Refactoring

.gitignore

@@ -1 +1,2 @@
 termstats
+*.swp

cmdline.go

@@ -0,0 +1,15 @@
+package main
+
+import (
+	"path/filepath"
+)
+
+// BaseCommand returns cleaned command name from Cmdline array.
+//
+// I.e. "./some.service/binary.name -arg 1 -arg" will be "binary.name".
+func BaseCommand(cmdline []string) string {
+	if len(cmdline) == 0 {
+		return ""
+	}
+	return filepath.Base(cmdline[0])
+}

data.go

@@ -0,0 +1,31 @@
+package main
+
+import "time"
+
+// Data represents data to be passed to UI.
+type Data struct {
+	Services      Services
+	TotalMemory   *Stack
+	LastTimestamp time.Time
+}
+
+// NewData inits and return new data object.
+func NewData() *Data {
+	return &Data{
+		TotalMemory: NewStack(140),
+	}
+}
+
+// FindService returns existing service by port.
+func (d *Data) FindService(port string) *Service {
+	if d.Services == nil {
+		return nil
+	}
+	for _, service := range d.Services {
+		if service.Port == port {
+			return service
+		}
+	}
+
+	return nil
+}

expvars.go

@@ -2,16 +2,13 @@ package main
 
 import (
 	"encoding/json"
-	"fmt"
 	"io"
-	"net/http"
 	"runtime"
 )
 
-// Expvars holds all vars we support via expvars. It implements Source interface.
-
 const ExpvarsUrl = "/debug/vars"
 
+// ExpvarsSource implements Source interface for retrieving Expvars.
 type ExpvarsSource struct {
 	Ports []string
 }
@@ -19,9 +16,8 @@ type ExpvarsSource struct {
 type Expvars map[string]Expvar
 
 type Expvar struct {
-	MemStats   *runtime.MemStats `json:"memstats"`
-	Cmdline    []string          `json:"cmdline"`
-	Goroutines int64             `json:"goroutines,omitempty"`
+	MemStats *runtime.MemStats `json:"memstats"`
+	Cmdline  []string          `json:"cmdline"`
 
 	Err error `json:"-,omitempty"`
 }
@@ -32,37 +28,6 @@ func NewExpvarsSource(ports []string) *ExpvarsSource {
 	}
 }
 
-func (e *ExpvarsSource) Update() (interface{}, error) {
-	vars := make(Expvars)
-	for _, port := range e.Ports {
-		addr := fmt.Sprintf("http://localhost:%s%s", port, ExpvarsUrl)
-		resp, err := http.Get(addr)
-		if err != nil {
-			expvar := &Expvar{}
-			expvar.Err = err
-			vars[port] = *expvar
-			continue
-		}
-		if resp.StatusCode == http.StatusNotFound {
-			expvar := &Expvar{}
-			expvar.Err = fmt.Errorf("Page not found. Did you import expvars?")
-			vars[port] = *expvar
-			continue
-		}
-		defer resp.Body.Close()
-
-		expvar, err := ParseExpvar(resp.Body)
-		if err != nil {
-			expvar = &Expvar{}
-			expvar.Err = err
-		}
-
-		vars[port] = *expvar
-	}
-
-	return vars, nil
-}
-
 // ParseExpvar unmarshals data to Expvar variable.
 func ParseExpvar(r io.Reader) (*Expvar, error) {
 	var vars Expvar

expvars_test.go

@@ -5,7 +5,10 @@ import (
 	"testing"
 )
 
-const expvarsTestFile = "./expvars.json"
+const (
+	expvarsTestFile    = "./expvars.json"
+	expvarsAdvTestFile = "./expvars_advanced.json"
+)
 
 func TestExpvars(t *testing.T) {
 	file, err := os.Open(expvarsTestFile)
@@ -23,3 +26,36 @@ func TestExpvars(t *testing.T) {
 		t.Fatalf("Cmdline should have 3 items, but has %d", len(vars.Cmdline))
 	}
 }
+
+/*
+func TestExpvarsAdvanced(t *testing.T) {
+	file, err := os.Open(expvarsAdvTestFile)
+	if err != nil {
+		t.Fatalf("cannot open test file %v", err)
+	}
+	defer file.Close()
+
+	vars, err := ParseExpvar(file)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	if len(vars.Vars) != 4 {
+		t.Fatalf("vars should have 2 items, but has %d", len(vars.Vars))
+	}
+
+	if int(vars.Vars["goroutines"].(float64)) != 10 {
+		t.Logf("Expecting 'goroutines' to be %d, but got %d", 10, vars.Vars["goroutines"])
+	}
+
+	counters := vars.Vars["counters"].(map[string]interface{})
+	counterA := counters["A"].(float64)
+	counterB := counters["B"].(float64)
+	if counterA != 123.12 {
+		t.Logf("Expecting 'counter.A' to be %f, but got %f", 123.12, counterA)
+	}
+	if int(counterB) != 245342 {
+		t.Logf("Expecting 'counter.B' to be %d, but got %d", 245342, counterB)
+	}
+}
+*/

main.go

@@ -3,8 +3,6 @@ package main
 import (
 	"flag"
 	"log"
-	"path/filepath"
-	"strings"
 	"time"
 
