xref: /sqlite-3.40.0/src/os.c (revision 5665b3ea)
1 /*
2 ** 2005 November 29
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 **
13 ** This file contains OS interface code that is common to all
14 ** architectures.
15 */
16 #define _SQLITE_OS_C_ 1
17 #include "sqliteInt.h"
18 #include "os.h"
19 #undef _SQLITE_OS_C_
20 
21 /*
22 ** The following routines are convenience wrappers around methods
23 ** of the OsFile object.  This is mostly just syntactic sugar.  All
24 ** of this would be completely automatic if SQLite were coded using
25 ** C++ instead of plain old C.
26 */
27 int sqlite3OsClose(OsFile **pId){
28   OsFile *id;
29   if( pId!=0 && (id = *pId)!=0 ){
30     return id->pMethod->xClose(pId);
31   }else{
32     return SQLITE_OK;
33   }
34 }
35 int sqlite3OsOpenDirectory(OsFile *id, const char *zName){
36   return id->pMethod->xOpenDirectory(id, zName);
37 }
38 int sqlite3OsRead(OsFile *id, void *pBuf, int amt){
39   return id->pMethod->xRead(id, pBuf, amt);
40 }
41 int sqlite3OsWrite(OsFile *id, const void *pBuf, int amt){
42   return id->pMethod->xWrite(id, pBuf, amt);
43 }
44 int sqlite3OsSeek(OsFile *id, i64 offset){
45   return id->pMethod->xSeek(id, offset);
46 }
47 int sqlite3OsTruncate(OsFile *id, i64 size){
48   return id->pMethod->xTruncate(id, size);
49 }
50 int sqlite3OsSync(OsFile *id, int fullsync){
51   return id->pMethod->xSync(id, fullsync);
52 }
53 void sqlite3OsSetFullSync(OsFile *id, int value){
54   id->pMethod->xSetFullSync(id, value);
55 }
56 int sqlite3OsFileSize(OsFile *id, i64 *pSize){
57   return id->pMethod->xFileSize(id, pSize);
58 }
59 int sqlite3OsLock(OsFile *id, int lockType){
60   return id->pMethod->xLock(id, lockType);
61 }
62 int sqlite3OsUnlock(OsFile *id, int lockType){
63   return id->pMethod->xUnlock(id, lockType);
64 }
65 int sqlite3OsCheckReservedLock(OsFile *id){
66   return id->pMethod->xCheckReservedLock(id);
67 }
68 int sqlite3OsSectorSize(OsFile *id){
69   int (*xSectorSize)(OsFile*) = id->pMethod->xSectorSize;
70   return xSectorSize ? xSectorSize(id) : SQLITE_DEFAULT_SECTOR_SIZE;
71 }
72 
73 #if defined(SQLITE_TEST) || defined(SQLITE_DEBUG)
74   /* These methods are currently only used for testing and debugging. */
75   int sqlite3OsFileHandle(OsFile *id){
76     return id->pMethod->xFileHandle(id);
77   }
78   int sqlite3OsLockState(OsFile *id){
79     return id->pMethod->xLockState(id);
80   }
81 #endif
82 
83 #ifdef SQLITE_ENABLE_REDEF_IO
84 /*
85 ** A function to return a pointer to the virtual function table.
86 ** This routine really does not accomplish very much since the
87 ** virtual function table is a global variable and anybody who
88 ** can call this function can just as easily access the variable
89 ** for themselves.  Nevertheless, we include this routine for
90 ** backwards compatibility with an earlier redefinable I/O
91 ** interface design.
92 */
93 struct sqlite3OsVtbl *sqlite3_os_switch(void){
94   return &sqlite3Os;
95 }
96 #endif
97