/*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You under the Apache License, Version 2.0
* (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.apache.lucene.analysis.ngram;
import java.io.IOException;
import java.io.StringReader;
import java.util.Arrays;
import org.apache.lucene.analysis.Analyzer;
import org.apache.lucene.analysis.BaseTokenStreamTestCase;
import org.apache.lucene.analysis.Tokenizer;
import org.apache.lucene.analysis.tokenattributes.CharTermAttribute;
import org.apache.lucene.analysis.tokenattributes.OffsetAttribute;
import org.apache.lucene.analysis.tokenattributes.PositionIncrementAttribute;
import org.apache.lucene.analysis.tokenattributes.PositionLengthAttribute;
import org.apache.lucene.util.TestUtil;
import com.carrotsearch.randomizedtesting.generators.RandomStrings;
/**
* Tests {@link NGramTokenizer} for correctness.
*/
public class NGramTokenizerTest extends BaseTokenStreamTestCase {
private StringReader input;
@Override
public void setUp() throws Exception {
super.setUp();
input = new StringReader("abcde");
}
public void testInvalidInput() throws Exception {
expectThrows(IllegalArgumentException.class, () -> {
NGramTokenizer tok = new NGramTokenizer(2, 1);
});
}
public void testInvalidInput2() throws Exception {
expectThrows(IllegalArgumentException.class, () -> {
NGramTokenizer tok = new NGramTokenizer(0, 1);
tok.setReader(input);
});
}
public void testUnigrams() throws Exception {
NGramTokenizer tokenizer = new NGramTokenizer(1, 1);
tokenizer.setReader(input);
assertTokenStreamContents(tokenizer, new String[]{"a","b","c","d","e"}, new int[]{0,1,2,3,4}, new int[]{1,2,3,4,5}, 5 /* abcde */);
}
public void testBigrams() throws Exception {
NGramTokenizer tokenizer = new NGramTokenizer(2, 2);
tokenizer.setReader(input);
assertTokenStreamContents(tokenizer, new String[]{"ab","bc","cd","de"}, new int[]{0,1,2,3}, new int[]{2,3,4,5}, 5 /* abcde */);
}
public void testNgrams() throws Exception {
NGramTokenizer tokenizer = new NGramTokenizer(1, 3);
tokenizer.setReader(input);
assertTokenStreamContents(tokenizer,
new String[]{"a","ab", "abc", "b", "bc", "bcd", "c", "cd", "cde", "d", "de", "e"},
new int[]{0,0,0,1,1,1,2,2,2,3,3,4},
new int[]{1,2,3,2,3,4,3,4,5,4,5,5},
null,
null,
null,
5 /* abcde */,
false
);
}
public void testOversizedNgrams() throws Exception {
NGramTokenizer tokenizer = new NGramTokenizer(6, 7);
tokenizer.setReader(input);
assertTokenStreamContents(tokenizer, new String[0], new int[0], new int[0], 5 /* abcde */);
}
public void testReset() throws Exception {
NGramTokenizer tokenizer = new NGramTokenizer(1, 1);
tokenizer.setReader(input);
assertTokenStreamContents(tokenizer, new String[]{"a","b","c","d","e"}, new int[]{0,1,2,3,4}, new int[]{1,2,3,4,5}, 5 /* abcde */);
tokenizer.setReader(new StringReader("abcde"));
assertTokenStreamContents(tokenizer, new String[]{"a","b","c","d","e"}, new int[]{0,1,2,3,4}, new int[]{1,2,3,4,5}, 5 /* abcde */);
}
/** blast some random strings through the analyzer */
public void testRandomStrings() throws Exception {
int numIters = TEST_NIGHTLY ? 10 : 1;
for (int i = 0; i < numIters; i++) {
final int min = TestUtil.nextInt(random(), 2, 10);
final int max = TestUtil.nextInt(random(), min, 20);
Analyzer a = new Analyzer() {
@Override
protected TokenStreamComponents createComponents(String fieldName) {
Tokenizer tokenizer = new NGramTokenizer(min, max);
return new TokenStreamComponents(tokenizer, tokenizer);
}
};
checkRandomData(random(), a, 200*RANDOM_MULTIPLIER, 20);
checkRandomData(random(), a, 10*RANDOM_MULTIPLIER, 1027);
a.close();
}
}
private static void testNGrams(int minGram, int maxGram, int length, final String nonTokenChars) throws IOException {
final String s = RandomStrings.randomAsciiOfLength(random(), length);
testNGrams(minGram, maxGram, s, nonTokenChars);
}
private static void testNGrams(int minGram, int maxGram, String s, String nonTokenChars) throws IOException {
testNGrams(minGram, maxGram, s, nonTokenChars, false);
}
static int[] toCodePoints(CharSequence s) {
