org.apache.joshua.decoder.ff.lm.ClassMap.java Source code

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Here is the source code for org.apache.joshua.decoder.ff.lm.ClassMap.java

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/*
 * 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.joshua.decoder.ff.lm;

import java.io.IOException;

import org.apache.joshua.corpus.Vocabulary;
import org.apache.joshua.util.io.LineReader;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import com.google.common.collect.ImmutableMap;

public class ClassMap {

    private static final Logger LOG = LoggerFactory.getLogger(ClassMap.class);

    private static final int OOV_ID = Vocabulary.getUnknownId();
    private final ImmutableMap<Integer, Integer> mapping;

    public ClassMap(String file_name) {
        this.mapping = read(file_name);
        LOG.info("{} entries read from class map", this.mapping.size());
    }

    public int getClassID(int wordID) {
        return this.mapping.getOrDefault(wordID, OOV_ID);
    }

    public int size() {
        return mapping.size();
    }

    /**
     * Reads a class map from file_name
     */
    private static ImmutableMap<Integer, Integer> read(String file_name) {
        final ImmutableMap.Builder<Integer, Integer> builder = ImmutableMap.builder();
        int lineno = 0;
        try {
            for (String line : new LineReader(file_name, false)) {
                lineno++;
                String[] lineComp = line.trim().split("\\s+");
                try {
                    builder.put(Vocabulary.id(lineComp[0]), Vocabulary.id(lineComp[1]));
                } catch (java.lang.ArrayIndexOutOfBoundsException e) {
                    LOG.warn("bad vocab line #{} '{}'. skipping!", lineno, line);
                    LOG.warn(e.getMessage(), e);
                }
            }
        } catch (IOException e) {
            throw new RuntimeException(e);
        }
        return builder.build();
    }

}