|
|
|
if depth == 0 and i < len(expr) - 1: |
|
161
|
|
|
# Found end of first tuple, there are multiple tuples |
|
162
|
|
|
break |
|
163
|
|
|
else: |
|
164
|
|
|
# Single tuple, remove outer parentheses |
|
165
|
|
|
expr = expr[1:-1] |
|
166
|
|
|
|
|
167
|
|
|
# Split by "), (" pattern to separate tuples |
|
168
|
|
|
# This pattern appears between tuples |
|
169
|
|
|
parts = re.split(r'\)\s*,\s*\(', expr) |
|
170
|
|
|
|
|
171
|
|
|
# Process each tuple part |
|
172
|
|
|
for part in parts: |
|
173
|
|
|
# Remove leading/trailing parentheses and whitespace |
|
174
|
|
|
part = part.strip().lstrip('(').rstrip(')') |
|
175
|
|
|
|
|
176
|
|
|
# Find the comma that separates value from condition |
|
177
|
|
|
# We need the rightmost comma that's not inside nested parentheses |
|
178
|
|
|
depth = 0 |
|
179
|
|
|
last_comma_pos = -1 |
|
180
|
|
|
for i, char in enumerate(part): |
|
181
|
|
|
if char == '(': |
|
182
|
|
|
depth += 1 |
|
183
|
|
|
elif char == ')': |
|
184
|
|
|
depth -= 1 |
|
185
|
|
|
elif char == ',' and depth == 0: |
|
186
|
|
|
last_comma_pos = i |
|
187
|
|
|
|
|
188
|
|
|
if last_comma_pos == -1: |
|
189
|
|
|
raise ValueError(f"Invalid piecewise tuple format: {part}. Missing comma separator.") |
|
190
|
|
|
|
|
191
|
|
|
value_str = part[:last_comma_pos].strip() |
|
192
|
|
|
condition_str = part[last_comma_pos+1:].strip() |
|
193
|
|
|
|
|
194
|
|
|
if not value_str or not condition_str: |
|
195
|
|
|
raise ValueError(f"Invalid piecewise tuple format: {part}. Empty value or condition.") |
|
196
|
|
|
|
|
197
|
|
|
# Parse value and condition using sympify (safe) |
|
198
|
|
|
value_expr = sympify(value_str) |
|
199
|
|
|
condition_expr = sympify(condition_str) |
|
200
|
|
|
|
|
201
|
|
|
piecewise_parts.append((value_expr, condition_expr)) |
|
202
|
|
|
|
|
203
|
|
|
if not piecewise_parts: |
|
204
|
|
|
raise ValueError("No valid piecewise parts found in expression") |
|
205
|
|
|
|
|
206
|
|
|
return piecewise_parts |
|
207
|
|
|
except Exception as e: |
|
208
|
|
|
raise ValueError(f"Failed to parse piecewise expression: {str(e)}") |
|
209
|
|
|
|
|
210
|
|
|
|
|
211
|
|
|
######################################################################################################################## |
|
212
|
|
|
# Virtual Point Calculation Procedures: |
|
213
|
|
|
# Step 1: Query all virtual points and their mathematical expressions from system database |
|
214
|
|
|
# Step 2: Create multiprocessing pool to call worker processes in parallel |
|
215
|
|
|
######################################################################################################################## |
|
216
|
|
|
|
|
217
|
|
View Code Duplication |
def calculate(logger): |
|
|
|
|
|
|
218
|
|
|
""" |
|
219
|
|
|
Main function for virtual point calculation using mathematical expressions. |
|
220
|
|
|
|
|
221
|
|
|
This function runs continuously, retrieving all virtual points from the system database |
|
222
|
|
|
and processing them in parallel to calculate virtual point values using their |
|
223
|
|
|
configured mathematical expressions. |
|
224
|
|
|
|
|
225
|
|
|
Args: |
|
226
|
|
|
logger: Logger instance for recording calculation activities and errors |
|
227
|
|
|
""" |
|
228
|
|
|
while True: |
|
229
|
|
|
# The outermost while loop to reconnect to server if there is a connection error |
|
230
|
|
|
cnx_system_db = None |
|
231
|
|
|
cursor_system_db = None |
|
232
|
|
|
|
|
233
|
|
|
# Connect to system database to retrieve virtual point configuration |
|
234
|
|
|
try: |
|
235
|
|
|
cnx_system_db = mysql.connector.connect(**config.myems_system_db) |
|
236
|
|
|
