@phren/cli/dist/bridge/socket-budget.js

Knowledge layer for AI agents - CLI, MCP server, and data layer

import { requestPeer } from "./request-origin.js";
/** Sockets one identity may hold per client kind, and in all. */
export const SOCKETS_PER_KIND = 16;
export const SOCKETS_PER_IDENTITY = 32;
/** Every identity together; the backstop if identities themselves multiply. */
export const SOCKETS_TOTAL = 128;
/**
 * Who a WebSocket belongs to, from what the Hook itself trusts rather than a
 * client hint: a peer key's gateway rebuilds its request with `x-phren-origin:
 * peer` and the peer's fingerprint, so that is its own identity; everything
 * else arrives on the owner's local socket or the owner's SSH pipe and is the
 * owner. `x-phren-client` only picks a sub-pool inside the identity.
 */
export function socketIdentity(request) {
    const peer = requestPeer(request);
    return peer ? `peer:${peer.fingerprint}` : "owner";
}
export const socketKind = (request) => request.headers["x-phren-client"] === "desktop" ? "desktop" : "default";
/** Admits sockets oldest-first under the per-kind, per-identity and total caps. */
export class SocketBudget {
    limits;
    entries = new Set();
    constructor(limits = { kind: SOCKETS_PER_KIND, identity: SOCKETS_PER_IDENTITY, total: SOCKETS_TOTAL }) {
        this.limits = limits;
    }
    /** Register a socket; returns the sockets to close to stay inside the caps. */
    add(socket, identity, kind) {
        const entry = { socket, identity, kind };
        this.entries.add(entry);
        const evicted = [];
        const drop = (match) => {
            const oldest = [...this.entries].find(match);
            if (!oldest)
                return;
            this.entries.delete(oldest);
            evicted.push(oldest.socket);
        };
        while ([...this.entries].filter(e => e.identity === identity && e.kind === kind).length > this.limits.kind)
            drop(e => e.identity === identity && e.kind === kind);
        while ([...this.entries].filter(e => e.identity === identity).length > this.limits.identity)
            drop(e => e.identity === identity);
        while (this.entries.size > this.limits.total) {
            const counts = new Map();
            for (const e of this.entries)
                counts.set(e.identity, (counts.get(e.identity) ?? 0) + 1);
            // Ties go against a peer identity, so forged peer budgets never push out the owner's own devices first.
            const [heaviest] = [...counts].sort((a, b) => b[1] - a[1] || Number(a[0] === "owner") - Number(b[0] === "owner"))[0];
            drop(e => e.identity === heaviest);
        }
        return evicted;
    }
    remove(socket) {
        for (const e of this.entries)
            if (e.socket === socket) {
                this.entries.delete(e);
                return;
            }
    }
    count(identity) {
        return identity === undefined ? this.entries.size : [...this.entries].filter(e => e.identity === identity).length;
    }
}