engine/sqlite/src/pager.h
changeset 71 fbd95db6a4e1
parent 69 4a65cc85c4f3
child 72 2e267e7da513
equal deleted inserted replaced
69:4a65cc85c4f3 71:fbd95db6a4e1
     1 /*
       
     2 ** 2001 September 15
       
     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 that the sqlite page cache
       
    13 ** subsystem.  The page cache subsystem reads and writes a file a page
       
    14 ** at a time and provides a journal for rollback.
       
    15 **
       
    16 ** @(#) $Id: pager.h 1282 2008-11-13 09:31:33Z LarsPson $
       
    17 */
       
    18 
       
    19 #ifndef _PAGER_H_
       
    20 #define _PAGER_H_
       
    21 
       
    22 /*
       
    23 ** The type used to represent a page number.  The first page in a file
       
    24 ** is called page 1.  0 is used to represent "not a page".
       
    25 */
       
    26 typedef unsigned int Pgno;
       
    27 
       
    28 /*
       
    29 ** Each open file is managed by a separate instance of the "Pager" structure.
       
    30 */
       
    31 typedef struct Pager Pager;
       
    32 
       
    33 /*
       
    34 ** Handle type for pages.
       
    35 */
       
    36 typedef struct PgHdr DbPage;
       
    37 
       
    38 /*
       
    39 ** Allowed values for the flags parameter to sqlite3PagerOpen().
       
    40 **
       
    41 ** NOTE: This values must match the corresponding BTREE_ values in btree.h.
       
    42 */
       
    43 #define PAGER_OMIT_JOURNAL  0x0001    /* Do not use a rollback journal */
       
    44 #define PAGER_NO_READLOCK   0x0002    /* Omit readlocks on readonly files */
       
    45 
       
    46 /*
       
    47 ** Valid values for the second argument to sqlite3PagerLockingMode().
       
    48 */
       
    49 #define PAGER_LOCKINGMODE_QUERY      -1
       
    50 #define PAGER_LOCKINGMODE_NORMAL      0
       
    51 #define PAGER_LOCKINGMODE_EXCLUSIVE   1
       
    52 
       
    53 /*
       
    54 ** See source code comments for a detailed description of the following
       
    55 ** routines:
       
    56 */
       
    57 int sqlite3PagerOpen(sqlite3_vfs *, Pager **ppPager, const char*, int,int,int);
       
    58 void sqlite3PagerSetBusyhandler(Pager*, BusyHandler *pBusyHandler);
       
    59 void sqlite3PagerSetDestructor(Pager*, void(*)(DbPage*,int));
       
    60 void sqlite3PagerSetReiniter(Pager*, void(*)(DbPage*,int));
       
    61 int sqlite3PagerSetPagesize(Pager*, u16*);
       
    62 int sqlite3PagerMaxPageCount(Pager*, int);
       
    63 int sqlite3PagerReadFileheader(Pager*, int, unsigned char*);
       
    64 void sqlite3PagerSetCachesize(Pager*, int);
       
    65 int sqlite3PagerClose(Pager *pPager);
       
    66 int sqlite3PagerAcquire(Pager *pPager, Pgno pgno, DbPage **ppPage, int clrFlag);
       
    67 #define sqlite3PagerGet(A,B,C) sqlite3PagerAcquire(A,B,C,0)
       
    68 DbPage *sqlite3PagerLookup(Pager *pPager, Pgno pgno);
       
    69 int sqlite3PagerRef(DbPage*);
       
    70 int sqlite3PagerUnref(DbPage*);
       
    71 int sqlite3PagerWrite(DbPage*);
       
    72 int sqlite3PagerOverwrite(Pager *pPager, Pgno pgno, void*);
       
    73 int sqlite3PagerPagecount(Pager*);
       
    74 int sqlite3PagerTruncate(Pager*,Pgno);
       
    75 int sqlite3PagerBegin(DbPage*, int exFlag);
       
    76 int sqlite3PagerCommitPhaseOne(Pager*,const char *zMaster, Pgno);
       
    77 int sqlite3PagerCommitPhaseTwo(Pager*);
       
    78 int sqlite3PagerRollback(Pager*);
       
    79 int sqlite3PagerIsreadonly(Pager*);
       
    80 int sqlite3PagerStmtBegin(Pager*);
       
    81 int sqlite3PagerStmtCommit(Pager*);
       
    82 int sqlite3PagerStmtRollback(Pager*);
       
    83 void sqlite3PagerDontRollback(DbPage*);
       
    84 void sqlite3PagerDontWrite(DbPage*);
       
    85 int sqlite3PagerRefcount(Pager*);
       
    86 void sqlite3PagerSetSafetyLevel(Pager*,int,int);
       
    87 const char *sqlite3PagerFilename(Pager*);
       
    88 const sqlite3_vfs *sqlite3PagerVfs(Pager*);
       
    89 sqlite3_file *sqlite3PagerFile(Pager*);
       
    90 const char *sqlite3PagerDirname(Pager*);
       
    91 const char *sqlite3PagerJournalname(Pager*);
       
    92 int sqlite3PagerNosync(Pager*);
       
    93 int sqlite3PagerMovepage(Pager*,DbPage*,Pgno);
       
    94 void *sqlite3PagerGetData(DbPage *); 
       
    95 void *sqlite3PagerGetExtra(DbPage *); 
       
    96 int sqlite3PagerLockingMode(Pager *, int);
       
    97 void *sqlite3PagerTempSpace(Pager*);
       
    98 
       
    99 #if defined(SQLITE_ENABLE_MEMORY_MANAGEMENT) && !defined(SQLITE_OMIT_DISKIO)
       
   100   int sqlite3PagerReleaseMemory(int);
       
   101 #endif
       
   102 
       
   103 #ifdef SQLITE_HAS_CODEC
       
   104   void sqlite3PagerSetCodec(Pager*,void*(*)(void*,void*,Pgno,int),void*);
       
   105 #endif
       
   106 
       
   107 #if !defined(NDEBUG) || defined(SQLITE_TEST)
       
   108   Pgno sqlite3PagerPagenumber(DbPage*);
       
   109   int sqlite3PagerIswriteable(DbPage*);
       
   110 #endif
       
   111 
       
   112 #ifdef SQLITE_TEST
       
   113   int *sqlite3PagerStats(Pager*);
       
   114   void sqlite3PagerRefdump(Pager*);
       
   115   int pager3_refinfo_enable;
       
   116 #endif
       
   117 
       
   118 #ifdef SQLITE_TEST
       
   119 void disable_simulated_io_errors(void);
       
   120 void enable_simulated_io_errors(void);
       
   121 #else
       
   122 # define disable_simulated_io_errors()
       
   123 # define enable_simulated_io_errors()
       
   124 #endif
       
   125 
       
   126 #endif /* _PAGER_H_ */