use cached DependencyResolver classpath from file

Author: ktoso

JavaKit/src/main/java/org/swift/javakit/dependencies/DependencyResolver.java

@@ -32,7 +32,7 @@
 public class DependencyResolver {
 
     private static final String COMMAND_OUTPUT_LINE_PREFIX_CLASSPATH = "CLASSPATH:";
-    private static final String CLASSPATH_CACHE_FILENAME = "JavaKitDependencyResolver.classpath.swift-java";
+    private static final String CLASSPATH_CACHE_FILENAME = "JavaKitDependencyResolver.swift-java.classpath";
 
     public static String GRADLE_API_DEPENDENCY = "dev.gradleplugins:gradle-api:8.10.1";
     public static String[] BASE_DEPENDENCIES = {
@@ -46,42 +46,42 @@ public class DependencyResolver {
     @UsedFromSwift
     @SuppressWarnings("unused")
     public static String resolveDependenciesToClasspath(String projectBaseDirectoryString, String[] dependencies) throws IOException {
-try {
-    simpleLog("Fetch dependencies: " + Arrays.toString(dependencies));
-    simpleLog("projectBaseDirectoryString =  " + projectBaseDirectoryString);
-    var projectBasePath = new File(projectBaseDirectoryString).toPath();
-
-    File projectDir = Files.createTempDirectory("java-swift-dependencies").toFile();
-    projectDir.mkdirs();
-
-    if (hasDependencyResolverDependenciesLoaded()) {
-        // === Resolve dependencies using Gradle API in-process
-        simpleLog("Gradle API runtime dependency is available, resolve dependencies...");
-        return resolveDependenciesUsingAPI(projectDir, dependencies);
-    }
+        try {
+            simpleLog("Fetch dependencies: " + Arrays.toString(dependencies));
+            simpleLog("Classpath: " + System.getProperty("java.class.path"));
+            var projectBasePath = new File(projectBaseDirectoryString).toPath();
 
-    // === Bootstrap the resolver dependencies and cache them
-    simpleLog("Gradle API not available on classpath, bootstrap %s dependencies: %s"
-            .formatted(DependencyResolver.class.getSimpleName(), Arrays.toString(BASE_DEPENDENCIES)));
-    String dependencyResolverDependenciesClasspath = bootstrapDependencyResolverClasspath();
-    writeDependencyResolverClasspath(projectBasePath, dependencyResolverDependenciesClasspath);
-
-    // --- Resolve dependencies using sub-process process
-    // TODO: it would be nice to just add the above classpath to the system classloader and here call the API
-    //       immediately, but that's challenging and not a stable API we can rely on (hacks exist to add paths
-    //       to system classloader but are not reliable).
-    printBuildFiles(projectDir, dependencies);
-    return resolveDependenciesWithSubprocess(projectDir);
-} catch (Exception e) {
-    e.printStackTrace();
-    throw e;
-}
+            File projectDir = Files.createTempDirectory("java-swift-dependencies").toFile();
+            projectDir.mkdirs();
+
+            if (hasDependencyResolverDependenciesLoaded()) {
+                // === Resolve dependencies using Gradle API in-process
+                simpleLog("Gradle API runtime dependency is available, resolve dependencies...");
+                return resolveDependenciesUsingAPI(projectDir, dependencies);
+            }
+
+            // === Bootstrap the resolver dependencies and cache them
+            simpleLog("Gradle API not available on classpath, bootstrap %s dependencies: %s"
+                    .formatted(DependencyResolver.class.getSimpleName(), Arrays.toString(BASE_DEPENDENCIES)));
+            String dependencyResolverDependenciesClasspath = bootstrapDependencyResolverClasspath();
+            writeDependencyResolverClasspath(projectBasePath, dependencyResolverDependenciesClasspath);
+
+            // --- Resolve dependencies using sub-process process
+            // TODO: it would be nice to just add the above classpath to the system classloader and here call the API
+            //       immediately, but that's challenging and not a stable API we can rely on (hacks exist to add paths
+            //       to system classloader but are not reliable).
+            printBuildFiles(projectDir, dependencies);
+            return resolveDependenciesWithSubprocess(projectDir);
+        } catch (Exception e) {
+            e.printStackTrace();
+            throw e;
+        }
     }
 
