1509 typedef struct sqlite3_vfs sqlite3_vfs;  typedef
1511 struct sqlite3_vfs {  struct
1515   sqlite3_vfs *pNext;      /* Next registered VFS */  argument
1518   int (*xOpen)(sqlite3_vfs*, const char *zName, sqlite3_file*,  argument
1520   int (*xDelete)(sqlite3_vfs*, const char *zName, int syncDir);  argument
1521   int (*xAccess)(sqlite3_vfs*, const char *zName, int flags, int *pResOut);  argument
1522   int (*xFullPathname)(sqlite3_vfs*, const char *zName, int nOut, char *zOut);  argument
1523   void *(*xDlOpen)(sqlite3_vfs*, const char *zFilename);  argument
1524   void (*xDlError)(sqlite3_vfs*, int nByte, char *zErrMsg);  argument
1525   void (*(*xDlSym)(sqlite3_vfs*,void*, const char *zSymbol))(void);  argument
1526   void (*xDlClose)(sqlite3_vfs*, void*);  argument
1527   int (*xRandomness)(sqlite3_vfs*, int nByte, char *zOut);  argument
1528   int (*xSleep)(sqlite3_vfs*, int microseconds);  argument
1529   int (*xCurrentTime)(sqlite3_vfs*, double*);  argument
1530   int (*xGetLastError)(sqlite3_vfs*, int, char *);  argument
1535   int (*xCurrentTimeInt64)(sqlite3_vfs*, sqlite3_int64*);  argument
1540   int (*xSetSystemCall)(sqlite3_vfs*, const char *zName, sqlite3_syscall_ptr);  argument
1541   sqlite3_syscall_ptr (*xGetSystemCall)(sqlite3_vfs*, const char *zName);  argument
1542   const char *(*xNextSystemCall)(sqlite3_vfs*, const char *zName);  argument