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3840
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1 /**
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2 * @test
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3 * @bug 7070134
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4 * @summary Hotspot crashes with sigsegv from PorterStemmer
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5 *
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6 * @run shell Test7070134.sh
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7 */
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8
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9 /*
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10
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11 Porter stemmer in Java. The original paper is in
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12
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13 Porter, 1980, An algorithm for suffix stripping, Program, Vol. 14,
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14 no. 3, pp 130-137,
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15
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6046
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16 http://www.tartarus.org/~martin/PorterStemmer
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17
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18 The software is completely free for any purpose, unless notes at the head
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19 of the program text indicates otherwise (which is rare). In any case,
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20 the notes about licensing are never more restrictive than the BSD License.
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21
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22 In every case where the software is not written by me (Martin Porter),
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23 this licensing arrangement has been endorsed by the contributor, and it is
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24 therefore unnecessary to ask the contributor again to confirm it.
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25
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26 I have not asked any contributors (or their employers, if they have them)
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27 for proofs that they have the right to distribute their software in this way.
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3840
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28
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29 History:
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30
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31 Release 1
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32
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33 Bug 1 (reported by Gonzalo Parra 16/10/99) fixed as marked below.
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34 The words 'aed', 'eed', 'oed' leave k at 'a' for step 3, and b[k-1]
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35 is then out outside the bounds of b.
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36
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37 Release 2
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38
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39 Similarly,
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40
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41 Bug 2 (reported by Steve Dyrdahl 22/2/00) fixed as marked below.
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42 'ion' by itself leaves j = -1 in the test for 'ion' in step 5, and
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43 b[j] is then outside the bounds of b.
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44
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45 Release 3
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46
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47 Considerably revised 4/9/00 in the light of many helpful suggestions
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48 from Brian Goetz of Quiotix Corporation (brian@quiotix.com).
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49
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50 Release 4
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51
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52 */
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53
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54 import java.io.*;
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55
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56 /**
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57 * Stemmer, implementing the Porter Stemming Algorithm
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58 *
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59 * The Stemmer class transforms a word into its root form. The input
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60 * word can be provided a character at time (by calling add()), or at once
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61 * by calling one of the various stem(something) methods.
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62 */
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63
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64 class Stemmer
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65 { private char[] b;
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66 private int i, /* offset into b */
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67 i_end, /* offset to end of stemmed word */
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68 j, k;
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69 private static final int INC = 50;
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70 /* unit of size whereby b is increased */
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71 public Stemmer()
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72 { b = new char[INC];
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73 i = 0;
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74 i_end = 0;
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75 }
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76
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77 /**
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78 * Add a character to the word being stemmed. When you are finished
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79 * adding characters, you can call stem(void) to stem the word.
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80 */
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81
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82 public void add(char ch)
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83 { if (i == b.length)
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84 { char[] new_b = new char[i+INC];
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85 for (int c = 0; c < i; c++) new_b[c] = b[c];
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86 b = new_b;
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87 }
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88 b[i++] = ch;
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89 }
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90
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91
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92 /** Adds wLen characters to the word being stemmed contained in a portion
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93 * of a char[] array. This is like repeated calls of add(char ch), but
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94 * faster.
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95 */
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96
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97 public void add(char[] w, int wLen)
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98 { if (i+wLen >= b.length)
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99 { char[] new_b = new char[i+wLen+INC];
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100 for (int c = 0; c < i; c++) new_b[c] = b[c];
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101 b = new_b;
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102 }
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103 for (int c = 0; c < wLen; c++) b[i++] = w[c];
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104 }
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105
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106 /**
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107 * After a word has been stemmed, it can be retrieved by toString(),
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108 * or a reference to the internal buffer can be retrieved by getResultBuffer
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109 * and getResultLength (which is generally more efficient.)
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110 */
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111 public String toString() { return new String(b,0,i_end); }
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112
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113 /**
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114 * Returns the length of the word resulting from the stemming process.
