72 lines
1.6 KiB
Go
72 lines
1.6 KiB
Go
//go:build !(sqlite3_flock || sqlite3_nosys)
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package vfs
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import (
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"math/rand"
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"os"
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"time"
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"golang.org/x/sys/unix"
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)
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func osSync(file *os.File, _ /*fullsync*/, _ /*dataonly*/ bool) error {
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// SQLite trusts Linux's fdatasync for all fsync's.
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return unix.Fdatasync(int(file.Fd()))
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}
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func osAllocate(file *os.File, size int64) error {
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if size == 0 {
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return nil
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}
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return unix.Fallocate(int(file.Fd()), 0, 0, size)
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}
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func osUnlock(file *os.File, start, len int64) _ErrorCode {
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err := unix.FcntlFlock(file.Fd(), unix.F_OFD_SETLK, &unix.Flock_t{
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Type: unix.F_UNLCK,
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Start: start,
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Len: len,
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})
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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 osLock(file *os.File, typ int16, start, len int64, timeout time.Duration, def _ErrorCode) _ErrorCode {
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lock := unix.Flock_t{
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Type: typ,
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Start: start,
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Len: len,
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}
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var err error
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switch {
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case timeout == 0:
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err = unix.FcntlFlock(file.Fd(), unix.F_OFD_SETLK, &lock)
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case timeout < 0:
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err = unix.FcntlFlock(file.Fd(), unix.F_OFD_SETLKW, &lock)
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default:
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before := time.Now()
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for {
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err = unix.FcntlFlock(file.Fd(), unix.F_OFD_SETLK, &lock)
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if errno, _ := err.(unix.Errno); errno != unix.EAGAIN {
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break
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}
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if timeout < time.Since(before) {
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break
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}
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osSleep(time.Duration(rand.Int63n(int64(time.Millisecond))))
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}
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}
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return osLockErrorCode(err, def)
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}
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func osReadLock(file *os.File, start, len int64, timeout time.Duration) _ErrorCode {
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return osLock(file, unix.F_RDLCK, start, len, timeout, _IOERR_RDLOCK)
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}
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func osWriteLock(file *os.File, start, len int64, timeout time.Duration) _ErrorCode {
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return osLock(file, unix.F_WRLCK, start, len, timeout, _IOERR_LOCK)
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}
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