76 lines
1.3 KiB
V
76 lines
1.3 KiB
V
module filelock
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import time
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fn C.DeleteFileW(&u16) bool
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fn C.CreateFileW(&u16, u32, u32, voidptr, u32, u32, voidptr) voidptr
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fn C.CloseHandle(voidptr) bool
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pub fn (mut l FileLock) unlink() {
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if l.fd != -1 {
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C.CloseHandle(l.fd)
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l.fd = -1
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}
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t_wide := l.name.to_wide()
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C.DeleteFileW(t_wide)
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}
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pub fn (mut l FileLock) acquire() ?bool {
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if l.fd != -1 {
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// lock already acquired by this instance
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return false
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}
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fd := open(l.name)
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if fd == -1 {
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return error('cannot create lock file $l.name')
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}
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l.fd = fd
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return true
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}
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pub fn (mut l FileLock) release() bool {
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if l.fd != -1 {
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C.CloseHandle(l.fd)
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l.fd = -1
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t_wide := l.name.to_wide()
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C.DeleteFileW(t_wide)
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return true
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}
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return false
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}
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pub fn (mut l FileLock) wait_acquire(s int) ?bool {
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fin := time.now().add(s)
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for time.now() < fin {
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if l.try_acquire() {
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return true
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}
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time.sleep(1 * time.millisecond)
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}
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return false
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}
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fn open(f string) voidptr {
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f_wide := f.to_wide()
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// locking it
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fd := C.CreateFileW(f_wide, C.GENERIC_READ | C.GENERIC_WRITE, 0, 0, C.OPEN_ALWAYS,
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C.FILE_ATTRIBUTE_NORMAL, 0)
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if fd == C.INVALID_HANDLE_VALUE {
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fd == -1
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}
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return fd
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}
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pub fn (mut l FileLock) try_acquire() bool {
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if l.fd != -1 {
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// lock already acquired by this instance
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return false
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}
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fd := open(l.name)
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if fd == -1 {
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return false
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}
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l.fd = fd
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return true
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}
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