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1 /** |
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2 * SQL-DK |
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3 * Copyright © 2013 František Kučera (frantovo.cz) |
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4 * |
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5 * This program is free software: you can redistribute it and/or modify |
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6 * it under the terms of the GNU General Public License as published by |
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7 * the Free Software Foundation, either version 3 of the License, or |
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8 * (at your option) any later version. |
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9 * |
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10 * This program is distributed in the hope that it will be useful, |
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11 * but WITHOUT ANY WARRANTY; without even the implied warranty of |
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12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
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13 * GNU General Public License for more details. |
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14 * |
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15 * You should have received a copy of the GNU General Public License |
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16 * along with this program. If not, see <http://www.gnu.org/licenses/>. |
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17 */ |
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18 package info.globalcode.sql.dk.formatting; |
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19 |
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20 import java.util.ArrayList; |
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21 import java.util.List; |
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22 |
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23 /** |
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24 * <p> |
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25 * Prefetches whole result set and computes column widths. Whole table is flushed at once in |
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26 * {@linkplain #writeEndResultSet()}. |
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27 * </p> |
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28 * |
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29 * <p> |
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30 * Long values will not overflow the cells, but whole result set must be loaded into the memory. |
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31 * </p> |
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32 * |
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33 * @author Ing. František Kučera (frantovo.cz) |
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34 */ |
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35 public class TabularPrefetchingFormatter extends TabularFormatter { |
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36 |
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37 public static final String NAME = "tabular-prefetching"; // bash-completion:formatter |
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38 private ColumnsHeader currentHeader; |
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39 private List<Object[]> currentResultSet; |
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40 private Object[] currentRow; |
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41 private int currentColumnsCount; |
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42 private boolean prefetchDone = false; |
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43 |
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44 public TabularPrefetchingFormatter(FormatterContext formatterContext) { |
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45 super(formatterContext); |
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46 } |
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47 |
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48 @Override |
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49 protected int getCurrentColumnsCount() { |
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50 if (prefetchDone) { |
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51 return super.getCurrentColumnsCount(); |
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52 } else { |
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53 return currentColumnsCount; |
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54 } |
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55 } |
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56 |
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57 @Override |
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58 public void writeStartResultSet(ColumnsHeader header) { |
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59 currentResultSet = new ArrayList<>(); |
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60 currentHeader = header; |
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61 initColumnWidths(header.getColumnCount()); |
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62 } |
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63 |
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64 @Override |
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65 public void writeStartRow() { |
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66 currentRow = new Object[currentHeader.getColumnCount()]; |
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67 currentResultSet.add(currentRow); |
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68 currentColumnsCount = 0; |
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69 } |
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70 |
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71 @Override |
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72 public void writeColumnValue(Object value) { |
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73 currentRow[currentColumnsCount] = value; |
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74 currentColumnsCount++; |
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75 String textRepresentation = toString(value); |
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76 /** TODO: count only printable characters (currently not an issue) */ |
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77 updateColumnWidth(currentColumnsCount, textRepresentation.length()); |
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78 } |
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79 |
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80 @Override |
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81 public void writeEndRow() { |
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82 // do nothing |
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83 } |
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84 |
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85 @Override |
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86 public void writeEndResultSet() { |
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87 prefetchDone = true; |
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88 |
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89 postprocessPrefetchedResultSet(currentHeader, currentResultSet); |
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90 |
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91 super.writeStartResultSet(currentHeader); |
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92 |
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93 for (Object[] row : currentResultSet) { |
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94 super.writeStartRow(); |
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95 for (Object cell : row) { |
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96 super.writeColumnValue(cell); |
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97 } |
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98 super.writeEndRow(); |
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99 } |
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100 |
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101 currentColumnsCount = 0; |
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102 currentHeader = null; |
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103 currentRow = null; |
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104 currentResultSet = null; |
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105 super.writeEndResultSet(); |
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106 prefetchDone = false; |
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107 } |
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108 |
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109 /** |
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110 * Optional post-processing – override in sub-classes if needed. |
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111 * Don't forget to {@linkplain #updateColumnWidth(int, int)} |
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112 * |
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113 * @param currentHeader |
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114 * @param currentResultSet |
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115 */ |
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116 protected void postprocessPrefetchedResultSet(ColumnsHeader currentHeader, List<Object[]> currentResultSet) { |
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117 } |
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118 |
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119 } |