cursor_system_db = cnx_system_db.cursor() |
|
237
|
|
|
except Exception as e: |
|
238
|
|
|
logger.error("Error in step 0 of virtual point calculate " + str(e)) |
|
239
|
|
|
if cursor_system_db: |
|
240
|
|
|
cursor_system_db.close() |
|
241
|
|
|
if cnx_system_db: |
|
242
|
|
|
cnx_system_db.close() |
|
243
|
|
|
# Sleep and continue the outer loop to reconnect the database |
|
244
|
|
|
time.sleep(60) |
|
245
|
|
|
continue |
|
246
|
|
|
|
|
247
|
|
|
print("Connected to MyEMS System Database") |
|
248
|
|
|
|
|
249
|
|
|
# Retrieve all virtual points with their configuration data |
|
250
|
|
|
virtual_point_list = list() |
|
251
|
|
|
try: |
|
252
|
|
|
cursor_system_db.execute(" SELECT id, name, data_source_id, object_type, high_limit, low_limit, address " |
|
253
|
|
|
" FROM tbl_points " |
|
254
|
|
|
" WHERE is_virtual = 1 ") |
|
255
|
|
|
rows_virtual_points = cursor_system_db.fetchall() |
|
256
|
|
|
|
|
257
|
|
|
# Check if virtual points were found |
|
258
|
|
|
if rows_virtual_points is None or len(rows_virtual_points) == 0: |
|
259
|
|
|
# Sleep several minutes and continue the outer loop to reconnect the database |
|
260
|
|
|
time.sleep(60) |
|
261
|
|
|
continue |
|
262
|
|
|
|
|
263
|
|
|
# Build virtual point list with configuration data |
|
264
|
|
|
for row in rows_virtual_points: |
|
265
|
|
|
meta_result = {"id": row[0], |
|
266
|
|
|
"name": row[1], |
|
267
|
|
|
"data_source_id": row[2], |
|
268
|
|
|
"object_type": row[3], |
|
269
|
|
|
"high_limit": row[4], |
|
270
|
|
|
"low_limit": row[5], |
|
271
|
|
|
"address": row[6]} |
|
272
|
|
|
virtual_point_list.append(meta_result) |
|
273
|
|
|
|
|
274
|
|
|
except Exception as e: |
|
275
|
|
|
logger.error("Error in step 1 of virtual point calculate " + str(e)) |
|
276
|
|
|
# sleep and continue the outer loop to reconnect the database |
|
277
|
|
|
time.sleep(60) |
|
278
|
|
|
continue |
|
279
|
|
|
finally: |
|
280
|
|
|
if cursor_system_db: |
|
281
|
|
|
cursor_system_db.close() |
|
282
|
|
|
if cnx_system_db: |
|
283
|
|
|
cnx_system_db.close() |
|
284
|
|
|
|
|
285
|
|
|
# Shuffle the virtual point list for randomly calculating point values |
|
286
|
|
|
# This helps distribute processing load evenly across time |
|
287
|
|
|
random.shuffle(virtual_point_list) |
|
288
|
|
|
|
|
289
|
|
|
print("Got all virtual points in MyEMS System Database") |
|
290
|
|
|
################################################################################################################ |
|
291
|
|
|
# Step 2: Create multiprocessing pool to call worker processes in parallel |
|
292
|
|
|
################################################################################################################ |
|
293
|
|
|
# Create process pool with configured size for parallel processing |
|
294
|
|
|
p = Pool(processes=config.pool_size) |
|
295
|
|
|
error_list = p.map(worker, virtual_point_list) |
|
296
|
|
|
p.close() |
|
297
|
|
|
p.join() |
|
298
|
|
|
|
|
299
|
|
|
# Log any errors from worker processes |
|
300
|
|
|
for error in error_list: |
|
301
|
|
|
if error is not None and len(error) > 0: |
|
302
|
|
|
logger.error(error) |
|
303
|
|
|
|
|
304
|
|
|
print("go to sleep ") |
|
305
|
|
|
time.sleep(60) # Sleep for 1 minute before next processing cycle |
|
306
|
|
|
print("wake from sleep, and continue to work") |
|
307
|
|
|
|
|
308
|
|
|
|
|
309
|
|
|
######################################################################################################################## |
|
310
|
|
|
# Worker Process Procedures for Individual Virtual Point Processing: |
|
311
|
|
|
# Step 1: Get start datetime and end datetime for processing |
|
