Add telemetry for restoring dependency caches

src/dependency-caching.ts

@@ -84,20 +84,44 @@ async function makeGlobber(patterns: string[]): Promise<glob.Globber> {
   return glob.create(patterns.join("\n"));
 }
 
+/** Enumerates possible outcomes for cache hits. */
+export enum CacheHitResult {
+  /** We were unable to calculate a hash for the key. */
+  NoHash = "no-hash",
+  /** No cache was found. */
+  Miss = "miss",
+  /** The primary cache key matched. */
+  Exact = "exact",
+  /** A restore key matched. */
+  Partial = "partial",
+}
+
+/** Represents results of trying to restore a dependency cache for a language. */
+export interface DependencyCacheRestoreStatus {
+  hit: CacheHitResult;
+  download_size_bytes?: number;
+  download_duration_ms?: number;
+}
+
+/** A partial mapping from languages to the results of restoring dependency caches for them. */
+export type DependencyCacheRestoreStatusReport = Partial<
+  Record<Language, DependencyCacheRestoreStatus>
+>;
+
 /**
  * Attempts to restore dependency caches for the languages being analyzed.
  *
  * @param languages The languages being analyzed.
  * @param logger A logger to record some informational messages to.
  * @param minimizeJavaJars Whether the Java extractor should rewrite downloaded JARs to minimize their size.
- * @returns A list of languages for which dependency caches were restored.
+ * @returns A partial mapping of languages to results of restoring dependency caches for them.
  */
 export async function downloadDependencyCaches(
   languages: Language[],
   logger: Logger,
   minimizeJavaJars: boolean,
-): Promise<Language[]> {
-  const restoredCaches: Language[] = [];
+): Promise<DependencyCacheRestoreStatusReport> {
+  const status: DependencyCacheRestoreStatusReport = {};
 
   for (const language of languages) {
     const cacheConfig = getDefaultCacheConfig()[language];
@@ -114,6 +138,7 @@ export async function downloadDependencyCaches(
     const globber = await makeGlobber(cacheConfig.hash);
 
     if ((await globber.glob()).length === 0) {
+      status[language] = { hit: CacheHitResult.NoHash };
       logger.info(
         `Skipping download of dependency cache for ${language} as we cannot calculate a hash for the cache key.`,
       );
@@ -131,21 +156,29 @@ export async function downloadDependencyCaches(
       )}`,
     );
 
+    const start = performance.now();
     const hitKey = await actionsCache.restoreCache(
       cacheConfig.paths,
       primaryKey,
       restoreKeys,
     );
+    const download_duration_ms = Math.round(performance.now() - start);
+    const download_size_bytes = Math.round(
+      await getTotalCacheSize(cacheConfig.paths, logger),
+    );
 
     if (hitKey !== undefined) {
       logger.info(`Cache hit on key ${hitKey} for ${language}.`);
-      restoredCaches.push(language);
+      const hit =
+        hitKey === primaryKey ? CacheHitResult.Exact : CacheHitResult.Partial;
+      status[language] = { hit, download_duration_ms, download_size_bytes };
     } else {
+      status[language] = { hit: CacheHitResult.Miss };
       logger.info(`No suitable cache found for ${language}.`);
     }
   }
 
-  return restoredCaches;
+  return status;
 }
 
 /**

src/init-action.ts

@@ -23,7 +23,10 @@ import {
 } from "./caching-utils";
 import { CodeQL } from "./codeql";
 import * as configUtils from "./config-utils";
-import { downloadDependencyCaches } from "./dependency-caching";
+import {
+  DependencyCacheRestoreStatusReport,
+  downloadDependencyCaches,
+} from "./dependency-caching";
 import {
   addDiagnostic,
   flushDiagnostics,
@@ -102,6 +105,7 @@ async function sendCompletedStatusReport(
   toolsSource: ToolsSource,
   toolsVersion: string,
   overlayBaseDatabaseStats: OverlayBaseDatabaseDownloadStats | undefined,
+  dependencyCachingResults: DependencyCacheRestoreStatusReport | undefined,
   logger: Logger,
   error?: Error,
 ) {
@@ -151,6 +155,7 @@ async function sendCompletedStatusReport(
           await getTotalCacheSize(Object.values(config.trapCaches), logger),
         ),
         overlayBaseDatabaseStats,
+        dependencyCachingResults,
       );
     await sendStatusReport({
       ...initWithConfigStatusReport,
@@ -351,6 +356,7 @@ async function run() {
   }
 
   let overlayBaseDatabaseStats: OverlayBaseDatabaseDownloadStats | undefined;
+  let dependencyCachingResults: DependencyCacheRestoreStatusReport | undefined;
   try {
     if (
       config.overlayDatabaseMode === OverlayDatabaseMode.Overlay &&
@@ -562,7 +568,7 @@ async function run() {
       codeql,
     );
     if (shouldRestoreCache(config.dependencyCachingEnabled)) {
-      await downloadDependencyCaches(
+      dependencyCachingResults = await downloadDependencyCaches(
         config.languages,
         logger,
         minimizeJavaJars,
@@ -714,6 +720,7 @@ async function run() {
       toolsSource,
       toolsVersion,
       overlayBaseDatabaseStats,
+      dependencyCachingResults,
       logger,
       error,
     );
@@ -736,6 +743,7 @@ async function run() {
     toolsSource,
     toolsVersion,
     overlayBaseDatabaseStats,
+    dependencyCachingResults,
     logger,
   );
 }

src/status-report.test.ts

@@ -286,6 +286,7 @@ const testCreateInitWithConfigStatusReport = test.macro({
             undefined,
             1024,
             undefined,
+            undefined,
           );
 
         if (t.truthy(initWithConfigStatusReport)) {

src/status-report.ts

@@ -13,6 +13,7 @@ import {
 } from "./actions-util";
 import { getAnalysisKey, getApiClient } from "./api-client";
 import { parseRegistriesWithoutCredentials, type Config } from "./config-utils";
+import { DependencyCacheRestoreStatusReport } from "./dependency-caching";
 import { DocUrl } from "./doc-url";
 import { EnvVar } from "./environment";
 import { getRef } from "./git-utils";
@@ -497,6 +498,8 @@ export interface InitWithConfigStatusReport extends InitStatusReport {
   overlay_base_database_download_size_bytes?: number;
   /** Time taken to download the overlay-base database, in milliseconds. */
   overlay_base_database_download_duration_ms?: number;
+  /** Stringified JSON object representing information about the results of restoring dependency caches. */
+  dependency_caching_restore_results: string;
   /** Stringified JSON array of registry configuration objects, from the 'registries' config field
   or workflow input. **/
   registries: string;
@@ -522,6 +525,7 @@ export async function createInitWithConfigStatusReport(
   configFile: string | undefined,
   totalCacheSize: number,
   overlayBaseDatabaseStats: OverlayBaseDatabaseDownloadStats | undefined,
+  dependencyCachingResults: DependencyCacheRestoreStatusReport | undefined,
 ): Promise<InitWithConfigStatusReport> {
   const languages = config.languages.join(",");
   const paths = (config.originalUserInput.paths || []).join(",");
@@ -570,6 +574,9 @@ export async function createInitWithConfigStatusReport(
       overlayBaseDatabaseStats?.databaseSizeBytes,
     overlay_base_database_download_duration_ms:
       overlayBaseDatabaseStats?.databaseDownloadDurationMs,
+    dependency_caching_restore_results: JSON.stringify(
+      dependencyCachingResults ?? {},
+    ),
     query_filters: JSON.stringify(
       config.originalUserInput["query-filters"] ?? [],
     ),