diff --git a/clientconn.go b/clientconn.go
index e81a48868..038ed884c 100644
--- a/clientconn.go
+++ b/clientconn.go
@@ -91,12 +91,16 @@ func WithCodec(c Codec) DialOption {
 	}
 }
 
+// WithCompressor returns a DialOption which sets a CompressorGenerator for generating message
+// compressor.
 func WithCompressor(f CompressorGenerator) DialOption {
 	return func(o *dialOptions) {
 		o.cg = f
 	}
 }
 
+// WithDecompressor returns a DialOption which sets a DecompressorGenerator for generating
+// message decompressor.
 func WithDecompressor(f DecompressorGenerator) DialOption {
 	return func(o *dialOptions) {
 		o.dg = f
diff --git a/rpc_util.go b/rpc_util.go
index f48ad32c7..427b49e00 100644
--- a/rpc_util.go
+++ b/rpc_util.go
@@ -78,11 +78,15 @@ func (protoCodec) String() string {
 	return "proto"
 }
 
+// Compressor defines the interface gRPC uses to compress a message.
 type Compressor interface {
+	// Do compresses p into w.
 	Do(w io.Writer, p []byte) error
+	// Type returns the compression algorithm the Compressor uses.
 	Type() string
 }
 
+// NewGZIPCompressor creates a Compressor based on GZIP.
 func NewGZIPCompressor() Compressor {
 	return &gzipCompressor{}
 }
@@ -102,14 +106,18 @@ func (c *gzipCompressor) Type() string {
 	return "gzip"
 }
 
+// Decompressor defines the interface gRPC uses to decompress a message.
 type Decompressor interface {
+	// Do reads the data from r and uncompress them.
 	Do(r io.Reader) ([]byte, error)
+	// Type returns the compression algorithm the Decompressor uses.
 	Type() string
 }
 
 type gzipDecompressor struct {
 }
 
+// NewGZIPDecompressor creates a Decompressor based on GZIP.
 func NewGZIPDecompressor() Decompressor {
 	return &gzipDecompressor{}
 }
@@ -127,8 +135,10 @@ func (d *gzipDecompressor) Type() string {
 	return "gzip"
 }
 
+// CompressorGenerator defines the function generating a Compressor.
 type CompressorGenerator func() Compressor
 
+// DecompressorGenerator defines the function generating a Decompressor.
 type DecompressorGenerator func() Decompressor
 
 // callInfo contains all related configuration and information about an RPC.
diff --git a/test/end2end_test.go b/test/end2end_test.go
index 7823ba5ee..22ca8778d 100644
--- a/test/end2end_test.go
+++ b/test/end2end_test.go
@@ -563,7 +563,7 @@ func testEmptyUnaryWithUserAgent(t *testing.T, e env) {
 		t.Fatalf("header[\"ua\"] = %q, %t, want %q, true", v, ok, testAppUA)
 	}
 	tearDown(s, cc)
-	ctx, _ = context.WithTimeout(context.Background(), 5 * time.Second)
+	ctx, _ = context.WithTimeout(context.Background(), 5*time.Second)
 	if _, err := cc.WaitForStateChange(ctx, grpc.Ready); err != nil {
 		t.Fatalf("cc.WaitForStateChange(_, %s) = _, %v, want _, <nil>", grpc.Ready, err)
 	}
@@ -823,12 +823,12 @@ func testCancelNoIO(t *testing.T, e env) {
 	go func() {
 		defer close(ch)
 		// This should be blocked until the 1st is canceled.
-		ctx, _ := context.WithTimeout(context.Background(), 2 * time.Second)
+		ctx, _ := context.WithTimeout(context.Background(), 2*time.Second)
 		if _, err := tc.StreamingInputCall(ctx); err != nil {
 			t.Errorf("%v.StreamingInputCall(_) = _, %v, want _, <nil>", tc, err)
 		}
 	}()
-	cancel();
+	cancel()
 	<-ch
 }
 
diff --git a/transport/http2_client.go b/transport/http2_client.go
index a23f6a723..7006cd879 100644
--- a/transport/http2_client.go
+++ b/transport/http2_client.go
@@ -208,13 +208,13 @@ func (t *http2Client) newStream(ctx context.Context, callHdr *CallHdr) *Stream {
 	}
 	// TODO(zhaoq): Handle uint32 overflow of Stream.id.
 	s := &Stream{
-		id:             t.nextID,
-		method:         callHdr.Method,
-		sendCompress:   callHdr.SendCompress,
-		buf:            newRecvBuffer(),
-		fc:             fc,
-		sendQuotaPool:  newQuotaPool(int(t.streamSendQuota)),
-		headerChan:     make(chan struct{}),
+		id:            t.nextID,
+		method:        callHdr.Method,
+		sendCompress:  callHdr.SendCompress,
+		buf:           newRecvBuffer(),
+		fc:            fc,
+		sendQuotaPool: newQuotaPool(int(t.streamSendQuota)),
+		headerChan:    make(chan struct{}),
 	}
 	t.nextID += 2
 	s.windowHandler = func(n int) {
diff --git a/transport/transport.go b/transport/transport.go
index 9d6f4647a..8017bc154 100644
--- a/transport/transport.go
+++ b/transport/transport.go
@@ -170,13 +170,13 @@ type Stream struct {
 	ctx    context.Context
 	cancel context.CancelFunc
 	// method records the associated RPC method of the stream.
-	method    string
+	method       string
 	recvCompress string
-	sendCompress  string
-	buf       *recvBuffer
-	dec       io.Reader
-	fc        *inFlow
-	recvQuota uint32
+	sendCompress string
+	buf          *recvBuffer
+	dec          io.Reader
+	fc           *inFlow
+	recvQuota    uint32
 	// The accumulated inbound quota pending for window update.
 	updateQuota uint32
 	// The handler to control the window update procedure for both this
@@ -358,8 +358,8 @@ type Options struct {
 
 // CallHdr carries the information of a particular RPC.
 type CallHdr struct {
-	Host   string // peer host
-	Method string // the operation to perform on the specified host
+	Host         string // peer host
+	Method       string // the operation to perform on the specified host
 	RecvCompress string
 	SendCompress string
 }