File size: 3,153 Bytes
29393b6 | 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 | /**
* WO-2 Pipeline 1, T2 — browser audio session state.
*
* Holds each connected browser's PCM audio entirely in this process's
* memory, the same pattern run.mjs already uses for eveChat/nodeChats.
* Deliberately does NOT touch /dev/shm/miranda_bus — Pipeline 1's audio
* never needs to cross into the WO-1 ring buffer. See
* .kiro/specs/wo2-acoustic-ingress-routing/tasks.md, "Architectural
* resolution #2" for the reasoning: that ring buffer is WO-1's contract for
* the Rust-native Pipeline 2 path (native cpal capture), not for browser
* audio arriving over a WebSocket.
*
* Expected wire format: binary WebSocket frames, each frame a
* little-endian Float32Array of PCM samples at 16 kHz mono. The browser
* side (client-apps/web) sends 160-sample (10 ms) frames to match WO-1's
* AudioChunk.samples size, but this module does not assume a fixed frame
* size — it just accumulates whatever arrives until a caller asks for the
* buffered audio (T3 will do this on speech-end).
*/
/** One browser connection's accumulated audio state. */
class AudioSession {
constructor(id) {
this.id = id;
/** @type {Float32Array[]} raw frames, oldest first */
this.frames = [];
this.totalSamples = 0;
this.createdAt = Date.now();
this.lastFrameAt = null;
}
/**
* Accepts one binary WS frame (a Node Buffer) and appends it as PCM.
* Returns the number of samples in this frame, for logging/telemetry.
*/
pushFrame(buf) {
if (buf.length % 4 !== 0) {
throw new Error(
`audio frame length ${buf.length} is not a multiple of 4 bytes (Float32)`,
);
}
// Float32Array requires its buffer's byteOffset to be 4-byte aligned.
// A Buffer view into a larger pooled allocation may not be — copy the
// bytes out to guarantee correct alignment rather than assume it.
const aligned = buf.byteOffset % 4 === 0 ? buf : Buffer.from(buf);
const samples = new Float32Array(
aligned.buffer,
aligned.byteOffset,
aligned.length / 4,
);
this.frames.push(samples);
this.totalSamples += samples.length;
this.lastFrameAt = Date.now();
return samples.length;
}
/** Concatenates all buffered frames into one Float32Array and clears them. */
drain() {
const out = new Float32Array(this.totalSamples);
let offset = 0;
for (const frame of this.frames) {
out.set(frame, offset);
offset += frame.length;
}
this.frames = [];
this.totalSamples = 0;
return out;
}
/** Non-destructive peek at the current buffered sample count. */
bufferedSamples() {
return this.totalSamples;
}
}
/** Registry of active audio sessions, keyed by an opaque connection id. */
export class AudioSessionRegistry {
constructor() {
/** @type {Map<string, AudioSession>} */
this.sessions = new Map();
}
getOrCreate(id) {
let session = this.sessions.get(id);
if (!session) {
session = new AudioSession(id);
this.sessions.set(id, session);
}
return session;
}
get(id) {
return this.sessions.get(id);
}
remove(id) {
this.sessions.delete(id);
}
}
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