Add Rm; Add Ls

etcc.go

@@ -11,13 +11,13 @@ import (
 	"golang.org/x/net/context"
 )
 
-type Etcd struct {
+type Etcc struct {
 	api client.KeysAPI
 }
 
 // New trys to connect to etcd server.  endpoints must be addreses
 // delimited by comma, like "http://127.0.0.1:4001,http://127.0.0.1:2379".
-func New(endpoints string) (*Etcd, error) {
+func New(endpoints string) (*Etcc, error) {
 	eps := strings.Split(endpoints, ",")
 	for i, ep := range eps {
 		u, e := url.Parse(ep)
@@ -31,68 +31,95 @@ func New(endpoints string) (*Etcd, error) {
 		eps[i] = u.String()
 	}
 
-	tr, e := transport.NewTransport(transport.TLSInfo{},
-		10*time.Second) // timeout = 10sec
+	tr, e := transport.NewTransport(transport.TLSInfo{}, 10*time.Second)
 	if e != nil {
-		return nil, fmt.Errorf("transport.NewTransport: %v", e)
+		return nil, e
 	}
 
 	c, e := client.New(client.Config{Endpoints: eps, Transport: tr})
 	if e != nil {
-		return nil, fmt.Errorf("client.New: %v", e)
+		return nil, e
 	}
 
-	ctx, cancel := context.WithTimeout(context.Background(), client.DefaultRequestTimeout)
+	ctx, cancel := timeoutContext()
 	e = c.Sync(ctx)
 	cancel()
 	if e != nil {
-		return nil, fmt.Errorf("(etc)client.Sync: %v", e)
+		return nil, e
 	}
 
-	return &Etcd{client.NewKeysAPI(c)}, nil
+	return &Etcc{client.NewKeysAPI(c)}, nil
+}
+
+func timeoutContext() (context.Context, context.CancelFunc) {
+	return context.WithTimeout(context.Background(), client.DefaultRequestTimeout)
 }
 
 // Mkdir creates a directory. The directory could be multiple-level,
 // like /home/yi/hello. But it must not exist before; otherwise Mkdir
 // returns an error.
-func (c *Etcd) Mkdir(dir string) error {
-	ctx, cancel := context.WithTimeout(context.Background(), client.DefaultRequestTimeout)
+func (c *Etcc) Mkdir(dir string) error {
+	ctx, cancel := timeoutContext()
 	defer cancel()
-	if _, e := c.api.Set(ctx, dir, "", &client.SetOptions{Dir: true, PrevExist: client.PrevNoExist}); e != nil {
-		return fmt.Errorf("Etcd.Mkdir: %v", e)
-	}
-	return nil
+	_, e := c.api.Set(ctx, dir, "", &client.SetOptions{Dir: true, PrevExist: client.PrevNoExist})
+	return e
 }
 
-func (c *Etcd) SetWithTTL(key, value string, ttl time.Duration) error {
-	ctx, cancel := context.WithTimeout(context.Background(), client.DefaultRequestTimeout)
+func (c *Etcc) SetWithTTL(key, value string, ttl time.Duration) error {
+	ctx, cancel := timeoutContext()
 	defer cancel()
-	if _, e := c.api.Set(ctx, key, value, &client.SetOptions{TTL: ttl}); e != nil {
-		return fmt.Errorf("Etcd.Set: %v", e)
-	}
-	return nil
+	_, e := c.api.Set(ctx, key, value, &client.SetOptions{TTL: ttl})
+	return e
 }
 
-func (c *Etcd) Set(key, value string) error {
+func (c *Etcc) Set(key, value string) error {
 	return c.SetWithTTL(key, value, time.Duration(0))
 }
 
-func (c *Etcd) Get(key string) (string, error) {
-	ctx, cancel := context.WithTimeout(context.Background(), client.DefaultRequestTimeout)
+func (c *Etcc) Get(key string) (string, error) {
+	ctx, cancel := timeoutContext()
 	defer cancel()
 	r, e := c.api.Get(ctx, key, &client.GetOptions{Sort: true})
 	if e != nil {
-		return "", fmt.Errorf("Etcd.Get: %v", e)
+		return "", e
 	}
 	return r.Node.Value, nil
 }
 
