mirror of
https://github.com/ncruces/go-sqlite3.git
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92 lines
2.1 KiB
Go
92 lines
2.1 KiB
Go
//go:build unix
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package vfs
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import (
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"os"
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"syscall"
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"time"
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"golang.org/x/sys/unix"
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)
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func osAccess(path string, flags AccessFlag) error {
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var access uint32 // unix.F_OK
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switch flags {
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case ACCESS_READWRITE:
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access = unix.R_OK | unix.W_OK
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case ACCESS_READ:
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access = unix.R_OK
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}
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return unix.Access(path, access)
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}
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func osSetMode(file *os.File, modeof string) error {
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fi, err := os.Stat(modeof)
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if err != nil {
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return err
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}
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file.Chmod(fi.Mode())
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if sys, ok := fi.Sys().(*syscall.Stat_t); ok {
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file.Chown(int(sys.Uid), int(sys.Gid))
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}
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return nil
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}
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func osGetSharedLock(file *os.File) _ErrorCode {
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// Test the PENDING lock before acquiring a new SHARED lock.
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if pending, _ := osCheckLock(file, _PENDING_BYTE, 1); pending {
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return _BUSY
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}
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// Acquire the SHARED lock.
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return osReadLock(file, _SHARED_FIRST, _SHARED_SIZE, 0)
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}
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func osGetExclusiveLock(file *os.File) _ErrorCode {
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// Acquire the EXCLUSIVE lock.
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return osWriteLock(file, _SHARED_FIRST, _SHARED_SIZE, time.Millisecond)
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}
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func osDowngradeLock(file *os.File, state LockLevel) _ErrorCode {
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if state >= LOCK_EXCLUSIVE {
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// Downgrade to a SHARED lock.
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if rc := osReadLock(file, _SHARED_FIRST, _SHARED_SIZE, 0); rc != _OK {
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// In theory, the downgrade to a SHARED cannot fail because another
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// process is holding an incompatible lock. If it does, this
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// indicates that the other process is not following the locking
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// protocol. If this happens, return _IOERR_RDLOCK. Returning
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// BUSY would confuse the upper layer.
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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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return osUnlock(file, _PENDING_BYTE, 2)
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}
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func osReleaseLock(file *os.File, _ LockLevel) _ErrorCode {
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// Release all locks.
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return osUnlock(file, 0, 0)
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}
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func osLockErrorCode(err error, def _ErrorCode) _ErrorCode {
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if err == nil {
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return _OK
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}
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if errno, ok := err.(unix.Errno); ok {
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switch errno {
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case
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unix.EACCES,
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unix.EAGAIN,
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unix.EBUSY,
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unix.EINTR,
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unix.ENOLCK,
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unix.EDEADLK,
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unix.ETIMEDOUT:
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return _BUSY
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case unix.EPERM:
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return _PERM
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}
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}
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return def
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}
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