#919 - io.ebean package initial

src/test/java/org/tests/query/other/TestFindIterateHeapDump.java

@@ -0,0 +1,126 @@
+package org.tests.query.other;
+
+import io.ebean.BaseTestCase;
+import io.ebean.Ebean;
+import io.ebean.EbeanServer;
+import org.tests.model.basic.EBasic;
+import com.sun.management.HotSpotDiagnosticMXBean;
+import org.junit.Ignore;
+import org.junit.Test;
+
+import javax.management.MBeanServer;
+import java.io.File;
+import java.lang.management.ManagementFactory;
+import java.util.concurrent.atomic.AtomicInteger;
+
+@SuppressWarnings("restriction")
+public class TestFindIterateHeapDump extends BaseTestCase {
+
+  // All that heap dumping code from :
+  // https://blogs.oracle.com/sundararajan/entry/programmatically_dumping_heap_from_java
+  private static final String HOTSPOT_BEAN_NAME = "com.sun.management:type=HotSpotDiagnostic";
+
+  /**
+   * field to store the hotspot diagnostic MBean
+   */
+  private static volatile HotSpotDiagnosticMXBean hotspotMBean;
+
+  /**
+   * Ignore this test generally - run it manually against MySQL specifically for Issue #56.
+   */
+  @Ignore
+  @Test
+  public void test() {
+
+    EbeanServer server = Ebean.getDefaultServer();
+
+//    Transaction transaction = server.beginTransaction();
+//    try {
+//      transaction.setBatchMode(true);
+//      transaction.setBatchSize(20);
+//      for (int i = 0; i < 20000; i++) {
+//        EBasic dumbModel = new EBasic();
+//        dumbModel.setName("Goodbye now");
+//        server.save(dumbModel);
+//      }
+//      transaction.commit();
+//
+//    } finally {
+//      transaction.end();
+//    }
+//
+//    if (true) {
+//      return;
+//    }
+
+    // Intentionally not iterating through the iterator to
+
+    final AtomicInteger counter = new AtomicInteger();
+
+    server.find(EBasic.class)
+      .findEach(bean -> {
+
+        int count = counter.incrementAndGet();
+        if (count == 1) {
+          dumpHeap("heap-dump13-initial.snapshot", true);
+        }
+      });
+
+    // try {
+    // while (iterate.hasNext()) {
+    // EBasic eBasic = iterate.next();
+    // eBasic.getDescription();
+    // }
+    // } finally {
+    // iterate.close();
+    // }
+
+    String fileName = "heap-dump13.snapshot";
+
+    File file = new File(fileName);
+    if (file.exists())
+      file.delete();
+
+    dumpHeap(fileName, true);
+  }
+
+  static void dumpHeap(String fileName, boolean live) {
+    // initialize hotspot diagnostic MBean
+    initHotspotMBean();
+    try {
+      hotspotMBean.dumpHeap(fileName, live);
+    } catch (RuntimeException re) {
+      throw re;
+    } catch (Exception exp) {
+      throw new RuntimeException(exp);
+    }
+  }
+
+  /**
+   * initialize the hotspot diagnostic MBean field
+   */
+  private static void initHotspotMBean() {
+    if (hotspotMBean == null) {
+      synchronized (TestFindIterateHeapDump.class) {
+        if (hotspotMBean == null) {
+          hotspotMBean = getHotspotMBean();
+        }
+      }
+    }
+  }
+
+  /**
+   * get the hotspot diagnostic MBean from the ManagementFactory.
+   */
+  private static HotSpotDiagnosticMXBean getHotspotMBean() {
+    try {
+      final MBeanServer server = ManagementFactory.getPlatformMBeanServer();
+      return ManagementFactory.newPlatformMXBeanProxy(server, HOTSPOT_BEAN_NAME, HotSpotDiagnosticMXBean.class);
+    } catch (RuntimeException re) {
+      throw re;
+    } catch (Exception exp) {
+      throw new RuntimeException(exp);
+    }
+  }
+
+}