Add methods to DatabaseEventListener to notify of statement start and statement end.

Patch from Steve McLeod steve.mcleod@gmail.com

h2/src/docsrc/html/changelog.html

@@ -18,7 +18,8 @@ Change Log
 <h1>Change Log</h1>
 
 <h2>Next Version (unreleased)</h2>
-<ul><li>The table INFORMATION_SCHEMA.FUNCTION_ALIASES now includes a column TYPE_NAME.
+<ul><li>DatabaseEventListener now calls setProgress whenever a statement starts and ends.
+</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!
 </li></ul>

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

@@ -44,6 +44,16 @@ public interface DatabaseEventListener extends EventListener {
      */
     int STATE_RECONNECTED = 4;
 
+    /**
+     * This state is used when a query starts.
+     */
+    int STATE_STATEMENT_START = 5;
+
+    /**
+     * This state is used when a query ends.
+     */
+    int STATE_STATEMENT_END = 6;
+
     /**
      * This method is called just after creating the object.
      * This is done when opening the database if the listener is specified
@@ -79,7 +89,7 @@ public interface DatabaseEventListener extends EventListener {
      * @param state the state
      * @param name the object name
      * @param x the current position
-     * @param max the highest value
+     * @param max the highest value, -1 if the max value is unknown
      */
     void setProgress(int state, String name, int x, int max);
 

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

@@ -8,6 +8,8 @@ package org.h2.command;
 
 import java.sql.SQLException;
 import java.util.ArrayList;
+
+import org.h2.api.DatabaseEventListener;
 import org.h2.constant.ErrorCode;
 import org.h2.engine.Constants;
 import org.h2.engine.Database;
@@ -123,6 +125,14 @@ public abstract class Command implements CommandInterface {
         }
     }
 
+    void publishStart() {
+        session.getDatabase().publishEvent(DatabaseEventListener.STATE_STATEMENT_START, sql);
+    }
+
+    void publishEnd() {
+        session.getDatabase().publishEvent(DatabaseEventListener.STATE_STATEMENT_END, sql);
+    }
+
     /**
      * Check if this command has been canceled, and throw an exception if yes.
      *

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

@@ -67,20 +67,24 @@ class CommandContainer extends Command {
 
     public int update() {
         recompileIfRequired();
+        publishStart();
         start();
         session.setLastIdentity(ValueNull.INSTANCE);
         prepared.checkParameters();
         int updateCount = prepared.update();
         prepared.trace(startTime, updateCount);
+        publishEnd();
         return updateCount;
     }
 
     public ResultInterface query(int maxrows) {
         recompileIfRequired();
+        publishStart();
         start();
         prepared.checkParameters();
         ResultInterface result = prepared.query(maxrows);
         prepared.trace(startTime, result.getRowCount());
+        publishEnd();
         return result;
     }
 

h2/src/main/org/h2/engine/Database.java

@@ -2406,4 +2406,9 @@ public class Database implements DataHandler {
         throw DbException.throwInternalError();
     }
 
+    public void publishEvent(int state, String sql) {
+        if (eventListener!= null) {
+            eventListener.setProgress(state, sql, 0, -1);
+        }
+    }
 }

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

@@ -23,6 +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;
 
     /**
      * Run just this test.
@@ -40,6 +41,7 @@ public class TestDatabaseEventListener extends TestBase implements DatabaseEvent
         testCalled();
         testCloseLog0(false);
         testCloseLog0(true);
+        testCalledForStatement();
         deleteDb("databaseEventListener");
     }
 
@@ -90,7 +92,7 @@ public class TestDatabaseEventListener extends TestBase implements DatabaseEvent
         }
         deleteDb("databaseEventListener");
         String url = getURL("databaseEventListener", true);
-        url += ";DATABASE_EVENT_LISTENER='"+ Init.class.getName() + "'";
+        url += ";DATABASE_EVENT_LISTENER='" + Init.class.getName() + "'";
         Connection conn = DriverManager.getConnection(url, "sa", "sa");
         Statement stat = conn.createStatement();
         stat.execute("select * from test");
@@ -210,6 +212,24 @@ public class TestDatabaseEventListener extends TestBase implements DatabaseEvent
         assertTrue(calledClosingDatabase);
     }
 
+    private void testCalledForStatement() throws SQLException {
+        Properties p = new Properties();
+        p.setProperty("user", "sa");
+        p.setProperty("password", "sa");
+        calledStatementStart = false;
+        calledStatementEnd = false;
+        p.put("DATABASE_EVENT_LISTENER", getClass().getName());
+        org.h2.Driver.load();
+        String url = "jdbc:h2:mem:databaseEventListener";
+        Connection conn = org.h2.Driver.load().connect(url, p);
+        Statement stat = conn.createStatement();
+        stat.execute("create table test(id int primary key, name varchar)");
+        stat.execute("select * from test");
+        conn.close();
+        assertTrue(calledStatementStart);
+        assertTrue(calledStatementEnd);
+    }
+
     public void closingDatabase() {
         calledClosingDatabase = true;
     }
@@ -235,6 +255,17 @@ public class TestDatabaseEventListener extends TestBase implements DatabaseEvent
                 calledCreateIndex = true;
             }
         }
+        if (state == STATE_STATEMENT_START) {
+            System.out.println("name = " + name);
+            if (name.equals("select * from test")) {
+                calledStatementStart = true;
+            }
+        }
+        if (state == STATE_STATEMENT_END) {
+            if (name.equals("select * from test")) {
+                calledStatementEnd = true;
+            }
+        }
     }
 
 }