fixed bug

doorman.go

@@ -39,6 +39,7 @@ type Doorman struct {
 	LastChangeTimestamp int64          // an always increasing int that represent the last time the doorman has beed updated
 	Probabilities       []*big.Rat     //  The probability of each cases.  The sum of probabilities needs to be one
 	wg                  sync.WaitGroup // waitgroup for goroutine safety
+	hashKey             []byte         // the decoded id
 }
 
 func New(id string, probabilities []*big.Rat) (*Doorman, error) {
@@ -47,6 +48,9 @@ func New(id string, probabilities []*big.Rat) (*Doorman, error) {
 		return nil, err
 	} else if len(bid) != 16 {
 		return nil, errors.New("id must be base64 encoded of a 16 bytes array")
+	} else {
+		wab.hashKey = bid
+		wab.Id = id
 	}
 	wab.Probabilities = probabilities
 	return wab, wab.Validate()
@@ -133,7 +137,7 @@ func (w *Doorman) GenerateRandomProbabilityFromInteger(data uint64) *big.Rat {
 }
 
 func (w *Doorman) Hash(data ...[]byte) uint64 {
-	h := siphash.New(make([]byte, 16))
+	h := siphash.New(w.hashKey)
 	for _, datum := range data {
 		h.Write(datum)
 	}

doorman_test.go

@@ -58,7 +58,9 @@ func TestNew(t *testing.T) {
 		t.Error()
 	}
 	goodId := "MTIzNDU2Nzg5MDEyMzQ1Ng=="
-	if _, err := New(goodId, getProbs("1/4", "1/4")); err == nil {
+	if dm, err := New(goodId, getProbs("1/4", "1/4")); err == nil {
+		t.Error()
+	} else if dm.Id != goodId {
 		t.Error()
 	}
 }
@@ -131,6 +133,7 @@ func TestGenerateRandomProbabilityFromBitSlice(t *testing.T) {
 func TestHash(t *testing.T) {
 	m := []byte("doormen are great")
 	w := new(Doorman)
+	w.hashKey = make([]byte, 16)
 	var expt uint64 = 0x3973fc1b3e324215
 	result := w.Hash(m)
 

example/main.go

@@ -10,7 +10,6 @@ import (
 	"strconv"
 
 	"github.com/didiercrunch/doorman"
-	"gopkg.in/mgo.v2/bson"
 )
 
 func getProbs(probs ...float64) []*big.Rat {
@@ -21,9 +20,13 @@ func getProbs(probs ...float64) []*big.Rat {
 	return ret
 }
 
-var wab = doorman.New(bson.ObjectIdHex("558701a2f6fb5e29a4000003"), getProbs(1, 0, 0))
+var wab *doorman.Doorman
 
 func init() {
+	var err error
+	if wab, err = doorman.New("zST8_FWcPDT2-14wDQAAAQ==", getProbs(1, 0, 0)); err != nil {
+		panic(err)
+	}
 	if err := wab.Subscriber("http://localhost:1999"); err != nil {
 		panic(err)
 	}
@@ -47,13 +50,16 @@ var tmpl = `
 <html>
 	<head></head>
 	<body style="background:{{ .color }};width:100%;height:100%">
+		<div style="width: 62.5rem;">
 		<h1 style="text-align:center;">the doorman value is {{ .value }}</h1>
 		<p style="text-align:center;">
-			this doorman depend solely on the url.  If you hit different url you
+			This doorman depend solely on the url.  If you hit different url you
 			will have different doorman results.  For example, here is a random
 			url: <a href="{{ .nextUrl }}" style="color: black;"> {{ .nextUrl }} </a>
 		</p>
 
+		</div>
+
 	</body>
 </html>
 `
@@ -84,5 +90,4 @@ func main() {
 	port := getPort()
 	log.Println("serving on port", port)
 	log.Fatal(http.ListenAndServe(":"+port, nil))
-
 }