--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/java/sql-dk/src/main/java/info/globalcode/sql/dk/formatting/TabularPrefetchingFormatter.java	Mon Mar 04 20:15:24 2019 +0100
@@ -0,0 +1,119 @@
+/**
+ * SQL-DK
+ * Copyright © 2013 František Kučera (frantovo.cz)
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ */
+package info.globalcode.sql.dk.formatting;
+
+import java.util.ArrayList;
+import java.util.List;
+
+/**
+ * <p>
+ * Prefetches whole result set and computes column widths. Whole table is flushed at once in
+ * {@linkplain #writeEndResultSet()}.
+ * </p>
+ *
+ * <p>
+ * Long values will not overflow the cells, but whole result set must be loaded into the memory.
+ * </p>
+ *
+ * @author Ing. František Kučera (frantovo.cz)
+ */
+public class TabularPrefetchingFormatter extends TabularFormatter {
+
+	public static final String NAME = "tabular-prefetching"; // bash-completion:formatter
+	private ColumnsHeader currentHeader;
+	private List<Object[]> currentResultSet;
+	private Object[] currentRow;
+	private int currentColumnsCount;
+	private boolean prefetchDone = false;
+
+	public TabularPrefetchingFormatter(FormatterContext formatterContext) {
+		super(formatterContext);
+	}
+
+	@Override
+	protected int getCurrentColumnsCount() {
+		if (prefetchDone) {
+			return super.getCurrentColumnsCount();
+		} else {
+			return currentColumnsCount;
+		}
+	}
+
+	@Override
+	public void writeStartResultSet(ColumnsHeader header) {
+		currentResultSet = new ArrayList<>();
+		currentHeader = header;
+		initColumnWidths(header.getColumnCount());
+	}
+
+	@Override
+	public void writeStartRow() {
+		currentRow = new Object[currentHeader.getColumnCount()];
+		currentResultSet.add(currentRow);
+		currentColumnsCount = 0;
+	}
+
+	@Override
+	public void writeColumnValue(Object value) {
+		currentRow[currentColumnsCount] = value;
+		currentColumnsCount++;
+		String textRepresentation = toString(value);
+		/** TODO: count only printable characters (currently not an issue) */
+		updateColumnWidth(currentColumnsCount, textRepresentation.length());
+	}
+
+	@Override
+	public void writeEndRow() {
+		// do nothing
+	}
+
+	@Override
+	public void writeEndResultSet() {
+		prefetchDone = true;
+
+		postprocessPrefetchedResultSet(currentHeader, currentResultSet);
+
+		super.writeStartResultSet(currentHeader);
+
+		for (Object[] row : currentResultSet) {
+			super.writeStartRow();
+			for (Object cell : row) {
+				super.writeColumnValue(cell);
+			}
+			super.writeEndRow();
+		}
+
+		currentColumnsCount = 0;
+		currentHeader = null;
+		currentRow = null;
+		currentResultSet = null;
+		super.writeEndResultSet();
+		prefetchDone = false;
+	}
+
+	/**
+	 * Optional post-processing – override in sub-classes if needed.
+	 * Don't forget to {@linkplain #updateColumnWidth(int, int)}
+	 *
+	 * @param currentHeader
+	 * @param currentResultSet
+	 */
+	protected void postprocessPrefetchedResultSet(ColumnsHeader currentHeader, List<Object[]> currentResultSet) {
+	}
+
+}