312
|
|
|
# Step 2: Parse the expression and get all points in substitutions |
|
313
|
|
|
# Step 3: Query points type from system database |
|
314
|
|
|
# Step 4: Query points value from historical database |
|
315
|
|
|
# Step 5: Evaluate the equation with points values and store results |
|
316
|
|
|
# Returns the error string for logging or returns None on success |
|
317
|
|
|
######################################################################################################################## |
|
318
|
|
|
|
|
319
|
|
|
def worker(virtual_point): |
|
320
|
|
|
""" |
|
321
|
|
|
Worker function to process a single virtual point's calculation. |
|
322
|
|
|
|
|
323
|
|
|
This function processes one virtual point at a time, evaluating its mathematical |
|
324
|
|
|
expression using data from dependent points and storing the calculated results. |
|
325
|
|
|
|
|
326
|
|
|
Args: |
|
327
|
|
|
virtual_point: Dictionary containing virtual point configuration (id, name, object_type, address, etc.) |
|
328
|
|
|
|
|
329
|
|
|
Returns: |
|
330
|
|
|
None on success, error string on failure |
|
331
|
|
|
""" |
|
332
|
|
|
cnx_historical_db = None |
|
333
|
|
|
cursor_historical_db = None |
|
334
|
|
|
|
|
335
|
|
|
# Connect to historical database to check existing processed data |
|
336
|
|
|
try: |
|
337
|
|
|
cnx_historical_db = mysql.connector.connect(**config.myems_historical_db) |
|
338
|
|
|
cursor_historical_db = cnx_historical_db.cursor() |
|
339
|
|
|
except Exception as e: |
|
340
|
|
|
if cursor_historical_db: |
|
341
|
|
|
cursor_historical_db.close() |
|
342
|
|
|
if cnx_historical_db: |
|
343
|
|
|
cnx_historical_db.close() |
|
344
|
|
|
# Return generic error message to avoid information disclosure |
|
345
|
|
|
return f"Error connecting to historical database for virtual point '{virtual_point['name']}': {type(e).__name__}" |
|
346
|
|
|
|
|
347
|
|
|
print("Start to process virtual point: " + "'" + virtual_point['name'] + "'") |
|
348
|
|
|
|
|
349
|
|
|
#################################################################################################################### |
|
350
|
|
|
# Step 1: Get start datetime and end datetime for processing |
|
351
|
|
|
#################################################################################################################### |
|
352
|
|
|
# Determine the appropriate table based on virtual point object type |
|
353
|
|
|
if virtual_point['object_type'] == 'ANALOG_VALUE': |
|
354
|
|
|
table_name = "tbl_analog_value" |
|
355
|
|
|
elif virtual_point['object_type'] == 'ENERGY_VALUE': |
|
356
|
|
|
table_name = "tbl_energy_value" |
|
357
|
|
|
else: |
|
358
|
|
|
if cursor_historical_db: |
|
359
|
|
|
cursor_historical_db.close() |
|
360
|
|
|
if cnx_historical_db: |
|
361
|
|
|
cnx_historical_db.close() |
|
362
|
|
|
return "variable point type should not be DIGITAL_VALUE " + " for '" + virtual_point['name'] + "'" |
|
363
|
|
|
|
|
364
|
|
|
try: |
|
365
|
|
|
query = (" SELECT MAX(utc_date_time) " |
|
366
|
|
|
" FROM " + table_name + |
|
367
|
|
|
" WHERE point_id = %s ") |
|
368
|
|
|
cursor_historical_db.execute(query, (virtual_point['id'],)) |
|
369
|
|
|
row = cursor_historical_db.fetchone() |
|
370
|
|
|
except Exception as e: |
|
371
|
|
|
if cursor_historical_db: |
|
372
|
|
|
cursor_historical_db.close() |
|
373
|
|
|
if cnx_historical_db: |
|
374
|
|
|
cnx_historical_db.close() |
|
375
|
|
|
# Return generic error message to avoid information disclosure |
|
376
|
|
|
return f"Error querying historical database for virtual point '{virtual_point['name']}': {type(e).__name__}" |
|
377
|
|
|
|
|
378
|
