File size: 19,065 Bytes
2cb9dec
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
# import logging
# from typing import Dict, List, Optional, AsyncGenerator
# from pydantic import BaseSettings, PostgresDsn
# import pg8000
# from pg8000 import Connection, Cursor
# from pg8000.exceptions import DatabaseError
# import asyncio
# from contextlib import asynccontextmanager
# from dataclasses import dataclass
# from threading import Lock

# # Set up structured logging
# logging.basicConfig(
#     level=logging.INFO, format="%(asctime)s - %(name)s - %(levelname)s - %(message)s"
# )
# logger = logging.getLogger(__name__)


# class DatabaseSettings(BaseSettings):
#     db_url: PostgresDsn
#     pool_size: int = 5

#     class Config:
#         env_file = ".env"


# @dataclass
# class DatabaseConfig:
#     username: str
#     password: str
#     hostname: str
#     port: int
#     database: str


# class DatabaseError(Exception):
#     """Custom exception for database errors."""

#     pass


# class Database:
#     def __init__(self, db_url: str, pool_size: int):
#         self.db_url = db_url
#         self.pool_size = pool_size
#         self.pool: List[Connection] = []
#         self.lock = Lock()
#         self.config = self._parse_db_url()

#     def _parse_db_url(self) -> DatabaseConfig:
#         """Parse the database URL into components."""
#         result = urlparse(self.db_url)
#         return DatabaseConfig(
#             username=result.username,
#             password=result.password,
#             hostname=result.hostname,
#             port=result.port or 5432,
#             database=result.path.lstrip("/"),
#         )

#     async def connect(self) -> None:
#         """Create a connection pool."""
#         try:
#             for _ in range(self.pool_size):
#                 conn = await self._create_connection()
#                 self.pool.append(conn)
#             logger.info(
#                 f"Database connection pool created with {self.pool_size} connections."
#             )
#         except DatabaseError as e:
#             logger.error(f"Failed to create database connection pool: {e}")
#             raise

#     async def _create_connection(self) -> Connection:
#         """Create a single database connection."""
#         try:
#             conn = pg8000.connect(
#                 user=self.config.username,
#                 password=self.config.password,
#                 host=self.config.hostname,
#                 port=self.config.port,
#                 database=self.config.database,
#             )
#             return conn
#         except DatabaseError as e:
#             logger.error(f"Failed to create database connection: {e}")
#             raise DatabaseError("Failed to create database connection.")

#     async def disconnect(self) -> None:
#         """Close all connections in the pool."""
#         with self.lock:
#             for conn in self.pool:
#                 conn.close()
#             self.pool.clear()
#             logger.info("Database connection pool closed.")

#     @asynccontextmanager
#     async def get_connection(self) -> AsyncGenerator[Connection, None]:
#         """Acquire a connection from the pool."""
#         with self.lock:
#             if not self.pool:
#                 raise DatabaseError("Database connection pool is empty.")
#             conn = self.pool.pop()
#         try:
#             yield conn
#         finally:
#             with self.lock:
#                 self.pool.append(conn)

#     async def fetch(self, query: str, *args) -> List[Dict]:
#         """
#         Execute a SELECT query and return the results as a list of dictionaries.

#         Args:
#             query (str): The SQL query to execute.
#             *args: Query parameters.

#         Returns:
#             List[Dict]: A list of dictionaries where keys are column names and values are column values.
#         """
#         try:
#             async with self.get_connection() as conn:
#                 cursor: Cursor = conn.cursor()
#                 cursor.execute(query, args)
#                 rows = cursor.fetchall()
#                 columns = [desc[0] for desc in cursor.description]
#                 return [dict(zip(columns, row)) for row in rows]
#         except DatabaseError as e:
#             logger.error(f"Error executing query: {query}. Error: {e}")
#             raise DatabaseError(f"Failed to execute query: {query}")

#     async def execute(self, query: str, *args) -> None:
#         """
#         Execute an INSERT, UPDATE, or DELETE query.

