Also cache negative uri cache lookups.

Serving views or resources which do not have a controller is pretty slow due to uri lookups on every request.
This fixes it by also caching uri looks which do not have a controller.

To avoid DOS attacks, the cache is also limited in size, and the size can
be controlled via the grails.urlmapping.cache.maxsize config property.

Author: recht

grails-bootstrap/build.gradle

@@ -25,6 +25,10 @@ dependencies {
         }
     }
 
+    compile( "com.googlecode.concurrentlinkedhashmap:concurrentlinkedhashmap-lru:${concurrentlinkedhashmapVersion}" ) {
+        exclude group: 'commons-logging', module:'commons-logging'
+    }
+	
     // These 3 are required by UAA but not Grails (non OSGI version of excludes above)
     compile 'com.google.protobuf:protobuf-java:2.3.0',
             'com.googlecode.json-simple:json-simple:1.1',

grails-core/src/main/groovy/org/codehaus/groovy/grails/commons/ControllerArtefactHandler.java

@@ -17,26 +17,48 @@
 
 import grails.util.Environment;
 
-import java.util.concurrent.ConcurrentHashMap;
+import org.codehaus.groovy.grails.plugins.support.aware.GrailsApplicationAware;
+
+import com.googlecode.concurrentlinkedhashmap.ConcurrentLinkedHashMap;
 
 /**
+ * Lookup controllers for uris.
+ * 
+ * <p>This class is responsible for looking up controller classes for uris.</p>
+ * 
+ * <p>Lookups are cached in non-development mode, and the cache size can be controlled using the grails.urlmapping.cache.maxsize config property.</p>
+ * 
  * @author Marc Palmer ([email protected])
 */
-public class ControllerArtefactHandler extends ArtefactHandlerAdapter {
+public class ControllerArtefactHandler extends ArtefactHandlerAdapter implements GrailsApplicationAware {
 
+	private static final String URL_MAPPING_CACHE_MAX_SIZE = "grails.urlmapping.cache.maxsize";
+	private static final GrailsClass NO_CONTROLLER = new AbstractGrailsClass(Object.class, "Controller") {};
+	
     public static final String TYPE = "Controller";
     public static final String PLUGIN_NAME = "controllers";
-    private ConcurrentHashMap<String, GrailsClass> uriToControllerClassCache;
+    private ConcurrentLinkedHashMap<String, GrailsClass> uriToControllerClassCache;
     private ArtefactInfo artefactInfo;
 
+	private GrailsApplication grailsApplication;
+
     public ControllerArtefactHandler() {
         super(TYPE, GrailsControllerClass.class, DefaultGrailsControllerClass.class,
                 DefaultGrailsControllerClass.CONTROLLER, false);
     }
 
     @Override
     public void initialize(ArtefactInfo artefacts) {
-        uriToControllerClassCache = new ConcurrentHashMap<String, GrailsClass>();
+    	Object cacheSize = grailsApplication.getFlatConfig().get(URL_MAPPING_CACHE_MAX_SIZE);
+    	if (cacheSize == null) {
+    		cacheSize = 10000;
+    	}
+        
+    	uriToControllerClassCache = new ConcurrentLinkedHashMap.Builder<String, GrailsClass>()
+    			.initialCapacity(500)
+                .maximumWeightedCapacity(new Integer(cacheSize.toString()))
+                .build();
+    	
         artefactInfo = artefacts;
     }
 
@@ -63,13 +85,23 @@ public GrailsClass getArtefactForFeature(Object feature) {
                     break;
                 }
             }
-            if (controllerClass != null) {
-                // don't cache for dev environment
-                if (Environment.getCurrent() != Environment.DEVELOPMENT) {
-                    uriToControllerClassCache.putIfAbsent(uri, controllerClass);
-                }
+            if (controllerClass == null) {
+            	controllerClass = NO_CONTROLLER;
             }
+            
+            // don't cache for dev environment
+            if (Environment.getCurrent() != Environment.DEVELOPMENT) {
+                uriToControllerClassCache.put(uri, controllerClass);
+            }
+        }
+        
+        if (controllerClass == NO_CONTROLLER) {
+        	controllerClass = null;
         }
         return controllerClass;
     }
+
+	public void setGrailsApplication(GrailsApplication grailsApplication) {
+		this.grailsApplication = grailsApplication;
+	}
 }

grails-web/build.gradle

@@ -18,9 +18,6 @@ dependencies {
     compile "commons-io:commons-io:${commonsIOVersion}"
     compile "commons-lang:commons-lang:$commonsLangVersion"
 
-    compile( "com.googlecode.concurrentlinkedhashmap:concurrentlinkedhashmap-lru:${concurrentlinkedhashmapVersion}" ) {
-        exclude group: 'commons-logging', module:'commons-logging'
-    }
     compile 'opensymphony:sitemesh:2.4'
 
     compile "org.springframework:spring-webmvc:${springVersion}"