edu.cmu.lti.oaqa.annographix.solr.AnnotEncoderVer3.java Source code

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Here is the source code for edu.cmu.lti.oaqa.annographix.solr.AnnotEncoderVer3.java

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/*
 *  Copyright 2014 Carnegie Mellon University
 *
 *  Licensed 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 edu.cmu.lti.oaqa.annographix.solr;

import org.apache.lucene.analysis.payloads.AbstractEncoder;
import org.apache.lucene.analysis.payloads.PayloadEncoder;
import org.apache.lucene.analysis.payloads.PayloadHelper;
import org.apache.lucene.util.BytesRef;
import org.apache.lucene.util.ArrayUtil;

/**
 *  Encode annotation-related information as a {@link BytesRef}.
 *  <p>
 *  This information includes the following comma-separated values:
 *  start offset, end offset, id, parent id.
 *  <p>
 *  See {@link org.apache.lucene.analysis.payloads.PayloadHelper#encodeInt(int, byte[], int)}.
 * 
 * @author Leonid Boytsov
 *    
 **/
//  TODO: Try to use some light-weight compression?
public class AnnotEncoderVer3 extends AbstractEncoder implements PayloadEncoder {
    @Override
    public BytesRef encode(char[] buffer, int offset, int length) {
        int sep1pos = -1, sep2pos = -1, sep3pos = -1, sepQty = 0;

        for (int i = 0; i < length; ++i) {
            char c = buffer[offset + i];
            if (c == UtilConst.PAYLOAD_ID_SEP_CHAR) {
                ++sepQty;
                if (1 == sepQty)
                    sep1pos = i;
                else if (2 == sepQty)
                    sep2pos = i;
                else if (3 == sepQty)
                    sep3pos = i;
                else {
                    String errData = new String(buffer, offset, length);
                    throw new RuntimeException("Cannot parse payload input: " + errData);
                }
            }
        }

        int wordStartPos = ArrayUtil.parseInt(buffer, offset, sep1pos);
        int wordEndPos = ArrayUtil.parseInt(buffer, offset + sep1pos + 1, sep2pos - sep1pos - 1);
        int annotId = ArrayUtil.parseInt(buffer, offset + sep2pos + 1, sep3pos - sep2pos - 1);
        int parentId = ArrayUtil.parseInt(buffer, offset + sep3pos + 1, length - sep3pos - 1);

        BytesRef result = new BytesRef(PayloadHelper.encodeInt(wordStartPos));
        result.append(new BytesRef(PayloadHelper.encodeInt(wordEndPos)));
        result.append(new BytesRef(PayloadHelper.encodeInt(annotId)));
        result.append(new BytesRef(PayloadHelper.encodeInt(parentId)));
        return result;
    }

    /**
     *  Decodes payload data.
     *  
     *  @param buffer   A buffer that stores encoded payload data.
     *  @param res      A reusable result variable, which is used 
     *                  to prevent unnecessary memory allocations.
     */
    public static void decode(BytesRef buffer, ElemInfoData res /* reuse this variable */) {
        byte[] bytes = buffer.bytes;
        int offset = buffer.offset;
        res.mStartOffset = PayloadHelper.decodeInt(bytes, offset);
        offset += 4;
        res.mEndOffset = PayloadHelper.decodeInt(bytes, offset);
        offset += 4;
        res.mId = PayloadHelper.decodeInt(bytes, offset);
        offset += 4;
        res.mParentId = PayloadHelper.decodeInt(bytes, offset);
    }
}