Crate pdk_websockets_lib 

PDK WebSockets Library

Library for decoding and encoding WebSocket frames in Flex Gateway custom policies. It wraps [websocket-sans-io] to provide ergonomic frame-level access for policies that operate on WebSocket upgrade connections.

Primary types

• Frame: a single WebSocket frame with its payload and metadata
• FrameType: the kind of frame (Text, Binary, Ping, Pong, etc.)
• Decoder: incrementally decodes raw bytes into Frames
• Encoder: re-encodes a collection of Frames into bytes
• SinkResult: outcome of feeding bytes to the Decoder
• UpgradeTracker: tracks HTTP to WebSocket protocol upgrade

Examples

Incremental decoding with sink()

use pdk_websockets_lib::{Decoder, Encoder, Frame, FrameType, SinkResult};

let mut decoder = Decoder::default();
match decoder.sink(raw_bytes) {
    SinkResult::MidFrame => { /* pause and wait for more bytes */ }
    SinkResult::Complete(mut frames) => {
        // inspect frames
        if let Some(frame) = frames.first() {
            if let FrameType::Text = frame.frame_type() {
                let text = String::from_utf8_lossy(frame.data());
            }
        }
        // modify frames, then re-encode
        frames.push(Frame::ping());
        let bytes = Encoder::default().encode_server(frames);
    }
}

Stateless parsing with parse()

use pdk_websockets_lib::{Decoder, Encoder};

// In your event loop, when new bytes arrive:
fn on_websocket_data(bytes: Vec<u8>, remainder: &mut Vec<u8>) -> Vec<Vec<u8>> {
    // Concatenate previous remainder + new bytes
    let full_buffer = [&remainder[..], &bytes[..]].concat();

    // Parse into frames
    let (frames, new_remainder) = Decoder::parse(full_buffer);

    // Store remainder for next iteration
    *remainder = new_remainder;

    // Re-encode frames (e.g., to forward to upstream)
    let encoder = Encoder::default();
    frames.into_iter()
        .map(|f| encoder.encode_server(vec![f]))
        .collect()
}

Structs

Decoder

Incrementally decodes raw bytes into Frames.

Encoder

Encodes a collection of Frames back into raw bytes suitable for writing to a WebSocket connection.

Frame

A single WebSocket frame.

UpgradeTracker

Tracks HTTP to WebSocket protocol upgrade.

Enums

FrameType

The kind of a WebSocket frame, derived from its opcode.

SinkResult

The result of feeding bytes to Decoder::sink.