Extract Metrics out of ReportText

Metrics will be reused with other Reporters

lib/metrics.go

@@ -0,0 +1,55 @@
+package vegeta
+
+import (
+	"time"
+)
+
+// Metrics holds the stats computed out of a slice of Results
+// that is used for some of the Reporters
+type Metrics struct {
+	TotalRequests uint64            `json:"total_requests"`
+	TotalTiming   time.Duration     `json:"total_timing"`
+	MeanTiming    time.Duration     `json:"mean_timing"`
+	TotalBytesIn  uint64            `json:"total_bytes_in"`
+	MeanBytesIn   float64           `json:"mean_bytes_in"`
+	TotalBytesOut uint64            `json:"total_bytes_out"`
+	MeanBytesOut  float64           `json:"mean_bytes_out"`
+	TotalSuccess  uint64            `json:"total_success"`
+	MeanSuccess   float64           `json:"mean_success"`
+	StatusCodes   map[uint16]uint64 `json:"status_codes"`
+	Errors        []string          `json:"errors"`
+}
+
+// NewMetrics computes and returns a Metrics struct out of a slice of Results
+func NewMetrics(results []Result) *Metrics {
+	m := &Metrics{
+		TotalRequests: uint64(len(results)),
+		StatusCodes:   map[uint16]uint64{},
+	}
+	errorSet := map[string]struct{}{}
+
+	for _, result := range results {
+		m.StatusCodes[result.Code]++
+		m.TotalTiming += result.Timing
+		m.TotalBytesOut += result.BytesOut
+		m.TotalBytesIn += result.BytesIn
+		if result.Code >= 200 && result.Code < 300 {
+			m.TotalSuccess++
+		}
+		if result.Error != nil {
+			errorSet[result.Error.Error()] = struct{}{}
+		}
+	}
+
+	m.MeanTiming = time.Duration(float64(m.TotalTiming) / float64(m.TotalRequests))
+	m.MeanBytesOut = float64(m.TotalBytesOut) / float64(m.TotalRequests)
+	m.MeanBytesIn = float64(m.TotalBytesIn) / float64(m.TotalRequests)
+	m.MeanSuccess = float64(m.TotalSuccess) / float64(m.TotalRequests)
+
+	m.Errors = make([]string, 0, len(errorSet))
+	for err, _ := range errorSet {
+		m.Errors = append(m.Errors, err)
+	}
+
+	return m
+}

lib/metrics_test.go

@@ -0,0 +1,54 @@
+package vegeta
+
+import (
+	"errors"
+	"testing"
+	"time"
+)
+
+func TestNewMetrics(t *testing.T) {
+	m := NewMetrics([]Result{
+		Result{500, time.Now(), 100 * time.Millisecond, 10, 30, errors.New("Internal server error")},
+		Result{200, time.Now(), 20 * time.Millisecond, 20, 20, nil},
+		Result{200, time.Now(), 30 * time.Millisecond, 30, 10, nil},
+	})
+
+	for field, values := range map[string][]float64{
+		"MeanBytesIn":  []float64{m.MeanBytesIn, 20.0},
+		"MeanBytesOut": []float64{m.MeanBytesOut, 20.0},
+		"MeanSuccess":  []float64{m.MeanSuccess, 0.6666666666666666},
+	} {
+		if values[0] != values[1] {
+			t.Errorf("%s: want: %f, got: %f", field, values[1], values[0])
+		}
+	}
+
+	for field, values := range map[string][]time.Duration{
+		"TotalTiming": []time.Duration{m.TotalTiming, 150 * time.Millisecond},
+		"MeanTiming":  []time.Duration{m.MeanTiming, 50 * time.Millisecond},
+	} {
+		if values[0] != values[1] {
+			t.Errorf("%s: want: %s, got: %s", field, values[1], values[0])
+		}
+	}
+
+	for field, values := range map[string][]uint64{
+		"TotalSuccess":  []uint64{m.TotalSuccess, 2},
+		"TotalBytesOut": []uint64{m.TotalBytesOut, 60},
+		"TotalRequests": []uint64{m.TotalRequests, 3},
+		"TotalBytesIn":  []uint64{m.TotalBytesIn, 60},
+	} {
+		if values[0] != values[1] {
+			t.Errorf("%s: want: %d, got: %d", field, values[1], values[0])
+		}
+	}
+
+	if len(m.StatusCodes) != 2 || m.StatusCodes[200] != 2 || m.StatusCodes[500] != 1 {
+		t.Errorf("StatusCodes: want: %v, got: %v", map[int]int{200: 2, 500: 1}, m.StatusCodes)
+	}
+
+	err := "Internal server error"
+	if len(m.Errors) != 1 || m.Errors[0] != err {
+		t.Errorf("Errors: want: %v, got: %v", []string{err}, m.Errors)
+	}
+}

