HHH-3823:

- adding a method to obtain the current revision entity + test

git-svn-id: https://svn.jboss.org/repos/hibernate/core/trunk@16485 1b8cb986-b30d-0410-93ca-fae66ebed9b2

envers/src/main/java/org/hibernate/envers/AuditReader.java

@@ -100,6 +100,20 @@ public interface AuditReader {
     <T> T findRevision(Class<T> revisionEntityClass, Number revision) throws IllegalArgumentException,
             RevisionDoesNotExistException, IllegalStateException;
 
+	/**
+	 * Gets an instance of the current revision entity, to which any entries in the audit tables will be bound.
+	 * Please note the if {@code persist} is {@code false}, and no audited entities are modified in this session,
+	 * then the obtained revision entity instance won't be persisted. If {@code persist} is {@code true}, the revision
+	 * entity instance will always be persisted, regardless of whether audited entities are changed or not.
+	 * @param revisionEntityClass Class of the revision entity. Should be annotated with {@link RevisionEntity}.
+	 * @param persist If the revision entity is not yet persisted, should it become persisted. This way, the primary
+	 * identifier (id) will be filled (if it's assigned by the DB) and available, but the revision entity will be
+	 * persisted even if there are no changes to audited entities. Otherwise, the revision number (id) can be
+	 * {@code null}.
+	 * @return The current revision entity, to which any entries in the audit tables will be bound.
+	 */
+	<T> T getCurrentRevision(Class<T> revisionEntityClass, boolean persist);
+
     /**
      *
      * @return A query creator, associated with this AuditReader instance, with which queries can be

envers/src/main/java/org/hibernate/envers/reader/AuditReaderImpl.java

@@ -34,10 +34,12 @@ import org.hibernate.envers.exception.AuditException;
 import org.hibernate.envers.query.AuditEntity;
 import static org.hibernate.envers.tools.ArgumentsTools.checkNotNull;
 import static org.hibernate.envers.tools.ArgumentsTools.checkPositive;
+import org.hibernate.envers.synchronization.AuditSync;
 
 import org.hibernate.NonUniqueResultException;
 import org.hibernate.Query;
 import org.hibernate.Session;
+import org.hibernate.event.EventSource;
 import org.hibernate.engine.SessionImplementor;
 import org.jboss.envers.query.VersionsQueryCreator;
 
@@ -190,7 +192,20 @@ public class AuditReaderImpl implements AuditReaderImplementor {
         }
     }
 
-    public VersionsQueryCreator createQuery() {
+	@SuppressWarnings({"unchecked"})
+	public <T> T getCurrentRevision(Class<T> revisionEntityClass, boolean persist) {
+		if (!(session instanceof EventSource)) {
+			throw new IllegalArgumentException("The provided session is not an EventSource!");
+		}
+
+		// Obtaining the current audit sync
+		AuditSync auditSync = verCfg.getSyncManager().get((EventSource) session);
+
+		// And getting the current revision data
+		return (T) auditSync.getCurrentRevisionData(session, persist);
+	}
+
+	public VersionsQueryCreator createQuery() {
         return new VersionsQueryCreator(verCfg, this);
     }
 }

envers/src/main/java/org/hibernate/envers/revisioninfo/DefaultRevisionInfoGenerator.java

@@ -63,14 +63,18 @@ public class DefaultRevisionInfoGenerator implements RevisionInfoGenerator {
         }
     }
 
-    private Object newRevision() {
+	public void saveRevisionData(Session session, Object revisionData) {
-        Object revisionInfo;
+        session.save(revisionInfoEntityName, revisionData);
+	}
+
+    public Object generate() {
+		Object revisionInfo;
         try {
             revisionInfo = revisionInfoClass.newInstance();
         } catch (Exception e) {
             throw new RuntimeException(e);
         }
-        
+
         revisionTimestampSetter.set(revisionInfo, System.currentTimeMillis(), null);
 
         if (listener != null) {
@@ -79,10 +83,4 @@ public class DefaultRevisionInfoGenerator implements RevisionInfoGenerator {
 
         return revisionInfo;
     }
-
-    public Object generate(Session session) {
-        Object revisionData = newRevision();
-        session.save(revisionInfoEntityName, revisionData);
-        return revisionData;
-    }
 }

envers/src/main/java/org/hibernate/envers/revisioninfo/RevisionInfoGenerator.java

