1 | /*
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2 | * This program is free software; you can redistribute it and/or modify
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3 | * it under the terms of the GNU General Public License as published by
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4 | * the Free Software Foundation; either version 2 of the License, or
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5 | * (at your option) any later version.
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6 | *
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7 | * This program is distributed in the hope that it will be useful,
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8 | * but WITHOUT ANY WARRANTY; without even the implied warranty of
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9 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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10 | * GNU General Public License for more details.
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11 | *
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12 | * You should have received a copy of the GNU General Public License
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13 | * along with this program; if not, write to the Free Software
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14 | * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
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15 | */
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16 |
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17 | /*
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18 | * SerializedObject.java
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19 | * Copyright (C) 2000 Webmind Inc.
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20 | *
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21 | */
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22 |
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23 | package weka.core;
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24 |
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25 | import java.io.BufferedInputStream;
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26 | import java.io.BufferedOutputStream;
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27 | import java.io.ByteArrayInputStream;
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28 | import java.io.ByteArrayOutputStream;
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29 | import java.io.InputStream;
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30 | import java.io.ObjectInputStream;
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31 | import java.io.ObjectOutputStream;
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32 | import java.io.OutputStream;
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33 | import java.io.Serializable;
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34 | import java.util.zip.GZIPInputStream;
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35 | import java.util.zip.GZIPOutputStream;
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36 |
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37 | /**
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38 | * This class stores an object serialized in memory. It allows compression,
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39 | * to be used to conserve memory (for example, when storing large strings
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40 | * in memory), or can be used as a mechanism for deep copying objects.
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41 | *
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42 | * @author Len Trigg ([email protected])
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43 | * @version $Revision: 8815 $
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44 | */
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45 | public class SerializedObject implements Serializable {
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46 |
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47 | /** Stores the serialized object */
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48 | private byte [] m_Serialized;
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49 |
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50 | /** True if the object has been compressed during storage */
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51 | private boolean m_Compressed;
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52 |
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53 | /**
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54 | * Serializes the supplied object into a byte array without compression.
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55 | *
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56 | * @param obj the Object to serialize.
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57 | * @exception Exception if the object is not Serializable.
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58 | */
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59 | public SerializedObject(Object obj) throws Exception {
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60 |
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61 | this(obj, false);
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62 | }
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63 |
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64 | /**
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65 | * Serializes the supplied object into a byte array.
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66 | *
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67 | * @param obj the Object to serialize.
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68 | * @param compress true if the object should be stored compressed.
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69 | * @exception Exception if the object is not Serializable.
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70 | */
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71 | public SerializedObject(Object obj, boolean compress) throws Exception {
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72 |
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73 | //System.err.print("."); System.err.flush();
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74 | m_Compressed = compress;
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75 | m_Serialized = toByteArray(obj, m_Compressed);
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76 | }
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77 |
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78 | /**
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79 | * Serializes the supplied object to a byte array.
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80 | *
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81 | * @param obj the Object to serialize
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82 | * @param compress true if the object should be compressed.
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83 | * @return the byte array containing the serialized object.
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84 | * @exception Exception if the object is not Serializable.
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85 | */
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86 | protected static byte [] toByteArray(Object obj, boolean compress)
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87 | throws Exception {
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88 |
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89 | ByteArrayOutputStream bo = new ByteArrayOutputStream();
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90 | OutputStream os = bo;
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91 | if (compress) {
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92 | os = new GZIPOutputStream(os);
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93 | }
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94 | os = new BufferedOutputStream(os);
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95 | ObjectOutputStream oo = new ObjectOutputStream(os);
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96 | oo.writeObject(obj);
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97 | oo.close();
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98 | return bo.toByteArray();
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99 | }
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100 |
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101 | /**
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102 | * Gets the object stored in this SerializedObject. The object returned
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103 | * will be a deep copy of the original stored object.
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104 | *
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105 | * @return the deserialized Object.
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106 | */
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107 | public Object getObject() {
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108 | try {
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109 | InputStream is = new ByteArrayInputStream(m_Serialized);
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110 | if (m_Compressed) {
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111 | is = new GZIPInputStream(is);
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112 | }
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113 | is = new BufferedInputStream(is);
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114 | ObjectInputStream oi = new ObjectInputStream(is);
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115 | Object result = oi.readObject();
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116 | oi.close();
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117 | return result;
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118 | } catch (Exception ex) {
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119 | ex.printStackTrace();
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120 | }
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121 | return null;
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122 | }
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123 |
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124 | /**
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125 | * Compares this object with another for equality.
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126 | *
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127 | * @param other the other Object.
