Shoubhit Dash
38 lines
1.3 KiB
TypeScript
38 lines
1.3 KiB
TypeScript
export * as PtyProtocol from "./protocol"
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// Wire protocol for PTY websocket transports. The PTY domain service is transport-free; server
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// routes adapt Pty.attach to websockets with these helpers so every surface speaks one protocol.
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//
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// Outbound frames are raw UTF-8 terminal chunks. One control frame — a 0x00 byte followed by
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// UTF-8 JSON — carries the absolute output cursor after replay so clients can resume later.
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const encoder = new TextEncoder()
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const decoder = new TextDecoder("utf-8", { fatal: true })
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// Replay can be megabytes; send it in bounded frames.
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export const REPLAY_CHUNK = 64 * 1024
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export function metaFrame(cursor: number) {
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const bytes = encoder.encode(JSON.stringify({ cursor }))
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const out = new Uint8Array(bytes.length + 1)
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out[0] = 0
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out.set(bytes, 1)
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return out
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}
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export function chunks(data: string) {
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const out: string[] = []
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for (let i = 0; i < data.length; i += REPLAY_CHUNK) out.push(data.slice(i, i + REPLAY_CHUNK))
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return out
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}
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// Inbound client frames are UTF-8 text or binary; invalid UTF-8 input is dropped.
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export function decodeInput(message: string | Uint8Array | ArrayBuffer) {
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if (typeof message === "string") return message
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try {
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return decoder.decode(message instanceof ArrayBuffer ? new Uint8Array(message) : message)
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} catch {
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return undefined
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}
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}
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