@@ -29,5 +29,6 @@ import org.hibernate.Session;
  * @author Adam Warski (adam at warski dot org)
  */
 public interface RevisionInfoGenerator {
-    Object generate(Session session);
+	void saveRevisionData(Session session, Object revisionData);
+    Object generate();
 }

envers/src/main/java/org/hibernate/envers/synchronization/AuditSync.java

@@ -111,9 +111,8 @@ public class AuditSync implements Synchronization {
     }
 
     private void executeInSession(Session session) {
-        if (revisionData == null) {
+		// Making sure the revision data is persisted.
-            revisionData = revisionInfoGenerator.generate(session);
+        getCurrentRevisionData(session, true);
-        }
 
         AuditWorkUnit vwu;
 
@@ -127,6 +126,20 @@ public class AuditSync implements Synchronization {
         }
     }
 
+	public Object getCurrentRevisionData(Session session, boolean persist) {
+		// Generating the revision data if not yet generated
+		if (revisionData == null) {
+            revisionData = revisionInfoGenerator.generate();
+        }
+
+		// Saving the revision data, if not yet saved and persist is true
+		if (!session.contains(revisionData) && persist) {
+			revisionInfoGenerator.saveRevisionData(session, revisionData);
+		}
+
+		return revisionData;
+	}
+
     public void beforeCompletion() {
         if (workUnits.size() == 0 && undoQueue.size() == 0) {
             return;

envers/src/test/java/org/hibernate/envers/test/entities/reventity/CustomDataRevEntity.java

@@ -0,0 +1,95 @@
+/*
+ * Hibernate, Relational Persistence for Idiomatic Java
+ *
+ * Copyright (c) 2008, Red Hat Middleware LLC or third-party contributors as
+ * indicated by the @author tags or express copyright attribution
+ * statements applied by the authors.  All third-party contributions are
+ * distributed under license by Red Hat Middleware LLC.
+ *
+ * This copyrighted material is made available to anyone wishing to use, modify,
+ * copy, or redistribute it subject to the terms and conditions of the GNU
+ * Lesser General Public License, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
+ * or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU Lesser General Public License
+ * for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public License
+ * along with this distribution; if not, write to:
+ * Free Software Foundation, Inc.
+ * 51 Franklin Street, Fifth Floor
+ * Boston, MA  02110-1301  USA
+ */
+package org.hibernate.envers.test.entities.reventity;
+
+import javax.persistence.Entity;
+import javax.persistence.GeneratedValue;
+import javax.persistence.Id;
+
+import org.hibernate.envers.RevisionEntity;
+import org.hibernate.envers.RevisionNumber;
+import org.hibernate.envers.RevisionTimestamp;
+
+/**
+ * @author Adam Warski (adam at warski dot org)
+ */
+@Entity
+@RevisionEntity
+public class CustomDataRevEntity {
+    @Id
+    @GeneratedValue
+    @RevisionNumber
+    private int customId;
+
+    @RevisionTimestamp
+    private long customTimestamp;
+
+	private String data;
+
+    public int getCustomId() {
+        return customId;
+    }
+
+    public void setCustomId(int customId) {
+        this.customId = customId;
+    }
+
+    public long getCustomTimestamp() {
+        return customTimestamp;
+    }
+
+    public void setCustomTimestamp(long customTimestamp) {
+        this.customTimestamp = customTimestamp;
+    }
+
+	public String getData() {
+		return data;
+	}
+
+	public void setData(String data) {
+		this.data = data;
+	}
+
+	@Override
+	public boolean equals(Object o) {
+		if (this == o) return true;
+		if (!(o instanceof CustomDataRevEntity)) return false;
+
+		CustomDataRevEntity that = (CustomDataRevEntity) o;
+
+		if (customId != that.customId) return false;
+		if (customTimestamp != that.customTimestamp) return false;
+		if (data != null ? !data.equals(that.data) : that.data != null) return false;
+
+		return true;
+	}
+
+	@Override
+	public int hashCode() {
+		int result = customId;
+		result = 31 * result + (int) (customTimestamp ^ (customTimestamp >>> 32));
+		result = 31 * result + (data != null ? data.hashCode() : 0);
+		return result;
+	}
+}

envers/src/test/java/org/hibernate/envers/test/integration/reventity/CustomNoListener.java