final int[] codePoints = new int[Character.codePointCount(s, 0, s.length())];
for (int i = 0, j = 0; i < s.length(); ++j) {
codePoints[j] = Character.codePointAt(s, i);
i += Character.charCount(codePoints[j]);
}
return codePoints;
}
static boolean isTokenChar(String nonTokenChars, int codePoint) {
for (int i = 0; i < nonTokenChars.length(); ) {
final int cp = nonTokenChars.codePointAt(i);
if (cp == codePoint) {
return false;
}
i += Character.charCount(cp);
}
return true;
}
static void testNGrams(int minGram, int maxGram, String s, final String nonTokenChars, boolean edgesOnly) throws IOException {
// convert the string to code points
final int[] codePoints = toCodePoints(s);
final int[] offsets = new int[codePoints.length + 1];
for (int i = 0; i < codePoints.length; ++i) {
offsets[i+1] = offsets[i] + Character.charCount(codePoints[i]);
}
final Tokenizer grams = new NGramTokenizer(minGram, maxGram, edgesOnly) {
@Override
protected boolean isTokenChar(int chr) {
return nonTokenChars.indexOf(chr) < 0;
}
};
grams.setReader(new StringReader(s));
final CharTermAttribute termAtt = grams.addAttribute(CharTermAttribute.class);
final PositionIncrementAttribute posIncAtt = grams.addAttribute(PositionIncrementAttribute.class);
final PositionLengthAttribute posLenAtt = grams.addAttribute(PositionLengthAttribute.class);
final OffsetAttribute offsetAtt = grams.addAttribute(OffsetAttribute.class);
grams.reset();
for (int start = 0; start < codePoints.length; ++start) {
nextGram:
for (int end = start + minGram; end <= start + maxGram && end <= codePoints.length; ++end) {
if (edgesOnly && start > 0 && isTokenChar(nonTokenChars, codePoints[start - 1])) {
// not on an edge
continue nextGram;
}
for (int j = start; j < end; ++j) {
if (!isTokenChar(nonTokenChars, codePoints[j])) {
continue nextGram;
}
}
assertTrue(grams.incrementToken());
assertArrayEquals(Arrays.copyOfRange(codePoints, start, end), toCodePoints(termAtt));
assertEquals(1, posIncAtt.getPositionIncrement());
assertEquals(1, posLenAtt.getPositionLength());
assertEquals(offsets[start], offsetAtt.startOffset());
assertEquals(offsets[end], offsetAtt.endOffset());
}
}
assertFalse(grams.incrementToken());
grams.end();
assertEquals(s.length(), offsetAtt.startOffset());
assertEquals(s.length(), offsetAtt.endOffset());
}
public void testLargeInput() throws IOException {
// test sliding
final int minGram = TestUtil.nextInt(random(), 1, 100);
final int maxGram = TestUtil.nextInt(random(), minGram, 100);
testNGrams(minGram, maxGram, TestUtil.nextInt(random(), 3 * 1024, 4 * 1024), "");
}
public void testLargeMaxGram() throws IOException {
// test sliding with maxGram > 1024
final int minGram = TestUtil.nextInt(random(), 1290, 1300);
final int maxGram = TestUtil.nextInt(random(), minGram, 1300);
testNGrams(minGram, maxGram, TestUtil.nextInt(random(), 3 * 1024, 4 * 1024), "");
}
public void testPreTokenization() throws IOException {
final int minGram = TestUtil.nextInt(random(), 1, 100);
final int maxGram = TestUtil.nextInt(random(), minGram, 100);
testNGrams(minGram, maxGram, TestUtil.nextInt(random(), 0, 4 * 1024), "a");
}
public void testHeavyPreTokenization() throws IOException {
final int minGram = TestUtil.nextInt(random(), 1, 100);
final int maxGram = TestUtil.nextInt(random(), minGram, 100);
testNGrams(minGram, maxGram, TestUtil.nextInt(random(), 0, 4 * 1024), "abcdef");
}
public void testFewTokenChars() throws IOException {
final char[] chrs = new char[TestUtil.nextInt(random(), 4000, 5000)];
Arrays.fill(chrs, ' ');
for (int i = 0; i < chrs.length; ++i) {
if (random().nextFloat() < 0.1) {
chrs[i] = 'a';
}
}
final int minGram = TestUtil.nextInt(random(), 1, 2);
final int maxGram = TestUtil.nextInt(random(), minGram, 2);
testNGrams(minGram, maxGram, new String(chrs), " ");
}
public void testFullUTF8Range() throws IOException {
final int minGram = TestUtil.nextInt(random(), 1, 100);
final int maxGram = TestUtil.nextInt(random(), minGram, 100);
final String s = TestUtil.randomUnicodeString(random(), 4 * 1024);
testNGrams(minGram, maxGram, s, "");
testNGrams(minGram, maxGram, s, "abcdef");
}
}