The H2 Console now abbreviates large texts in results.

h2/src/docsrc/html/changelog.html

@@ -18,7 +18,8 @@ Change Log
 <h1>Change Log</h1>
 
 <h2>Next Version (unreleased)</h2>
-<ul><li>Multiple UNION queries could not be used in derived tables. 
+<ul><li>The H2 Console now abbreviates large texts in results.
+</li><li>Multiple UNION queries could not be used in derived tables. 
 </li><li>Linked tables can now be read-only.
 </li><li>Temporary linked tables are now supported.
 </li><li>The optimization for IN(...) is now enabled by default. Use -Dh2.optimizeInJoin=false to disable it.

h2/src/main/org/h2/constant/SysProperties.java

@@ -210,6 +210,12 @@ public class SysProperties {
      */
     public static final int EMERGENCY_SPACE_MIN = getIntSetting("h2.emergencySpaceMin", 64 * 1024);
 
+    /**
+     * System property <code>h2.largeResultBufferSize</code> (default: 4096).<br />
+     * Buffer size for large result sets. Set this value to 0 to disable the buffer.
+     */
+    public static final int LARGE_RESULT_BUFFER_SIZE = getIntSetting("h2.largeResultBufferSize", 4 * 1024);
+
     /**
      * System property <code>h2.lobCloseBetweenReads</code> (default: false).<br />
      * Close LOB files between read operations.
@@ -463,10 +469,10 @@ public class SysProperties {
     public static final boolean TRACE_IO = getBooleanSetting("h2.traceIO", false);
 
     /**
-     * System property <code>h2.largeResultBufferSize</code> (default: 4096).<br />
-     * Buffer size for large result sets. Set this value to 0 to disable the buffer.
+     * System property <code>h2.webMaxValueLength</code> (default: 10000).<br />
+     * The H2 Console will abbreviate result values larger than this size.
      */
-    public static final int LARGE_RESULT_BUFFER_SIZE = getIntSetting("h2.largeResultBufferSize", 4 * 1024);
+    public static final int WEB_MAX_VALUE_LENGTH = getIntSetting("h2.webMaxValueLength", 10000);
 
     /**
      * System property <code>h2.collatorCacheSize</code> (default: 10000).<br />

h2/src/main/org/h2/server/web/WebThread.java

@@ -48,6 +48,7 @@ import java.util.Map.Entry;
 import org.h2.api.DatabaseEventListener;
 import org.h2.bnf.Bnf;
 import org.h2.constant.ErrorCode;
+import org.h2.constant.SysProperties;
 import org.h2.engine.Constants;
 import org.h2.jdbc.JdbcSQLException;
 import org.h2.message.Message;
@@ -1373,7 +1374,7 @@ class WebThread extends Thread implements DatabaseEventListener {
                 }
                 for (int i = 0; i < rs.getMetaData().getColumnCount(); i++) {
                     String x = attributes.getProperty("r" + row + "c" + (i + 1));
-                    rs.updateString(i + 1, unescapeData(x));
+                    unescapeData(x, rs, i + 1);
                 }
                 if (insert) {
                     rs.insertRow();
@@ -1950,7 +1951,7 @@ class WebThread extends Thread implements DatabaseEventListener {
                     buff.append(PageParser.escapeHtml(meta.getColumnLabel(i + 1)));
                     buff.append("</td>");
                     buff.append("<td>");
-                    buff.append(escapeData(rs.getString(i + 1)));
+                    buff.append(escapeData(rs, i + 1));
                     buff.append("</td></tr>");
                 }
             }
@@ -1986,7 +1987,7 @@ class WebThread extends Thread implements DatabaseEventListener {
                 }
                 for (int i = 0; i < columns; i++) {
                     buff.append("<td>");
-                    buff.append(escapeData(rs.getString(i + 1)));
+                    buff.append(escapeData(rs, i + 1));
                     buff.append("</td>");
                 }
                 buff.append("</tr>");
@@ -2059,24 +2060,30 @@ class WebThread extends Thread implements DatabaseEventListener {
         return "index.do";
     }
 
-    private String escapeData(String d) {
+    private String escapeData(ResultSet rs, int columnIndex) throws SQLException {
+        String d = rs.getString(columnIndex);
         if (d == null) {
             return "<i>null</i>";
-        } else if (d.startsWith("null")) {
-            return "<div style='display: none'>=</div>" + PageParser.escapeHtml(d);
+        } else if (d.length() > SysProperties.WEB_MAX_VALUE_LENGTH) {
+            return "<div style='display: none'>=+</div>" + 
+                PageParser.escapeHtml(d.substring(0, 100) + "... (" + d.length() + ")");
+        } else if (d.equals("null") || d.startsWith("= ") || d.startsWith("=+")) {
+            return "<div style='display: none'>= </div>" + PageParser.escapeHtml(d);
         }
         return PageParser.escapeHtml(d);
     }
 
-    private String unescapeData(String d) {
-        if (d.endsWith("null")) {
-            if (d.equals("null")) {
-                return null;
-            } else if (d.startsWith("=")) {
-                return d.substring(1);
-            }
+    private void unescapeData(String d, ResultSet rs, int columnIndex) throws SQLException {
+        if (d.equals("null")) {
+            rs.updateNull(columnIndex);
+        } else if (d.startsWith("=+")) {
+            // don't update
+        } else if (d.startsWith("= ")) {
+            d = d.substring(2);
+            rs.updateString(columnIndex, d);
+        } else {
+            rs.updateString(columnIndex, d);
         }
-        return d;
     }
 
     private String settingRemove() {

h2/src/test/org/h2/test/TestAll.java

@@ -275,9 +275,7 @@ java org.h2.test.TestAll timer
 
 main methods for the tests and make that work
 
-H2 Console: don't display very large blobs; instead show first view bytes and length
-
-MVCC:
+TestMVCC:
 Concurrent update in table test: another transaction has updated or 
 deleted the same row when exactly does it occur in other databases 
 (PostgreSQL, Oracle)?