Major rewrite

* use dep for vendoring
* lets encrypt
* moved web to transfer.sh-web repo
* single command install
* added first tests

server/codec.go

@@ -0,0 +1,65 @@
+/*
+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)
+}