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128 | * @return true if the objects are equal.
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129 | */
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130 | public final boolean equals(Object other) {
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131 |
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132 | // Check class type
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133 | if ((other == null) || !(other.getClass().equals(this.getClass()))) {
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134 | return false;
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135 | }
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136 | // Check serialized length
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137 | byte [] os = ((SerializedObject)other).m_Serialized;
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138 | if (os.length != m_Serialized.length) {
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139 | return false;
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140 | }
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141 | // Check serialized contents
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142 | for (int i = 0; i < m_Serialized.length; i++) {
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143 | if (m_Serialized[i] != os[i]) {
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144 | return false;
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145 | }
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146 | }
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147 | return true;
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148 | }
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149 |
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150 | /**
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151 | * Returns a hashcode for this object.
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152 | *
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153 | * @return the hashcode for this object.
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154 | */
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155 | public final int hashCode() {
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156 |
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157 | return m_Serialized.length;
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158 | }
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159 |
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160 | /**
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161 | * Returns a text representation of the state of this object.
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162 | *
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163 | * @return a String representing this object.
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164 | */
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165 | public String toString() {
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166 |
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167 | return (m_Compressed ? "Compressed object: " : "Uncompressed object: ")
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168 | + m_Serialized.length + " bytes";
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169 | }
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170 |
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171 | /**
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172 | * Test routine, reads text from stdin and measures memory usage
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173 | */
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174 | public static void main2(String []args) {
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175 |
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176 | try {
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177 | Runtime r = Runtime.getRuntime();
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178 | r.gc();
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179 | java.io.LineNumberReader lnr = new java.io.LineNumberReader(new java.io.InputStreamReader(System.in));
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180 | StringBuffer sb = new StringBuffer();
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181 | String line;
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182 | while ((line = lnr.readLine()) != null) {
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183 | sb.append(line).append('\n');
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184 | }
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185 | String text = sb.toString();
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186 | //System.err.println("TEXT:");
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187 | //System.err.println(text);
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188 | r.gc();
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189 |
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190 | System.err.print("TOTAL: " + r.totalMemory());
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191 | System.err.println("\tFREE: " + r.freeMemory());
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192 | long used = r.totalMemory() - r.freeMemory();
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193 |
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194 | // convert to a compressedobject
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195 | SerializedObject co = new SerializedObject(text, true);
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196 |
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197 | System.err.print("TOTAL: " + r.totalMemory());
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198 | System.err.println("\tFREE: " + r.freeMemory());
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199 | r.gc();
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200 | long used1 = r.totalMemory() - r.freeMemory();
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201 | long csize = used1 - used;
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202 | System.err.println("CompressedSize = " + csize);
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203 |
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204 | String newstr = (String)co.getObject();
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205 | r.gc();
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206 | System.err.print("TOTAL: " + r.totalMemory());
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207 | System.err.println("\tFREE: " + r.freeMemory());
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208 | long used2 = r.totalMemory() - r.freeMemory();
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209 | long usize = used2 - used1;
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210 | System.err.println("UncompressedSize = " + usize);
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211 |
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212 | // A couple of references to the original objects
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213 | // so they don't get freed prematurely and muck up the
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214 | // measurements.
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215 | newstr = newstr.toLowerCase();
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216 | text = text.toLowerCase();
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217 | System.err.println("Byte array: " + co.toString());
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218 | System.err.println("Length of text: " + text.length());
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219 | } catch (Exception ex) {
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220 | ex.printStackTrace();
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221 | }
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222 | }
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223 |
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224 |
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225 | /**
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226 | * Test routine, reads an arff file from stdin and measures memory usage
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227 | * (the arff file should have long string attribute values)
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228 | */
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229 | public static void main(String []args) {
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230 |
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231 | try {
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232 | Runtime r = Runtime.getRuntime();
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233 | r.gc();
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234 | System.err.print("TOTAL: " + r.totalMemory());
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235 | System.err.println("\tFREE: " + r.freeMemory());
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236 | long used = r.totalMemory() - r.freeMemory();
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237 | Instances inst = new Instances(new java.io.BufferedReader(new java.io.InputStreamReader(System.in)));
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238 | r.gc();
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239 | long used1 = r.totalMemory() - r.freeMemory();
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240 | long csize = used1 - used;
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241 | System.err.print("\nTOTAL: " + r.totalMemory());
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242 | System.err.println("\tFREE: " + r.freeMemory());
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243 | System.err.println("size = " + csize);
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244 | int blah = inst.numAttributes();
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245 | } catch (Exception ex) {
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246 | ex.printStackTrace();
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247 | }
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248 | }
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249 | }
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