#         Args:
#             query (str): The SQL query to execute.
#             *args: Query parameters.
#         """
#         try:
#             async with self.get_connection() as conn:
#                 cursor: Cursor = conn.cursor()
#                 cursor.execute(query, args)
#                 conn.commit()
#         except DatabaseError as e:
#             logger.error(f"Error executing query: {query}. Error: {e}")
#             raise DatabaseError(f"Failed to execute query: {query}")


# # Dependency to get the database instance
# async def get_db() -> AsyncGenerator[Database, None]:
#     settings = DatabaseSettings()
#     db = Database(db_url=settings.db_url, pool_size=settings.pool_size)
#     await db.connect()
#     try:
#         yield db
#     finally:
#         await db.disconnect()


# # Example usage
# if __name__ == "__main__":

#     async def main():
#         settings = DatabaseSettings()
#         db = Database(db_url=settings.db_url, pool_size=settings.pool_size)
#         await db.connect()

#         try:
#             # Example query
#             query = """
# SELECT
#     ppt.type AS product_type,
#     pc.name AS product_category
# FROM
#     product_producttype ppt
# INNER JOIN
#     product_category pc
# ON
#     ppt.category_id = pc.id
# """
#             result = await db.fetch(query)
#             print(result)
#         finally:
#             await db.disconnect()

#     asyncio.run(main())

# import logging
# from urllib.parse import urlparse
# from typing import Dict, List, Optional, AsyncGenerator
# from pydantic_settings import BaseSettings
# from pydantic import PostgresDsn
# import pg8000
# from pg8000 import Connection, Cursor
# from pg8000.exceptions import DatabaseError
# import asyncio
# from contextlib import asynccontextmanager
# from dataclasses import dataclass
# from threading import Lock

# # Set up structured logging
# logging.basicConfig(
#     level=logging.INFO, format="%(asctime)s - %(name)s - %(levelname)s - %(message)s"
# )
# logger = logging.getLogger(__name__)


# class DatabaseSettings(BaseSettings):
#     db_url: PostgresDsn
#     pool_size: int = 5

#     class Config:
#         env_file = ".env"


# @dataclass
# class DatabaseConfig:
#     username: str
#     password: str
#     hostname: str
#     port: int
#     database: str


# class DatabaseError(Exception):
#     """Custom exception for database errors."""

#     pass


# class Database:
#     def __init__(self, db_url: str, pool_size: int):
#         self.db_url = db_url
#         self.pool_size = pool_size
#         self.pool: List[Connection] = []
#         self.lock = Lock()
#         self.config = self._parse_db_url()

#     def _parse_db_url(self) -> DatabaseConfig:
#         """Parse the database URL into components."""
#         # Convert PostgresDsn to a string
#         db_url_str = str(self.db_url)
#         result = urlparse(db_url_str)
#         return DatabaseConfig(
#             username=result.username,
#             password=result.password,
#             hostname=result.hostname,
#             port=result.port or 5432,
#             database=result.path.lstrip("/"),
#         )

#     async def connect(self) -> None:
#         """Create a connection pool."""
#         try:
#             for _ in range(self.pool_size):
#                 conn = await self._create_connection()
#                 self.pool.append(conn)
#             logger.info(
#                 f"Database connection pool created with {self.pool_size} connections."
#             )
#         except DatabaseError as e:
#             logger.error(f"Failed to create database connection pool: {e}")
#             raise

#     async def _create_connection(self) -> Connection:
#         """Create a single database connection."""
#         try:
#             conn = pg8000.connect(
#                 user=self.config.username,
#                 password=self.config.password,
#                 host=self.config.hostname,
#                 port=self.config.port,
#                 database=self.config.database,
#             )
#             return conn
#         except DatabaseError as e:
#             logger.error(f"Failed to create database connection: {e}")
#             raise DatabaseError("Failed to create database connection.")

#     async def disconnect(self) -> None:
#         """Close all connections in the pool."""
#         with self.lock:
#             for conn in self.pool:
#                 conn.close()
#             self.pool.clear()
#             logger.info("Database connection pool closed.")

