connection.go raw

   1  package nostr
   2  
   3  import (
   4  	"context"
   5  	"crypto/tls"
   6  	"errors"
   7  	"fmt"
   8  	"io"
   9  	"net/http"
  10  	"time"
  11  
  12  	ws "github.com/coder/websocket"
  13  )
  14  
  15  // Connection represents a websocket connection to a Nostr relay.
  16  type Connection struct {
  17  	conn *ws.Conn
  18  }
  19  
  20  // NewConnection creates a new websocket connection to a Nostr relay.
  21  func NewConnection(ctx context.Context, url string, requestHeader http.Header, tlsConfig *tls.Config) (*Connection, error) {
  22  	c, _, err := ws.Dial(ctx, url, getConnectionOptions(requestHeader, tlsConfig))
  23  	if err != nil {
  24  		return nil, err
  25  	}
  26  
  27  	c.SetReadLimit(2 << 24) // 33MB
  28  
  29  	return &Connection{
  30  		conn: c,
  31  	}, nil
  32  }
  33  
  34  // WriteMessage writes arbitrary bytes to the websocket connection.
  35  func (c *Connection) WriteMessage(ctx context.Context, data []byte) error {
  36  	if err := c.conn.Write(ctx, ws.MessageText, data); err != nil {
  37  		return fmt.Errorf("failed to write message: %w", err)
  38  	}
  39  
  40  	return nil
  41  }
  42  
  43  // ReadMessage reads arbitrary bytes from the websocket connection into the provided buffer.
  44  func (c *Connection) ReadMessage(ctx context.Context, buf io.Writer) error {
  45  	_, reader, err := c.conn.Reader(ctx)
  46  	if err != nil {
  47  		return fmt.Errorf("failed to get reader: %w", err)
  48  	}
  49  	if _, err := io.Copy(buf, reader); err != nil {
  50  		return fmt.Errorf("failed to read message: %w", err)
  51  	}
  52  	return nil
  53  }
  54  
  55  // Close closes the websocket connection.
  56  func (c *Connection) Close() error {
  57  	return c.conn.Close(ws.StatusNormalClosure, "")
  58  }
  59  
  60  // Ping sends a ping message to the websocket connection.
  61  func (c *Connection) Ping(ctx context.Context) error {
  62  	ctx, cancel := context.WithTimeoutCause(ctx, time.Millisecond*800, errors.New("ping took too long"))
  63  	defer cancel()
  64  	return c.conn.Ping(ctx)
  65  }
  66