Merge pull request #2802 from github/mbg/dependency-caching/java-buildless

Set and cache dependency directory for Java `build-mode: none`

src/analyze-action-post.ts

@@ -3,6 +3,8 @@
  * It will run after the all steps in this job, in reverse order in relation to
  * other `post:` hooks.
  */
+import * as fs from "fs";
+
 import * as core from "@actions/core";
 
 import * as actionsUtil from "./actions-util";
@@ -10,6 +12,7 @@ import { getGitHubVersion } from "./api-client";
 import { getCodeQL } from "./codeql";
 import { getConfig } from "./config-utils";
 import * as debugArtifacts from "./debug-artifacts";
+import { getJavaTempDependencyDir } from "./dependency-caching";
 import { EnvVar } from "./environment";
 import { getActionsLogger } from "./logging";
 import { checkGitHubVersionInRange, getErrorMessage } from "./util";
@@ -38,6 +41,20 @@ async function runWrapper() {
         );
       }
     }
+
+    // If we analysed Java in build-mode: none, we may have downloaded dependencies
+    // to the temp directory. Clean these up so they don't persist unnecessarily
+    // long on self-hosted runners.
+    const javaTempDependencyDir = getJavaTempDependencyDir();
+    if (fs.existsSync(javaTempDependencyDir)) {
+      try {
+        fs.rmSync(javaTempDependencyDir, { recursive: true });
+      } catch (error) {
+        logger.info(
+          `Failed to remove temporary Java dependencies directory: ${getErrorMessage(error)}`,
+        );
+      }
+    }
   } catch (error) {
     core.setFailed(
       `analyze post-action step failed: ${getErrorMessage(error)}`,

src/analyze.ts

@@ -11,6 +11,7 @@ import { getApiClient } from "./api-client";
 import { setupCppAutobuild } from "./autobuild";
 import { CodeQL, getCodeQL } from "./codeql";
 import * as configUtils from "./config-utils";
+import { getJavaTempDependencyDir } from "./dependency-caching";
 import { addDiagnostic, makeDiagnostic } from "./diagnostics";
 import {
   DiffThunkRange,
@@ -166,6 +167,16 @@ export async function runExtraction(
         ) {
           await setupCppAutobuild(codeql, logger);
         }
+
+        // The Java `build-mode: none` extractor places dependencies (.jar files) in the
+        // database scratch directory by default. For dependency caching purposes, we want
+        // a stable path that caches can be restored into and that we can cache at the
+        // end of the workflow (i.e. that does not get removed when the scratch directory is).
+        if (language === Language.java && config.buildMode === BuildMode.None) {
+          process.env["CODEQL_EXTRACTOR_JAVA_OPTION_BUILDLESS_DEPENDENCY_DIR"] =
+            getJavaTempDependencyDir();
+        }
+
         await codeql.extractUsingBuildMode(config, language);
       } else {
         await codeql.extractScannedLanguage(config, language);

src/dependency-caching.ts

@@ -4,6 +4,7 @@ import { join } from "path";
 import * as actionsCache from "@actions/cache";
 import * as glob from "@actions/glob";
 
+import { getTemporaryDirectory } from "./actions-util";
 import { getTotalCacheSize } from "./caching-utils";
 import { Config } from "./config-utils";
 import { EnvVar } from "./environment";
@@ -28,6 +29,15 @@ interface CacheConfig {
 const CODEQL_DEPENDENCY_CACHE_PREFIX = "codeql-dependencies";
 const CODEQL_DEPENDENCY_CACHE_VERSION = 1;
 
+/**
+ * Returns a path to a directory intended to be used to store .jar files
+ * for the Java `build-mode: none` extractor.
+ * @returns The path to the directory that should be used by the `build-mode: none` extractor.
+ */
+export function getJavaTempDependencyDir(): string {
+  return join(getTemporaryDirectory(), "codeql_java", "repository");
+}
+
 /**
  * Default caching configurations per language.
  */
@@ -38,6 +48,8 @@ const CODEQL_DEFAULT_CACHE_CONFIG: { [language: string]: CacheConfig } = {
       join(os.homedir(), ".m2", "repository"),
       // Gradle
       join(os.homedir(), ".gradle", "caches"),
+      // CodeQL Java build-mode: none
+      getJavaTempDependencyDir(),
     ],
     hash: [
       // Maven