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115 */
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116 public int getResultLength() { return i_end; }
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117
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118 /**
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119 * Returns a reference to a character buffer containing the results of
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120 * the stemming process. You also need to consult getResultLength()
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121 * to determine the length of the result.
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122 */
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123 public char[] getResultBuffer() { return b; }
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124
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125 /* cons(i) is true <=> b[i] is a consonant. */
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126
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127 private final boolean cons(int i)
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128 { switch (b[i])
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129 { case 'a': case 'e': case 'i': case 'o': case 'u': return false;
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130 case 'y': return (i==0) ? true : !cons(i-1);
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131 default: return true;
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132 }
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133 }
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134
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135 /* m() measures the number of consonant sequences between 0 and j. if c is
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136 a consonant sequence and v a vowel sequence, and <..> indicates arbitrary
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137 presence,
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138
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139 <c><v> gives 0
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140 <c>vc<v> gives 1
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141 <c>vcvc<v> gives 2
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142 <c>vcvcvc<v> gives 3
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143 ....
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144 */
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145
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146 private final int m()
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147 { int n = 0;
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148 int i = 0;
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149 while(true)
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150 { if (i > j) return n;
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151 if (! cons(i)) break; i++;
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152 }
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153 i++;
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154 while(true)
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155 { while(true)
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156 { if (i > j) return n;
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157 if (cons(i)) break;
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158 i++;
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159 }
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160 i++;
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161 n++;
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162 while(true)
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163 { if (i > j) return n;
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164 if (! cons(i)) break;
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165 i++;
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166 }
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167 i++;
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168 }
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169 }
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170
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171 /* vowelinstem() is true <=> 0,...j contains a vowel */
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172
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173 private final boolean vowelinstem()
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174 { int i; for (i = 0; i <= j; i++) if (! cons(i)) return true;
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175 return false;
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176 }
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177
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178 /* doublec(j) is true <=> j,(j-1) contain a double consonant. */
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179
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180 private final boolean doublec(int j)
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181 { if (j < 1) return false;
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182 if (b[j] != b[j-1]) return false;
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183 return cons(j);
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184 }
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185
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186 /* cvc(i) is true <=> i-2,i-1,i has the form consonant - vowel - consonant
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187 and also if the second c is not w,x or y. this is used when trying to
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188 restore an e at the end of a short word. e.g.
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189
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190 cav(e), lov(e), hop(e), crim(e), but
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191 snow, box, tray.
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192
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193 */
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194
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195 private final boolean cvc(int i)
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196 { if (i < 2 || !cons(i) || cons(i-1) || !cons(i-2)) return false;
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197 { int ch = b[i];
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198 if (ch == 'w' || ch == 'x' || ch == 'y') return false;
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199 }
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200 return true;
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201 }
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202
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203 private final boolean ends(String s)
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204 { int l = s.length();
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205 int o = k-l+1;
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206 if (o < 0) return false;
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207 for (int i = 0; i < l; i++) if (b[o+i] != s.charAt(i)) return false;
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208 j = k-l;
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209 return true;
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210 }
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211
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212 /* setto(s) sets (j+1),...k to the characters in the string s, readjusting
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213 k. */
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214
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215 private final void setto(String s)
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216 { int l = s.length();
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217 int o = j+1;
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218 for (int i = 0; i < l; i++) b[o+i] = s.charAt(i);
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219 k = j+l;
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220 }
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221
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222 /* r(s) is used further down. */
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223
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224 private final void r(String s) { if (m() > 0) setto(s); }
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225
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226 /* step1() gets rid of plurals and -ed or -ing. e.g.
