Rate Limiting.

Signed-off-by: Jeff Ortel <[email protected]>

cmd/main.go

@@ -1,6 +1,7 @@
 package main
 
 import (
+	"github.com/konveyor/tackle2-addon/command"
 	hub "github.com/konveyor/tackle2-hub/addon"
 )
 
@@ -10,6 +11,19 @@ var (
 
 func main() {
 	addon.Run(func() (err error) {
+		for n := -2; n < 2; n++ {
+			addon.Activity("VERBOSITY: %d", n)
+			cmd := command.Command{Path: "ps"}
+			cmd.Options.Add("-ef")
+			cmd.Reporter.Verbosity = n
+			err = cmd.Run()
+
+			addon.Activity("VERBOSITY: %d (Error)", n)
+			cmd = command.Command{Path: "ps"}
+			cmd.Options.Add("hello")
+			cmd.Reporter.Verbosity = n
+			err = cmd.Run()
+		}
 		return
 	})
 }

command/cmd.go

@@ -49,15 +49,15 @@ func (r *Command) RunWith(ctx context.Context) (err error) {
 		} else {
 			r.Reporter.Succeeded(r.Path)
 		}
+		r.writer.End()
+		r.Reporter.End()
 	}()
 	cmd := exec.CommandContext(ctx, r.Path, r.Options...)
 	cmd.Dir = r.Dir
 	cmd.Stdout = &r.writer
 	cmd.Stderr = &r.writer
 	err = cmd.Start()
-	if err == nil {
-		defer r.writer.Close()
-	} else {
+	if err != nil {
 		return
 	}
 	err = cmd.Wait()

command/reporter.go

@@ -1,6 +1,10 @@
 package command
 
-import "strings"
+import (
+	"strings"
+	"fmt"
+	"time"
+)
 
 const (
 	// Disabled reports: NOTHING.
@@ -17,6 +21,7 @@ const (
 // Reporter activity reporter.
 type Reporter struct {
 	Verbosity int
+	queue     chan string
 }
 
 //
@@ -27,7 +32,7 @@ func (r *Reporter) Run(path string, options Options) {
 	case Error:
 	case Default,
 		LiveOutput:
-		addon.Activity(
+		r.report(
 			"[CMD] Running: %s %s",
 			path,
 			strings.Join(options, " "))
@@ -42,7 +47,7 @@ func (r *Reporter) Succeeded(path string) {
 	case Error:
 	case Default,
 		LiveOutput:
-		addon.Activity("[CMD] %s succeeded.", path)
+		r.report("[CMD] %s succeeded.", path)
 	}
 }
 
@@ -53,13 +58,13 @@ func (r *Reporter) Error(path string, err error, output []byte) {
 	case Disabled:
 	case Error,
 		Default:
-		addon.Activity(
+		r.report(
 			"[CMD] %s failed: %s.\n%s",
 			path,
 			err.Error(),
 			output)
 	case LiveOutput:
-		addon.Activity(
+		r.report(
 			"[CMD] %s failed: %s.",
 			path,
 			err.Error())
@@ -74,6 +79,30 @@ func (r *Reporter) Output(output string) {
 	case Error:
 	case Default:
 	case LiveOutput:
-		addon.Activity("> %s", output)
+		r.report("> %s", output)
+	}
+}
+
+//
+// report activity in task Report.Activity.
+// Rate limited.
+func (r *Reporter) report(entry string, v ...interface{}) {
+	if r.queue == nil {
+		r.queue = make(chan string)
+		go func() {
+			for entry := range r.queue {
+				time.Sleep(time.Second)
+				addon.Activity(entry)
+			}
+		}()
+	}
+	r.queue <- fmt.Sprintf(entry, v...)
+}
+
+//
+// End of reporting.
+func (r *Reporter) End() {
+	if r.queue != nil {
+		close(r.queue)
 	}
 }

command/writer.go

@@ -1,6 +1,8 @@
 package command
 
-import "strings"
+import (
+	"strings"
+)
 
 //
 // Writer records command output.
@@ -28,9 +30,9 @@ func (w *Writer) Write(p []byte) (n int, err error) {
 }
 
 //
-// Close the writer.
+// End of writing.
 // When verbosity > 0, output is reported in task Report.Activity.
-func (w *Writer) Close() {
+func (w *Writer) End() {
 	batch := string(w.buffer[w.index:])
 	if len(batch) > 0 {
 		w.reporter.Output(batch)