improve statusLine and StatusMessage by using slice instead of map

status.go

@@ -2,14 +2,19 @@ package fasthttp
 
 import (
 	"fmt"
-	"sync/atomic"
+)
+
+const (
+	statusMessageMin = 100
+	statusMessageMax = 511
 )
 
 // HTTP status codes were stolen from net/http.
 const (
 	StatusContinue           = 100 // RFC 7231, 6.2.1
 	StatusSwitchingProtocols = 101 // RFC 7231, 6.2.2
 	StatusProcessing         = 102 // RFC 2518, 10.1
+	StatusEarlyHints         = 103 // RFC 8297
 
 	StatusOK                   = 200 // RFC 7231, 6.3.1
 	StatusCreated              = 201 // RFC 7231, 6.3.2
@@ -51,6 +56,7 @@ const (
 	StatusRequestedRangeNotSatisfiable = 416 // RFC 7233, 4.4
 	StatusExpectationFailed            = 417 // RFC 7231, 6.5.14
 	StatusTeapot                       = 418 // RFC 7168, 2.3.3
+	StatusMisdirectedRequest           = 421 // RFC 7540, 9.1.2
 	StatusUnprocessableEntity          = 422 // RFC 4918, 11.2
 	StatusLocked                       = 423 // RFC 4918, 11.3
 	StatusFailedDependency             = 424 // RFC 4918, 11.4
@@ -74,12 +80,13 @@ const (
 )
 
 var (
-	statusLines atomic.Value
+	statusLines = make([][]byte, statusMessageMax+1)
 
-	statusMessages = map[int]string{
+	statusMessages = []string{
 		StatusContinue:           "Continue",
 		StatusSwitchingProtocols: "Switching Protocols",
 		StatusProcessing:         "Processing",
+		StatusEarlyHints:         "Early Hints",
 
 		StatusOK:                   "OK",
 		StatusCreated:              "Created",
@@ -120,6 +127,7 @@ var (
 		StatusRequestedRangeNotSatisfiable: "Requested Range Not Satisfiable",
 		StatusExpectationFailed:            "Expectation Failed",
 		StatusTeapot:                       "I'm a teapot",
+		StatusMisdirectedRequest:           "Misdirected Request",
 		StatusUnprocessableEntity:          "Unprocessable Entity",
 		StatusLocked:                       "Locked",
 		StatusFailedDependency:             "Failed Dependency",
@@ -145,6 +153,10 @@ var (
 
 // StatusMessage returns HTTP status message for the given status code.
 func StatusMessage(statusCode int) string {
+	if statusCode < statusMessageMin || statusCode > statusMessageMax {
+		return "Unknown Status Code"
+	}
+
 	s := statusMessages[statusCode]
 	if s == "" {
 		s = "Unknown Status Code"
@@ -153,24 +165,21 @@ func StatusMessage(statusCode int) string {
 }
 
 func init() {
-	statusLines.Store(make(map[int][]byte))
+	// Fill all valid status lines
+	for i := 0; i < len(statusLines); i++ {
+		statusLines[i] = []byte(fmt.Sprintf("HTTP/1.1 %d %s\r\n", i, StatusMessage(i)))
+	}
 }
 
 func statusLine(statusCode int) []byte {
-	m := statusLines.Load().(map[int][]byte)
-	h := m[statusCode]
-	if h != nil {
-		return h
+	if statusCode < 0 || statusCode > statusMessageMax {
+		return invalidStatusLine(statusCode)
 	}
 
-	statusText := StatusMessage(statusCode)
+	return statusLines[statusCode]
+}
 
-	h = []byte(fmt.Sprintf("HTTP/1.1 %d %s\r\n", statusCode, statusText))
-	newM := make(map[int][]byte, len(m)+1)
-	for k, v := range m {
-		newM[k] = v
-	}
-	newM[statusCode] = h
-	statusLines.Store(newM)
-	return h
+func invalidStatusLine(statusCode int) []byte {
+	statusText := StatusMessage(statusCode)
+	return []byte(fmt.Sprintf("HTTP/1.1 %d %s\r\n", statusCode, statusText))
 }

status_test.go

@@ -0,0 +1,24 @@
+package fasthttp
+
+import (
+	"bytes"
+	"testing"
+)
+
+func TestStatusLine(t *testing.T) {
+	t.Parallel()
+
+	testStatusLine(t, -1, []byte("HTTP/1.1 -1 Unknown Status Code\r\n"))
+	testStatusLine(t, 99, []byte("HTTP/1.1 99 Unknown Status Code\r\n"))
+	testStatusLine(t, 200, []byte("HTTP/1.1 200 OK\r\n"))
+	testStatusLine(t, 512, []byte("HTTP/1.1 512 Unknown Status Code\r\n"))
+	testStatusLine(t, 512, []byte("HTTP/1.1 512 Unknown Status Code\r\n"))
+	testStatusLine(t, 520, []byte("HTTP/1.1 520 Unknown Status Code\r\n"))
+}
+
+func testStatusLine(t *testing.T, statusCode int, expected []byte) {
+	line := statusLine(statusCode)
+	if !bytes.Equal(expected, line) {
+		t.Fatalf("unexpected status line %s. Expecting %s", string(line), string(expected))
+	}
+}

status_timing_test.go

@@ -0,0 +1,29 @@
+package fasthttp
+
+import (
+	"bytes"
+	"testing"
+)
+
+func BenchmarkStatusLine99(b *testing.B) {
+	benchmarkStatusLine(b, 99, []byte("HTTP/1.1 99 Unknown Status Code\r\n"))
+}
+
+func BenchmarkStatusLine200(b *testing.B) {
+	benchmarkStatusLine(b, 200, []byte("HTTP/1.1 200 OK\r\n"))
+}
+
+func BenchmarkStatusLine512(b *testing.B) {
+	benchmarkStatusLine(b, 512, []byte("HTTP/1.1 512 Unknown Status Code\r\n"))
+}
+
+func benchmarkStatusLine(b *testing.B, statusCode int, expected []byte) {
+	b.RunParallel(func(pb *testing.PB) {
+		for pb.Next() {
+			line := statusLine(statusCode)
+			if !bytes.Equal(expected, line) {
+				b.Fatalf("unexpected status line %s. Expecting %s", string(line), string(expected))
+			}
+		}
+	})
+}