From a3540057b7f594e9ab226622711e81829411ebff Mon Sep 17 00:00:00 2001
From: Roland Praml <roland.praml@foconis.de>
Date: Wed, 18 Jan 2023 09:24:47 +0100
Subject: [PATCH] BUG: Memory-leak on streaming queries when LoadBuffers are
 not aligned

---
 .../basic/TestPersistenceContextMany.java     | 169 ++++++++++++++++++
 1 file changed, 169 insertions(+)
 create mode 100644 ebean-test/src/test/java/org/tests/basic/TestPersistenceContextMany.java

diff --git a/ebean-test/src/test/java/org/tests/basic/TestPersistenceContextMany.java b/ebean-test/src/test/java/org/tests/basic/TestPersistenceContextMany.java
new file mode 100644
index 000000000..2a5f9b6f8
--- /dev/null
+++ b/ebean-test/src/test/java/org/tests/basic/TestPersistenceContextMany.java
@@ -0,0 +1,169 @@
+package org.tests.basic;
+
+import io.ebean.DB;
+import io.ebean.DatabaseFactory;
+import io.ebean.QueryIterator;
+import io.ebean.config.DatabaseConfig;
+import io.ebean.xtest.BaseTestCase;
+import org.junit.jupiter.api.Disabled;
+import org.junit.jupiter.api.Test;
+
+import javax.persistence.CascadeType;
+import javax.persistence.DiscriminatorValue;
+import javax.persistence.Entity;
+import javax.persistence.Id;
+import javax.persistence.Inheritance;
+import javax.persistence.ManyToOne;
+import javax.persistence.OneToMany;
+import javax.validation.constraints.Size;
+import java.util.ArrayList;
+import java.util.List;
+import java.util.concurrent.atomic.AtomicInteger;
+
+public class TestPersistenceContextMany extends BaseTestCase {
+
+
+  @Entity
+  @Inheritance
+  public abstract static class TestModel3 {
+
+    @Id
+    private int id;
+
+    @Size(max = 255)
+    private String someData;
+
+    @OneToMany(cascade = CascadeType.REFRESH)
+    //@Where(clause = "1=1")
+    private List<TestModel3Many1> many1;
+
+    public int getId() {
+      return id;
+    }
+
+    public void setId(int id) {
+      this.id = id;
+    }
+
+    public void setSomeData(String someData) {
+      this.someData = someData;
+    }
+
+    public String getSomeData() {
+      return someData;
+    }
+  }
+
+  @Entity
+  @Inheritance
+  @DiscriminatorValue("A")
+  public static class TestModel3A extends TestModel3 {
+
+  }
+
+  @Entity
+  @Inheritance
+  @DiscriminatorValue("B")
+  public static class TestModel3B extends TestModel3 {
+    @OneToMany(cascade = CascadeType.REFRESH)
+    private List<TestModel3Many2> many2;
+
+  }
+
+  @Entity
+  public static class TestModel3Many1 {
+    @Id
+    private int id;
+
+    @ManyToOne
+    private TestModel3 base;
+  }
+
+  @Entity
+  public static class TestModel3Many2 {
+    @Id
+    private int id;
+
+    @ManyToOne
+    private TestModel3B base;
+  }
+
+  @Test
+  @Disabled
+  void initDb() {
+    DatabaseConfig config = new DatabaseConfig();
+    config.setName("h2-batch");
+    config.loadFromProperties();
+    config.setDdlExtra(false);
+    config.getDataSourceConfig().setUsername("sa");
+    config.getDataSourceConfig().setPassword("sa");
+    config.getDataSourceConfig().setUrl("jdbc:h2:file:./testsFileMany;DB_CLOSE_ON_EXIT=FALSE;NON_KEYWORDS=KEY,VALUE");
+    config.addClass(TestModel3.class);
+    config.addClass(TestModel3A.class);
+    config.addClass(TestModel3B.class);
+    config.addClass(TestModel3Many1.class);
+    config.addClass(TestModel3Many2.class);
+    DatabaseFactory.create(config);
+
+    String base = "x".repeat(240);
+    // 10 mio TestModel - each needs about 1/4 kbytes -> 2,5 GB in total
+    List<TestModel3> batch = new ArrayList<>();
+    for (int i = 0; i < 1_000_000; i++) {
+
+      TestModel3 m = i == 5 ? new TestModel3A() : new TestModel3B(); // produces "off-by-one"
+      m.setSomeData(base + i); // ensure we have not duplicates
+      batch.add(m);
+      if (i % 1000 == 0) {
+        DB.saveAll(batch);
+        batch.clear();
+      }
+      if (i % 100000 == 0) {
+        System.out.println(i);
+      }
+    }
+    DB.saveAll(batch);
+  }
+
+  @Test
+  @Disabled
+  void testFindEachFindList() {
+    DatabaseConfig config = new DatabaseConfig();
+    config.setName("h2-batch");
+    config.loadFromProperties();
+    config.setDdlRun(false);
+    config.getDataSourceConfig().setUsername("sa");
+    config.getDataSourceConfig().setPassword("sa");
+    config.getDataSourceConfig().setUrl("jdbc:h2:file:./testsFileMany;DB_CLOSE_ON_EXIT=FALSE;NON_KEYWORDS=KEY,VALUE");
+    config.addClass(TestModel3.class);
+    config.addClass(TestModel3A.class);
+    config.addClass(TestModel3B.class);
+    config.addClass(TestModel3Many1.class);
+    config.addClass(TestModel3Many2.class);
+    DatabaseFactory.create(config);
+
+    AtomicInteger i = new AtomicInteger();
+    System.out.println("Doing findEach");
+    DB.find(TestModel3.class).select("*").findEach(c -> {
+      i.incrementAndGet();
+    });
+    System.out.println("Read " + i + " entries");
+
+    i.set(0);
+    System.out.println("Doing findStream");
+    DB.find(TestModel3.class).select("*").findStream().forEach(c -> i.incrementAndGet());
+    System.out.println("Read " + i + " entries");
+
+    i.set(0);
+    System.out.println("Doing findIterate");
+    QueryIterator<TestModel3> iter = DB.find(TestModel3.class).select("*").findIterate();
+    while (iter.hasNext()) {
+      iter.next();
+      i.incrementAndGet();
+    }
+    System.out.println("Read " + i + " entries");
+
+    System.out.println("Doing FindList, will hold all entries in memory. Expect OOM with -Xmx100m.");
+    List<TestModel3> lst = DB.find(TestModel3.class).select("*").findList();
+    System.out.println("Read " + lst.size() + " entries");
+  }
+}