|
|
start_datetime_utc = datetime.strptime(config.start_datetime_utc, '%Y-%m-%d %H:%M:%S').replace(tzinfo=None) |
|
379
|
|
|
|
|
380
|
|
|
if row is not None and len(row) > 0 and isinstance(row[0], datetime): |
|
381
|
|
|
start_datetime_utc = row[0].replace(tzinfo=None) |
|
382
|
|
|
|
|
383
|
|
|
end_datetime_utc = datetime.utcnow().replace(tzinfo=None) |
|
384
|
|
|
|
|
385
|
|
|
if end_datetime_utc <= start_datetime_utc: |
|
386
|
|
|
if cursor_historical_db: |
|
387
|
|
|
cursor_historical_db.close() |
|
388
|
|
|
if cnx_historical_db: |
|
389
|
|
|
cnx_historical_db.close() |
|
390
|
|
|
return "it isn't time to calculate" + " for '" + virtual_point['name'] + "'" |
|
391
|
|
|
|
|
392
|
|
|
print("start_datetime_utc: " + start_datetime_utc.isoformat()[0:19] |
|
393
|
|
|
+ "end_datetime_utc: " + end_datetime_utc.isoformat()[0:19]) |
|
394
|
|
|
|
|
395
|
|
|
############################################################################################################ |
|
396
|
|
|
# Step 2: parse the expression and get all points in substitutions |
|
397
|
|
|
############################################################################################################ |
|
398
|
|
|
point_list = list() |
|
399
|
|
|
expression = None |
|
400
|
|
|
substitutions = None |
|
401
|
|
|
try: |
|
402
|
|
|
######################################################################################################## |
|
403
|
|
|
# parse the expression and get all points in substitutions |
|
404
|
|
|
######################################################################################################## |
|
405
|
|
|
address = json.loads(virtual_point['address']) |
|
406
|
|
|
# algebraic expression example: '{"expression": "x1-x2", "substitutions": {"x1":1,"x2":2}}' |
|
407
|
|
|
# piecewise function example: '{"expression":"(1,x<200 ), (2,x>=500), (0,True)", "substitutions":{"x":101}}' |
|
408
|
|
|
if 'expression' not in address.keys() \ |
|
409
|
|
|
or 'substitutions' not in address.keys() \ |
|
410
|
|
|
or len(address['expression']) == 0 \ |
|
411
|
|
|
or len(address['substitutions']) == 0: |
|
412
|
|
|
if cursor_historical_db: |
|
413
|
|
|
cursor_historical_db.close() |
|
414
|
|
|
if cnx_historical_db: |
|
415
|
|
|
cnx_historical_db.close() |
|
416
|
|
|
return "Error in step 2.1 of virtual point worker for '" + virtual_point['name'] + "'" |
|
417
|
|
|
|
|
418
|
|
|
expression = address['expression'] |
|
419
|
|
|
substitutions = address['substitutions'] |
|
420
|
|
|
|
|
421
|
|
|
# Security: Validate expression and substitutions |
|
422
|
|
|
try: |
|
423
|
|
|
validate_expression_safe(expression) |
|
424
|
|
|
except ValueError as e: |
|
425
|
|
|
if cursor_historical_db: |
|
426
|
|
|
cursor_historical_db.close() |
|
427
|
|
|
if cnx_historical_db: |
|
428
|
|
|
cnx_historical_db.close() |
|
429
|
|
|
return f"Error in step 2.1.1: Invalid expression for '{virtual_point['name']}': {str(e)}" |
|
430
|
|
|
|
|
431
|
|
|
# Security: Validate substitutions count |
|
432
|
|
|
if len(substitutions) > MAX_SUBSTITUTIONS: |
|
433
|
|
|
if cursor_historical_db: |
|
434
|
|
|
cursor_historical_db.close() |
|
435
|
|
|
if cnx_historical_db: |
|
436
|
|
|
cnx_historical_db.close() |
|
437
|
|
|
return f"Error in step 2.1.2: Too many substitutions ({len(substitutions)}) for '{virtual_point['name']}'" |
|
438
|
|
|
|
|
439
|
|
|
# Security: Validate variable names and point IDs |
|
440
|
|
|
for variable_name, point_id in substitutions.items(): |
|
441
|
|
|
try: |
|
442
|
|
|
validate_variable_name(variable_name) |
|
443
|
|
|
validate_point_id(point_id) |
|
444
|
|
|
