Merge pull request #10 from machinebox/promote-boxutil

Move boxutil out of x package

Author: matryer

boxutil/doc.go

@@ -0,0 +1,2 @@
+// Package boxutil provides some helpful utilities for consuming Machine Box services.
+package boxutil

boxutil/info.go

@@ -0,0 +1,15 @@
+package boxutil
+
+// Box represents a box client capable of returning
+// Info.
+type Box interface {
+	Info() (*Info, error)
+}
+
+// Info describes box information.
+type Info struct {
+	Name    string
+	Version int
+	Build   string
+	Status  string
+}

boxutil/status.go

@@ -0,0 +1,61 @@
+package boxutil
+
+import (
+	"context"
+	"time"
+)
+
+// readyCheckInterval is the interval to wait between checking
+// the status in StatusChan.
+// Unexported because 1 second is sensible, but configurable to make
+// tests run quicker.
+var readyCheckInterval = 1 * time.Second
+
+// StatusChan gets a channel that periodically gets the box info
+// and sends a message whenever the status changes.
+func StatusChan(ctx context.Context, i Box) <-chan string {
+	statusChan := make(chan string)
+	go func() {
+		var lastStatus string
+		for {
+			select {
+			case <-ctx.Done():
+				return
+			default:
+				time.Sleep(readyCheckInterval)
+				status := "unavailable"
+				info, err := i.Info()
+				if err == nil {
+					status = info.Status
+				}
+				if status != lastStatus {
+					lastStatus = status
+					statusChan <- status
+				}
+			}
+		}
+	}()
+	return statusChan
+}
+
+// WaitForReady blocks until the Box is ready.
+func WaitForReady(ctx context.Context, i Box) error {
+	ctx, cancel := context.WithCancel(ctx)
+	defer cancel()
+	statusChan := StatusChan(ctx, i)
+	for {
+		select {
+		case <-ctx.Done():
+			return ctx.Err()
+		case status := <-statusChan:
+			if IsReady(status) {
+				return nil
+			}
+		}
+	}
+}
+
+// IsReady gets whether the box info status is ready or not.
+func IsReady(status string) bool {
+	return status == "ready"
+}

boxutil/status_test.go

@@ -0,0 +1,95 @@
+package boxutil
+
+import (
+	"context"
+	"errors"
+	"sync"
+	"testing"
+	"time"
+
+	"github.com/matryer/is"
+)
+
+func init() {
+	// quicker for testing
+	readyCheckInterval = 100 * time.Millisecond
+}
+
+func TestStatusChan(t *testing.T) {
+	is := is.New(t)
+
+	i := &testBox{}
+	ctx, cancel := context.WithCancel(context.Background())
+	defer cancel()
+
+	status := StatusChan(ctx, i)
+	is.Equal(<-status, "starting...")
+	i.setReady()
+	is.Equal(<-status, "ready")
+	i.setError()
+	is.Equal(<-status, "unavailable")
+	i.clearError()
+	is.Equal(<-status, "ready")
+
+}
+
+func TestWaitForReady(t *testing.T) {
+	is := is.New(t)
+	i := &testBox{}
+	ctx, cancel := context.WithCancel(context.Background())
+	time.AfterFunc(300*time.Millisecond, cancel)
+	go func() {
+		i.setReady()
+	}()
+	err := WaitForReady(ctx, i)
+	is.NoErr(err)
+}
+
+func TestWaitForReadyTimeout(t *testing.T) {
+	is := is.New(t)
+	i := &testBox{}
+	ctx, cancel := context.WithCancel(context.Background())
+	time.AfterFunc(100*time.Millisecond, cancel)
+	go func() {
+		time.Sleep(200 * time.Millisecond)
+		i.setReady()
+	}()
+	err := WaitForReady(ctx, i)
+	is.Equal(err, context.Canceled)
+}
+
+type testBox struct {
+	lock  sync.Mutex
+	ready bool
+	err   error
+}
+
+func (i *testBox) setReady() {
+	i.lock.Lock()
+	defer i.lock.Unlock()
+	i.ready = true
+}
+
+func (i *testBox) setError() {
+	i.lock.Lock()
+	defer i.lock.Unlock()
+	i.err = errors.New("cannot reach server")
+}
+
+func (i *testBox) clearError() {
+	i.lock.Lock()
+	defer i.lock.Unlock()
+	i.err = nil
+}
+
+func (i *testBox) Info() (*Info, error) {
+	i.lock.Lock()
+	defer i.lock.Unlock()
+	if i.err != nil {
+		return nil, i.err
+	}
+	if i.ready {
+		return &Info{Status: "ready"}, nil
+	}
+	return &Info{Status: "starting..."}, nil
+}

x/boxutil/status.go

@@ -3,6 +3,7 @@ package boxutil
 import (
 	"context"
 	"errors"
+	"log"
 	"time"
 )
 
@@ -19,6 +20,7 @@ var readyCheckInterval = 1 * time.Second
 // StatusChan gets a channel that periodically gets the box info
 // and sends a message whenever the status changes.
 func StatusChan(ctx context.Context, i Box) <-chan string {
+	log.Println("boxutil: DEPRECATED use github.com/machinebox/sdk-go/boxutil instead")
 	statusChan := make(chan string)
 	go func() {
 		var lastStatus string
@@ -45,6 +47,7 @@ func StatusChan(ctx context.Context, i Box) <-chan string {
 
 // WaitForReady blocks until the Box is ready.
 func WaitForReady(ctx context.Context, i Box) error {
+	log.Println("boxutil: DEPRECATED use github.com/machinebox/sdk-go/boxutil instead")
 	ctx, cancel := context.WithCancel(ctx)
 	defer cancel()
 	statusChan := StatusChan(ctx, i)
@@ -62,5 +65,6 @@ func WaitForReady(ctx context.Context, i Box) error {
 
 // IsReady gets whether the box info status is ready or not.
 func IsReady(status string) bool {
+	log.Println("boxutil: DEPRECATED use github.com/machinebox/sdk-go/boxutil instead")
 	return status == "ready"
 }