-// Rmdir removes a directory and recursively its all content, like bash command `rm -rf`.
-func (c *Etcd) Rmdir(dir string) error {
-	ctx, cancel := context.WithTimeout(context.Background(), client.DefaultRequestTimeout)
+// Rm removes a either a key-value pair or a directory.  If it is a
+// directory, Rm removes all recursive content as well.
+func (c *Etcc) Rm(key string) error {
+	ctx, cancel := timeoutContext()
+	defer cancel()
+	_, e := c.api.Delete(ctx, key, &client.DeleteOptions{Recursive: true})
+	return e
+}
+
+// Ls returns a list if key is a directory, or the key itself
+// otherwise.  Ls uses quorum=true read.  For more about what does
+// quorum=true mean, please refer to
+// https://github.com/philips/etcd/blob/05bfb369ef1a8d6c56c9eed7e1ec972dccb25492/Documentation/api.md#read-linearization
+func (c *Etcc) Ls(key string) ([]string, error) {
+	if len(key) == 0 {
+		key = "/"
+	}
+
+	ctx, cancel := timeoutContext()
 	defer cancel()
-	if _, e := c.api.Delete(ctx, dir, &client.DeleteOptions{Dir: true, Recursive: true}); e != nil {
-		return fmt.Errorf("Etcd.Rmdir: %v", e)
+
+	resp, e := c.api.Get(ctx, key, &client.GetOptions{Sort: false, Recursive: false, Quorum: true})
+
+	if e != nil {
+		return nil, e
+	}
+
+	if !resp.Node.Dir {
+		return []string{resp.Node.Key}, nil
+	}
+
+	var keys []string
+	for _, node := range resp.Node.Nodes {
+		keys = append(keys, node.Key)
 	}
-	return nil
+	return keys, e
 }

etcc_test.go

@@ -20,11 +20,11 @@ func ExampleNew() {
 	c.Set("/home/yi/b", "Banana")
 	c.Get("/home/yi/a")
 	c.Get("home/yi/b")
-	c.Rmdir("/home")
+	c.Rm("/home")
 }
 
 var (
-	c *Etcd
+	c *Etcc
 )
 
 func init() {
@@ -38,10 +38,10 @@ func init() {
 	Must(e)
 }
 
-func TestEtcdBasicSession(t *testing.T) {
+func TestEtccBasicSession(t *testing.T) {
 	assert := assert.New(t)
 
-	c.Rmdir("/home/yi")
+	c.Rm("/home/yi")
 
 	assert.Nil(c.Mkdir("/home/yi"))
 	assert.NotNil(c.Mkdir("/home/yi"))
@@ -62,7 +62,7 @@ func TestEtcdBasicSession(t *testing.T) {
 	assert.Nil(e)
 	assert.Equal("Aloha", r)
 
-	assert.Nil(c.Rmdir("/home"))
+	assert.Nil(c.Rm("/home"))
 }
 
 func TestSetWithTTL(t *testing.T) {
@@ -82,3 +82,36 @@ func TestSetWithTTL(t *testing.T) {
 	assert.NotNil(e)
 	assert.Equal("", r)
 }
+
+func TestLs(t *testing.T) {
+	assert := assert.New(t)
+
+	c.Rm("/home/yi")
+
+	assert.Nil(c.Mkdir("/home/yi"))
+	{
+		ns, e := c.Ls("")
+		assert.Nil(e)
+		assert.Equal(1, len(ns))
+		assert.Equal("/home", ns[0])
+	}
+
+	assert.Nil(c.Set("/home/yi/a", "Apple"))
+	{
+		ns, e := c.Ls("/home/yi")
+		assert.Nil(e)
+		assert.Equal(1, len(ns))
+		assert.Equal("/home/yi/a", ns[0])
+	}
+
+	assert.Nil(c.Mkdir("home/yi/b"))
+	assert.Nil(c.Rm("/home/yi/a"))
+	{
+		ns, e := c.Ls("/home/yi")
+		assert.Nil(e)
+		assert.Equal(1, len(ns))
+		assert.Equal("/home/yi/b", ns[0])
+	}
+
+	assert.Nil(c.Rm("/home"))
+}