mirror of https://github.com/hak5/bolt.git
61 lines
1.5 KiB
Go
61 lines
1.5 KiB
Go
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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 nil
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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 nil
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}
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// mmap memory maps a file to a byte slice.
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// Based on: https://github.com/edsrzf/mmap-go
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func mmap(f *os.File, sz int) ([]byte, error) {
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// Open a file mapping handle.
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sizelo, sizehi := uint32(sz>>32), uint32(sz&0xffffffff)
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h, errno := syscall.CreateFileMapping(syscall.Handle(f.Fd()), nil, syscall.PAGE_READONLY, sizehi, sizelo, nil)
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if h == 0 {
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return nil, os.NewSyscallError("CreateFileMapping", errno)
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}
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// Create the memory map.
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addr, errno := syscall.MapViewOfFile(h, syscall.FILE_MAP_READ, 0, 0, uintptr(sz))
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if addr == 0 {
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return nil, os.NewSyscallError("MapViewOfFile", errno)
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}
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// Close mapping handle.
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if err := syscall.CloseHandle(syscall.Handle(h)); err != nil {
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return nil, os.NewSyscallError("CloseHandle", err)
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}
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// Convert to a byte slice.
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b := ((*[0xFFFFFFF]byte)(unsafe.Pointer(addr)))[0:sz]
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return b, nil
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}
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// munmap unmaps a pointer from a file.
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// Based on: https://github.com/edsrzf/mmap-go
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func munmap(b []byte) error {
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addr := (uintptr)(unsafe.Pointer(&b[0]))
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if err := syscall.UnmapViewOfFile(addr); err != nil {
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return os.NewSyscallError("UnmapViewOfFile", err)
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}
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return nil
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}
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