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Diffstat (limited to 'kexi/3rdparty/kexisql3/src/os.h')
-rw-r--r-- | kexi/3rdparty/kexisql3/src/os.h | 208 |
1 files changed, 208 insertions, 0 deletions
diff --git a/kexi/3rdparty/kexisql3/src/os.h b/kexi/3rdparty/kexisql3/src/os.h new file mode 100644 index 00000000..ebbd7541 --- /dev/null +++ b/kexi/3rdparty/kexisql3/src/os.h @@ -0,0 +1,208 @@ +/* +** 2001 September 16 +** +** The author disclaims copyright to this source code. In place of +** a legal notice, here is a blessing: +** +** May you do good and not evil. +** May you find forgiveness for yourself and forgive others. +** May you share freely, never taking more than you give. +** +****************************************************************************** +** +** This header file (together with is companion C source-code file +** "os.c") attempt to abstract the underlying operating system so that +** the SQLite library will work on both POSIX and windows systems. +*/ +#ifndef _SQLITE_OS_H_ +#define _SQLITE_OS_H_ + +/* +** Figure out if we are dealing with Unix, Windows or MacOS. +** +** N.B. MacOS means Mac Classic (or Carbon). Treat Darwin (OS X) as Unix. +** The MacOS build is designed to use CodeWarrior (tested with v8) +*/ +#if !defined(OS_UNIX) && !defined(OS_TEST) && !defined(OS_OTHER) +# define OS_OTHER 0 +# ifndef OS_WIN +# if defined(_WIN32) || defined(WIN32) || defined(__CYGWIN__) || defined(__MINGW32__) || defined(__BORLANDC__) +# define OS_WIN 1 +# define OS_UNIX 0 +# else +# define OS_WIN 0 +# define OS_UNIX 1 +# endif +# else +# define OS_UNIX 0 +# endif +#else +# ifndef OS_WIN +# define OS_WIN 0 +# endif +#endif + +/* +** Invoke the appropriate operating-system specific header file. +*/ +#if OS_TEST +# include "os_test.h" +#endif +#if OS_UNIX +# include "os_unix.h" +#endif +#if OS_WIN +# include "os_win.h" +#endif + +/* os_other.c and os_other.h are not delivered with SQLite. These files +** are place-holders that can be filled in by third-party developers to +** implement backends to their on proprietary operating systems. +*/ +#if OS_OTHER +# include "os_other.h" +#endif + +/* If the SET_FULLSYNC macro is not defined above, then make it +** a no-op +*/ +#ifndef SET_FULLSYNC +# define SET_FULLSYNC(x,y) +#endif + +/* +** Temporary files are named starting with this prefix followed by 16 random +** alphanumeric characters, and no file extension. They are stored in the +** OS's standard temporary file directory, and are deleted prior to exit. +** If sqlite is being embedded in another program, you may wish to change the +** prefix to reflect your program's name, so that if your program exits +** prematurely, old temporary files can be easily identified. This can be done +** using -DTEMP_FILE_PREFIX=myprefix_ on the compiler command line. +*/ +#ifndef TEMP_FILE_PREFIX +# define TEMP_FILE_PREFIX "sqlite_" +#endif + +/* +** The following values may be passed as the second argument to +** sqlite3OsLock(). The various locks exhibit the following semantics: +** +** SHARED: Any number of processes may hold a SHARED lock simultaneously. +** RESERVED: A single process may hold a RESERVED lock on a file at +** any time. Other processes may hold and obtain new SHARED locks. +** PENDING: A single process may hold a PENDING lock on a file at +** any one time. Existing SHARED locks may persist, but no new +** SHARED locks may be obtained by other processes. +** EXCLUSIVE: An EXCLUSIVE lock precludes all other locks. +** +** PENDING_LOCK may not be passed directly to sqlite3OsLock(). Instead, a +** process that requests an EXCLUSIVE lock may actually obtain a PENDING +** lock. This can be upgraded to an EXCLUSIVE lock by a subsequent call to +** sqlite3OsLock(). +*/ +#define NO_LOCK 0 +#define SHARED_LOCK 1 +#define RESERVED_LOCK 2 +#define PENDING_LOCK 3 +#define EXCLUSIVE_LOCK 4 + +/* +** File Locking Notes: (Mostly about windows but also some info for Unix) +** +** We cannot use LockFileEx() or UnlockFileEx() on Win95/98/ME because +** those functions are not available. So we use only LockFile() and +** UnlockFile(). +** +** LockFile() prevents not just writing but also reading by other processes. +** A SHARED_LOCK is obtained