lib/reporters.go

@@ -9,7 +9,6 @@ import (
 	"fmt"
 	"io"
 	"text/tabwriter"
-	"time"
 )
 
 // Reporter represents any function which takes a slice of Results and
@@ -17,51 +16,25 @@ import (
 // in case of failure
 type Reporter func([]Result, io.Writer) error
 
-// ReportText computes and prints some metrics out of results
-// as formatted text. Metrics include avg time per request, success ratio,
-// total number of request, avg bytes in and avg bytes out.
+// ReportText writes a computed Metrics struct to out as aligned, formatted text
 func ReportText(results []Result, out io.Writer) error {
-	totalRequests := float64(len(results))
-	totalTime := time.Duration(0)
-	totalBytesOut := uint64(0)
-	totalBytesIn := uint64(0)
-	totalSuccess := uint64(0)
-	histogram := map[uint16]uint64{}
-	errors := map[string]struct{}{}
-
-	for _, res := range results {
-		histogram[res.Code]++
-		totalTime += res.Timing
-		totalBytesOut += res.BytesOut
-		totalBytesIn += res.BytesIn
-		if res.Code >= 200 && res.Code < 300 {
-			totalSuccess++
-		}
-		if res.Error != nil {
-			errors[res.Error.Error()] = struct{}{}
-		}
-	}
-
-	avgTime := time.Duration(float64(totalTime) / totalRequests)
-	avgBytesOut := float64(totalBytesOut) / totalRequests
-	avgBytesIn := float64(totalBytesIn) / totalRequests
-	avgSuccess := float64(totalSuccess) / totalRequests
+	m := NewMetrics(results)
 
 	w := tabwriter.NewWriter(out, 0, 8, 2, '\t', tabwriter.StripEscape)
 	fmt.Fprintf(w, "Time(avg)\tRequests\tSuccess\tBytes(rx/tx)\n")
-	fmt.Fprintf(w, "%s\t%d\t%.2f%%\t%.2f/%.2f\n", avgTime, int(totalRequests), avgSuccess*100, avgBytesIn, avgBytesOut)
+	fmt.Fprintf(w, "%s\t%d\t%.2f%%\t%.2f/%.2f\n", m.MeanTiming, m.TotalRequests, m.MeanSuccess*100, m.MeanBytesIn, m.MeanBytesOut)
 
 	fmt.Fprintf(w, "\nCount:\t")
-	for _, count := range histogram {
+	for _, count := range m.StatusCodes {
 		fmt.Fprintf(w, "%d\t", count)
 	}
 	fmt.Fprintf(w, "\nStatus:\t")
-	for code := range histogram {
+	for code := range m.StatusCodes {
 		fmt.Fprintf(w, "%d\t", code)
 	}
 
 	fmt.Fprintln(w, "\n\nError Set:")
-	for err := range errors {
+	for err := range m.Errors {
 		fmt.Fprintln(w, err)
 	}