[369359] Improve performance of QueryRequest/Indication

https://bugs.eclipse.org/bugs/show_bug.cgi?id=369359

2 files changed, 26 insertions, 6 deletions

diff --git a/plugins/org.eclipse.emf.cdo.common/src/org/eclipse/emf/cdo/common/util/CDOQueryInfo.java b/plugins/org.eclipse.emf.cdo.common/src/org/eclipse/emf/cdo/common/util/CDOQueryInfo.java
index c87ad81216..6a9f6d4e76 100644
--- a/plugins/org.eclipse.emf.cdo.common/src/org/eclipse/emf/cdo/common/util/CDOQueryInfo.java
+++ b/plugins/org.eclipse.emf.cdo.common/src/org/eclipse/emf/cdo/common/util/CDOQueryInfo.java
@@ -20,7 +20,7 @@ import java.util.Map;
 /**
  * Encapsulates all the transferrable information that fully specifies a query from a {@link CDOCommonView view} to a
  * {@link CDOCommonRepository repository}.
- * 
+ *
  * @author Simon McDuff
  * @since 3.0
  * @noextend This interface is not intended to be extended by clients.
@@ -31,6 +31,13 @@ public interface CDOQueryInfo
   public static final int UNLIMITED_RESULTS = -1;
 
   /**
+   * The name of a {@link Boolean} typed {@link #getParameters() parameter} to influence automatic response flushing (the default) after each query result.
+   *
+   * @since 4.2
+   */
+  public static final String PARAM_DISABLE_RESPONSE_FLUSHING = "disable.response.flushing";
+
+  /**
    * Returns the language identifier of this query, never <code>null</code>.
    */
   public String getQueryLanguage();
@@ -47,7 +54,7 @@ public interface CDOQueryInfo
 
   /**
    * Returns the context object, or <code>null</code> if no context is bound.
-   * 
+   *
    * @since 4.0
    */
   public Object getContext();
@@ -60,7 +67,7 @@ public interface CDOQueryInfo
   /**
    * Returns <code>true</code> if the view of this query had legacy mode enabled at the time this query was created,
    * <code>false</code> otherwise.
-   * 
+   *
    * @since 4.0
    */
   public boolean isLegacyModeEnabled();
@@ -68,7 +75,7 @@ public interface CDOQueryInfo
   /**
    * Returns the {@link CDOChangeSetData change set} to be considered if this query has been created by a dirty
    * transaction, <code>null</code> otherwise.
-   * 
+   *
    * @since 4.0
    */
   public CDOChangeSetData getChangeSetData();
diff --git a/plugins/org.eclipse.emf.cdo.server.net4j/src/org/eclipse/emf/cdo/server/internal/net4j/protocol/QueryIndication.java b/plugins/org.eclipse.emf.cdo.server.net4j/src/org/eclipse/emf/cdo/server/internal/net4j/protocol/QueryIndication.java
index f72aed1aab..2748a84269 100644
--- a/plugins/org.eclipse.emf.cdo.server.net4j/src/org/eclipse/emf/cdo/server/internal/net4j/protocol/QueryIndication.java
+++ b/plugins/org.eclipse.emf.cdo.server.net4j/src/org/eclipse/emf/cdo/server/internal/net4j/protocol/QueryIndication.java
@@ -35,6 +35,8 @@ public class QueryIndication extends CDOServerReadIndication
 
   private boolean xrefs;
 
+  private boolean disableResponseFlushing;
+
   private InternalQueryResult queryResult;
 
   public QueryIndication(CDOServerProtocol protocol)
@@ -51,6 +53,9 @@ public class QueryIndication extends CDOServerReadIndication
     CDOQueryInfo queryInfo = new CDOQueryInfoImpl(in);
     xrefs = queryInfo.getQueryLanguage().equals(CDOProtocolConstants.QUERY_LANGUAGE_XREFS);
 
+    Object param = queryInfo.getParameters().get(CDOQueryInfo.PARAM_DISABLE_RESPONSE_FLUSHING);
+    disableResponseFlushing = xrefs || Boolean.TRUE.equals(param);
+
     InternalQueryManager queryManager = getRepository().getQueryManager();
     queryResult = queryManager.execute(view, queryInfo);
   }
@@ -60,7 +65,7 @@ public class QueryIndication extends CDOServerReadIndication
   {
     // Return queryID immediately.
     out.writeInt(queryResult.getQueryID());
-    flush();
+    flushUnlessDisabled();
 
     int numberOfResults = 0;
     while (queryResult.hasNext())
@@ -83,7 +88,7 @@ public class QueryIndication extends CDOServerReadIndication
 
       if (queryResult.peek() == null)
       {
-        flush();
+        flushUnlessDisabled();
       }
     }
 
@@ -95,4 +100,12 @@ public class QueryIndication extends CDOServerReadIndication
     // Query is done successfully
     out.writeBoolean(false);
   }
+
+  private void flushUnlessDisabled() throws IOException
+  {
+    if (!disableResponseFlushing)
+    {
+      flush();
+    }
+  }
 }