parser: Optimize multi bulk request parsing.

parser.go

@@ -114,16 +114,12 @@ func _parseReply(rd reader, useIfaceSlice bool) (interface{}, error) {
 		}
 
 		if useIfaceSlice {
-			vals := make([]interface{}, 0)
-			if len(line) == 2 && line[1] == '0' {
-				return vals, nil
-			}
-
 			numReplies, err := strconv.ParseInt(string(line[1:]), 10, 64)
 			if err != nil {
 				return nil, err
 			}
 
+			vals := make([]interface{}, 0, numReplies)
 			for i := int64(0); i < numReplies; i++ {
 				v, err := parseReply(rd)
 				if err == Nil {
@@ -137,16 +133,12 @@ func _parseReply(rd reader, useIfaceSlice bool) (interface{}, error) {
 
 			return vals, nil
 		} else {
-			vals := make([]string, 0)
-			if len(line) == 2 && line[1] == '0' {
-				return vals, nil
-			}
-
 			numReplies, err := strconv.ParseInt(string(line[1:]), 10, 64)
 			if err != nil {
 				return nil, err
 			}
 
+			vals := make([]string, 0, numReplies)
 			for i := int64(0); i < numReplies; i++ {
 				v, err := parseReply(rd)
 				if err != nil {

req_test.go

@@ -35,21 +35,17 @@ func (t *RequestTest) TearDownTest(c *C) {}
 
 //------------------------------------------------------------------------------
 
-func (t *RequestTest) BenchmarkStatusReq(c *C) {
+func (t *RequestTest) benchmarkReq(c *C, reqString string, req redis.Req, checker Checker, expected interface{}) {
 	c.StopTimer()
 
-	lineReader := NewLineReader([]byte("+OK\r\n"))
+	lineReader := NewLineReader([]byte(reqString))
 	rd := bufio.NewReaderSize(lineReader, 1024)
-	req := redis.NewStatusReq()
 
 	for i := 0; i < 10; i++ {
-		vI, err := req.ParseReply(rd)
+		vIface, err := req.ParseReply(rd)
 		c.Check(err, IsNil)
-		c.Check(vI, Equals, "OK")
+		c.Check(vIface, checker, expected)
-
+		req.SetVal(vIface)
-		req.SetVal(vI)
-		c.Check(req.Err(), IsNil)
-		c.Check(req.Val(), Equals, "OK")
 	}
 
 	c.StartTimer()
@@ -57,7 +53,23 @@ func (t *RequestTest) BenchmarkStatusReq(c *C) {
 	for i := 0; i < c.N; i++ {
 		v, _ := req.ParseReply(rd)
 		req.SetVal(v)
-		req.Err()
-		req.Val()
 	}
 }
+
+func (t *RequestTest) BenchmarkStatusReq(c *C) {
+	t.benchmarkReq(c, "+OK\r\n", redis.NewStatusReq(), Equals, "OK")
+}
+
+func (t *RequestTest) BenchmarkStringReq(c *C) {
+	t.benchmarkReq(c, "$5\r\nhello\r\n", redis.NewStringReq(), Equals, "hello")
+}
+
+func (t *RequestTest) BenchmarkStringSliceReq(c *C) {
+	t.benchmarkReq(
+		c,
+		"*2\r\n$5\r\nhello\r\n$5\r\nhello\r\n",
+		redis.NewStringSliceReq(),
+		DeepEquals,
+		[]string{"hello", "hello"},
+	)
+}