Mercurial > p > roundup > code
comparison roundup/backends/back_sqlite.py @ 2374:31cb1014300c
Switch to using sqlite's own locking mechanisms...
Automatically start a new transaction on hyperdb commit().
Better RDBMS demo.py nuke handling.
(minor doc fixes)
| author | Richard Jones <richard@users.sourceforge.net> |
|---|---|
| date | Fri, 28 May 2004 01:09:11 +0000 |
| parents | c77483d2cda4 |
| children | 091711fb2f8c |
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| 2372:c26bb78d2f0c | 2374:31cb1014300c |
|---|---|
| 1 # $Id: back_sqlite.py,v 1.28 2004-05-10 00:39:40 richard Exp $ | 1 # $Id: back_sqlite.py,v 1.29 2004-05-28 01:09:11 richard Exp $ |
| 2 '''Implements a backend for SQLite. | 2 '''Implements a backend for SQLite. |
| 3 | 3 |
| 4 See https://pysqlite.sourceforge.net/ for pysqlite info | 4 See https://pysqlite.sourceforge.net/ for pysqlite info |
| 5 | 5 |
| 6 | 6 |
| 48 hyperdb.Number : rdbms_common._num_cvt, | 48 hyperdb.Number : rdbms_common._num_cvt, |
| 49 hyperdb.Multilink : lambda x: x, # used in journal marshalling | 49 hyperdb.Multilink : lambda x: x, # used in journal marshalling |
| 50 } | 50 } |
| 51 | 51 |
| 52 def sql_open_connection(self): | 52 def sql_open_connection(self): |
| 53 '''Open a standard, non-autocommitting connection. | |
| 54 | |
| 55 pysqlite will automatically BEGIN TRANSACTION for us. | |
| 56 ''' | |
| 53 db = os.path.join(self.config.DATABASE, 'db') | 57 db = os.path.join(self.config.DATABASE, 'db') |
| 54 conn = sqlite.connect(db=db) | 58 conn = sqlite.connect(db=db) |
| 59 # set a 30 second timeout (extraordinarily generous) for handling | |
| 60 # locked database | |
| 61 conn.db.sqlite_busy_timeout(30 * 1000) | |
| 55 cursor = conn.cursor() | 62 cursor = conn.cursor() |
| 56 return (conn, cursor) | 63 return (conn, cursor) |
| 57 | 64 |
| 58 def open_connection(self): | 65 def open_connection(self): |
| 59 # ensure files are group readable and writable | 66 # ensure files are group readable and writable |
| 60 os.umask(0002) | 67 os.umask(0002) |
| 61 | |
| 62 # lock the database | |
| 63 lockfilenm = os.path.join(self.dir, 'lock') | |
| 64 self.lockfile = locking.acquire_lock(lockfilenm) | |
| 65 self.lockfile.write(str(os.getpid())) | |
| 66 self.lockfile.flush() | |
| 67 | 68 |
| 68 (self.conn, self.cursor) = self.sql_open_connection() | 69 (self.conn, self.cursor) = self.sql_open_connection() |
| 69 | 70 |
| 70 try: | 71 try: |
| 71 self.load_dbschema() | 72 self.load_dbschema() |
| 243 def sql_close(self): | 244 def sql_close(self): |
| 244 ''' Squash any error caused by us already having closed the | 245 ''' Squash any error caused by us already having closed the |
| 245 connection. | 246 connection. |
| 246 ''' | 247 ''' |
| 247 try: | 248 try: |
| 248 try: | 249 self.conn.close() |
| 249 self.conn.close() | 250 except sqlite.ProgrammingError, value: |
| 250 except sqlite.ProgrammingError, value: | 251 if str(value) != 'close failed - Connection is closed.': |
| 251 if str(value) != 'close failed - Connection is closed.': | 252 raise |
| 252 raise | |
| 253 finally: | |
| 254 # always release the lock | |
| 255 if self.lockfile is not None: | |
| 256 locking.release_lock(self.lockfile) | |
| 257 self.lockfile.close() | |
| 258 self.lockfile = None | |
| 259 | 253 |
| 260 def sql_rollback(self): | 254 def sql_rollback(self): |
| 261 ''' Squash any error caused by us having closed the connection (and | 255 ''' Squash any error caused by us having closed the connection (and |
| 262 therefore not having anything to roll back) | 256 therefore not having anything to roll back) |
| 263 ''' | 257 ''' |
| 278 try: | 272 try: |
| 279 self.conn.commit() | 273 self.conn.commit() |
| 280 except sqlite.DatabaseError, error: | 274 except sqlite.DatabaseError, error: |
| 281 if str(error) != 'cannot commit - no transaction is active': | 275 if str(error) != 'cannot commit - no transaction is active': |
| 282 raise | 276 raise |
| 277 # open a new cursor for subsequent work | |
| 278 self.cursor = self.conn.cursor() | |
| 283 | 279 |
| 284 def sql_index_exists(self, table_name, index_name): | 280 def sql_index_exists(self, table_name, index_name): |
| 285 self.cursor.execute('pragma index_list(%s)'%table_name) | 281 self.cursor.execute('pragma index_list(%s)'%table_name) |
| 286 for entry in self.cursor.fetchall(): | 282 for entry in self.cursor.fetchall(): |
| 287 if entry[1] == index_name: | 283 if entry[1] == index_name: |