Network Library Extensions

Network Library Extensions provided by Hertz.

Hertz provides the ability to extend the network library. If users need to replace with other network libraries, they can implement the corresponding interfaces according to their needs. Server needs to implement the network.Conn or the network.StreamConn interface, Client needs to implement the network.Dialer interface.

Server Interface Definition

network.Conn

This interface is typically used to implement byte stream based connections, such as TCP connection.

type Conn interface {
    net.Conn
    Reader
    Writer
    SetReadTimeout(t time.Duration) error
}

// Reader is for buffered Reader
type Reader interface {
   // Peek returns the next n bytes without advancing the reader.
   Peek(n int) ([]byte, error)

   // Skip discards the next n bytes.
   Skip(n int) error

   // Release the memory space occupied by all read slices. This method needs to be executed actively to
   // recycle the memory after confirming that the previously read data is no longer in use.
   // After invoking Release, the slices obtained by the method such as Peek will
   // become an invalid address and cannot be used anymore.
   Release() error

   // Len returns the total length of the readable data in the reader.
   Len() int

   // ReadByte is used to read one byte with advancing the read pointer.
   ReadByte() (byte, error)

   // ReadBinary is used to read next n byte with copy, and the read pointer will be advanced.
   ReadBinary(n int) (p []byte, err error)
}

type Writer interface {
   // Malloc will provide a n bytes buffer to send data.
   Malloc(n int) (buf []byte, err error)

   // WriteBinary will use the user buffer to flush.
   // NOTE: Before flush successfully, the buffer b should be valid.
   WriteBinary(b []byte) (n int, err error)

   // Flush will send data to the peer end.
   Flush() error
}

network.StreamConn

This interface is typically used to implement streaming based connections, such as QUIC connection.

 // StreamConn is interface for stream-based connection abstraction.
type StreamConn interface {
    GetRawConnection() interface{}
    // HandshakeComplete blocks until the handshake completes (or fails).
    HandshakeComplete() context.Context
    // CloseWithError closes the connection with an error.
    // The error string will be sent to the peer.
    CloseWithError(err ApplicationError, errMsg string) error
    // LocalAddr returns the local address.
    LocalAddr() net.Addr
    // RemoteAddr returns the address of the peer.
    RemoteAddr() net.Addr
    // The context is cancelled when the connection is closed.
    Context() context.Context
    // Streamer is the interface for stream operations.
    Streamer
}

type Streamer interface {
    // AcceptStream returns the next stream opened by the peer, blocking until one is available.
    // If the connection was closed due to a timeout, the error satisfies
    // the net.Error interface, and Timeout() will be true.
    AcceptStream(context.Context) (Stream, error)
    // AcceptUniStream returns the next unidirectional stream opened by the peer, blocking until one is available.
    // If the connection was closed due to a timeout, the error satisfies
    // the net.Error interface, and Timeout() will be true.
    AcceptUniStream(context.Context) (ReceiveStream, error)
    // OpenStream opens a new bidirectional QUIC stream.
    // There is no signaling to the peer about new streams:
    // The peer can only accept the stream after data has been sent on the stream.
    // If the error is non-nil, it satisfies the net.Error interface.
    // When reaching the peer's stream limit, err.Temporary() will be true.
    // If the connection was closed due to a timeout, Timeout() will be true.
    OpenStream() (Stream, error)
    // OpenStreamSync opens a new bidirectional QUIC stream.
    // It blocks until a new stream can be opened.
    // If the error is non-nil, it satisfies the net.Error interface.
    // If the connection was closed due to a timeout, Timeout() will be true.
    OpenStreamSync(context.Context) (Stream, error)
    // OpenUniStream opens a new outgoing unidirectional QUIC stream.
    // If the error is non-nil, it satisfies the net.Error interface.
    // When reaching the peer's stream limit, Temporary() will be true.
    // If the connection was closed due to a timeout, Timeout() will be true.
    OpenUniStream() (SendStream, error)
    // OpenUniStreamSync opens a new outgoing unidirectional QUIC stream.
    // It blocks until a new stream can be opened.
    // If the error is non-nil, it satisfies the net.Error interface.
    // If the connection was closed due to a timeout, Timeout() will be true.
    OpenUniStreamSync(context.Context) (SendStream, error)
}

type Stream interface {
    ReceiveStream
    SendStream
}

type ReceiveStream interface {
    StreamID() int64
    io.Reader

    // CancelRead aborts receiving on this stream.
    // It will ask the peer to stop transmitting stream data.
    // Read will unblock immediately, and future Read calls will fail.
    // When called multiple times or after reading the io.EOF it is a no-op.
    CancelRead(err ApplicationError)

    // SetReadDeadline sets the deadline for future Read calls and
    // any currently-blocked Read call.
    // A zero value for t means Read will not time out.
    SetReadDeadline(t time.Time) error
}

type SendStream interface {
    StreamID() int64
    // Writer writes data to the stream.
    // Write can be made to time out and return a net.Error with Timeout() == true
    // after a fixed time limit; see SetDeadline and SetWriteDeadline.
    // If the stream was canceled by the peer, the error implements the StreamError
    // interface, and Canceled() == true.
    // If the connection was closed due to a timeout, the error satisfies
    // the net.Error interface, and Timeout() will be true.
    io.Writer
    // CancelWrite aborts sending on this stream.
    // Data already written, but not yet delivered to the peer is not guaranteed to be     delivered reliably.
    // Write will unblock immediately, and future calls to Write will fail.
    // When called multiple times or after closing the stream it is a no-op.
    CancelWrite(err ApplicationError)
    // Closer closes the write-direction of the stream.
    // Future calls to Write are not permitted after calling Close.
    // It must not be called concurrently with Write.
    // It must not be called after calling CancelWrite.
    io.Closer

    // The Context is canceled as soon as the write-side of the stream is closed.
    // This happens when Close() or CancelWrite() is called, or when the peer
    // cancels the read-side of their stream.
    Context() context.Context
    // SetWriteDeadline sets the deadline for future Write calls
    // and any currently-blocked Write call.
    // Even if write times out, it may return n > 0, indicating that
    // some data was successfully written.
    // A zero value for t means Write will not time out.
    SetWriteDeadline(t time.Time) error
}

type ApplicationError interface {
    ErrCode() uint64
    fmt.Stringer
}

Client Interface Definition

For Client, you should implement the following interface in order to replace the Client-side network library.

type Dialer interface {
    DialConnection(network, address string, timeout time.Duration, tlsConfig *tls.Config) (conn Conn, err error)
    DialTimeout(network, address string, timeout time.Duration, tlsConfig *tls.Config) (conn net.Conn, err error)
    AddTLS(conn Conn, tlsConfig *tls.Config) (Conn, error)
}

Custom Network Library

Hertz’s Server and Client respectively provide initialization configuration items for registering custom network libraries.

Server

server.New(server.WithTransport(YOUR_TRANSPORT))

Client

client.NewClient(client.WithDialer(YOUR_DIALER))

Last modified June 24, 2024 : fix: correct the file path (#1096) (b3fa1a4)