001/*
002 * (C) Copyright 2010 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 * Contributors:
016 * Nuxeo - initial API and implementation
017 */
018
019package org.nuxeo.ecm.platform.rendition.impl;
020
021import java.util.List;
022
023import org.nuxeo.ecm.core.api.Blob;
024import org.nuxeo.ecm.platform.rendition.Rendition;
025import org.nuxeo.ecm.platform.rendition.service.RenditionDefinition;
026
027/**
028 * Implementation of the {@link Rendition} interface that allows lazy computation of the rendition Blobs
029 *
030 * @author <a href="mailto:tdelprat@nuxeo.com">Tiry</a>
031 */
032public abstract class LazyRendition extends AbstractRendition implements Rendition {
033
034    public static final String EMPTY_MARKER = "empty=true";
035
036    public static final String ERROR_MARKER = "error=true";
037
038    public static final String STALE_MARKER = "stale=true";
039
040    public static final String IN_PROGRESS_MARKER = "inprogress";
041
042    protected List<Blob> blobs = null;
043
044    public LazyRendition(RenditionDefinition definition) {
045        super(definition);
046    }
047
048    @Override
049    public Blob getBlob() {
050        List<Blob> blobs = getBlobs();
051        if (blobs != null && blobs.size() > 0) {
052            return blobs.get(0);
053        }
054        return null;
055    }
056
057    @Override
058    public List<Blob> getBlobs() {
059        if (blobs == null) {
060            blobs = computeRenditionBlobs();
061        }
062        return blobs;
063    }
064
065    @Override
066    public boolean isCompleted() {
067        Blob blob = getBlob();
068        if (blob == null) {
069            return true;
070        }
071        String mimeType = blob.getMimeType();
072        // lazy rendition with build in-progress has blob mimeType containing "empty=true"
073        return mimeType == null || !mimeType.contains(EMPTY_MARKER);
074    }
075
076    protected abstract List<Blob> computeRenditionBlobs();
077
078}