Results: Extraction + Encoding, Decoding

lib/attack.go

@@ -4,29 +4,17 @@ import (
 	"errors"
 	"io/ioutil"
 	"net/http"
-	"sort"
 	"time"
 )
 
-// Result represents the metrics defined out of an http.Response
-// generated by each target hit
-type Result struct {
-	Code      uint16
-	Timestamp time.Time
-	Timing    time.Duration
-	BytesOut  uint64
-	BytesIn   uint64
-	Error     error
-}
-
 // Attack hits the passed Targets (http.Requests) at the rate specified for
 // duration time and then waits for all the requests to come back.
 // The results of the attack are put into a slice which is returned.
-func Attack(targets Targets, rate uint64, duration time.Duration) []Result {
+func Attack(targets Targets, rate uint64, duration time.Duration) Results {
 	total := rate * uint64(duration.Seconds())
 	hits := make(chan *http.Request, total)
 	res := make(chan Result, total)
-	results := make(results, total)
+	results := make(Results, total)
 	// Scatter
 	go drill(rate, hits, res)
 	for i := 0; i < cap(hits); i++ {
@@ -39,18 +27,9 @@ func Attack(targets Targets, rate uint64, duration time.Duration) []Result {
 	}
 	close(res)
 
-	sort.Sort(results)
+	return results.Sort()
-
-	return results
 }
 
-// results is a slice of Result defined only to be sortable with sort.Interface
-type results []Result
-
-func (r results) Len() int           { return len(r) }
-func (r results) Less(i, j int) bool { return r[i].Timestamp.Before(r[j].Timestamp) }
-func (r results) Swap(i, j int)      { r[i], r[j] = r[j], r[i] }
-
 // drill loops over the passed reqs channel and executes each request.
 // It is throttled to the rate specified.
 func drill(rate uint64, reqs chan *http.Request, res chan Result) {

lib/results.go

@@ -0,0 +1,46 @@
+package vegeta
+
+import (
+	"encoding/gob"
+	"io"
+	"sort"
+	"time"
+)
+
+// Result represents the metrics defined out of an http.Response
+// generated by each target hit
+type Result struct {
+	Code      uint16
+	Timestamp time.Time
+	Timing    time.Duration
+	BytesOut  uint64
+	BytesIn   uint64
+	Error     error
+}
+
+// Results is a slice of Result structs with encoding,
+// decoding and sorting behavior attached
+type Results []Result
+
+// WriteTo encodes the results and writes it to an io.Writer
+// returning an error in case of failure
+func (r Results) WriteTo(out io.Writer) error {
+	return gob.NewEncoder(out).Encode(r)
+}
+
+// ReadFrom reads data from an io.Reader and decodes it into a Results struct
+// returning an error in case of failure
+func (r *Results) ReadFrom(in io.Reader) error {
+	return gob.NewDecoder(in).Decode(r)
+}
+
+// Sort sorts Results by Timestamp in ascending order and returns
+// the sorted slice
+func (r Results) Sort() Results {
+	sort.Sort(r)
+	return r
+}
+
+func (r Results) Len() int           { return len(r) }
+func (r Results) Less(i, j int) bool { return r[i].Timestamp.Before(r[j].Timestamp) }
+func (r Results) Swap(i, j int)      { r[i], r[j] = r[j], r[i] }

lib/results_test.go

@@ -0,0 +1,50 @@
+package vegeta
+
+import (
+	"bytes"
+	"sort"
+	"testing"
+	"time"
+)
+
+func TestEncoding(t *testing.T) {
+	results := Results{
+		Result{200, time.Now(), 100 * time.Millisecond, 10, 30, nil},
+		Result{200, time.Now(), 20 * time.Millisecond, 20, 20, nil},
+		Result{200, time.Now(), 30 * time.Millisecond, 30, 10, nil},
+	}
+	buffer := &bytes.Buffer{}
+
+	if err := results.WriteTo(buffer); err != nil {
+		t.Fatalf("Failed WriteTo: %s", err)
+	}
+
+	decoded := Results{}
+	if err := decoded.ReadFrom(buffer); err != nil {
+		t.Fatalf("Failed ReadFrom: %s", err)
+	}
+
+	if len(decoded) != len(results) {
+		t.Fatalf("Length mismatch. Want: %d, Got: %d", len(results), len(decoded))
+	}
+
+	for i, result := range results {
+		if decoded[i].Timestamp != result.Timestamp {
+			t.Fatalf("Expected result with timestamp: %s, got: %s", result.Timestamp, decoded[i].Timestamp)
+		}
+	}
+}
+
+func TestSort(t *testing.T) {
+	results := Results{
+		Result{Timestamp: time.Date(2013, 9, 10, 20, 4, 0, 3, time.UTC)},
+		Result{Timestamp: time.Date(2013, 9, 10, 20, 4, 0, 2, time.UTC)},
+		Result{Timestamp: time.Date(2013, 9, 10, 20, 4, 0, 1, time.UTC)},
+	}
+
+	results.Sort()
+
+	if !sort.IsSorted(results) {
+		t.Fatalf("Sort failed: %v", results)
+	}
+}