DatabaseEventListener now calls setProgress periodically while a query statement is running

h2/src/docsrc/html/changelog.html

@@ -29,6 +29,7 @@ Change Log
 </li><li>Then reading from a resource using the prefix "classpath:", the ContextClassLoader
     is now used if the resource can't be read otherwise.
 </li><li>DatabaseEventListener now calls setProgress whenever a statement starts and ends.
+</li><li>DatabaseEventListener now calls setProgress periodically while a statement is running.
 </li><li>The table INFORMATION_SCHEMA.FUNCTION_ALIASES now includes a column TYPE_NAME.
 </li><li>Issue 378: when using views, the wrong values were bound to a parameter in some cases.
 </li><li>Terrence Huang has translated the error messages to Chinese. Thanks a lot!

h2/src/main/org/h2/api/DatabaseEventListener.java

@@ -54,6 +54,11 @@ public interface DatabaseEventListener extends EventListener {
      */
     int STATE_STATEMENT_END = 6;
 
+    /**
+     * This state is used for periodic notification during long-running queries
+     */
+    int STATE_STATEMENT_PROGRESS = 7;
+
     /**
      * This method is called just after creating the object.
      * This is done when opening the database if the listener is specified

h2/src/main/org/h2/command/Prepared.java

@@ -7,6 +7,7 @@
 package org.h2.command;
 
 import java.util.ArrayList;
+import org.h2.api.DatabaseEventListener;
 import org.h2.constant.ErrorCode;
 import org.h2.engine.Database;
 import org.h2.engine.Session;
@@ -331,6 +332,7 @@ public abstract class Prepared {
             checkCanceled();
         }
         this.currentRowNumber = rowNumber;
+        setProgress();
     }
 
     /**
@@ -342,6 +344,15 @@ public abstract class Prepared {
         return currentRowNumber;
     }
 
+    /**
+     * Notifies query progress via the DatabaseEventListener
+     */
+    private void setProgress() {
+        if ((currentRowNumber & 127) == 0) {
+            session.getDatabase().setProgress(DatabaseEventListener.STATE_STATEMENT_PROGRESS, sqlStatement, currentRowNumber, 0);
+        }
+    }
+
     /**
      * Convert the statement to a String.
      *

h2/src/main/org/h2/res/help.csv

@@ -973,7 +973,7 @@ HASH(algorithmString, dataBytes, iterationInt)
 ","
 Calculate the hash value using an algorithm, and repeat this process for a number of iterations."
 "Functions (Numeric)","TRUNCATE","
-TRUNCATE(numeric, digitsInt)
+{ TRUNC | TRUNCATE } (numeric, digitsInt)
 ","
 Truncates to a number of digits (to the next value closer to 0)."
 "Functions (Numeric)","COMPRESS","

h2/src/test/org/h2/test/db/TestListener.java

@@ -69,7 +69,7 @@ public class TestListener extends TestBase implements DatabaseEventListener {
         if (state == lastState && time < last + 1000) {
             return;
         }
-        if (state == STATE_STATEMENT_START || state == STATE_STATEMENT_END) {
+        if (state == STATE_STATEMENT_START || state == STATE_STATEMENT_END || state == STATE_STATEMENT_PROGRESS) {
             return;
         }
         if (name.length() > 30) {

h2/src/test/org/h2/test/jdbc/TestDatabaseEventListener.java

@@ -23,7 +23,7 @@ import org.h2.test.TestBase;
 public class TestDatabaseEventListener extends TestBase implements DatabaseEventListener {
 
     private static boolean calledOpened, calledClosingDatabase, calledScan, calledCreateIndex;
-    private static boolean calledStatementStart, calledStatementEnd;
+    private static boolean calledStatementStart, calledStatementEnd, calledStatementProgress;
 
     /**
      * Run just this test.
@@ -218,6 +218,7 @@ public class TestDatabaseEventListener extends TestBase implements DatabaseEvent
         p.setProperty("password", "sa");
         calledStatementStart = false;
         calledStatementEnd = false;
+        calledStatementProgress = false;
         p.put("DATABASE_EVENT_LISTENER", getClass().getName());
         org.h2.Driver.load();
         String url = "jdbc:h2:mem:databaseEventListener";
@@ -228,6 +229,7 @@ public class TestDatabaseEventListener extends TestBase implements DatabaseEvent
         conn.close();
         assertTrue(calledStatementStart);
         assertTrue(calledStatementEnd);
+        assertTrue(calledStatementProgress);
     }
 
     public void closingDatabase() {
@@ -265,6 +267,11 @@ public class TestDatabaseEventListener extends TestBase implements DatabaseEvent
                 calledStatementEnd = true;
             }
         }
+        if (state == STATE_STATEMENT_PROGRESS) {
+            if (name.equals("select * from test")) {
+                calledStatementProgress = true;
+            }
+        }
     }
 
 }