autosnippet/dist/lib/infrastructure/signal/SignalAggregator.js

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/**
 * SignalAggregator — 滑窗统计 + 异常检测
 *
 * 订阅可聚合的事实型信号，周期性写入 Report（统计）并在异常时发射 Signal。
 *
 * @module infrastructure/signal/SignalAggregator
 */
export class SignalAggregator {
    #bus;
    #reportStore;
    #windows = new Map();
    #intervalMs;
    #windowMs;
    #timer = null;
    constructor(signalBus, reportStore, opts = {}) {
        this.#bus = signalBus;
        this.#reportStore = reportStore;
        this.#intervalMs = opts.intervalMs ?? 60_000;
        this.#windowMs = opts.windowMs ?? 300_000;
        // 订阅可聚合的事实型信号
        signalBus.subscribe('guard|search|usage|lifecycle|forge|decay|quality', (signal) => {
            this.#record(signal);
        });
    }
    start() {
        if (this.#timer) {
            return;
        }
        this.#timer = setInterval(() => {
            void this.#flush();
        }, this.#intervalMs);
    }
    stop() {
        if (this.#timer) {
            clearInterval(this.#timer);
            this.#timer = null;
        }
    }
    #record(signal) {
        const key = signal.type;
        if (!this.#windows.has(key)) {
            this.#windows.set(key, { entries: [], baseline: 0 });
        }
        const win = this.#windows.get(key);
        win.entries.push({ value: signal.value, ts: signal.timestamp });
    }
    async #flush() {
        const now = Date.now();
        for (const [type, win] of this.#windows) {
            // 清理过期条目
            win.entries = win.entries.filter((e) => now - e.ts < this.#windowMs);
            if (win.entries.length === 0) {
                continue;
            }
            const count = win.entries.length;
            const avg = win.entries.reduce((s, e) => s + e.value, 0) / count;
            const max = Math.max(...win.entries.map((e) => e.value));
            const min = Math.min(...win.entries.map((e) => e.value));
            // 周期统计 → Report
            await this.#reportStore.write({
                category: 'metrics',
                type: `aggregate_${type}`,
                producer: 'SignalAggregator',
                data: {
                    window: `${this.#windowMs / 1000}s`,
                    count,
                    avg,
                    max,
                    min,
                    baseline: win.baseline,
                },
                timestamp: now,
            });
            // 异常检测 → Signal（信号量突增 3 倍）
            if (win.baseline > 0 && count > win.baseline * 3) {
                this.#bus.send('anomaly', `Aggregator.${type}`, 1, {
                    metadata: { reason: 'spike', count, baseline: win.baseline },
                });
            }
            // 更新 baseline（指数移动平均）
            win.baseline = win.baseline === 0 ? count : win.baseline * 0.8 + count * 0.2;
        }
    }
}