refine client comments

client.go

@@ -10,16 +10,20 @@ type Dialer interface {
 	DialContext(ctx context.Context, network, addr string) (net.Conn, error)
 }
 
-// Client is an UDP client that supports DNS protocol.
+// Client represents a DNS client that communicates over UDP.
+// It supports sending DNS queries to a specified server.
 type Client struct {
-	// Address specifies the address of dns server.
+	// Addr defines the DNS server's address to which the client will send queries.
+	// This field is used if no custom Dialer is provided.
 	Addr string
 
-	// Timeout
+	// Timeout specifies the maximum duration for a query to complete.
+	// If a query exceeds this duration, it will result in a timeout error.
 	Timeout time.Duration
 
-	// Dialer specifies the dialer for creating TCP/UDP connections.
-	// If it is set, Addr and Timeout will be ignored.
+	// Dialer allows for customizing the way connections are established.
+	// If set, it overrides the Addr field and uses the provided dialer to
+	// create connections for DNS queries.
 	Dialer Dialer
 }
 

client_dialer.go

@@ -13,9 +13,15 @@ import (
 	"unsafe"
 )
 
+// UDPDialer is a custom dialer for creating UDP connections.
+// It manages a pool of connections to optimize performance in scenarios
+// where multiple UDP connections to the same server are required.
 type UDPDialer struct {
-	Addr     *net.UDPAddr
-	Timeout  time.Duration
+	// Addr specifies the remote UDP address that the dialer will connect to.
+	Addr *net.UDPAddr
+
+	// MaxConns limits the maximum number of UDP connections that can be created
+	// and reused. Once this limit is reached, no new connections will be made.
 	MaxConns uint16
 
 	once  sync.Once
@@ -52,9 +58,19 @@ type udpConn struct {
 	mu sync.Mutex
 }
 
+// HTTPDialer is a custom dialer for creating HTTP connections.
+// It allows sending HTTP requests with a specified endpoint, user agent, and transport configuration.
 type HTTPDialer struct {
-	Endpoint  *url.URL
+	// Endpoint specifies the HTTP server's URL that the dialer will connect to.
+	// This is the base address used for sending HTTP requests.
+	Endpoint *url.URL
+
+	// UserAgent defines the User-Agent header that will be included in the HTTP requests
+	// sent by this dialer. It can be customized for specific needs.
 	UserAgent string
+
+	// Transport allows for customizing the underlying transport mechanism used
+	// for making HTTP requests. If set, it overrides the default RoundTripper behavior.
 	Transport http.RoundTripper
 }