package org.apache.lucene.search.suggest.fst;
/*
* 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.
*/
import java.io.BufferedReader;
import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;
import java.io.InputStreamReader;
import java.nio.charset.StandardCharsets;
import org.apache.lucene.util.BytesRef;
import org.apache.lucene.util.OfflineSorter;
/**
* Try to build a suggester from a large data set. The input is a simple text
* file, newline-delimited.
*/
public class LargeInputFST {
public static void main(String[] args) throws IOException {
File input = new File("/home/dweiss/tmp/shuffled.dict");
int buckets = 20;
int shareMaxTail = 10;
ExternalRefSorter sorter = new ExternalRefSorter(new OfflineSorter());
FSTCompletionBuilder builder = new FSTCompletionBuilder(buckets, sorter, shareMaxTail);
BufferedReader reader = new BufferedReader(
new InputStreamReader(
new FileInputStream(input), StandardCharsets.UTF_8));
BytesRef scratch = new BytesRef();
String line;
int count = 0;
while ((line = reader.readLine()) != null) {
scratch.copyChars(line);
builder.add(scratch, count % buckets);
if ((count++ % 100000) == 0) {
System.err.println("Line: " + count);
}
}
System.out.println("Building FSTCompletion.");
FSTCompletion completion = builder.build();
File fstFile = new File("completion.fst");
System.out.println("Done. Writing automaton: " + fstFile.getAbsolutePath());
completion.getFST().save(fstFile);
sorter.close();
}
}