package org.apache.lucene.analysis.ko.util;
import java.io.BufferedReader;
import java.io.IOException;
import java.nio.charset.Charset;
import java.nio.file.Files;
import java.nio.file.Path;
import java.text.Normalizer;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Comparator;
import java.util.List;
import java.util.stream.Collectors;
import java.util.stream.Stream;
import org.apache.lucene.util.IntsRefBuilder;
import org.apache.lucene.util.fst.Builder;
import org.apache.lucene.util.fst.FST;
import org.apache.lucene.util.fst.PositiveIntOutputs;
class TokenInfoDictionaryBuilder {
private int offset = 0;
private String encoding;
private Normalizer.Form normalForm;
TokenInfoDictionaryBuilder(String encoding, boolean normalizeEntries) {
this.encoding = encoding;
normalForm = normalizeEntries ? Normalizer.Form.NFKC : null;
}
public TokenInfoDictionaryWriter build(Path dir) throws IOException {
try (Stream<Path> files = Files.list(dir)) {
List<Path> csvFiles = files
.filter(path -> path.getFileName().toString().endsWith(".csv"))
.sorted()
.collect(Collectors.toList());
return buildDictionary(csvFiles);
}
}
private TokenInfoDictionaryWriter buildDictionary(List<Path> csvFiles) throws IOException {
TokenInfoDictionaryWriter dictionary = new TokenInfoDictionaryWriter(10 * 1024 * 1024);
List<String[]> lines = new ArrayList<>(400000);
for (Path path : csvFiles) {
try (BufferedReader reader = Files.newBufferedReader(path, Charset.forName(encoding))) {
String line;
while ((line = reader.readLine()) != null) {
String[] entry = CSVUtil.parse(line);
if (entry.length < 12) {
throw new IllegalArgumentException("Entry in CSV is not valid (12 field values expected): " + line);
}
if (normalForm != null) {
String[] normalizedEntry = new String[entry.length];
for (int i = 0; i < entry.length; i++) {
normalizedEntry[i] = Normalizer.normalize(entry[i], normalForm);
}
lines.add(normalizedEntry);
} else {
lines.add(entry);
}
}
}
}
lines.sort(Comparator.comparing(left -> left[0]));
PositiveIntOutputs fstOutput = PositiveIntOutputs.getSingleton();
Builder<Long> fstBuilder = new Builder<>(FST.INPUT_TYPE.BYTE2, 0, 0, true, true, Integer.MAX_VALUE, fstOutput, true, 15);
IntsRefBuilder scratch = new IntsRefBuilder();
long ord = -1;
String lastValue = null;
for (String[] entry : lines) {
String surfaceForm = entry[0].trim();
if (surfaceForm.isEmpty()) {
continue;
}
int next = dictionary.put(entry);
if(next == offset) {
throw new IllegalStateException("Failed to process line: " + Arrays.toString(entry));
}
if (!surfaceForm.equals(lastValue)) {
ord++;
lastValue = surfaceForm;
scratch.grow(surfaceForm.length());
scratch.setLength(surfaceForm.length());
for (int i = 0; i < surfaceForm.length(); i++) {
scratch.setIntAt(i, surfaceForm.charAt(i));
}
fstBuilder.add(scratch.get(), ord);
}
dictionary.addMapping((int) ord, offset);
offset = next;
}
dictionary.setFST(fstBuilder.finish());
return dictionary;
}
}