1 /**

     2  * SQL-DK

     3  * Copyright © 2013 František Kučera (frantovo.cz)

     4  *

     5  * This program is free software: you can redistribute it and/or modify

     6  * it under the terms of the GNU General Public License as published by

     7  * the Free Software Foundation, either version 3 of the License, or

     8  * (at your option) any later version.

     9  *

    10  * This program is distributed in the hope that it will be useful,

    11  * but WITHOUT ANY WARRANTY; without even the implied warranty of

    12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the

    13  * GNU General Public License for more details.

    14  *

    15  * You should have received a copy of the GNU General Public License

    16  * along with this program. If not, see <http://www.gnu.org/licenses/>.

    17  */

    18 package info.globalcode.sql.dk.formatting;

    19 

    20 import info.globalcode.sql.dk.Parameter;

    21 import java.util.ArrayList;

    22 import java.util.List;

    23 

    24 /**

    25  * Prefetches whole result set and computes column widths. Whole table is flushed at once in

    26  * {@linkplain #writeEndResultSet()}.

    27  *

    28  * Long values will not overflow the cells, but whole result set must be loaded into memory.

    29  *

    30  * @author Ing. František Kučera (frantovo.cz)

    31  */

    32 public class TabularPrefetchingFormatter extends TabularFormatter {

    33 

    34 	public static final String NAME = "tabular-prefetching"; // bash-completion:formatter

    35 	private String currentSql;

    36 	private List<? extends Parameter> currentParameters;

    37 	private ColumnsHeader currentHeader;

    38 	private List<Object[]> currentResultSet;

    39 	private Object[] currentRow;

    40 	private int currentColumnsCount;

    41 	private boolean prefetchDone = false;

    42 

    43 	public TabularPrefetchingFormatter(FormatterContext formatterContext) {

    44 		super(formatterContext);

    45 	}

    46 

    47 	@Override

    48 	protected int getCurrentColumnsCount() {

    49 		if (prefetchDone) {

    50 			return super.getCurrentColumnsCount();

    51 		} else {

    52 			return currentColumnsCount;

    53 		}

    54 	}

    55 

    56 	@Override

    57 	public void writeStartResultSet() {

    58 		currentResultSet = new ArrayList<>();

    59 	}

    60 

    61 	@Override

    62 	public void writeQuery(String sql) {

    63 		currentSql = sql;

    64 	}

    65 

    66 	@Override

    67 	public void writeParameters(List<? extends Parameter> parameters) {

    68 		currentParameters = parameters;

    69 	}

    70 

    71 	@Override

    72 	public void writeColumnsHeader(ColumnsHeader header) {

    73 		currentHeader = header;

    74 		initColumnWidths(header.getColumnCount());

    75 	}

    76 

    77 	@Override

    78 	public void writeStartRow() {

    79 		currentRow = new Object[currentHeader.getColumnCount()];

    80 		currentResultSet.add(currentRow);

    81 		currentColumnsCount = 0;

    82 	}

    83 

    84 	@Override

    85 	public void writeColumnValue(Object value) {

    86 		currentRow[currentColumnsCount] = value;

    87 		currentColumnsCount++;

    88 		String textRepresentation = toString(value);

    89 		/** TODO: count only printable characters (currently not an issue) */

    90 		updateColumnWidth(currentColumnsCount, textRepresentation.length());

    91 	}

    92 

    93 	@Override

    94 	public void writeEndRow() {

    95 		// do nothing

    96 	}

    97 

    98 	@Override

    99 	public void writeEndResultSet() {

   100 		prefetchDone = true;

   101 

   102 		super.writeStartResultSet();

   103 		super.writeQuery(currentSql);

   104 		super.writeParameters(currentParameters);

   105 		super.writeColumnsHeader(currentHeader);

   106 

   107 		for (Object[] row : currentResultSet) {

   108 			super.writeStartRow();

   109 			for (Object cell : row) {

   110 				super.writeColumnValue(cell);

   111 			}

   112 			super.writeEndRow();

   113 		}

   114 

   115 		currentColumnsCount = 0;

   116 		currentSql = null;

   117 		currentParameters = null;

   118 		currentHeader = null;

   119 		currentRow = null;

   120 		currentResultSet = null;

   121 		super.writeEndResultSet();

   122 		prefetchDone = false;

   123 	}

   124 }