From 53f2d1d0942575d43e214b0c3ab3750c32b40ba6 Mon Sep 17 00:00:00 2001
From: danielsun1106 <realbluesun@hotmail.com>
Date: Sat, 27 Oct 2018 19:38:01 +0800
Subject: [PATCH] GROOVY-8858: Refine GCL to avoid occupying Permanent
 Area/Metaspace repeatedly for same source code

---
 .../groovy/groovy/lang/GroovyClassLoader.java | 34 ++++++++++++++++++-
 1 file changed, 33 insertions(+), 1 deletion(-)

diff --git a/src/main/groovy/groovy/lang/GroovyClassLoader.java b/src/main/groovy/groovy/lang/GroovyClassLoader.java
index 90402ee1693..fd355248163 100644
--- a/src/main/groovy/groovy/lang/GroovyClassLoader.java
+++ b/src/main/groovy/groovy/lang/GroovyClassLoader.java
@@ -41,6 +41,7 @@
 import org.codehaus.groovy.control.CompilerConfiguration;
 import org.codehaus.groovy.control.Phases;
 import org.codehaus.groovy.control.SourceUnit;
+import org.codehaus.groovy.runtime.EncodingGroovyMethods;
 import org.codehaus.groovy.runtime.IOGroovyMethods;
 import org.codehaus.groovy.runtime.InvokerHelper;
 import org.codehaus.groovy.runtime.memoize.EvictableCache;
@@ -66,6 +67,7 @@
 import java.net.URLDecoder;
 import java.security.AccessController;
 import java.security.CodeSource;
+import java.security.NoSuchAlgorithmException;
 import java.security.Permission;
 import java.security.PermissionCollection;
 import java.security.Permissions;
@@ -315,8 +317,13 @@ public Class parseClass(GroovyCodeSource codeSource) throws CompilationFailedExc
      * @return the main class defined in the given script
      */
     public Class parseClass(final GroovyCodeSource codeSource, boolean shouldCacheSource) throws CompilationFailedException {
+        // it's better to cache class instances by the source code
+        // GCL will load the unique class instance for the same source code
+        // and avoid occupying Permanent Area/Metaspace repeatedly for same source code
+        String cacheKey = genSourceCacheKey(codeSource);
+
         return ((StampedCommonCache<String, Class>) sourceCache).getAndPut(
-                codeSource.getName(),
+                cacheKey,
                 new EvictableCache.ValueProvider<String, Class>() {
                     @Override
                     public Class provide(String key) {
@@ -327,6 +334,31 @@ public Class provide(String key) {
         );
     }
 
+    private String genSourceCacheKey(GroovyCodeSource codeSource) {
+        String strToDigest;
+
+        String scriptText = codeSource.getScriptText();
+        if (null != scriptText) {
+            strToDigest = "scriptText:" + scriptText;
+            CodeSource cs = codeSource.getCodeSource();
+            if (null != cs) {
+                strToDigest = strToDigest + "/codeSource:" + cs;
+            }
+        } else {
+            // if the script text is null, i.e. the script content is invalid
+            // use the name as cache key for the time being to trigger the validation by `groovy.lang.GroovyClassLoader.validate`
+            // note: the script will not be cached due to the invalid script content,
+            //       so it does not matter even if cache key is not the md5 value of script content
+            strToDigest = "name:" + codeSource.getName();
+        }
+
+        try {
+            return EncodingGroovyMethods.md5(strToDigest);
+        } catch (NoSuchAlgorithmException e) {
+            throw new GroovyRuntimeException(e); // should never reach here!
+        }
+    }
+
     private Class doParseClass(GroovyCodeSource codeSource) {
         validate(codeSource);
         Class answer;  // Was neither already loaded nor compiling, so compile and add to cache.