prometheus/db_windows.go
2017-04-05 15:37:48 +02:00

35 lines
851 B
Go

package tsdb
import (
"os"
"syscall"
"unsafe"
)
func mmap(f *os.File, sz int) ([]byte, error) {
low, high := uint32(sz), uint32(sz>>32)
h, errno := syscall.CreateFileMapping(syscall.Handle(f.Fd()), nil, syscall.PAGE_READONLY, low, high, nil)
if h == 0 {
return nil, os.NewSyscallError("CreateFileMapping", errno)
}
addr, errno := syscall.MapViewOfFile(h, syscall.FILE_MAP_READ, 0, 0, uintptr(sz))
if addr == 0 {
return nil, os.NewSyscallError("MapViewOfFile", errno)
}
if err := syscall.CloseHandle(syscall.Handle(h)); err != nil {
return nil, os.NewSyscallError("CloseHandle", err)
}
return (*[1 << 30]byte)(unsafe.Pointer(addr))[:sz], nil
}
func munmap(b []byte) error {
if err := syscall.UnmapViewOfFile((uintptr)(unsafe.Pointer(&b[0]))); err != nil {
return os.NewSyscallError("UnmapViewOfFile", err)
}
return nil
}