001/*
002 * (C) Copyright 2017 Nuxeo SA (http://nuxeo.com/) and others.
003 *
004 * Licensed under the Apache License, Version 2.0 (the "License");
005 * you may not use this file except in compliance with the License.
006 * You may obtain a copy of the License at
007 *
008 *     http://www.apache.org/licenses/LICENSE-2.0
009 *
010 * Unless required by applicable law or agreed to in writing, software
011 * distributed under the License is distributed on an "AS IS" BASIS,
012 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
013 * See the License for the specific language governing permissions and
014 * limitations under the License.
015 *
016 * Contributors:
017 *     bdelbosc
018 */
019
020package org.nuxeo.importer.stream.producer;
021
022import java.time.Duration;
023
024import org.nuxeo.ecm.core.blob.BlobInfo;
025import org.nuxeo.importer.stream.message.BlobInfoMessage;
026import org.nuxeo.importer.stream.message.DocumentMessage;
027import org.nuxeo.lib.stream.log.LogRecord;
028import org.nuxeo.lib.stream.log.LogTailer;
029
030/**
031 * Returns blob information from a Log, loop on the log.
032 *
033 * @since 9.3
034 */
035public class RandomLogBlobInfoFetcher implements BlobInfoFetcher {
036    protected static final int READ_DELAY_MS = 10;
037
038    protected final LogTailer<BlobInfoMessage> tailer;
039
040    public RandomLogBlobInfoFetcher(LogTailer<BlobInfoMessage> blobInfoTailer) {
041        this.tailer = blobInfoTailer;
042    }
043
044    @Override
045    public BlobInfo get(DocumentMessage.Builder builder) {
046        LogRecord<BlobInfoMessage> record;
047        try {
048            record = tailer.read(Duration.ofMillis(READ_DELAY_MS));
049        } catch (InterruptedException e) {
050            Thread.currentThread().interrupt();
051            throw new RuntimeException(e);
052        }
053        if (record == null) {
054            // start again from beginning
055            tailer.toStart();
056            return get(builder);
057        }
058        return record.message();
059    }
060
061    @Override
062    public void close() throws Exception {
063        tailer.close();
064    }
065}