| dan | 6700d02 | 2010-04-12 19:05:58 +0000 | [diff] [blame^] | 1 | /* |
| 2 | ** 2010 February 1 |
| 3 | ** |
| 4 | ** The author disclaims copyright to this source code. In place of |
| 5 | ** a legal notice, here is a blessing: |
| 6 | ** |
| 7 | ** May you do good and not evil. |
| 8 | ** May you find forgiveness for yourself and forgive others. |
| 9 | ** May you share freely, never taking more than you give. |
| 10 | ** |
| 11 | ************************************************************************* |
| 12 | ** This header file defines the interface to the write-ahead logging |
| 13 | ** system. Refer to the comments below and the header comment attached to |
| 14 | ** the implementation of each function in log.c for further details. |
| 15 | */ |
| 16 | |
| 17 | #ifndef _LOG_H_ |
| 18 | #define _LOG_H_ |
| 19 | |
| 20 | #include "sqliteInt.h" |
| 21 | |
| 22 | /* Flags that may be set in the 'flags' argument to sqlite3LogWrite(): */ |
| 23 | #define LOG_MASK_COMMIT 0x08 |
| 24 | #define LOG_MASK_MASTERJOURNAL 0x10 |
| 25 | #define LOG_MASK_TRUNCATE 0x20 |
| 26 | |
| 27 | |
| 28 | #define LOG_TRUNCATE_BIT 0x80000000 |
| 29 | |
| 30 | /* Connection to a log file. There is one object of this type for each pager. */ |
| 31 | typedef struct Log Log; |
| 32 | |
| 33 | /* Open and close a connection to a log file. */ |
| 34 | int sqlite3LogOpen(sqlite3_vfs*, const char *zDb, Log **ppLog); |
| 35 | int sqlite3LogClose(Log *pLog, sqlite3_file *pFd, u8 *zBuf); |
| 36 | |
| 37 | /* Configure the log connection. */ |
| 38 | void sqlite3LogSetSyncflags(Log *, int sync_flags); |
| 39 | |
| 40 | /* Used by readers to open (lock) and close (unlock) a database snapshot. */ |
| 41 | int sqlite3LogOpenSnapshot(Log *pLog, int *); |
| 42 | void sqlite3LogCloseSnapshot(Log *pLog); |
| 43 | |
| 44 | /* Read a page from the log, if it is present. */ |
| 45 | int sqlite3LogRead(Log *pLog, Pgno pgno, int *pInLog, u8 *pOut); |
| 46 | void sqlite3LogMaxpgno(Log *pLog, Pgno *pPgno); |
| 47 | |
| 48 | /* Obtain or release the WRITER lock. */ |
| 49 | int sqlite3LogWriteLock(Log *pLog, int op); |
| 50 | |
| 51 | /* Write a segment to the log. */ |
| 52 | int sqlite3LogFrames(Log *pLog, int, PgHdr *, Pgno, int, int); |
| 53 | |
| 54 | /* Copy pages from the log to the database file */ |
| 55 | int sqlite3LogCheckpoint( |
| 56 | Log *pLog, /* Log connection */ |
| 57 | sqlite3_file *pFd, /* File descriptor open on db file */ |
| 58 | u8 *zBuf /* Temporary buffer to use */ |
| 59 | ); |
| 60 | |
| 61 | #endif /* _LOG_H_ */ |