Merge pull request #13 from bojand/json_output

Add JSON output support. Actually implement -o output flag.

cmd/grpcannon/main.go

@@ -146,9 +146,20 @@ func main() {
 		errAndExit(err.Error())
 	}
 
+	output := os.Stdout
+	outputPath := strings.TrimSpace(cfg.Output)
+	if outputPath != "" {
+		f, err := os.Create(outputPath)
+		if err != nil {
+			errAndExit(err.Error())
+		}
+		defer f.Close()
+		output = f
+	}
+
 	p := printer.ReportPrinter{
 		Report: report,
-		Out:    os.Stdout}
+		Out:    output}
 
 	p.Print(cfg.Format)
 }

config/config.go

@@ -55,6 +55,7 @@ func New(proto, protoset, call, cert, cName string, n, c, qps int, z time.Durati
 		Timeout:       timeout,
 		DataPath:      dataPath,
 		MetadataPath:  mdPath,
+		Output:        output,
 		Format:        format,
 		Host:          host,
 		ImportPaths:   importPaths,

printer/printer.go

@@ -26,23 +26,30 @@ type ReportPrinter struct {
 // If format is "csv" detailed listing is printer in csv format.
 // Otherwise the summary of results is printed.
 func (rp *ReportPrinter) Print(format string) {
-	outputTmpl := format
-	switch outputTmpl {
-	case "":
-		outputTmpl = defaultTmpl
-	case "csv":
-		outputTmpl = csvTmpl
-	}
-	buf := &bytes.Buffer{}
-	templ := template.Must(template.New("tmpl").Funcs(tmplFuncMap).Parse(outputTmpl))
-	if err := templ.Execute(buf, *rp.Report); err != nil {
-		log.Println("error:", err.Error())
-		return
-	}
+	switch format {
+	case "", "csv":
+		outputTmpl := defaultTmpl
+		if format == "csv" {
+			outputTmpl = csvTmpl
+		}
+		buf := &bytes.Buffer{}
+		templ := template.Must(template.New("tmpl").Funcs(tmplFuncMap).Parse(outputTmpl))
+		if err := templ.Execute(buf, *rp.Report); err != nil {
+			log.Println("error:", err.Error())
+			return
+		}
 
-	rp.printf(buf.String())
+		rp.printf(buf.String())
 
-	rp.printf("\n")
+		rp.printf("\n")
+	case "json":
+		rep, err := json.Marshal(*rp.Report)
+		if err != nil {
+			log.Println("error:", err.Error())
+			return
+		}
+		rp.printf(string(rep))
+	}
 }
 
 func (rp *ReportPrinter) printf(s string, v ...interface{}) {

reporter.go

@@ -38,6 +38,26 @@ type Report struct {
 	Details             []ResultDetail
 }
 
+// LatencyDistribution holds latency distribution data
+type LatencyDistribution struct {
+	Percentage int
+	Latency    time.Duration
+}
+
+// Bucket holds histogram data
+type Bucket struct {
+	Mark      float64 // The Mark for histogram bucket in seconds
+	Count     int     // The count in the bucket
+	Frequency float64 // The frequency of results in the bucket as a decimal percentage
+}
+
+// ResultDetail data for each result
+type ResultDetail struct {
+	Latency time.Duration
+	Error   string
+	Status  string
+}
+
 func newReporter(results chan *callResult, n int) *Reporter {
 	cap := min(n, maxResult)
 	return &Reporter{
@@ -168,23 +188,3 @@ func histogram(latencies *[]float64, slowest, fastest float64) []Bucket {
 	}
 	return res
 }
-
-// LatencyDistribution holds latency distribution data
-type LatencyDistribution struct {
-	Percentage int
-	Latency    time.Duration
-}
-
-// Bucket holds histogram data
-type Bucket struct {
-	Mark      float64
-	Count     int
-	Frequency float64
-}
-
-// ResultDetail data for each result
-type ResultDetail struct {
-	Latency time.Duration
-	Error   string
-	Status  string
-}