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227
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228 caresses -> caress
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229 ponies -> poni
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230 ties -> ti
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231 caress -> caress
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232 cats -> cat
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233
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234 feed -> feed
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235 agreed -> agree
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236 disabled -> disable
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237
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238 matting -> mat
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239 mating -> mate
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240 meeting -> meet
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241 milling -> mill
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242 messing -> mess
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243
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244 meetings -> meet
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245
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246 */
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247
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248 private final void step1()
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249 { if (b[k] == 's')
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250 { if (ends("sses")) k -= 2; else
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251 if (ends("ies")) setto("i"); else
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252 if (b[k-1] != 's') k--;
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253 }
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254 if (ends("eed")) { if (m() > 0) k--; } else
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255 if ((ends("ed") || ends("ing")) && vowelinstem())
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256 { k = j;
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257 if (ends("at")) setto("ate"); else
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258 if (ends("bl")) setto("ble"); else
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259 if (ends("iz")) setto("ize"); else
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260 if (doublec(k))
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261 { k--;
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262 { int ch = b[k];
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263 if (ch == 'l' || ch == 's' || ch == 'z') k++;
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264 }
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265 }
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266 else if (m() == 1 && cvc(k)) setto("e");
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267 }
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268 }
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269
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270 /* step2() turns terminal y to i when there is another vowel in the stem. */
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271
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272 private final void step2() { if (ends("y") && vowelinstem()) b[k] = 'i'; }
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273
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274 /* step3() maps double suffices to single ones. so -ization ( = -ize plus
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275 -ation) maps to -ize etc. note that the string before the suffix must give
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276 m() > 0. */
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277
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278 private final void step3() { if (k == 0) return; /* For Bug 1 */ switch (b[k-1])
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279 {
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280 case 'a': if (ends("ational")) { r("ate"); break; }
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281 if (ends("tional")) { r("tion"); break; }
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282 break;
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283 case 'c': if (ends("enci")) { r("ence"); break; }
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284 if (ends("anci")) { r("ance"); break; }
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285 break;
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286 case 'e': if (ends("izer")) { r("ize"); break; }
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287 break;
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288 case 'l': if (ends("bli")) { r("ble"); break; }
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289 if (ends("alli")) { r("al"); break; }
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290 if (ends("entli")) { r("ent"); break; }
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291 if (ends("eli")) { r("e"); break; }
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292 if (ends("ousli")) { r("ous"); break; }
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293 break;
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294 case 'o': if (ends("ization")) { r("ize"); break; }
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295 if (ends("ation")) { r("ate"); break; }
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296 if (ends("ator")) { r("ate"); break; }
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297 break;
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298 case 's': if (ends("alism")) { r("al"); break; }
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299 if (ends("iveness")) { r("ive"); break; }
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300 if (ends("fulness")) { r("ful"); break; }
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301 if (ends("ousness")) { r("ous"); break; }
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302 break;
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303 case 't': if (ends("aliti")) { r("al"); break; }
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304 if (ends("iviti")) { r("ive"); break; }
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305 if (ends("biliti")) { r("ble"); break; }
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306 break;
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307 case 'g': if (ends("logi")) { r("log"); break; }
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308 } }
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309
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310 /* step4() deals with -ic-, -full, -ness etc. similar strategy to step3. */
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311
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312 private final void step4() { switch (b[k])
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313 {
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314 case 'e': if (ends("icate")) { r("ic"); break; }
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315 if (ends("ative")) { r(""); break; }
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316 if (ends("alize")) { r("al"); break; }
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317 break;
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318 case 'i': if (ends("iciti")) { r("ic"); break; }
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319 break;
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320 case 'l': if (ends("ical")) { r("ic"); break; }
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321 if (ends("ful")) { r(""); break; }
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322 break;
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323 case 's': if (ends("ness")) { r(""); break; }
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324 break;
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325 } }
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326
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327 /* step5() takes off -ant, -ence etc., in context <c>vcvc<v>. */
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328
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329 private final void step5()
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330 { if (k == 0) return; /* for Bug 1 */ switch (b[k-1])
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331 { case 'a': if (ends("al")) break; return;
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332 case 'c': if (ends("ance")) break;
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333 if (ends("ence")) break; return;
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334 case 'e': if (ends("er")) break; return;
