Files
gotgt/pkg/util/util.go
2016-11-28 11:11:24 +08:00

133 lines
2.7 KiB
Go

/*
Copyright 2016 The GoStor Authors All rights reserved.
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 util provides some basic util functions.
package util
import (
"encoding/binary"
"os"
"syscall"
)
type KeyValue struct {
Key string
Value string
}
func GetUnalignedUint16(u8 []uint8) uint16 {
return binary.BigEndian.Uint16(u8)
}
func GetUnalignedUint32(u8 []uint8) uint32 {
return binary.BigEndian.Uint32(u8)
}
func GetUnalignedUint64(u8 []uint8) uint64 {
return binary.BigEndian.Uint64(u8)
}
// ParseKVText parses iSCSI key value data.
func ParseKVText(txt []byte) map[string]string {
m := make(map[string]string)
var kv, sep int
var key string
for i := 0; i < len(txt); i++ {
if txt[i] == '=' {
if key == "" {
sep = i
key = string(txt[kv:sep])
}
continue
}
if txt[i] == 0 && key != "" {
m[key] = string(txt[sep+1 : i])
key = ""
kv = i + 1
}
}
return m
}
func MarshalKVText(kv []KeyValue) []byte {
var data []byte
for _, v := range kv {
data = append(data, []byte(v.Key)...)
data = append(data, '=')
data = append(data, []byte(v.Value)...)
data = append(data, 0)
}
return data
}
func MarshalUint32(i uint32) []byte {
var data []byte
for j := 24; j >= 0; j -= 8 {
b := byte(i >> uint32(j))
data = append(data, b)
}
return data
}
func MarshalUint64(i uint64) []byte {
var data []byte
for j := 56; j >= 0; j -= 8 {
b := byte(i >> uint32(j))
data = append(data, b)
}
return data
}
func StringToByte(str string, align int, maxlength int) []byte {
var (
data []byte
data2 []byte
length int
d int
)
data = []byte(str)
length = len(data)
d = align - (length % align)
if (length + d) > maxlength {
data = ([]byte(str))[0:maxlength]
return data
} else {
data2 = make([]byte, length+d)
copy(data2, data)
return data2
}
}
const (
POSIX_FADV_NORMAL = iota
POSIX_FADV_RANDOM
POSIX_FADV_SEQUENTIAL
POSIX_FADV_WILLNEED
POSIX_FADV_DONTNEED
POSIX_FADV_NOREUSE
)
func Fadvise(file *os.File, off, length int64, advise uint32) error {
// syscall.SYS_FADVISE64 = 221
_, _, err := syscall.Syscall6(221, file.Fd(), uintptr(off), uintptr(length), uintptr(advise), 0, 0)
if err != 0 {
return err
}
return nil
}