except ValueError as e: |
|
445
|
|
|
if cursor_historical_db: |
|
446
|
|
|
cursor_historical_db.close() |
|
447
|
|
|
if cnx_historical_db: |
|
448
|
|
|
cnx_historical_db.close() |
|
449
|
|
|
return f"Error in step 2.1.3: Invalid variable or point_id for '{virtual_point['name']}': {str(e)}" |
|
450
|
|
|
point_list.append({"variable_name": variable_name, "point_id": point_id}) |
|
451
|
|
|
except json.JSONDecodeError as e: |
|
452
|
|
|
if cursor_historical_db: |
|
453
|
|
|
cursor_historical_db.close() |
|
454
|
|
|
if cnx_historical_db: |
|
455
|
|
|
cnx_historical_db.close() |
|
456
|
|
|
return "Error in step 2.2: Invalid JSON in address for '" + virtual_point['name'] + "'" |
|
457
|
|
|
except Exception as e: |
|
458
|
|
|
if cursor_historical_db: |
|
459
|
|
|
cursor_historical_db.close() |
|
460
|
|
|
if cnx_historical_db: |
|
461
|
|
|
cnx_historical_db.close() |
|
462
|
|
|
return "Error in step 2.2 of virtual point worker " + str(e) + " for '" + virtual_point['name'] + "'" |
|
463
|
|
|
|
|
464
|
|
|
############################################################################################################ |
|
465
|
|
|
# Step 3: query points type from system database |
|
466
|
|
|
############################################################################################################ |
|
467
|
|
|
print("getting points type ") |
|
468
|
|
|
cnx_system_db = None |
|
469
|
|
|
cursor_system_db = None |
|
470
|
|
|
try: |
|
471
|
|
|
cnx_system_db = mysql.connector.connect(**config.myems_system_db) |
|
472
|
|
|
cursor_system_db = cnx_system_db.cursor() |
|
473
|
|
|
except Exception as e: |
|
474
|
|
|
if cursor_system_db: |
|
475
|
|
|
cursor_system_db.close() |
|
476
|
|
|
if cnx_system_db: |
|
477
|
|
|
cnx_system_db.close() |
|
478
|
|
|
print("Error in step 3 of virtual point worker " + str(e)) |
|
479
|
|
|
# Return generic error message to avoid information disclosure |
|
480
|
|
|
return f"Error connecting to system database for virtual point '{virtual_point['name']}': {type(e).__name__}" |
|
481
|
|
|
|
|
482
|
|
|
print("Connected to MyEMS System Database") |
|
483
|
|
|
|
|
484
|
|
|
all_point_dict = dict() |
|
485
|
|
|
try: |
|
486
|
|
|
cursor_system_db.execute(" SELECT id, object_type " |
|
487
|
|
|
" FROM tbl_points ") |
|
488
|
|
|
rows_points = cursor_system_db.fetchall() |
|
489
|
|
|
|
|
490
|
|
|
if rows_points is None or len(rows_points) == 0: |
|
491
|
|
|
return f"Error: No points found in system database for virtual point '{virtual_point['name']}'" |
|
492
|
|
|
|
|
493
|
|
|
for row in rows_points: |
|
494
|
|
|
all_point_dict[row[0]] = row[1] |
|
495
|
|
|
except Exception as e: |
|
496
|
|
|
# Return generic error message to avoid information disclosure |
|
497
|
|
|
return f"Error querying points from system database for virtual point '{virtual_point['name']}': {type(e).__name__}" |
|
498
|
|
|
finally: |
|
499
|
|
|
if cursor_system_db: |
|
500
|
|
|
cursor_system_db.close() |
|
501
|
|
|
if cnx_system_db: |
|
502
|
|
|
cnx_system_db.close() |
|
503
|
|
|
############################################################################################################ |
|
504
|
|
|
# Step 4: query points value from historical database |
|
505
|
|
|
############################################################################################################ |
|
506
|
|
|
|
|
507
|
|
|
print("getting point values ") |
|
508
|
|
|
point_values_dict = dict() |
|
509
|
|
|
if point_list is not None and len(point_list) > 0: |
|
510
|
|
|
try: |
|
511
|
|
|
for point in point_list: |
|
512
|
|
|
point_object_type = all_point_dict.get(point['point_id']) |
