#2677 - Change trimOnPut to be 10% of max or 1_000.

Can look to provide an explicit option via `@CacheBeanTuning` later.

ebean-core/src/main/java/io/ebeaninternal/server/cache/DefaultServerCache.java

@@ -49,6 +49,7 @@ public class DefaultServerCache implements ServerCache {
   protected final int trimFrequency;
   protected final int maxIdleSecs;
   protected final int maxSecsToLive;
+  protected final long trimOnPut;
   protected final ReentrantLock lock = new ReentrantLock();
   protected final AtomicLong mutationCounter = new AtomicLong();
 
@@ -60,6 +61,7 @@ public class DefaultServerCache implements ServerCache {
     this.maxIdleSecs = config.getMaxIdleSecs();
     this.maxSecsToLive = config.getMaxSecsToLive();
     this.trimFrequency = config.determineTrimFrequency();
+    this.trimOnPut = config.determineTrimOnPut();
 
     MetricFactory factory = MetricFactory.get();
     String prefix = "l2n.";
@@ -191,7 +193,7 @@ public class DefaultServerCache implements ServerCache {
   public void put(Object key, Object value) {
     map.put(key, new SoftReference<>(new CacheEntry(key, value)));
     putCount.increment();
-    if (mutationCounter.incrementAndGet() > 1000) {
+    if (mutationCounter.incrementAndGet() > trimOnPut) {
       runEviction();
     }
   }

ebean-core/src/main/java/io/ebeaninternal/server/cache/DefaultServerCacheConfig.java

@@ -76,4 +76,14 @@ public final class DefaultServerCacheConfig {
     }
     return 0;
   }
+
+  /**
+   * Determine the number of mutations/puts required to trigger a runEviction() in the foreground.
+   */
+  public long determineTrimOnPut() {
+    if (maxSize > 0) {
+      return maxSize / 10;
+    }
+    return 1000;
+  }
 }

ebean-core/src/test/java/io/ebeaninternal/server/cache/DefaultServerCacheConfigTest.java

@@ -6,8 +6,7 @@ import org.junit.jupiter.api.Test;
 
 import static org.junit.jupiter.api.Assertions.assertEquals;
 
-public class DefaultServerCacheConfigTest {
-
+class DefaultServerCacheConfigTest {
 
   private DefaultServerCacheConfig create(int maxSize, int maxIdleSecs, int maxSecsToLive, int trimFreq) {
     ServerCacheOptions options = new ServerCacheOptions();
@@ -20,33 +19,45 @@ public class DefaultServerCacheConfigTest {
   }
 
   @Test
-  public void trimFreq_halfIdle() {
-
+  void trimFreq_halfIdle() {
     assertEquals(create(10000,10,20, 0).determineTrimFrequency(), 4);
   }
 
-
   @Test
-  public void trimFreq_halfIdle_withRounding() {
-
+  void trimFreq_halfIdle_withRounding() {
     assertEquals(create(10000,11,20, 0).determineTrimFrequency(), 4);
   }
 
   @Test
-  public void trimFreq_halfTTL() {
-
+  void trimFreq_halfTTL() {
     assertEquals(create(10000,0,20, 0).determineTrimFrequency(), 9);
   }
 
   @Test
-  public void trimFreq_halfTTL_withRounding() {
-
+  void trimFreq_halfTTL_withRounding() {
     assertEquals(create(10000,0,21, 0).determineTrimFrequency(), 9);
   }
 
   @Test
-  public void trimFreq_explicit() {
-
+  void trimFreq_explicit() {
     assertEquals(create(10000,10,20, 42).determineTrimFrequency(), 42);
   }
+
+  @Test
+  void trimOnPut_default() {
+    assertEquals(create(0,0,0, 0).determineTrimOnPut(), 1_000);
+  }
+
+  @Test
+  void trimOnPut_tenPercent() {
+    assertEquals(create(10_000,0,0, 0).determineTrimOnPut(), 1_000);
+    assertEquals(create(9_000,0,0, 0).determineTrimOnPut(), 900);
+    assertEquals(create(100,0,0, 0).determineTrimOnPut(), 10);
+  }
+
+  @Test
+  void trimOnPut_roundDown() {
+    assertEquals(create(9010,0,0, 0).determineTrimOnPut(), 901);
+    assertEquals(create(9009,0,0, 0).determineTrimOnPut(), 900);
+  }
 }