#     @asynccontextmanager
#     async def get_connection(self) -> AsyncGenerator[Connection, None]:
#         """Acquire a connection from the pool."""
#         with self.lock:
#             if not self.pool:
#                 raise DatabaseError("Database connection pool is empty.")
#             conn = self.pool.pop()
#         try:
#             yield conn
#         finally:
#             with self.lock:
#                 self.pool.append(conn)

#     async def fetch(self, query: str, *args) -> List[Dict]:
#         """
#         Execute a SELECT query and return the results as a list of dictionaries.

#         Args:
#             query (str): The SQL query to execute.
#             *args: Query parameters.

#         Returns:
#             List[Dict]: A list of dictionaries where keys are column names and values are column values.
#         """
#         try:
#             async with self.get_connection() as conn:
#                 cursor: Cursor = conn.cursor()
#                 cursor.execute(query, args)
#                 rows = cursor.fetchall()
#                 columns = [desc[0] for desc in cursor.description]
#                 return [dict(zip(columns, row)) for row in rows]
#         except DatabaseError as e:
#             logger.error(f"Error executing query: {query}. Error: {e}")
#             raise DatabaseError(f"Failed to execute query: {query}")

#     async def execute(self, query: str, *args) -> None:
#         """
#         Execute an INSERT, UPDATE, or DELETE query.

#         Args:
#             query (str): The SQL query to execute.
#             *args: Query parameters.
#         """
#         try:
#             async with self.get_connection() as conn:
#                 cursor: Cursor = conn.cursor()
#                 cursor.execute(query, args)
#                 conn.commit()
#         except DatabaseError as e:
#             logger.error(f"Error executing query: {query}. Error: {e}")
#             raise DatabaseError(f"Failed to execute query: {query}")


# # Dependency to get the database instance
# async def get_db() -> AsyncGenerator[Database, None]:
#     settings = DatabaseSettings()
#     db = Database(db_url=settings.db_url, pool_size=settings.pool_size)
#     await db.connect()
#     try:
#         yield db
#     finally:
#         await db.disconnect()


# # Example usage
# if __name__ == "__main__":

#     async def main():
#         settings = DatabaseSettings()
#         db = Database(db_url=settings.db_url, pool_size=settings.pool_size)
#         await db.connect()

#         try:
#             # Example query
#             query = "SELECT * FROM your_table LIMIT 10"
#             query = """
# SELECT
#     ppt.type AS product_type,
#     pc.name AS product_category
# FROM
#     product_producttype ppt
# INNER JOIN
#     product_category pc
# ON
#     ppt.category_id = pc.id
# """
#             result = await db.fetch(query)
#             print(result)
#         finally:
#             await db.disconnect()

#     asyncio.run(main())

import logging
from typing import AsyncGenerator, List, Optional, Dict
from pydantic_settings import BaseSettings
from pydantic import PostgresDsn
import pg8000
from pg8000 import Connection
from pg8000.exceptions import DatabaseError as Pg8000DatabaseError
import asyncio
from contextlib import asynccontextmanager
from threading import Lock
from urllib.parse import urlparse

# Set up structured logging
logging.basicConfig(
    level=logging.INFO, format="%(asctime)s - %(name)s - %(levelname)s - %(message)s"
)
logger = logging.getLogger(__name__)


class DatabaseSettings(BaseSettings):
    db_url: PostgresDsn
    pool_size: int = 5  # Default pool size is 5

    class Config:
        env_file = ".env"


# Custom database errors
class DatabaseError(Exception):
    """Base exception for database errors."""

    pass


class ConnectionError(DatabaseError):
    """Exception raised when a database connection fails."""

    pass


class PoolExhaustedError(DatabaseError):
    """Exception raised when the connection pool is exhausted."""

    pass


class QueryExecutionError(DatabaseError):
    """Exception raised when a query execution fails."""

    pass


class HealthCheckError(DatabaseError):
    """Exception raised when a health check fails."""