|
513
|
|
|
if point_object_type is None: |
|
514
|
|
|
return "variable point type should not be None " + " for '" + virtual_point['name'] + "'" |
|
515
|
|
|
if point_object_type == 'ANALOG_VALUE': |
|
516
|
|
|
query = (" SELECT utc_date_time, actual_value " |
|
517
|
|
|
" FROM tbl_analog_value " |
|
518
|
|
|
" WHERE point_id = %s AND utc_date_time > %s AND utc_date_time < %s " |
|
519
|
|
|
" ORDER BY utc_date_time ") |
|
520
|
|
|
cursor_historical_db.execute(query, (point['point_id'], start_datetime_utc, end_datetime_utc,)) |
|
521
|
|
|
rows = cursor_historical_db.fetchall() |
|
522
|
|
|
if rows is not None and len(rows) > 0: |
|
523
|
|
|
point_values_dict[point['point_id']] = dict() |
|
524
|
|
|
for row in rows: |
|
525
|
|
|
point_values_dict[point['point_id']][row[0]] = row[1] |
|
526
|
|
|
elif point_object_type == 'ENERGY_VALUE': |
|
527
|
|
|
query = (" SELECT utc_date_time, actual_value " |
|
528
|
|
|
" FROM tbl_energy_value " |
|
529
|
|
|
" WHERE point_id = %s AND utc_date_time > %s AND utc_date_time < %s " |
|
530
|
|
|
" ORDER BY utc_date_time ") |
|
531
|
|
|
cursor_historical_db.execute(query, (point['point_id'], start_datetime_utc, end_datetime_utc,)) |
|
532
|
|
|
rows = cursor_historical_db.fetchall() |
|
533
|
|
|
if rows is not None and len(rows) > 0: |
|
534
|
|
|
point_values_dict[point['point_id']] = dict() |
|
535
|
|
|
for row in rows: |
|
536
|
|
|
point_values_dict[point['point_id']][row[0]] = row[1] |
|
537
|
|
|
else: |
|
538
|
|
|
point_values_dict[point['point_id']] = None |
|
539
|
|
|
else: |
|
540
|
|
|
# point type should not be DIGITAL_VALUE |
|
541
|
|
|
return "variable point type should not be DIGITAL_VALUE " + " for '" + virtual_point['name'] + "'" |
|
542
|
|
|
except Exception as e: |
|
543
|
|
|
if cursor_historical_db: |
|
544
|
|
|
cursor_historical_db.close() |
|
545
|
|
|
if cnx_historical_db: |
|
546
|
|
|
cnx_historical_db.close() |
|
547
|
|
|
# Return generic error message to avoid information disclosure |
|
548
|
|
|
return f"Error querying point values from historical database for virtual point '{virtual_point['name']}': {type(e).__name__}" |
|
549
|
|
|
|
|
550
|
|
|
############################################################################################################ |
|
551
|
|
|
# Step 5: evaluate the equation with points values |
|
552
|
|
|
############################################################################################################ |
|
553
|
|
|
|
|
554
|
|
|
print("getting date time set for all points") |
|
555
|
|
|
utc_date_time_set = set() |
|
556
|
|
|
if point_values_dict is not None and len(point_values_dict) > 0: |
|
557
|
|
|
for point_id, point_values in point_values_dict.items(): |
|
558
|
|
|
if point_values is not None and len(point_values) > 0: |
|
559
|
|
|
utc_date_time_set = utc_date_time_set.union(point_values.keys()) |
|
560
|
|
|
|
|
561
|
|
|
# Security: Resource limit check to prevent DoS attacks |
|
562
|
|
|
if len(utc_date_time_set) > MAX_DATETIME_POINTS: |
|
563
|
|
|
if cursor_historical_db: |
|
564
|
|
|
cursor_historical_db.close() |
|
565
|
|
|
if cnx_historical_db: |
|
566
|
|
|
cnx_historical_db.close() |
|
567
|
|
|
return f"Error: Too many datetime points to process ({len(utc_date_time_set)}) for '{virtual_point['name']}'. Maximum allowed: {MAX_DATETIME_POINTS}" |
|
568
|
|
|
|
|
569
|
|
|
print("evaluating the equation with SymPy") |
|
570
|
|
|
normalized_values = list() |
|
571
|
|
|
|
|
572
|
|
|
############################################################################################################ |
|
573
|
|
|
# Converting Strings to SymPy Expressions |
|
