List and cache bootstrap classes once ProjectManager is registered

build-tools/projects/src/main/java/com/itsaky/androidide/projects/ProjectManager.kt

@@ -26,6 +26,7 @@ import com.itsaky.androidide.projects.api.ModuleProject
 import com.itsaky.androidide.projects.api.Project
 import com.itsaky.androidide.projects.builder.BuildService
 import com.itsaky.androidide.projects.models.ActiveDocument
+import com.itsaky.androidide.projects.util.BootstrapClassesProvider
 import com.itsaky.androidide.projects.util.ProjectTransformer
 import com.itsaky.androidide.tooling.api.IProject
 import com.itsaky.androidide.utils.ILogger
@@ -37,6 +38,7 @@ import java.io.StringReader
 import java.nio.file.Files
 import java.nio.file.Path
 import java.time.Instant
+import java.util.concurrent.*
 import org.greenrobot.eventbus.EventBus
 import org.greenrobot.eventbus.Subscribe
 import org.greenrobot.eventbus.ThreadMode.BACKGROUND
@@ -257,6 +259,13 @@ object ProjectManager : EventReceiver {
   ////// TODO Subscribe to file creation/deletion/rename events and update source map //////
   //////////////////////////////////////////////////////////////////////////////////////////
 
+  override fun register() {
+    super.register()
+
+    // Make sure we list and store the bootstrap classes
+    CompletableFuture.runAsync { BootstrapClassesProvider.bootstrapClasses() }
+  }
+
   @Subscribe(threadMode = BACKGROUND)
   @Suppress("unused")
   fun onDocumentOpen(event: DocumentOpenEvent) {

build-tools/projects/src/main/java/com/itsaky/androidide/projects/util/BootstrapClassesProvider.java

@@ -0,0 +1,104 @@
+/*
+ *  This file is part of AndroidIDE.
+ *
+ *  AndroidIDE is free software: you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation, either version 3 of the License, or
+ *  (at your option) any later version.
+ *
+ *  AndroidIDE is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License
+ *   along with AndroidIDE.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+package com.itsaky.androidide.projects.util;
+
+import androidx.annotation.Nullable;
+
+import com.itsaky.androidide.utils.ILogger;
+
+import org.jetbrains.annotations.Contract;
+
+import java.io.File;
+import java.io.IOException;
+import java.lang.reflect.Method;
+import java.net.URI;
+import java.nio.file.FileSystem;
+import java.nio.file.FileSystems;
+import java.nio.file.Files;
+import java.util.Collections;
+import java.util.HashSet;
+import java.util.Map;
+import java.util.Set;
+
+/**
+ * Provides class names from the bootstrap classpath (i.e. android.jar).
+ *
+ * @author Akash Yadav
+ */
+public class BootstrapClassesProvider {
+
+  private static Set<String> sCachedClasses;
+  private static final ILogger LOG = ILogger.newInstance("BootstrapClassesProvider");
+
+  public static Set<String> bootstrapClasses() {
+    if (sCachedClasses != null && !sCachedClasses.isEmpty()) {
+      return sCachedClasses;
+    }
+
+    final var start = System.currentTimeMillis();
+    sCachedClasses = new HashSet<>();
+
+    try {
+      final var fs = getJRTFileSystem();
+      if (fs == null) {
+        LOG.error("Unable to create JRT FileSystem instance");
+        return sCachedClasses;
+      }
+
+      final var javaBase = fs.getPath("/modules/java.base/");
+      try (final var stream = Files.walk(javaBase)) {
+        final var it = stream.iterator();
+        while (it.hasNext()) {
+          final var classFile = it.next();
+          final String relative = javaBase.relativize(classFile).toString();
+          if (relative.endsWith(".class") && !relative.contains("$")) {
+            final String trim = relative.substring(0, relative.length() - ".class".length());
+            final String qualifiedName = trim.replace(File.separatorChar, '.');
+            sCachedClasses.add(qualifiedName);
+          }
+        }
+        LOG.info("Found", sCachedClasses.size(), "classes in bootstrap classpath");
+      } catch (IOException io) {
+        LOG.error("An error occurred while listing classes from bootstrap classpath", io);
+      }
+    } catch (Throwable err) {
+      LOG.error("Unable to find classes from bootstrap classpath", err);
+    }
+
+    return sCachedClasses;
+  }
+
+  @Nullable
+  @Contract(" -> new")
+  private static FileSystem getJRTFileSystem() throws Exception {
+    final URI uri = URI.create("jrt:/");
+    try {
+      // Tests run on the JVM, so we cannot directly access JRTFileSystemProvider
+      // But this method will work
+      return FileSystems.getFileSystem(uri);
+    } catch (Throwable th) {
+
+      // When on ART, JRT file system is not available
+      // So we create an instance of the FS manually
+      final Class<?> klass = Class.forName("jdk.internal.jrtfs.JrtFileSystemProvider");
+      final Method newFs = klass.getMethod("newFileSystem", URI.class, Map.class);
+      newFs.setAccessible(true);
+      return (FileSystem) newFs.invoke(klass.newInstance(), uri, Collections.emptyMap());
+    }
+  }
+}

lsp/java/src/main/java/com/itsaky/androidide/lsp/java/compiler/JavaCompilerService.java

