seaweedfs/go/storage/volume_ttl.go
2015-03-22 12:50:04 -07:00

136 lines
2.3 KiB
Go

package storage
import (
"strconv"
)
const (
//stored unit types
Empty byte = iota
Minute
Hour
Day
Week
Month
Year
)
type TTL struct {
count byte
unit byte
}
var EMPTY_TTL = &TTL{}
// translate a readable ttl to internal ttl
// Supports format example:
// 3m: 3 minutes
// 4h: 4 hours
// 5d: 5 days
// 6w: 6 weeks
// 7M: 7 months
// 8y: 8 years
func ReadTTL(ttlString string) (*TTL, error) {
if ttlString == "" {
return EMPTY_TTL, nil
}
ttlBytes := []byte(ttlString)
unitByte := ttlBytes[len(ttlBytes)-1]
countBytes := ttlBytes[0 : len(ttlBytes)-1]
if '0' <= unitByte && unitByte <= '9' {
countBytes = ttlBytes
unitByte = 'm'
}
count, err := strconv.Atoi(string(countBytes))
unit := toStoredByte(unitByte)
return &TTL{count: byte(count), unit: unit}, err
}
// read stored bytes to a ttl
func LoadTTLFromBytes(input []byte) (t *TTL) {
return &TTL{count: input[0], unit: input[1]}
}
// read stored bytes to a ttl
func LoadTTLFromUint32(ttl uint32) (t *TTL) {
input := make([]byte, 2)
input[1] = byte(ttl)
input[0] = byte(ttl >> 8)
return LoadTTLFromBytes(input)
}
// save stored bytes to an output with 2 bytes
func (t *TTL) ToBytes(output []byte) {
output[0] = t.count
output[1] = t.unit
}
func (t *TTL) ToUint32() (output uint32) {
output = uint32(t.count) << 8
output += uint32(t.unit)
return output
}
func (t *TTL) String() string {
if t == nil || t.count == 0 {
return ""
}
if t.unit == Empty {
return ""
}
countString := strconv.Itoa(int(t.count))
switch t.unit {
case Minute:
return countString + "m"
case Hour:
return countString + "h"
case Day:
return countString + "d"
case Week:
return countString + "w"
case Month:
return countString + "M"
case Year:
return countString + "y"
}
return ""
}
func toStoredByte(readableUnitByte byte) byte {
switch readableUnitByte {
case 'm':
return Minute
case 'h':
return Hour
case 'd':
return Day
case 'w':
return Week
case 'M':
return Month
case 'y':
return Year
}
return 0
}
func (t TTL) Minutes() uint32 {
switch t.unit {
case Empty:
return 0
case Minute:
return uint32(t.count)
case Hour:
return uint32(t.count) * 60
case Day:
return uint32(t.count) * 60 * 24
case Week:
return uint32(t.count) * 60 * 24 * 7
case Month:
return uint32(t.count) * 60 * 24 * 31
case Year:
return uint32(t.count) * 60 * 24 * 365
}
return 0
}