 
     /**
      * Use an external {@code gradle} invocation in order to download dependencies such that we can use `gradle-api`
-     * next time we want to resolve dependencies. This uses an external process and is sligtly worse than using the API
+     * next time we want to resolve dependencies. This uses an external process and is slightly worse than using the API
      * directly.
      *
      * @return classpath obtained for the dependencies
@@ -158,7 +158,8 @@ private static void writeDependencyResolverClasspath(Path projectBasePath, Strin
     /**
      * Detect if we have the necessary dependencies loaded.
      */
-    private static boolean hasDependencyResolverDependenciesLoaded() {
+    @UsedFromSwift
+    public static boolean hasDependencyResolverDependenciesLoaded() {
         return hasDependencyResolverDependenciesLoaded(DependencyResolver.class.getClassLoader());
     }
 

Samples/JavaDependencySampleApp/Sources/JavaCommonsCSV/swift-java.config

@@ -2,7 +2,6 @@
   "classes" : {
 
   },
-  "classpath" : "\/Users\/ktoso\/.gradle\/caches\/modules-2\/files-2.1\/org.apache.commons\/commons-csv\/1.12.0\/c77e053d7189bc0857f8d323ab61cb949965fbd1\/commons-csv-1.12.0.jar:\/Users\/ktoso\/.gradle\/caches\/modules-2\/files-2.1\/commons-io\/commons-io\/2.17.0\/ddcc8433eb019fb48fe25207c0278143f3e1d7e2\/commons-io-2.17.0.jar:\/Users\/ktoso\/.gradle\/caches\/modules-2\/files-2.1\/commons-codec\/commons-codec\/1.17.1\/973638b7149d333563584137ebf13a691bb60579\/commons-codec-1.17.1.jar",
   "dependencies" : [
     "org.apache.commons:commons-csv:1.12.0"
   ]

Sources/Java2Swift/JavaToSwift+FetchDependencies.swift

@@ -23,6 +23,32 @@ import JavaKitConfigurationShared
 import JavaKitShared
 
 extension JavaToSwift {
+
+  /// Must be the same as `DependencyResolver#CLASSPATH_CACHE_FILENAME` on the java side.
+  var JavaKitDependencyResolverClasspathCacheFilename: String {
+    "JavaKitDependencyResolver.swift-java.classpath"
+  }
+  var JavaKitDependencyResolverClasspathCacheFilePath: String {
+    ".build/\(JavaKitDependencyResolverClasspathCacheFilename)"
+  }
+
+  func fetchDependenciesCachedClasspath() -> [String]? {
+    guard let cachedClasspathURL = URL(string: "file://" + FileManager.default.currentDirectoryPath + "/" + JavaKitDependencyResolverClasspathCacheFilePath) else {
+      return []
+    }
+
+    guard FileManager.default.fileExists(atPath: cachedClasspathURL.path) else {
+      return []
+    }
+
+    guard let javaKitDependencyResolverCachedClasspath = try? String(contentsOf: cachedClasspathURL) else {
+      return []
+    }
+
+    print("[debug][swift-java] Cached dependency resolver classpath: \(javaKitDependencyResolverCachedClasspath)")
+    return javaKitDependencyResolverCachedClasspath.split(separator: ":").map(String.init)
+  }
+
   func fetchDependencies(moduleName: String,
                          dependencies: [JavaDependencyDescriptor],
                          baseClasspath: [String],

Sources/Java2Swift/JavaToSwift.swift

@@ -222,13 +222,16 @@ struct JavaToSwift: ParsableCommand {
         let extraClasspathEntries = extraClasspath.split(separator: ":").map(String.init)
         print("[debug][swift-java] Extra classpath: \(extraClasspathEntries)")
         classpathEntries += extraClasspathEntries
-      case .classWrappers/*(let config)*/,
-           .fetchDependencies/*(let config)*/:
+      case .fetchDependencies:
+        // if we have already fetched dependencies for the dependency loader,
+        // let's use them so we can in-process resolve rather than forking a new
+        // gradle process.
+        if let dependencyResolverClasspath = fetchDependenciesCachedClasspath() {
+          print("[debug][swift-java] Found cached dependency resolver classpath: \(dependencyResolverClasspath)")
+          classpathEntries += dependencyResolverClasspath
+        }
+      case .classWrappers:
         break;
-        //   * Classpath specified in the configuration file (if any)
-  //      let extraClasspathEntries = config.classpath?.split(separator: ":").map(String.init) ?? []
-  //      print("[debug][swift-java] Config classpath: \(extraClasspathEntries)")
-  //      classpathEntries += extraClasspathEntries
       }
 
       // Add extra classpath entries which are specific to building the JavaKit project and samples

Sources/JavaKitDependencyResolver/DependencyResolver.swift

@@ -26,4 +26,7 @@ extension JavaClass<DependencyResolver> {
     projectBaseDirectory: String,
     dependencies: [String]) throws -> String
 
+  @JavaStaticMethod
+  public func hasDependencyResolverDependenciesLoaded() -> Bool
+
 }