by locking a single randomly-chosen +** byte out of a specific range of bytes. The lock byte is obtained at +** random so two separate readers can probably access the file at the +** same time, unless they are unlucky and choose the same lock byte. +** An EXCLUSIVE_LOCK is obtained by locking all bytes in the range. +** There can only be one writer. A RESERVED_LOCK is obtained by locking +** a single byte of the file that is designated as the reserved lock byte. +** A PENDING_LOCK is obtained by locking a designated byte different from +** the RESERVED_LOCK byte. +** +** On WinNT/2K/XP systems, LockFileEx() and UnlockFileEx() are available, +** which means we can use reader/writer locks. When reader/writer locks +** are used, the lock is placed on the same range of bytes that is used +** for probabilistic locking in Win95/98/ME. Hence, the locking scheme +** will support two or more Win95 readers or two or more WinNT readers. +** But a single Win95 reader will lock out all WinNT readers and a single +** WinNT reader will lock out all other Win95 readers. +** +** The following #defines specify the range of bytes used for locking. +** SHARED_SIZE is the number of bytes available in the pool from which +** a random byte is selected for a shared lock. The pool of bytes for +** shared locks begins at SHARED_FIRST. +** +** These #defines are available in os.h so that Unix can use the same +** byte ranges for locking. This leaves open the possiblity of having +** clients on win95, winNT, and unix all talking to the same shared file +** and all locking correctly. To do so would require that samba (or whatever +** tool is being used for file sharing) implements locks correctly between +** windows and unix. I'm guessing that isn't likely to happen, but by +** using the same locking range we are at least open to the possibility. +** +** Locking in windows is manditory. For this reason, we cannot store +** actual data in the bytes used for locking. The pager never allocates +** the pages involved in locking therefore. SHARED_SIZE is selected so +** that all locks will fit on a single page even at the minimum page size. +** PENDING_BYTE defines the beginning of the locks. By default PENDING_BYTE +** is set high so that we don't have to allocate an unused page except +** for very large databases. But one should test the page skipping logic +** by setting PENDING_BYTE low and running the entire regression suite. +** +** Changing the value of PENDING_BYTE results in a subtly incompatible +** file format. Depending on how it is changed, you might not notice +** the incompatibility right away, even running a full regression test. +** The default location of PENDING_BYTE is the first byte past the +** 1GB boundary. +** +*/ +#ifndef SQLITE_TEST +#define PENDING_BYTE 0x40000000 /* First byte past the 1GB boundary */ +#else +extern unsigned int sqlite3_pending_byte; +#define PENDING_BYTE sqlite3_pending_byte +#endif + +#define RESERVED_BYTE (PENDING_BYTE+1) +#define SHARED_FIRST (PENDING_BYTE+2) +#define SHARED_SIZE 510 + + +int sqlite3OsDelete(const char*); +int sqlite3OsFileExists(const char*); +/* js: extended */ +int sqlite3OsOpenReadWrite(const char*, OsFile*, int*, int, int); +int sqlite3OsOpenExclusive(const char*, OsFile*, int); +int sqlite3OsOpenReadOnly(const char*, OsFile*); +int sqlite3OsOpenDirectory(const char*, OsFile*); +int sqlite3OsSyncDirectory(const char*); +int sqlite3OsTempFileName(char*); +int sqlite3OsIsDirWritable(char*); +int sqlite3OsClose(OsFile*); +int sqlite3OsRead(OsFile*, void*, int amt); +int sqlite3OsWrite(OsFile*, const void*, int amt); +int sqlite3OsSeek(OsFile*, i64 offset); +int sqlite3OsSync(OsFile*, int); +int sqlite3OsTruncate(OsFile*, i64 size); +int sqlite3OsFileSize(OsFile*, i64 *pSize); +char *sqlite3OsFullPathname(const char*); +int sqlite3OsLock(OsFile*, int); +int sqlite3OsUnlock(OsFile*, int); +int sqlite3OsCheckReservedLock(OsFile *id); + + +/* The interface for file I/O is above. Other miscellaneous functions +** are below */ + +int sqlite3OsRandomSeed(char*); +int sqlite3OsSleep(int ms); +int sqlite3OsCurrentTime(double*); +void sqlite3OsEnterMutex(void); +void sqlite3OsLeaveMutex(void); + +#endif /* _SQLITE_OS_H_ */ |