From 9c7bfc677a96cfc60713f40e339fd991d7697014 Mon Sep 17 00:00:00 2001
From: Joel Leitch <joel.leitch@gmail.com>
Date: Wed, 19 May 2010 20:47:27 +0000
Subject: [PATCH] Allow cache size to be configured.

---
 gson/pom.xml                                    |  4 ++--
 .../java/com/google/gson/FieldAttributes.java   | 17 +++++++++++++++--
 .../test/java/com/google/gson/LruCacheTest.java | 15 ++++++++++++---
 3 files changed, 29 insertions(+), 7 deletions(-)

diff --git a/gson/pom.xml b/gson/pom.xml
index 46bb1cea..a91e7355 100644
--- a/gson/pom.xml
+++ b/gson/pom.xml
@@ -134,7 +134,7 @@
            </workspaceCodeStylesURL>
          </configuration>
        </plugin>
-       <!-- plugin>
+       <plugin>
         <groupId>org.codehaus.mojo</groupId>
         <artifactId>javacc-maven-plugin</artifactId>
         <executions>
@@ -157,7 +157,7 @@
         <version>4.2</version>
         </dependency>
         </dependencies>
-      </plugin-->
+      </plugin>
       <plugin>
         <groupId>org.apache.maven.plugins</groupId>
         <artifactId>maven-jxr-plugin</artifactId>
diff --git a/gson/src/main/java/com/google/gson/FieldAttributes.java b/gson/src/main/java/com/google/gson/FieldAttributes.java
index 870b168d..c278288f 100644
--- a/gson/src/main/java/com/google/gson/FieldAttributes.java
+++ b/gson/src/main/java/com/google/gson/FieldAttributes.java
@@ -34,9 +34,11 @@ import java.util.Collections;
  * @since 1.4
  */
 public final class FieldAttributes {
-  // TODO(Joel): Fix how we configure this cache in a follow-up CL.
+  private static final String MAX_CACHE_PROPERTY_NAME =
+      "com.google.gson.annotation_cache_size_hint";
+  
   private static final Cache<Pair<Class<?>, String>, Collection<Annotation>> ANNOTATION_CACHE =
-      new LruCache<Pair<Class<?>,String>, Collection<Annotation>>(1500);
+      new LruCache<Pair<Class<?>,String>, Collection<Annotation>>(getMaxCacheSize());
 
   private final Class<?> parentClazz;
   private final Field field;
@@ -64,6 +66,17 @@ public final class FieldAttributes {
     field = f;
   }
 
+  private static int getMaxCacheSize() {
+    final int defaultMaxCacheSize = 2000;
+    try {
+      String propertyValue = System.getProperty(
+          MAX_CACHE_PROPERTY_NAME, String.valueOf(defaultMaxCacheSize));
+      return Integer.parseInt(propertyValue);
+    } catch (NumberFormatException e) {
+      return defaultMaxCacheSize;
+    }
+  }
+
   /**
    * @return the name of the field
    */
diff --git a/gson/src/test/java/com/google/gson/LruCacheTest.java b/gson/src/test/java/com/google/gson/LruCacheTest.java
index 4725db9a..dbf5034d 100644
--- a/gson/src/test/java/com/google/gson/LruCacheTest.java
+++ b/gson/src/test/java/com/google/gson/LruCacheTest.java
@@ -53,21 +53,30 @@ public class LruCacheTest extends TestCase {
   }
   
   public void testCacheEviction() throws Exception {
-    Cache<String, Integer> cache = new LruCache<String, Integer>(3);
+    Cache<String, Integer> cache = new LruCache<String, Integer>(5);
 
     cache.addElement("key1", 1);
     cache.addElement("key2", 2);
     cache.addElement("key3", 3);
+    cache.addElement("key4", 4);
+    cache.addElement("key5", 5);
     assertEquals(1, cache.getElement("key1").intValue());
     assertEquals(2, cache.getElement("key2").intValue());
     assertEquals(3, cache.getElement("key3").intValue());
+    assertEquals(4, cache.getElement("key4").intValue());
+    assertEquals(5, cache.getElement("key5").intValue());
 
     // Access key1 to show key2 will be evicted (shows not a FIFO cache)
     cache.getElement("key1");
-    cache.addElement("key4", 4);
+    cache.getElement("key3");
+    cache.addElement("key6", 6);
+    cache.addElement("key7", 7);
     assertEquals(1, cache.getElement("key1").intValue());
     assertNull(cache.getElement("key2"));
     assertEquals(3, cache.getElement("key3").intValue());
-    assertEquals(4, cache.getElement("key4").intValue());
+    assertNull(cache.getElement("key4"));
+    assertEquals(5, cache.getElement("key5").intValue());
+    assertEquals(6, cache.getElement("key6").intValue());
+    assertEquals(7, cache.getElement("key7").intValue());
   }
 }