574
|
|
|
# The sympify function(that's sympify, not to be confused with simplify) can be used to |
|
575
|
|
|
# convert strings into SymPy expressions. |
|
576
|
|
|
# SECURITY FIX: Removed eval() and replaced with safe SymPy parsing |
|
577
|
|
|
############################################################################################################ |
|
578
|
|
|
try: |
|
579
|
|
|
# Security: Use safe parsing instead of eval() |
|
580
|
|
|
if re.search(',', expression): |
|
581
|
|
|
# Piecewise function: parse safely without eval() |
|
582
|
|
|
piecewise_parts = parse_piecewise_safe(expression, substitutions) |
|
583
|
|
|
expr = Piecewise(*piecewise_parts) |
|
584
|
|
|
print("the expression will be evaluated as piecewise function: " + str(expr)) |
|
585
|
|
|
else: |
|
586
|
|
|
# Algebraic expression: use sympify (safe) |
|
587
|
|
|
expr = sympify(expression) |
|
588
|
|
|
print("the expression will be evaluated as algebraic expression: " + str(expr)) |
|
589
|
|
|
|
|
590
|
|
|
for utc_date_time in utc_date_time_set: |
|
591
|
|
|
meta_data = dict() |
|
592
|
|
|
meta_data['utc_date_time'] = utc_date_time |
|
593
|
|
|
|
|
594
|
|
|
#################################################################################################### |
|
595
|
|
|
# create a dictionary of Symbol: point pairs |
|
596
|
|
|
#################################################################################################### |
|
597
|
|
|
|
|
598
|
|
|
subs = dict() |
|
599
|
|
|
|
|
600
|
|
|
#################################################################################################### |
|
601
|
|
|
# Evaluating the expression at current_datetime_utc |
|
602
|
|
|
#################################################################################################### |
|
603
|
|
|
|
|
604
|
|
|
if point_list is not None and len(point_list) > 0: |
|
605
|
|
|
for point in point_list: |
|
606
|
|
|
actual_value = point_values_dict[point['point_id']].get(utc_date_time, None) |
|
607
|
|
|
if actual_value is None: |
|
608
|
|
|
break |
|
609
|
|
|
subs[point['variable_name']] = actual_value |
|
610
|
|
|
|
|
611
|
|
|
if len(subs) != len(point_list): |
|
612
|
|
|
continue |
|
613
|
|
|
|
|
614
|
|
|
#################################################################################################### |
|
615
|
|
|
# To numerically evaluate an expression with a Symbol at a point, |
|
616
|
|
|
# we might use subs followed by evalf, |
|
617
|
|
|
# but it is more efficient and numerically stable to pass the substitution to evalf |
|
618
|
|
|
# using the subs flag, which takes a dictionary of Symbol: point pairs. |
|
619
|
|
|
#################################################################################################### |
|
620
|
|
|
# Note: expr is already a Piecewise object for piecewise functions, or a SymPy expression for algebraic |
|
621
|
|
|
if re.search(',', expression): |
|
622
|
|
|
# expr is already a Piecewise object |
|
623
|
|
|
meta_data['actual_value'] = Decimal(str(expr.subs(subs))) |
|
624
|
|
|
normalized_values.append(meta_data) |
|
625
|
|
|
else: |
|
626
|
|
|
# expr is a SymPy expression |
|
627
|
|
|
meta_data['actual_value'] = Decimal(str(expr.evalf(subs=subs))) |
|
628
|
|
|
normalized_values.append(meta_data) |
|
629
|
|
|
except Exception as e: |
|
630
|
|
|
if cursor_historical_db: |
|
631
|
|
|
cursor_historical_db.close() |
|
632
|
|
|
if cnx_historical_db: |
|
633
|
|
|
cnx_historical_db.close() |
|
634
|
|
|
# Return generic error message to avoid information disclosure |
|
635
|
|
|
# Detailed error information should be logged separately if logger is available |
|