@@ -29,12 +29,12 @@ import com.itsaky.androidide.lsp.java.models.CompilationRequest;
 import com.itsaky.androidide.lsp.java.parser.ParseTask;
 import com.itsaky.androidide.lsp.java.parser.Parser;
 import com.itsaky.androidide.lsp.java.utils.Extractors;
-import com.itsaky.androidide.lsp.java.utils.ScanClassPath;
 import com.itsaky.androidide.lsp.java.visitors.FindTypeDeclarations;
 import com.itsaky.androidide.models.Range;
 import com.itsaky.androidide.projects.ProjectManager;
 import com.itsaky.androidide.projects.api.ModuleProject;
 import com.itsaky.androidide.projects.models.ActiveDocument;
+import com.itsaky.androidide.projects.util.BootstrapClassesProvider;
 import com.itsaky.androidide.projects.util.Cache;
 import com.itsaky.androidide.projects.util.SourceClassTrie;
 import com.itsaky.androidide.projects.util.StringSearch;
@@ -76,9 +76,9 @@ public class JavaCompilerService implements CompilerProvider {
   private static final Cache<Void, List<String>> cacheContainsType = new Cache<>();
   private static final ILogger LOG = ILogger.newInstance("JavaCompilerService");
 
-  protected final ScanClassPath classPathScanner = new ScanClassPath();
   protected final Set<Path> classPath;
-  protected final Set<String> jdkClasses = classPathScanner.jdkTopLevelClasses(), classPathClasses;
+  protected final Set<String> classPathClasses;
+  protected final Set<String> jdkClasses = BootstrapClassesProvider.bootstrapClasses();
   protected final List<Diagnostic<? extends JavaFileObject>> diagnostics = new ArrayList<>();
   protected final Map<JavaFileObject, Long> cachedModified = new HashMap<>();
   protected final Cache<Void, List<String>> cacheFileImports = new Cache<>();
@@ -94,15 +94,16 @@ public class JavaCompilerService implements CompilerProvider {
   // It is marked as nullable just for some special cases like tests
   public JavaCompilerService(@Nullable ModuleProject module) {
     this.module = module;
+    this.fileManager = new SourceFileManager(module);
     if (module == null) {
       this.classPath = Collections.unmodifiableSet(Collections.emptySet());
+      this.classPathClasses = Collections.emptySet();
     } else {
       this.classPath =
           Collections.unmodifiableSet(
               module.getCompileClasspaths().stream().map(File::toPath).collect(Collectors.toSet()));
+      this.classPathClasses = module.compileClasspathClasses.allClassNames();
     }
-    this.classPathClasses = classPathScanner.classPathTopLevelClasses(classPath);
-    this.fileManager = new SourceFileManager(module);
   }
 
   public ModuleProject getModule() {

lsp/java/src/main/java/com/itsaky/androidide/lsp/java/utils/ScanClassPath.java

@@ -82,58 +82,4 @@ public class ScanClassPath {
     LOG.info(String.format(Locale.ROOT, "Found %d classes in the java platform", classes.size()));
     return classes;
   }
-
-  @Nullable
-  @Contract(" -> new")
-  public FileSystem getJRTFileSystem() throws Exception {
-    final URI uri = URI.create("jrt:/");
-    try {
-      // Tests run on the JVM, so we cannot directly access JRTFileSystemProvider
-      // But this method will work
-      return FileSystems.getFileSystem(uri);
-    } catch (Throwable th) {
-
-      // When on ART, JRT file system is not available
-      // So we create an instance of the FS manually
-      final Class<?> klass = Class.forName("jdk.internal.jrtfs.JrtFileSystemProvider");
-      final Method newFs = klass.getMethod("newFileSystem", URI.class, Map.class);
-      newFs.setAccessible(true);
-      return (FileSystem) newFs.invoke(klass.newInstance(), uri, Collections.emptyMap());
-    }
-  }
-
-  public Set<String> classPathTopLevelClasses(Set<Path> classPath) {
-    LOG.info(
-        String.format(
-            Locale.getDefault(),
-            "Searching for top-level classes in %d classpath locations",
-            classPath.size()));
-
-    URL[] urls = classPath.stream().map(this::toUrl).toArray(URL[]::new);
-    ClassLoader classLoader = new URLClassLoader(urls, null);
-
-    ClassPath scanner;
-    try {
-      scanner = ClassPath.from(classLoader);
-    } catch (IOException e) {
-      throw new RuntimeException(e);
-    }
-
-    Set<String> classes = new HashSet<>();
-    for (ClassPath.ClassInfo c : scanner.getTopLevelClasses()) {
-      classes.add(c.getName());
-    }
-
-    LOG.info(String.format(Locale.ROOT, "Found %d classes in classpath", classes.size()));
-
-    return classes;
-  }
-
-  private URL toUrl(@NonNull Path p) {
-    try {
-      return p.toUri().toURL();
-    } catch (MalformedURLException e) {
-      throw new RuntimeException(e);
-    }
-  }
 }