feat: expose deep analysis llm metrics

apps/worker/src/deep-analysis-metrics.service.ts

@@ -0,0 +1,125 @@
+import { Injectable } from '@nestjs/common';
+
+import type {
+  QwenAuditStage,
+  QwenJsonResult,
+} from './qwen-deep-analysis.service';
+
+type RequestStatus = 'success' | 'error';
+type TokenType = 'input' | 'output' | 'total';
+
+@Injectable()
+export class DeepAnalysisMetricsService {
+  private readonly requestCounts = new Map<string, number>();
+  private readonly tokenCounts = new Map<string, number>();
+
+  public recordQwenResult(result: QwenJsonResult<unknown>): void {
+    if (!result.requestMeta.requested) {
+      return;
+    }
+
+    const phase = result.requestMeta.stage;
+    const model = result.usage?.model ?? 'unknown';
+    const status: RequestStatus = result.requestMeta.success
+      ? 'success'
+      : 'error';
+    const usageMissing = result.usage?.usageMissing ?? true;
+
+    this.incrementRequest(phase, model, status, usageMissing);
+
+    if (
+      result.usage?.promptTokens !== null &&
+      result.usage?.promptTokens !== undefined
+    ) {
+      this.incrementToken(phase, model, 'input', result.usage.promptTokens);
+    }
+    if (
+      result.usage?.completionTokens !== null &&
+      result.usage?.completionTokens !== undefined
+    ) {
+      this.incrementToken(
+        phase,
+        model,
+        'output',
+        result.usage.completionTokens,
+      );
+    }
+    if (
+      result.usage?.totalTokens !== null &&
+      result.usage?.totalTokens !== undefined
+    ) {
+      this.incrementToken(phase, model, 'total', result.usage.totalTokens);
+    }
+  }
+
+  public renderPrometheusMetrics(): string {
+    const lines: string[] = [
+      '# HELP mnemo_deep_analysis_requests_total Total number of deep analysis Qwen requests.',
+      '# TYPE mnemo_deep_analysis_requests_total counter',
+      ...this.renderSeries(
+        'mnemo_deep_analysis_requests_total',
+        this.requestCounts,
+      ),
+      '# HELP mnemo_deep_analysis_tokens_total Total number of deep analysis Qwen tokens consumed.',
+      '# TYPE mnemo_deep_analysis_tokens_total counter',
+      ...this.renderSeries(
+        'mnemo_deep_analysis_tokens_total',
+        this.tokenCounts,
+      ),
+    ];
+
+    return `${lines.join('\n')}\n`;
+  }
+
+  private incrementRequest(
+    phase: QwenAuditStage,
+    model: string,
+    status: RequestStatus,
+    usageMissing: boolean,
+  ): void {
+    const key = this.buildKey({
+      model,
+      phase,
+      status,
+      usage_missing: String(usageMissing),
+    });
+    this.requestCounts.set(key, (this.requestCounts.get(key) ?? 0) + 1);
+  }
+
+  private incrementToken(
+    phase: QwenAuditStage,
+    model: string,
+    type: TokenType,
+    value: number,
+  ): void {
+    const key = this.buildKey({
+      model,
+      phase,
+      type,
+    });
+    this.tokenCounts.set(key, (this.tokenCounts.get(key) ?? 0) + value);
+  }
+
+  private renderSeries(
+    metricName: string,
+    values: Map<string, number>,
+  ): string[] {
+    return [...values.entries()]
+      .sort(([left], [right]) => left.localeCompare(right))
+      .map(([labels, value]) => `${metricName}{${labels}} ${value}`);
+  }
+
+  private buildKey(labels: Record<string, string>): string {
+    return Object.entries(labels)
+      .sort(([left], [right]) => left.localeCompare(right))
+      .map(([key, value]) => `${key}="${this.escapeLabelValue(value)}"`)
+      .join(',');
+  }
+
+  private escapeLabelValue(value: string): string {
+    return value
+      .replaceAll('\\', '\\\\')
+      .replaceAll('\n', '\\n')
+      .replaceAll('"', '\\"');
+  }
+}