636
|
|
|
return f"Error evaluating expression for virtual point '{virtual_point['name']}': {type(e).__name__}" |
|
637
|
|
|
|
|
638
|
|
|
print("saving virtual points values to historical database") |
|
639
|
|
|
|
|
640
|
|
|
if len(normalized_values) > 0: |
|
641
|
|
|
latest_meta_data = normalized_values[0] |
|
642
|
|
|
|
|
643
|
|
|
# Security: Use parameterized queries to prevent SQL injection |
|
644
|
|
|
# Validate table_name is from whitelist (already validated via object_type) |
|
645
|
|
|
if table_name not in ['tbl_analog_value', 'tbl_energy_value']: |
|
646
|
|
|
if cursor_historical_db: |
|
647
|
|
|
cursor_historical_db.close() |
|
648
|
|
|
if cnx_historical_db: |
|
649
|
|
|
cnx_historical_db.close() |
|
650
|
|
|
return f"Error: Invalid table name '{table_name}' for '{virtual_point['name']}'" |
|
651
|
|
|
|
|
652
|
|
|
insert_query = ("INSERT INTO " + table_name + |
|
653
|
|
|
" (point_id, utc_date_time, actual_value) VALUES (%s, %s, %s)") |
|
654
|
|
|
|
|
655
|
|
|
while len(normalized_values) > 0: |
|
656
|
|
|
insert_100 = normalized_values[:100] |
|
657
|
|
|
normalized_values = normalized_values[100:] |
|
658
|
|
|
|
|
659
|
|
|
try: |
|
660
|
|
|
# Security: Use executemany with parameterized query |
|
661
|
|
|
values = [] |
|
662
|
|
|
for meta_data in insert_100: |
|
663
|
|
|
values.append(( |
|
664
|
|
|
virtual_point['id'], |
|
665
|
|
|
meta_data['utc_date_time'], |
|
666
|
|
|
meta_data['actual_value'] |
|
667
|
|
|
)) |
|
668
|
|
|
if meta_data['utc_date_time'] > latest_meta_data['utc_date_time']: |
|
669
|
|
|
latest_meta_data = meta_data |
|
670
|
|
|
|
|
671
|
|
|
cursor_historical_db.executemany(insert_query, values) |
|
672
|
|
|
cnx_historical_db.commit() |
|
673
|
|
|
except Exception as e: |
|
674
|
|
|
if cursor_historical_db: |
|
675
|
|
|
cursor_historical_db.close() |
|
676
|
|
|
if cnx_historical_db: |
|
677
|
|
|
cnx_historical_db.close() |
|
678
|
|
|
# Return generic error message to avoid information disclosure |
|
679
|
|
|
return f"Error saving calculated values to database for virtual point '{virtual_point['name']}': {type(e).__name__}" |
|
680
|
|
|
|
|
681
|
|
|
try: |
|
682
|
|
|
# Security: Use parameterized query for delete operation |
|
683
|
|
|
delete_query = "DELETE FROM " + table_name + "_latest WHERE point_id = %s" |
|
684
|
|
|
cursor_historical_db.execute(delete_query, (virtual_point['id'],)) |
|
685
|
|
|
cnx_historical_db.commit() |
|
686
|
|
|
|
|
687
|
|
|
# Security: Use parameterized query for insert operation |
|
688
|
|
|
insert_latest_query = ("INSERT INTO " + table_name + "_latest " + |
|
689
|
|
|
"(point_id, utc_date_time, actual_value) VALUES (%s, %s, %s)") |
|
690
|
|
|
cursor_historical_db.execute(insert_latest_query, ( |
|
691
|
|
|
virtual_point['id'], |
|
692
|
|
|
latest_meta_data['utc_date_time'], |
|
693
|
|
|
latest_meta_data['actual_value'] |
|
694
|
|
|
)) |
|
695
|
|
|
cnx_historical_db.commit() |
|
696
|
|
|
except Exception as e: |
|
697
|
|
|
if cursor_historical_db: |
|
698
|
|
|
cursor_historical_db.close() |
|
699
|
|
|
if cnx_historical_db: |
|
700
|
|
|
cnx_historical_db.close() |
|
701
|
|
|
# Return generic error message to avoid information disclosure |
|
702
|
|
|
return f"Error updating latest value in database for virtual point '{virtual_point['name']}': {type(e).__name__}" |
|
703
|
|
|
|
|
704
|
|
|
if cursor_historical_db: |
|
705
|
|
|
cursor_historical_db.close() |
|
706
|
|
|
if cnx_historical_db: |
|
707
|
|
|
cnx_historical_db.close() |
|
708
|
|
|
|
|
709
|
|
|
return None |
|
710
|
|
|
|
MyEMS /
myems
Loading history...