mirror of
https://gitlab.com/pulsechaincom/erigon-pulse.git
synced 2024-12-27 22:28:21 +00:00
72 lines
1.9 KiB
Go
72 lines
1.9 KiB
Go
/*
|
|
Copyright 2021 Erigon contributors
|
|
|
|
Licensed under the Apache License, Version 2.0 (the "License");
|
|
you may not use this file except in compliance with the License.
|
|
You may obtain a copy of the License at
|
|
|
|
http://www.apache.org/licenses/LICENSE-2.0
|
|
|
|
Unless required by applicable law or agreed to in writing, software
|
|
distributed under the License is distributed on an "AS IS" BASIS,
|
|
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
|
|
See the License for the specific language governing permissions and
|
|
limitations under the License.
|
|
*/
|
|
|
|
package mmap
|
|
|
|
import (
|
|
"os"
|
|
"unsafe"
|
|
|
|
"golang.org/x/sys/windows"
|
|
)
|
|
|
|
const MaxMapSize = 0xFFFFFFFFFFFF
|
|
|
|
func Mmap(f *os.File, size int) ([]byte, *[MaxMapSize]byte, error) {
|
|
// Open a file mapping handle.
|
|
sizelo := uint32(size >> 32)
|
|
sizehi := uint32(size) & 0xffffffff
|
|
h, errno := windows.CreateFileMapping(windows.Handle(f.Fd()), nil, windows.PAGE_READONLY, sizelo, sizehi, nil)
|
|
if h == 0 {
|
|
return nil, nil, os.NewSyscallError("CreateFileMapping", errno)
|
|
}
|
|
|
|
// Create the memory map.
|
|
addr, errno := windows.MapViewOfFile(h, windows.FILE_MAP_READ, 0, 0, uintptr(size))
|
|
if addr == 0 {
|
|
return nil, nil, os.NewSyscallError("MapViewOfFile", errno)
|
|
}
|
|
|
|
// Close mapping handle.
|
|
if err := windows.CloseHandle(windows.Handle(h)); err != nil {
|
|
return nil, nil, os.NewSyscallError("CloseHandle", err)
|
|
}
|
|
|
|
// Convert to a byte array.
|
|
mmapHandle2 := ((*[MaxMapSize]byte)(unsafe.Pointer(addr)))
|
|
return mmapHandle2[:size], mmapHandle2, nil
|
|
}
|
|
|
|
func MadviseSequential(mmapHandle1 []byte) error {
|
|
return nil
|
|
}
|
|
|
|
func MadviseRandom(mmapHandle1 []byte) error {
|
|
return nil
|
|
}
|
|
|
|
func Munmap(_ []byte, mmapHandle2 *[MaxMapSize]byte) error {
|
|
if mmapHandle2 == nil {
|
|
return nil
|
|
}
|
|
|
|
addr := (uintptr)(unsafe.Pointer(&mmapHandle2[0]))
|
|
if err := windows.UnmapViewOfFile(addr); err != nil {
|
|
return os.NewSyscallError("UnmapViewOfFile", err)
|
|
}
|
|
return nil
|
|
}
|