mirror of
https://github.com/dutchcoders/transfer.sh.git
synced 2024-12-27 12:50:18 +01:00
cb6e5cb0c7
* use dep for vendoring * lets encrypt * moved web to transfer.sh-web repo * single command install * added first tests
65 lines
2.1 KiB
Go
65 lines
2.1 KiB
Go
/*
|
|
https://github.com/fs111/kurz.go/blob/master/src/codec.go
|
|
|
|
Originally written and Copyright (c) 2011 André Kelpe
|
|
Modifications Copyright (c) 2015 John Ko
|
|
|
|
Permission is hereby granted, free of charge, to any person obtaining a copy of
|
|
this software and associated documentation files (the "Software"), to deal in
|
|
the Software without restriction, including without limitation the rights to
|
|
use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of
|
|
the Software, and to permit persons to whom the Software is furnished to do so,
|
|
subject to the following conditions:
|
|
|
|
The above copyright notice and this permission notice shall be included in all
|
|
copies or substantial portions of the Software.
|
|
|
|
THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
|
|
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS
|
|
FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR
|
|
COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER
|
|
IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
|
|
CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
|
|
*/
|
|
|
|
package server
|
|
|
|
import (
|
|
"math"
|
|
"strings"
|
|
)
|
|
|
|
const (
|
|
// characters used for short-urls
|
|
SYMBOLS = "0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ"
|
|
|
|
// someone set us up the bomb !!
|
|
BASE = int64(len(SYMBOLS))
|
|
)
|
|
|
|
// encodes a number into our *base* representation
|
|
// TODO can this be made better with some bitshifting?
|
|
func Encode(number int64) string {
|
|
rest := number % BASE
|
|
// strings are a bit weird in go...
|
|
result := string(SYMBOLS[rest])
|
|
if number-rest != 0 {
|
|
newnumber := (number - rest) / BASE
|
|
result = Encode(newnumber) + result
|
|
}
|
|
return result
|
|
}
|
|
|
|
// Decodes a string given in our encoding and returns the decimal
|
|
// integer.
|
|
func Decode(input string) int64 {
|
|
const floatbase = float64(BASE)
|
|
l := len(input)
|
|
var sum int = 0
|
|
for index := l - 1; index > -1; index -= 1 {
|
|
current := string(input[index])
|
|
pos := strings.Index(SYMBOLS, current)
|
|
sum = sum + (pos * int(math.Pow(floatbase, float64((l-index-1)))))
|
|
}
|
|
return int64(sum)
|
|
}
|