96 lines
2.2 KiB
Go
96 lines
2.2 KiB
Go
//go:build !sqlite3_flock && !sqlite3_nosys
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package vfs
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import (
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"io"
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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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const (
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// https://github.com/apple/darwin-xnu/blob/main/bsd/sys/fcntl.h
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_F_OFD_SETLK = 90
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_F_OFD_SETLKW = 91
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_F_OFD_SETLKWTIMEOUT = 93
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)
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type flocktimeout_t struct {
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fl unix.Flock_t
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timeout unix.Timespec
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}
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func osSync(file *os.File, fullsync, _ /*dataonly*/ bool) error {
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if fullsync {
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return file.Sync()
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}
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return unix.Fsync(int(file.Fd()))
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}
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func osAllocate(file *os.File, size int64) error {
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off, err := file.Seek(0, io.SeekEnd)
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if err != nil {
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return err
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}
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if size <= off {
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return nil
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}
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store := unix.Fstore_t{
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Flags: unix.F_ALLOCATEALL | unix.F_ALLOCATECONTIG,
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Posmode: unix.F_PEOFPOSMODE,
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Offset: 0,
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Length: size - off,
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}
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// Try to get a continuous chunk of disk space.
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err = unix.FcntlFstore(file.Fd(), unix.F_PREALLOCATE, &store)
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if err != nil {
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// OK, perhaps we are too fragmented, allocate non-continuous.
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store.Flags = unix.F_ALLOCATEALL
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unix.FcntlFstore(file.Fd(), unix.F_PREALLOCATE, &store)
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}
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return file.Truncate(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(), _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 := flocktimeout_t{fl: 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(), _F_OFD_SETLK, &lock.fl)
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case timeout < 0:
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err = unix.FcntlFlock(file.Fd(), _F_OFD_SETLKW, &lock.fl)
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default:
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lock.timeout = unix.NsecToTimespec(int64(timeout / time.Nanosecond))
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err = unix.FcntlFlock(file.Fd(), _F_OFD_SETLKWTIMEOUT, &lock.fl)
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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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