From 3b3fee84d9e68c82b23bf8204466412d1ba41c5d Mon Sep 17 00:00:00 2001
From: Eugene Zhuravlev <jeka@intellij.com>
Date: Fri, 11 Jul 2014 21:37:10 +0200
Subject: [PATCH] clear zip file caches on low memory

---
 .../jps/incremental/IncProjectBuilder.java    |  2 +
 .../org/jetbrains/jps/javac/JavacMain.java    | 55 +++++++++++++++++++
 2 files changed, 57 insertions(+)

diff --git a/jps/jps-builders/src/org/jetbrains/jps/incremental/IncProjectBuilder.java b/jps/jps-builders/src/org/jetbrains/jps/incremental/IncProjectBuilder.java
index baa67a0216d8..88fdef9eaad2 100644
--- a/jps/jps-builders/src/org/jetbrains/jps/incremental/IncProjectBuilder.java
+++ b/jps/jps-builders/src/org/jetbrains/jps/incremental/IncProjectBuilder.java
@@ -56,6 +56,7 @@ import org.jetbrains.jps.incremental.storage.BuildTargetConfiguration;
 import org.jetbrains.jps.incremental.storage.OneToManyPathsMapping;
 import org.jetbrains.jps.incremental.storage.OutputToTargetRegistry;
 import org.jetbrains.jps.indices.ModuleExcludeIndex;
+import org.jetbrains.jps.javac.JavacMain;
 import org.jetbrains.jps.model.java.JpsJavaExtensionService;
 import org.jetbrains.jps.model.java.compiler.JpsJavaCompilerConfiguration;
 import org.jetbrains.jps.model.module.JpsModule;
@@ -176,6 +177,7 @@ public class IncProjectBuilder {
     final LowMemoryWatcher memWatcher = LowMemoryWatcher.register(new Runnable() {
       @Override
       public void run() {
+        JavacMain.clearCompilerZipFileCache();
         myProjectDescriptor.dataManager.flush(false);
         myProjectDescriptor.timestamps.getStorage().force();
       }
diff --git a/jps/jps-builders/src/org/jetbrains/jps/javac/JavacMain.java b/jps/jps-builders/src/org/jetbrains/jps/javac/JavacMain.java
index c5b6d861a8e4..ac4f4a0b78fc 100644
--- a/jps/jps-builders/src/org/jetbrains/jps/javac/JavacMain.java
+++ b/jps/jps-builders/src/org/jetbrains/jps/javac/JavacMain.java
@@ -452,4 +452,59 @@ public class JavacMain {
     }
   }
 
+  private static class ZipFileIndexCleanupDataHolder {
+    @Nullable
+    static final Method cacheInstanceGetter;
+    @Nullable
+    static final Method cacheClearMethod;
+
+    static {
+      Method getterMethod = null;
+      Method clearMethod = null;
+      try {
+        //trying JDK 6
+        clearMethod = Class.forName("com.sun.tools.javac.zip.ZipFileIndex").getDeclaredMethod("clearCache");
+        clearMethod.setAccessible(true);
+      }
+      catch (Throwable e) {
+        try {
+          final Class<?> cacheClass = Class.forName("com.sun.tools.javac.file.ZipFileIndexCache");
+          clearMethod = cacheClass.getDeclaredMethod("clearCache");
+          getterMethod = cacheClass.getDeclaredMethod("getSharedInstance");
+          clearMethod.setAccessible(true);
+          getterMethod.setAccessible(true);
+        }
+        catch (Throwable ignored2) {
+          clearMethod = null;
+          getterMethod = null;
+        }
+      }
+
+      cacheInstanceGetter = getterMethod;
+      cacheClearMethod = clearMethod;
+    }
+  }
+
+  private static volatile boolean zipCacheCleanupPossible = true;
+
+  public static void clearCompilerZipFileCache() {
+    if (zipCacheCleanupPossible) {
+      final Method clearMethod = ZipFileIndexCleanupDataHolder.cacheClearMethod;
+      if (clearMethod != null) {
+        final Method getter = ZipFileIndexCleanupDataHolder.cacheInstanceGetter;
+        try {
+          Object instance = getter != null? getter.invoke(null) : null;
+          clearMethod.invoke(instance);
+        }
+        catch (Throwable e) {
+          zipCacheCleanupPossible = false;
+        }
+      }
+      else {
+        zipCacheCleanupPossible = false;
+      }
+    }
+  }
+
+
 }