[jps model] cache contents of loaded files when using the new implementation (IJPL-409)

Unlike the old implementation, the new one may call JpsComponentLoader.loadComponent multiple times for the same file, so it's better to cache content to speed up loading.

GitOrigin-RevId: 4c3630f24bdcb8740ef5cd3ba6d414febb0f9d77

jps/model-serialization/src/org/jetbrains/jps/model/serialization/JpsComponentLoader.java

@@ -17,6 +17,8 @@ import java.io.IOException;
 import java.nio.file.Files;
 import java.nio.file.NoSuchFileException;
 import java.nio.file.Path;
+import java.util.Objects;
+import java.util.concurrent.ConcurrentHashMap;
 
 @ApiStatus.Internal
 public class JpsComponentLoader {
@@ -24,10 +26,17 @@ public class JpsComponentLoader {
   private static final int MAX_ATTEMPTS = 5;
   protected final @Nullable Path myExternalConfigurationDirectory;
   private final JpsMacroExpander myMacroExpander;
+  private static final Element NULL_VALUE = new Element("null");
+  private final ConcurrentHashMap<Path, Element> myRootElementsCache;
 
   public JpsComponentLoader(@NotNull JpsMacroExpander macroExpander, @Nullable Path externalConfigurationDirectory) {
+    this(macroExpander, externalConfigurationDirectory, false);
+  }
+
+  public JpsComponentLoader(@NotNull JpsMacroExpander macroExpander, @Nullable Path externalConfigurationDirectory, boolean useCache) {
     myMacroExpander = macroExpander;
     myExternalConfigurationDirectory = externalConfigurationDirectory;
+    myRootElementsCache = useCache ? new ConcurrentHashMap<>() : null;
   }
 
   public @NotNull JpsMacroExpander getMacroExpander() {
@@ -38,7 +47,16 @@ public class JpsComponentLoader {
    * Returns null if file doesn't exist
    */
   public @Nullable Element loadRootElement(@NotNull Path file) {
-    return loadRootElement(file, myMacroExpander);
+    if (myRootElementsCache == null) {
+      return loadRootElement(file, myMacroExpander);
+    }
+    Element cached = myRootElementsCache.get(file);
+    if (cached != null) {
+      return cached != NULL_VALUE ? cached : null;
+    }
+    Element result = loadRootElement(file, myMacroExpander);
+    myRootElementsCache.put(file, Objects.requireNonNullElse(result, NULL_VALUE));
+    return result;
   }
 
   public @Nullable Element loadComponent(@NotNull Path file, @NotNull String componentName) {

platform/workspace/jps/src/com/intellij/platform/workspace/jps/bridge/impl/serialization/ProjectDirectJpsFileContentReader.kt

@@ -10,6 +10,7 @@ import org.jetbrains.jps.model.serialization.JpsProjectConfigurationLoading
 import org.jetbrains.jps.model.serialization.JpsProjectConfigurationLoading.createProjectMacroExpander
 import org.jetbrains.jps.util.JpsPathUtil
 import java.nio.file.Path
+import java.util.concurrent.ConcurrentHashMap
 import kotlin.io.path.Path
 
 /**
@@ -22,7 +23,8 @@ internal class ProjectDirectJpsFileContentReader(
 ) : JpsFileContentReader {
     
   private val projectMacroExpander = createProjectMacroExpander(pathVariables, projectBaseDir)
-  val projectComponentLoader = JpsComponentLoader(projectMacroExpander, externalConfigurationDirectory)
+  private val moduleLoadersCache = ConcurrentHashMap<String, JpsComponentLoader>()
+  val projectComponentLoader = JpsComponentLoader(projectMacroExpander, externalConfigurationDirectory, true)
   
   override fun loadComponent(fileUrl: String, componentName: String, customModuleFilePath: String?): Element? {
     if (fileUrl.endsWith(".iml")) {
@@ -58,9 +60,13 @@ internal class ProjectDirectJpsFileContentReader(
   }
 
   private fun getModuleLoader(imlFileUrl: String): JpsComponentLoader {
+    moduleLoadersCache[imlFileUrl]?.let {
+      return it
+    }
     val moduleFile = Path(JpsPathUtil.urlToPath(imlFileUrl))
     val macroExpander = JpsProjectConfigurationLoading.createModuleMacroExpander(pathVariables, moduleFile)
-    //todo cache
-    return JpsComponentLoader(macroExpander, null) 
+    val loader = JpsComponentLoader(macroExpander, null, true)
+    moduleLoadersCache[imlFileUrl] = loader
+    return loader 
   }
 }