added floating point limit support

limiter/limiter.go

@@ -54,7 +54,7 @@ func New(generalExpirableOptions *ExpirableOptions) *Limiter {
 // Limiter is a config struct to limit a particular request handler.
 type Limiter struct {
 	// Maximum number of requests to limit per second.
-	max int64
+	max float64
 
 	// Limiter burst size
 	burst int
@@ -151,7 +151,7 @@ func (l *Limiter) GetHeaderEntryExpirationTTL() time.Duration {
 }
 
 // SetMax is thread-safe way of setting maximum number of requests to limit per duration.
-func (l *Limiter) SetMax(max int64) *Limiter {
+func (l *Limiter) SetMax(max float64) *Limiter {
 	l.Lock()
 	l.max = max
 	l.Unlock()
@@ -160,7 +160,7 @@ func (l *Limiter) SetMax(max int64) *Limiter {
 }
 
 // GetMax is thread-safe way of getting maximum number of requests to limit per duration.
-func (l *Limiter) GetMax() int64 {
+func (l *Limiter) GetMax() float64 {
 	l.RLock()
 	defer l.RUnlock()
 	return l.max

limiter/limiter_test.go

@@ -50,6 +50,29 @@ func TestLimitReached(t *testing.T) {
 	}
 }
 
+func TestFloatingLimitReached(t *testing.T) {
+	lmt := New(nil).SetMax(0.1).SetBurst(1)
+	key := "127.0.0.1|/"
+
+	if lmt.LimitReached(key) == true {
+		t.Error("First time count should not reached the limit.")
+	}
+
+	if lmt.LimitReached(key) == false {
+		t.Error("Second time count should return true because it exceeds 1 request per 10 seconds.")
+	}
+
+	<-time.After(7 * time.Second)
+	if lmt.LimitReached(key) == false {
+		t.Error("Third time count should return true because it exceeds 1 request per 10 seconds.")
+	}
+
+	<-time.After(3 * time.Second)
+	if lmt.LimitReached(key) == true {
+		t.Error("Fourth time count should not reached the limit because the 10 second window has passed.")
+	}
+}
+
 func TestLimitReachedWithCustomTokenBucketTTL(t *testing.T) {
 	lmt := New(&ExpirableOptions{DefaultExpirationTTL: time.Second, ExpireJobInterval: 0}).SetMax(1).SetBurst(1)
 	key := "127.0.0.1|/"
@@ -71,7 +94,7 @@ func TestLimitReachedWithCustomTokenBucketTTL(t *testing.T) {
 func TestMuchHigherMaxRequests(t *testing.T) {
 	numRequests := 1000
 	delay := (1 * time.Second) / time.Duration(numRequests)
-	lmt := New(nil).SetMax(int64(numRequests)).SetBurst(1)
+	lmt := New(nil).SetMax(float64(numRequests)).SetBurst(1)
 	key := "127.0.0.1|/"
 
 	for i := 0; i < numRequests; i++ {
@@ -90,7 +113,7 @@ func TestMuchHigherMaxRequests(t *testing.T) {
 func TestMuchHigherMaxRequestsWithCustomTokenBucketTTL(t *testing.T) {
 	numRequests := 1000
 	delay := (1 * time.Second) / time.Duration(numRequests)
-	lmt := New(&ExpirableOptions{DefaultExpirationTTL: time.Minute, ExpireJobInterval: time.Minute}).SetMax(int64(numRequests)).SetBurst(1)
+	lmt := New(&ExpirableOptions{DefaultExpirationTTL: time.Minute, ExpireJobInterval: time.Minute}).SetMax(float64(numRequests)).SetBurst(1)
 	key := "127.0.0.1|/"
 
 	for i := 0; i < numRequests; i++ {

tollbooth.go

@@ -3,25 +3,26 @@ package tollbooth
 
 import (
 	"net/http"
-	"strconv"
 	"strings"
 
+	"fmt"
 	"github.com/didip/tollbooth/errors"
 	"github.com/didip/tollbooth/libstring"
 	"github.com/didip/tollbooth/limiter"
+	"math"
 )
 
 // setResponseHeaders configures X-Rate-Limit-Limit and X-Rate-Limit-Duration
 func setResponseHeaders(lmt *limiter.Limiter, w http.ResponseWriter, r *http.Request) {
-	w.Header().Add("X-Rate-Limit-Limit", strconv.FormatInt(lmt.GetMax(), 10))
+	w.Header().Add("X-Rate-Limit-Limit", fmt.Sprintf("%.2f", lmt.GetMax()))
 	w.Header().Add("X-Rate-Limit-Duration", "1")
 	w.Header().Add("X-Rate-Limit-Request-Forwarded-For", r.Header.Get("X-Forwarded-For"))
 	w.Header().Add("X-Rate-Limit-Request-Remote-Addr", r.RemoteAddr)
 }
 
 // NewLimiter is a convenience function to limiter.New.
-func NewLimiter(max int64, tbOptions *limiter.ExpirableOptions) *limiter.Limiter {
-	return limiter.New(tbOptions).SetMax(max).SetBurst(int(max))
+func NewLimiter(max float64, tbOptions *limiter.ExpirableOptions) *limiter.Limiter {
+	return limiter.New(tbOptions).SetMax(max).SetBurst(int(math.Max(1, max)))
 }
 
 // LimitByKeys keeps track number of request made by keys separated by pipe.