Sha256: e5e0efdfa420959dd5db40abfe23e3c0431857d25e1ac8b1e70870094ef4d727
Contents?: true
Size: 1.42 KB
Versions: 16
Compression:
Stored size: 1.42 KB
Contents
//go:build go1.18
// +build go1.18
// Copyright (c) Microsoft Corporation. All rights reserved.
// Licensed under the MIT License. See License.txt in the project root for license information.
package blockblob
import (
"fmt"
"os"
"reflect"
"syscall"
"unsafe"
)
// mmb is a memory mapped buffer
type mmb []byte
// newMMB creates a new memory mapped buffer with the specified size
func newMMB(size int64) (mmb, error) {
const InvalidHandleValue = ^uintptr(0) // -1
prot, access := uint32(syscall.PAGE_READWRITE), uint32(syscall.FILE_MAP_WRITE)
hMMF, err := syscall.CreateFileMapping(syscall.Handle(InvalidHandleValue), nil, prot, uint32(size>>32), uint32(size&0xffffffff), nil)
if err != nil {
return nil, os.NewSyscallError("CreateFileMapping", err)
}
defer syscall.CloseHandle(hMMF)
addr, err := syscall.MapViewOfFile(hMMF, access, 0, 0, uintptr(size))
if err != nil {
return nil, os.NewSyscallError("MapViewOfFile", err)
}
m := mmb{}
h := (*reflect.SliceHeader)(unsafe.Pointer(&m))
h.Data = addr
h.Len = int(size)
h.Cap = h.Len
return m, nil
}
// delete cleans up the memory mapped buffer
func (m *mmb) delete() {
addr := uintptr(unsafe.Pointer(&(([]byte)(*m)[0])))
*m = mmb{}
err := syscall.UnmapViewOfFile(addr)
if err != nil {
// if we get here, there is likely memory corruption.
// please open an issue https://github.com/Azure/azure-sdk-for-go/issues
panic(fmt.Sprintf("UnmapViewOfFile error: %v", err))
}
}
Version data entries
16 entries across 16 versions & 1 rubygems