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WebSocket Wire Format (std/wsframe) ​

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from "std/wsframe" import { computeAcceptKey, encodeWsFrame, parseWsFrame }

The WebSocket wire format from RFC 6455: the handshake's accept key and the frame codec, with no IO. std/http's ws routes and std/ws both use it. It is a separate module so a plain HTTP server can speak WebSocket without linking OpenSSL, which std/ws pulls in for its TLS client.

Most programs want a ws route in std/http or wsConnect in std/ws; reach for this module only to frame bytes yourself.

API reference ​

WsFrame ​

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pub struct WsFrame

One decoded frame, payload unmasked. size is how many bytes of the buffer it used.

Fields: opcode: i32, fin: bool, masked: bool, payload: string, size: i64.

WsFrameParse ​

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pub enum WsFrameParse

Variants:

  • Incomplete: The buffer holds only part of a frame.
  • Frame(WsFrame)
  • TooBig: The header claims a payload over the limit; nothing past the header was read.
  • Invalid: A reserved opcode, a reserved bit set (no extension was negotiated), or a fragmented or oversized control frame: the connection must fail (close 1002).

Functions ​

computeAcceptKey ​

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pub fn computeAcceptKey(clientKey: &string): string

The Sec-WebSocket-Accept value answering a client's Sec-WebSocket-Key (RFC 6455 4.2.2).

encodeWsFrame ​

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pub fn encodeWsFrame(opcode: i32, payload: &string, fin: bool, mask: &string): string

The bytes of one frame. mask is "" for a server frame and the 4-byte key for a client frame (RFC 6455 5.3: client frames must be masked, server frames must not).

parseWsFrame ​

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pub fn parseWsFrame(buf: &string, maxPayload: i64): WsFrameParse

Decode the frame at the start of buf, refusing a payload longer than maxPayload before any of it is buffered: the length is the peer's to claim.