    pass


class Database:
    def __init__(self, db_url: PostgresDsn, pool_size: int):
        self.db_url = db_url
        self.pool_size = pool_size
        self.pool: List[Connection] = []
        self.lock = Lock()

    async def connect(self) -> None:
        """Create a connection pool."""
        try:
            # Convert PostgresDsn to a string
            db_url_str = str(self.db_url)
            result = urlparse(db_url_str)
            for _ in range(self.pool_size):
                conn = pg8000.connect(
                    user=result.username,
                    password=result.password,
                    host=result.hostname,
                    port=result.port or 5432,
                    database=result.path.lstrip("/"),
                )
                self.pool.append(conn)
            logger.info(
                f"Database connection pool created with {self.pool_size} connections."
            )
        except Pg8000DatabaseError as e:
            logger.error(f"Failed to create database connection pool: {e}")
            raise ConnectionError("Failed to create database connection pool.") from e

    async def disconnect(self) -> None:
        """Close all connections in the pool."""
        with self.lock:
            for conn in self.pool:
                conn.close()
            self.pool.clear()
            logger.info("Database connection pool closed.")

    @asynccontextmanager
    async def get_connection(self) -> AsyncGenerator[Connection, None]:
        """Acquire a connection from the pool."""
        with self.lock:
            if not self.pool:
                logger.error("Connection pool is exhausted.")
                raise PoolExhaustedError("No available connections in the pool.")
            conn = self.pool.pop()
        try:
            yield conn
        except Pg8000DatabaseError as e:
            logger.error(f"Connection error: {e}")
            raise ConnectionError("Failed to use database connection.") from e
        finally:
            with self.lock:
                self.pool.append(conn)

    async def fetch(self, query: str, *args) -> List[Dict]:
        """
        Execute a SELECT query and return the results as a list of dictionaries.

        Args:
            query (str): The SQL query to execute.
            *args: Query parameters.

        Returns:
            List[Dict]: A list of dictionaries where keys are column names and values are column values.

        Raises:
            QueryExecutionError: If the query execution fails.
        """
        try:
            async with self.get_connection() as conn:
                cursor = conn.cursor()
                cursor.execute(query, args)
                rows = cursor.fetchall()
                columns = [desc[0] for desc in cursor.description]
                return [dict(zip(columns, row)) for row in rows]
        except Pg8000DatabaseError as e:
            logger.error(f"Query execution failed: {e}")
            raise QueryExecutionError(f"Failed to execute query: {query}") from e

    async def execute(self, query: str, *args) -> None:
        """
        Execute an INSERT, UPDATE, or DELETE query.

        Args:
            query (str): The SQL query to execute.
            *args: Query parameters.

        Raises:
            QueryExecutionError: If the query execution fails.
        """
        try:
            async with self.get_connection() as conn:
                cursor = conn.cursor()
                cursor.execute(query, args)
                conn.commit()
        except Pg8000DatabaseError as e:
            logger.error(f"Query execution failed: {e}")
            raise QueryExecutionError(f"Failed to execute query: {query}") from e

    async def health_check(self) -> bool:
        """
        Perform a health check by executing a simple query (e.g., SELECT 1).

        Returns:
            bool: True if the database is healthy, False otherwise.

        Raises:
            HealthCheckError: If the health check fails.
        """
        try:
            async with self.get_connection() as conn:
                cursor = conn.cursor()
                cursor.execute("SELECT 1")
                result = cursor.fetchone()
                cursor.close()

                # Check if the result is as expected
                if result and result[0] == 1:
                    logger.info("Database health check succeeded.")
                    return True
                else:
                    logger.error("Database health check failed: Unexpected result.")
                    raise HealthCheckError("Unexpected result from health check query.")
        except Pg8000DatabaseError as e:
            logger.error(f"Health check failed: {e}")
            raise HealthCheckError("Failed to perform health check.") from e


# Dependency to get the database instance
async def get_db() -> AsyncGenerator[Database, None]:
    settings = DatabaseSettings()
    db = Database(db_url=settings.db_url, pool_size=settings.pool_size)
    await db.connect()
    try:
        yield db
    finally:
        await db.disconnect()


# Example usage
if __name__ == "__main__":

    async def main():
        settings = DatabaseSettings()
        db = Database(db_url=settings.db_url, pool_size=settings.pool_size)
        await db.connect()

        try:
            # Perform a health check
            is_healthy = await db.health_check()
            print(f"Database health check: {'Success' if is_healthy else 'Failure'}")
        except HealthCheckError as e:
            print(f"Health check failed: {e}")
        finally:
            await db.disconnect()

    asyncio.run(main())