 	"github.com/gizak/termui"
@@ -24,7 +22,7 @@ func main() {
 	}
 
 	data := *NewData()
-	var source Source = NewExpvarsSource(ports)
+	var source = NewExpvarsSource(ports)
 	for _, port := range ports {
 		service := NewService(port)
 		data.Services = append(data.Services, service)
@@ -41,31 +39,17 @@ func main() {
 	evtCh := termui.EventCh()
 
 	update := func() {
-		d, err := source.Update()
-		if err != nil {
-			log.Println("[ERROR] Cannot update data from source:", err)
-			return
-		}
-		switch source.(type) {
-		case *ExpvarsSource:
-			dat := d.(Expvars)
-
-			for _, port := range source.(*ExpvarsSource).Ports {
-				service := data.FindService(port)
-				if service == nil {
-					continue
-				}
-
-				service.Err = dat[port].Err
-				service.Memstats = dat[port].MemStats
-				service.Goroutines = dat[port].Goroutines
-				service.Cmdline = strings.Join(dat[port].Cmdline, " ")
-				if dat[port].Cmdline != nil {
-					service.Name = filepath.Base(dat[port].Cmdline[0])
-				}
+		for _, port := range source.Ports {
+			service := data.FindService(port)
+			if service == nil {
+				continue
 			}
+
+			service.Update()
 		}
+
 		data.LastTimestamp = time.Now()
+
 		ui.Update(data)
 	}
 	update()

service.go

@@ -1,33 +1,21 @@
 package main
 
 import (
+	"fmt"
+	"net/http"
 	"runtime"
-	"time"
+	"strings"
 )
 
-// Data represents data to be passed to UI.
-type Data struct {
-	Services      Services
-	TotalMemory   *Stack
-	LastTimestamp time.Time
-}
-
-func NewData() *Data {
-	return &Data{
-		TotalMemory: NewStack(140),
-	}
-}
-
 type Services []*Service
 
 // Service represents constantly updating info about single service.
 type Service struct {
-	Name       string
-	Port       string
-	IsAlive    bool
-	Cmdline    string
-	Memstats   *runtime.MemStats
-	Goroutines int64
+	Port string
+	Name string
+
+	Cmdline  string
+	Memstats *runtime.MemStats
 
 	Err error
 }
@@ -40,15 +28,35 @@ func NewService(port string) *Service {
 	}
 }
 
-func (d *Data) FindService(port string) *Service {
-	if d.Services == nil {
-		return nil
-	}
-	for _, service := range d.Services {
-		if service.Port == port {
-			return service
+// Update updates Service info from Expvar variable.
+func (s *Service) Update() {
+	expvar := &Expvar{}
+	resp, err := http.Get(s.Addr())
+	defer resp.Body.Close()
+	if err != nil {
+		expvar.Err = err
+	} else if resp.StatusCode == http.StatusNotFound {
+		expvar.Err = fmt.Errorf("Vars not found. Did you import expvars?")
+	} else {
+		expvar, err = ParseExpvar(resp.Body)
+		if err != nil {
+			expvar = &Expvar{Err: err}
 		}
 	}
 
-	return nil
+	s.Err = expvar.Err
+	s.Memstats = expvar.MemStats
+
+	// Update name and cmdline only if empty
+	if len(s.Cmdline) == 0 {
+		s.Cmdline = strings.Join(expvar.Cmdline, " ")
+		s.Name = BaseCommand(expvar.Cmdline)
+	}
+}
+
+// Addr returns fully qualified host:port pair for service.
+//
+// If host is not specified, 'localhost' is used.
+func (s Service) Addr() string {
+	return fmt.Sprintf("http://localhost:%s%s", s.Port, ExpvarsUrl)
 }

ui_dummy.go

@@ -27,9 +27,11 @@ func (u *DummyUI) Update(data Data) {
 			fmt.Printf("%s/%s ", alloc, sys)
 		}
 
-		if service.Goroutines != 0 {
-			fmt.Printf("goroutines: %d", service.Goroutines)
-		}
+		/*
+			if service.Goroutines != 0 {
+				fmt.Printf("goroutines: %d", service.Goroutines)
+			}
+		*/
 		fmt.Printf("\n")
 	}
 }

ui_termui.go

@@ -78,11 +78,11 @@ func (t *TermUI) Update(data Data) {
 
 		name := fmt.Sprintf("[R] %s", service.Name)
 		meminfos := fmt.Sprintf("%s/%s", alloc, heap)
-		goroutine := fmt.Sprintf("%d", service.Goroutines)
+		//goroutine := fmt.Sprintf("%d", service.Goroutines)
 
 		names.Items = append(names.Items, name)
 		meminfo.Items = append(meminfo.Items, meminfos)
-		goroutines.Items = append(goroutines.Items, goroutine)
+		//goroutines.Items = append(goroutines.Items, goroutine)
 	}
 	data.TotalMemory.Push(int(totalAlloc / 1024))