mirror of https://github.com/etcd-io/bbolt.git
54 lines
1.1 KiB
Go
54 lines
1.1 KiB
Go
package bolt
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import (
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"os"
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"syscall"
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"unsafe"
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)
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var odirect int
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// fdatasync flushes written data to a file descriptor.
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func fdatasync(f *os.File) error {
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return f.Sync()
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}
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// flock acquires an advisory lock on a file descriptor.
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func flock(f *os.File) error {
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return syscall.Flock(int(f.Fd()), syscall.LOCK_EX)
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}
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// funlock releases an advisory lock on a file descriptor.
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func funlock(f *os.File) error {
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return syscall.Flock(int(f.Fd()), syscall.LOCK_UN)
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}
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// mmap memory maps a DB's data file.
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func mmap(db *DB, sz int) error {
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b, err := syscall.Mmap(int(db.file.Fd()), 0, sz, syscall.PROT_READ, syscall.MAP_SHARED)
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if err != nil {
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return err
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}
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// Save the original byte slice and convert to a byte array pointer.
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db.dataref = b
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db.data = (*[maxMapSize]byte)(unsafe.Pointer(&b[0]))
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db.datasz = sz
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return nil
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}
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// munmap unmaps a DB's data file from memory.
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func munmap(db *DB) error {
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// Ignore the unmap if we have no mapped data.
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if db.dataref == nil {
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return nil
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}
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// Unmap using the original byte slice.
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err := syscall.Munmap(db.dataref)
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db.dataref = nil
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db.data = nil
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db.datasz = 0
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return err
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}
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