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335 case 'i': if (ends("ic")) break; return;
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336 case 'l': if (ends("able")) break;
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337 if (ends("ible")) break; return;
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338 case 'n': if (ends("ant")) break;
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339 if (ends("ement")) break;
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340 if (ends("ment")) break;
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341 /* element etc. not stripped before the m */
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342 if (ends("ent")) break; return;
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343 case 'o': if (ends("ion") && j >= 0 && (b[j] == 's' || b[j] == 't')) break;
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344 /* j >= 0 fixes Bug 2 */
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345 if (ends("ou")) break; return;
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346 /* takes care of -ous */
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347 case 's': if (ends("ism")) break; return;
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348 case 't': if (ends("ate")) break;
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349 if (ends("iti")) break; return;
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350 case 'u': if (ends("ous")) break; return;
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351 case 'v': if (ends("ive")) break; return;
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352 case 'z': if (ends("ize")) break; return;
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353 default: return;
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354 }
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355 if (m() > 1) k = j;
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356 }
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357
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358 /* step6() removes a final -e if m() > 1. */
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359
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360 private final void step6()
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361 { j = k;
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362 if (b[k] == 'e')
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363 { int a = m();
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364 if (a > 1 || a == 1 && !cvc(k-1)) k--;
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365 }
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366 if (b[k] == 'l' && doublec(k) && m() > 1) k--;
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367 }
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368
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369 /** Stem the word placed into the Stemmer buffer through calls to add().
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370 * Returns true if the stemming process resulted in a word different
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371 * from the input. You can retrieve the result with
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372 * getResultLength()/getResultBuffer() or toString().
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373 */
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374 public void stem()
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375 { k = i - 1;
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376 if (k > 1) { step1(); step2(); step3(); step4(); step5(); step6(); }
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377 i_end = k+1; i = 0;
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378 }
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379
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380 /** Test program for demonstrating the Stemmer. It reads text from a
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381 * a list of files, stems each word, and writes the result to standard
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382 * output. Note that the word stemmed is expected to be in lower case:
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383 * forcing lower case must be done outside the Stemmer class.
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384 * Usage: Stemmer file-name file-name ...
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385 */
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386 public static void main(String[] args)
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387 {
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388 char[] w = new char[501];
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389 Stemmer s = new Stemmer();
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390 for (int i = 0; i < args.length; i++)
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391 try
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392 {
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393 FileInputStream in = new FileInputStream(args[i]);
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394
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395 try
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396 { while(true)
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397
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398 { int ch = in.read();
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399 if (Character.isLetter((char) ch))
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400 {
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401 int j = 0;
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402 while(true)
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403 { ch = Character.toLowerCase((char) ch);
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404 w[j] = (char) ch;
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405 if (j < 500) j++;
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406 ch = in.read();
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407 if (!Character.isLetter((char) ch))
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408 {
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409 /* to test add(char ch) */
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410 for (int c = 0; c < j; c++) s.add(w[c]);
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411
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412 /* or, to test add(char[] w, int j) */
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413 /* s.add(w, j); */
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414
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415 s.stem();
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416 { String u;
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417
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418 /* and now, to test toString() : */
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419 u = s.toString();
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420
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421 /* to test getResultBuffer(), getResultLength() : */
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422 /* u = new String(s.getResultBuffer(), 0, s.getResultLength()); */
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423
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424 System.out.print(u);
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425 }
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426 break;
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427 }
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428 }
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429 }
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430 if (ch < 0) break;
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431 System.out.print((char)ch);
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432 }
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433 }
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434 catch (IOException e)
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435 { System.out.println("error reading " + args[i]);
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436 break;
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437 }
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438 }
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439 catch (FileNotFoundException e)
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440 { System.out.println("file " + args[i] + " not found");
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441 break;
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442 }
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443 }
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444 }
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