Fix OPENDJ-409: Add support for optimistic concurrency control via ETag-lik...

Matthew Swift

23.23.2012 ab6eacf10af3f59ac3509c6a4e5e20192022c2ab

Fix OPENDJ-409: Add support for optimistic concurrency control via ETag-like attributes

Add a unit test for testing optimistic concurrency use case.

 opends/tests/unit-tests-testng/src/server/org/opends/server/extensions/EntityTagVirtualAttributeProviderTestCase.java

@@ -39,15 +39,22 @@
import org.opends.messages.MessageBuilder;
import org.opends.server.TestCaseUtils;
import org.opends.server.admin.server.ConfigurationChangeListener;
import org.opends.server.admin.std.meta.VirtualAttributeCfgDefn;
import org.opends.server.admin.std.meta.EntityTagVirtualAttributeCfgDefn.ChecksumAlgorithm;
import org.opends.server.admin.std.meta.VirtualAttributeCfgDefn;
import org.opends.server.admin.std.meta.VirtualAttributeCfgDefn.ConflictBehavior;
import org.opends.server.admin.std.meta.VirtualAttributeCfgDefn.Scope;
import org.opends.server.admin.std.server.EntityTagVirtualAttributeCfg;
import org.opends.server.admin.std.server.VirtualAttributeCfg;
import org.opends.server.controls.LDAPAssertionRequestControl;
import org.opends.server.core.DirectoryServer;
import org.opends.server.core.ModifyOperation;
import org.opends.server.core.SearchOperation;
import org.opends.server.core.SearchOperationWrapper;
import org.opends.server.protocols.internal.InternalClientConnection;
import org.opends.server.protocols.internal.InternalSearchOperation;
import org.opends.server.protocols.ldap.LDAPFilter;
import org.opends.server.protocols.ldap.LDAPModification;
import org.opends.server.schema.DirectoryStringSyntax;
import org.opends.server.types.*;
import org.opends.server.util.StaticUtils;
import org.testng.annotations.BeforeClass;
@@ -557,6 +564,120 @@



  /**
   * Simulates the main use case for entity tag support: optimistic concurrency.
   * <p>
   * This test reads an entry requesting its etag, then performs an update using
   * an assertion control to prevent the change from being applied if the etag
   * has changed since the read was performed.
   *
   * @throws Exception
   *           If an unexpected exception occurred.
   */
  public void testOptimisticConcurrency() throws Exception
  {
    // Use an internal connection.
    AttributeType etagType = DirectoryServer.getAttributeType("etag");
    AttributeType descrType = DirectoryServer.getAttributeType("description");
    String userDN = "uid=test.user,ou=People,o=test";
    InternalClientConnection conn = InternalClientConnection
        .getRootConnection();

    // Create a test backend containing the user entry to be modified.
    TestCaseUtils.initializeTestBackend(true);

    // @formatter:off
    TestCaseUtils.addEntries(
      "dn: ou=People,o=test",
      "objectClass: top",
      "objectClass: organizationalUnit",
      "ou: People",
      "",
      "dn: uid=test.user,ou=People,o=test",
      "objectClass: top",
      "objectClass: person",
      "objectClass: organizationalPerson",
      "objectClass: inetOrgPerson",
      "uid: test.user",
      "givenName: Test",
      "sn: User",
      "cn: Test User",
      "userPassword: password");
    // @formatter:on

    // Read the user entry and get the etag.
    Entry e1 = readEntry(conn, userDN);
    String etag1 = e1
        .getAttributeValue(etagType, DirectoryStringSyntax.DECODER);
    assertNotNull(etag1);

    // Apply a change using the assertion control for optimistic concurrency.
    List<RawModification> mods = Collections
        .<RawModification> singletonList(new LDAPModification(
            ModificationType.REPLACE, RawAttribute.create("description",
                "first modify")));
    List<Control> ctrls = Collections
        .<Control> singletonList(new LDAPAssertionRequestControl(true,
            LDAPFilter.createEqualityFilter("etag", ByteString.valueOf(etag1))));
    ModifyOperation modifyOperation = conn.processModify(userDN, mods, ctrls);
    assertEquals(modifyOperation.getResultCode(), ResultCode.SUCCESS);

    // Reread the entry and check that the description has been added and that
    // the etag has changed.
    Entry e2 = readEntry(conn, userDN);

    String etag2 = e2
        .getAttributeValue(etagType, DirectoryStringSyntax.DECODER);
    assertNotNull(etag2);
    assertFalse(etag1.equals(etag2));

    String description2 = e2.getAttributeValue(descrType,
        DirectoryStringSyntax.DECODER);
    assertNotNull(description2);
    assertEquals(description2, "first modify");

    // Simulate a concurrent update: perform another update using the old etag.
    mods = Collections.<RawModification> singletonList(new LDAPModification(
        ModificationType.REPLACE, RawAttribute.create("description",
            "second modify")));
    modifyOperation = conn.processModify(userDN, mods, ctrls);
    assertEquals(modifyOperation.getResultCode(), ResultCode.ASSERTION_FAILED);

    // Reread the entry and check that the description and etag have not
    // changed.
    Entry e3 = readEntry(conn, userDN);

    String etag3 = e3
        .getAttributeValue(etagType, DirectoryStringSyntax.DECODER);
    assertNotNull(etag3);
    assertEquals(etag2, etag3);

    String description3 = e3.getAttributeValue(descrType,
        DirectoryStringSyntax.DECODER);
    assertNotNull(description3);
    assertEquals(description3, description2);
  }



  private Entry readEntry(InternalClientConnection conn, String userDN)
      throws DirectoryException
  {
    LinkedHashSet<String> attrList = new LinkedHashSet<String>(2);
    attrList.add("*");
    attrList.add("etag");
    InternalSearchOperation searchOperation = conn.processSearch(userDN,
        SearchScope.BASE_OBJECT, DereferencePolicy.NEVER_DEREF_ALIASES, 0, 0,
        false, "(objectClass=*)", attrList);
    assertEquals(searchOperation.getResultCode(), ResultCode.SUCCESS);
    assertEquals(searchOperation.getSearchEntries().size(), 1);
    Entry e = searchOperation.getSearchEntries().get(0);
    assertNotNull(e);
    return e;
  }



  private AttributeValue getEntityTag(final Entry e)
  {
    final Set<AttributeValue> values = provider.getValues(e, null);