mirror of
https://github.com/ncruces/go-sqlite3.git
synced 2026-01-11 21:49:13 +00:00
103 lines
2.6 KiB
Go
103 lines
2.6 KiB
Go
package sqlite3
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import (
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"os"
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"syscall"
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"golang.org/x/sys/windows"
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)
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func (vfsOSMethods) DeleteOnClose(file *os.File) {}
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func (vfsOSMethods) GetExclusiveLock(file *os.File) xErrorCode {
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// Release the SHARED lock.
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vfsOS.unlock(file, _SHARED_FIRST, _SHARED_SIZE)
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// Acquire the EXCLUSIVE lock.
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rc := vfsOS.writeLock(file, _SHARED_FIRST, _SHARED_SIZE)
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// Reacquire the SHARED lock.
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if rc != _OK {
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vfsOS.readLock(file, _SHARED_FIRST, _SHARED_SIZE)
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}
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return rc
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}
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func (vfsOSMethods) DowngradeLock(file *os.File, state vfsLockState) xErrorCode {
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if state >= _EXCLUSIVE_LOCK {
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// Release the SHARED lock.
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vfsOS.unlock(file, _SHARED_FIRST, _SHARED_SIZE)
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// Reacquire the SHARED lock.
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if rc := vfsOS.readLock(file, _SHARED_FIRST, _SHARED_SIZE); rc != _OK {
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// This should never happen.
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// We should always be able to reacquire the read lock.
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return IOERR_RDLOCK
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}
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}
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// Release the PENDING and RESERVED locks.
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if state >= _RESERVED_LOCK {
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vfsOS.unlock(file, _RESERVED_BYTE, 1)
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}
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if state >= _PENDING_LOCK {
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vfsOS.unlock(file, _PENDING_BYTE, 1)
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}
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return _OK
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}
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func (vfsOSMethods) ReleaseLock(file *os.File, state vfsLockState) xErrorCode {
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// Release all locks.
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if state >= _RESERVED_LOCK {
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vfsOS.unlock(file, _RESERVED_BYTE, 1)
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}
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if state >= _SHARED_LOCK {
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vfsOS.unlock(file, _SHARED_FIRST, _SHARED_SIZE)
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}
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if state >= _PENDING_LOCK {
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vfsOS.unlock(file, _PENDING_BYTE, 1)
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}
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return _OK
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}
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func (vfsOSMethods) unlock(file *os.File, start, len uint32) xErrorCode {
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err := windows.UnlockFileEx(windows.Handle(file.Fd()),
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0, len, 0, &windows.Overlapped{Offset: start})
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if err != nil {
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return IOERR_UNLOCK
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}
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return _OK
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}
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func (vfsOSMethods) readLock(file *os.File, start, len uint32) xErrorCode {
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return vfsOS.lockErrorCode(windows.LockFileEx(windows.Handle(file.Fd()),
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windows.LOCKFILE_FAIL_IMMEDIATELY,
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0, len, 0, &windows.Overlapped{Offset: start}),
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IOERR_RDLOCK)
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}
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func (vfsOSMethods) writeLock(file *os.File, start, len uint32) xErrorCode {
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return vfsOS.lockErrorCode(windows.LockFileEx(windows.Handle(file.Fd()),
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windows.LOCKFILE_FAIL_IMMEDIATELY|windows.LOCKFILE_EXCLUSIVE_LOCK,
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0, len, 0, &windows.Overlapped{Offset: start}),
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IOERR_LOCK)
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}
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func (vfsOSMethods) checkLock(file *os.File, start, len uint32) (bool, xErrorCode) {
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rc := vfsOS.readLock(file, start, len)
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if rc == _OK {
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vfsOS.unlock(file, start, len)
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}
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return rc != _OK, _OK
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}
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func (vfsOSMethods) lockErrorCode(err error, def xErrorCode) xErrorCode {
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if err == nil {
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return _OK
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}
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if errno, _ := err.(syscall.Errno); errno == windows.ERROR_INVALID_HANDLE {
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return def
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}
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return xErrorCode(BUSY)
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}
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