xref: /sqlite-3.40.0/src/os.c (revision 74e4352a)
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 
20 /*
21 ** The following routines are convenience wrappers around methods
22 ** of the OsFile object.  This is mostly just syntactic sugar.  All
23 ** of this would be completely automatic if SQLite were coded using
24 ** C++ instead of plain old C.
25 */
26 int sqlite3OsClose(OsFile **pId){
27   OsFile *id;
28   if( pId!=0 && (id = *pId)!=0 ){
29     return id->pMethod->xClose(pId);
30   }else{
31     return SQLITE_OK;
32   }
33 }
34 int sqlite3OsOpenDirectory(OsFile *id, const char *zName){
35   return id->pMethod->xOpenDirectory(id, zName);
36 }
37 int sqlite3OsRead(OsFile *id, void *pBuf, int amt){
38   return id->pMethod->xRead(id, pBuf, amt);
39 }
40 int sqlite3OsWrite(OsFile *id, const void *pBuf, int amt){
41   return id->pMethod->xWrite(id, pBuf, amt);
42 }
43 int sqlite3OsSeek(OsFile *id, i64 offset){
44   return id->pMethod->xSeek(id, offset);
45 }
46 int sqlite3OsTruncate(OsFile *id, i64 size){
47   return id->pMethod->xTruncate(id, size);
48 }
49 int sqlite3OsSync(OsFile *id, int fullsync){
50   return id->pMethod->xSync(id, fullsync);
51 }
52 void sqlite3OsSetFullSync(OsFile *id, int value){
53   id->pMethod->xSetFullSync(id, value);
54 }
55 #if defined(SQLITE_TEST) || defined(SQLITE_DEBUG)
56 /* This method is currently only used while interactively debugging the
57 ** pager. More specificly, it can only be used when sqlite3DebugPrintf() is
58 ** included in the build. */
59 int sqlite3OsFileHandle(OsFile *id){
60   return id->pMethod->xFileHandle(id);
61 }
62 #endif
63 int sqlite3OsFileSize(OsFile *id, i64 *pSize){
64   return id->pMethod->xFileSize(id, pSize);
65 }
66 int sqlite3OsLock(OsFile *id, int lockType){
67   return id->pMethod->xLock(id, lockType);
68 }
69 int sqlite3OsUnlock(OsFile *id, int lockType){
70   return id->pMethod->xUnlock(id, lockType);
71 }
72 int sqlite3OsLockState(OsFile *id){
73   return id->pMethod->xLockState(id);
74 }
75 int sqlite3OsCheckReservedLock(OsFile *id){
76   return id->pMethod->xCheckReservedLock(id);
77 }
78 
79 #ifdef SQLITE_ENABLE_REDEF_IO
80 /*
81 ** A function to return a pointer to the virtual function table.
82 ** This routine really does not accomplish very much since the
83 ** virtual function table is a global variable and anybody who
84 ** can call this function can just as easily access the variable
85 ** for themselves.  Nevertheless, we include this routine for
86 ** backwards compatibility with an earlier redefinable I/O
87 ** interface design.
88 */
89 struct sqlite3OsVtbl *sqlite3_os_switch(void){
90   return &sqlite3Os;
91 }
92 #endif
93