@@ -0,0 +1,137 @@
+/*
+ * Hibernate, Relational Persistence for Idiomatic Java
+ *
+ * Copyright (c) 2008, Red Hat Middleware LLC or third-party contributors as
+ * indicated by the @author tags or express copyright attribution
+ * statements applied by the authors.  All third-party contributions are
+ * distributed under license by Red Hat Middleware LLC.
+ *
+ * This copyrighted material is made available to anyone wishing to use, modify,
+ * copy, or redistribute it subject to the terms and conditions of the GNU
+ * Lesser General Public License, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
+ * or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU Lesser General Public License
+ * for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public License
+ * along with this distribution; if not, write to:
+ * Free Software Foundation, Inc.
+ * 51 Franklin Street, Fifth Floor
+ * Boston, MA  02110-1301  USA
+ */
+package org.hibernate.envers.test.integration.reventity;
+
+import java.util.Arrays;
+import java.util.Date;
+import javax.persistence.EntityManager;
+
+import org.hibernate.envers.AuditReader;
+import org.hibernate.envers.exception.RevisionDoesNotExistException;
+import org.hibernate.envers.test.AbstractEntityTest;
+import org.hibernate.envers.test.entities.StrTestEntity;
+import org.hibernate.envers.test.entities.reventity.CustomDataRevEntity;
+import org.testng.annotations.BeforeClass;
+import org.testng.annotations.Test;
+
+import org.hibernate.ejb.Ejb3Configuration;
+
+/**
+ * @author Adam Warski (adam at warski dot org)
+ */
+public class CustomNoListener extends AbstractEntityTest {
+    private Integer id;
+
+    public void configure(Ejb3Configuration cfg) {
+        cfg.addAnnotatedClass(StrTestEntity.class);
+        cfg.addAnnotatedClass(CustomDataRevEntity.class);
+    }
+
+    @BeforeClass(dependsOnMethods = "init")
+    public void initData() throws InterruptedException {        
+        EntityManager em = getEntityManager();
+
+		// Revision 1
+        em.getTransaction().begin();
+        StrTestEntity te = new StrTestEntity("x");
+        em.persist(te);
+        id = te.getId();
+
+		// Setting the data on the revision entity
+		CustomDataRevEntity custom = getAuditReader().getCurrentRevision(CustomDataRevEntity.class, false);
+		custom.setData("data1");
+
+        em.getTransaction().commit();
+
+        // Revision 2
+        em.getTransaction().begin();
+        te = em.find(StrTestEntity.class, id);
+        te.setStr("y");
+
+		// Setting the data on the revision entity
+		custom = getAuditReader().getCurrentRevision(CustomDataRevEntity.class, false);
+		custom.setData("data2");
+
+        em.getTransaction().commit();
+
+		// Revision 3 - no changes, but rev entity should be persisted
+        em.getTransaction().begin();
+
+		// Setting the data on the revision entity
+		custom = getAuditReader().getCurrentRevision(CustomDataRevEntity.class, true);
+		custom.setData("data3");
+
+        em.getTransaction().commit();
+
+		// No changes, rev entity won't be persisted
+        em.getTransaction().begin();
+
+		// Setting the data on the revision entity
+		custom = getAuditReader().getCurrentRevision(CustomDataRevEntity.class, false);
+		custom.setData("data4");
+
+        em.getTransaction().commit();
+
+		// Revision 4
+        em.getTransaction().begin();
+        te = em.find(StrTestEntity.class, id);
+        te.setStr("z");
+
+		// Setting the data on the revision entity
+		custom = getAuditReader().getCurrentRevision(CustomDataRevEntity.class, false);
+		custom.setData("data5");
+
+		custom = getAuditReader().getCurrentRevision(CustomDataRevEntity.class, false);
+		custom.setData("data5bis");
+
+        em.getTransaction().commit();
+    }
+
+    @Test
+    public void testFindRevision() {
+        AuditReader vr = getAuditReader();
+
+		assert "data1".equals(vr.findRevision(CustomDataRevEntity.class, 1).getData());
+		assert "data2".equals(vr.findRevision(CustomDataRevEntity.class, 2).getData());
+		assert "data3".equals(vr.findRevision(CustomDataRevEntity.class, 3).getData());
+		assert "data5bis".equals(vr.findRevision(CustomDataRevEntity.class, 4).getData());
+    }
+
+    @Test
+    public void testRevisionsCounts() {
+        assert Arrays.asList(1, 2, 4).equals(getAuditReader().getRevisions(StrTestEntity.class, id));
+    }
+
+    @Test
+    public void testHistoryOfId1() {
+        StrTestEntity ver1 = new StrTestEntity("x", id);
+        StrTestEntity ver2 = new StrTestEntity("y", id);
+        StrTestEntity ver3 = new StrTestEntity("z", id);
+
+        assert getAuditReader().find(StrTestEntity.class, id, 1).equals(ver1);
+        assert getAuditReader().find(StrTestEntity.class, id, 2).equals(ver2);
+        assert getAuditReader().find(StrTestEntity.class, id, 3).equals(ver2);
+        assert getAuditReader().find(StrTestEntity.class, id, 4).equals(ver3);
+    }
+}