Introduce TRAP caching

src/trap-caching.ts

@@ -0,0 +1,155 @@
+import * as fs from "fs";
+import * as path from "path";
+
+import * as cache from "@actions/cache";
+
+import * as actionsUtil from "./actions-util";
+import { CodeQL, CODEQL_VERSION_BETTER_RESOLVE_LANGUAGES } from "./codeql";
+import { Config } from "./config-utils";
+import { Language } from "./languages";
+import { Logger } from "./logging";
+import { codeQlVersionAbove } from "./util";
+
+// This constant should be bumped if we make a breaking change
+// to how the CodeQL Action stores or retrieves the TRAP cache,
+// and will invalidate previous caches. We don't need to bump
+// this for CLI/extractor changes, since the CLI version also
+// goes into the cache key.
+const CACHE_VERSION = 1;
+
+export async function getTrapCachingExtractorConfigArgs(
+  config: Config
+): Promise<string[]> {
+  const result: string[] = [];
+  for (const language of config.languages)
+    result.push(
+      ...(await getTrapCachingExtractorConfigArgsForLang(config, language))
+    );
+  return result;
+}
+
+export async function getTrapCachingExtractorConfigArgsForLang(
+  config: Config,
+  language: Language
+): Promise<string[]> {
+  const cacheDir = config.trapCaches[language];
+  if (cacheDir === undefined) return [];
+  const write = await actionsUtil.isAnalyzingDefaultBranch();
+  return [
+    `-O=${language}.trap.cache.dir=${cacheDir}`,
+    `-O=${language}.trap.cache.bound=1024`,
+    `-O=${language}.trap.cache.write=${write}`,
+  ];
+}
+
+export async function downloadTrapCaches(
+  codeql: CodeQL,
+  languages: Language[],
+  logger: Logger
+): Promise<Partial<Record<Language, string>>> {
+  const result = {};
+  const languagesSupportingCaching = await getLanguagesSupportingCaching(
+    codeql,
+    languages,
+    logger
+  );
+  logger.info(
+    `Found ${languagesSupportingCaching.length} languages that support TRAP caching`
+  );
+  if (languagesSupportingCaching.length === 0) return result;
+
+  const cachesDir = path.join(
+    actionsUtil.getTemporaryDirectory(),
+    "trapCaches"
+  );
+  for (const language of languagesSupportingCaching) {
+    const cacheDir = path.join(cachesDir, language);
+    fs.mkdirSync(cacheDir, { recursive: true });
+    result[language] = cacheDir;
+  }
+
+  if (await actionsUtil.isAnalyzingDefaultBranch()) {
+    logger.info(
+      "Analyzing default branch. Skipping downloading of TRAP caches."
+    );
+    return result;
+  }
+
+  let baseSha = "unknown";
+  const eventPath = process.env.GITHUB_EVENT_PATH;
+  if (eventPath !== undefined) {
+    const event = JSON.parse(fs.readFileSync(path.resolve(eventPath), "utf-8"));
+    baseSha = event.pull_request?.base?.sha || "unknown";
+  }
+  for (const language of languages) {
+    const cacheDir = result[language];
+    if (cacheDir === undefined) continue;
+    // The SHA from the base of the PR is the most similar commit we might have a cache for
+    const preferredKey = `codeql-trap-${CACHE_VERSION}-${await codeql.getVersion()}-${language}-${baseSha}`;
+    logger.info(
+      `Looking in Actions cache for TRAP cache with key ${preferredKey}`
+    );
+    const found = await cache.restoreCache([cacheDir], preferredKey, [
+      `codeql-trap-${CACHE_VERSION}-${await codeql.getVersion()}-${language}-`, // Fall back to any cache with the right key prefix
+    ]);
+    if (found === undefined) {
+      // Didn't find any cache, let's unset to avoid lookups in an empty directory
+      logger.info(`No TRAP cache found in Actions cache for ${language}`);
+      result[language] = undefined;
+    }
+  }
+
+  return result;
+}
+
+export async function uploadTrapCaches(
+  codeql: CodeQL,
+  config: Config,
+  logger: Logger
+): Promise<void> {
+  if (!(await actionsUtil.isAnalyzingDefaultBranch())) return; // Only upload caches from the default branch
+
+  for (const language of config.languages) {
+    const cacheDir = config.trapCaches[language];
+    if (cacheDir === undefined) continue;
+    const key = `codeql-trap-${CACHE_VERSION}-${await codeql.getVersion()}-${language}-${
+      process.env.GITHUB_SHA || "unknown"
+    }`;
+    logger.info(`Uploading TRAP cache to Actions cache with key ${key}`);
+    await cache.saveCache([cacheDir], key);
+  }
+}
+
+export async function getLanguagesSupportingCaching(
+  codeql: CodeQL,
+  languages: Language[],
+  logger: Logger
+): Promise<Language[]> {
+  const result: Language[] = [];
+  if (
+    !(await codeQlVersionAbove(codeql, CODEQL_VERSION_BETTER_RESOLVE_LANGUAGES))
+  )
+    return result;
+  const resolveResult = await codeql.betterResolveLanguages();
+  outer: for (const lang of languages) {
+    const extractor = resolveResult.extractors[lang][0];
+    const trapCacheOptions =
+      extractor.extractor_options?.trap?.properties?.cache?.properties;
+    if (trapCacheOptions === undefined) {
+      logger.info(
+        `${lang} does not support TRAP caching (missing option group)`
+      );
+      continue;
+    }
+    for (const requiredOpt of ["dir", "bound", "write"]) {
+      if (!(requiredOpt in trapCacheOptions)) {
+        logger.info(
+          `${lang} does not support TRAP caching (missing ${requiredOpt} option)`
+        );
+        continue outer;
+      }
+    }
+    result.push(lang);
+  }
+  return result;
+}