001/*
002 * (C) Copyright 2015 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 *     <a href="mailto:tdelprat@nuxeo.com">Tiry</a>
018 */
019package org.nuxeo.ecm.platform.rendition.lazy;
020
021import java.util.ArrayList;
022import java.util.List;
023
024import org.apache.commons.logging.Log;
025import org.apache.commons.logging.LogFactory;
026import org.nuxeo.ecm.core.api.Blob;
027import org.nuxeo.ecm.core.api.CoreSession;
028import org.nuxeo.ecm.core.api.DocumentModel;
029import org.nuxeo.ecm.core.api.DocumentRef;
030import org.nuxeo.ecm.core.api.NuxeoException;
031import org.nuxeo.ecm.core.api.impl.blob.StringBlob;
032import org.nuxeo.ecm.core.transientstore.api.TransientStore;
033import org.nuxeo.ecm.core.transientstore.api.TransientStoreService;
034import org.nuxeo.ecm.core.transientstore.work.TransientStoreWork;
035import org.nuxeo.ecm.platform.rendition.extension.RenditionProvider;
036import org.nuxeo.ecm.platform.rendition.impl.LazyRendition;
037import org.nuxeo.ecm.platform.rendition.service.RenditionDefinition;
038import org.nuxeo.ecm.platform.rendition.service.RenditionService;
039import org.nuxeo.ecm.platform.rendition.service.RenditionServiceImpl;
040import org.nuxeo.runtime.api.Framework;
041
042/**
043 * @author <a href="mailto:tdelprat@nuxeo.com">Tiry</a>
044 * @since 7.2
045 */
046public abstract class AbstractRenditionBuilderWork extends TransientStoreWork {
047
048    private static final long serialVersionUID = 1L;
049
050    protected String key;
051
052    protected final DocumentRef docRef;
053
054    protected final String repositoryName;
055
056    protected final String renditionName;
057
058    protected static Log log = LogFactory.getLog(AbstractRenditionBuilderWork.class);
059
060    public static final String CATEGORY = "renditionBuilder";
061
062    public AbstractRenditionBuilderWork(String key, DocumentModel doc, RenditionDefinition def) {
063        this.key = key;
064        docRef = doc.getRef();
065        repositoryName = doc.getRepositoryName();
066        renditionName = def.getName();
067        setOriginatingUsername(doc.getCoreSession().getPrincipal().getName());
068        this.id = buildId(doc, def);
069    }
070
071    protected String buildId(DocumentModel doc, RenditionDefinition def) {
072        StringBuffer sb = new StringBuffer("rendition:");
073        sb.append(doc.getId());
074        String variant = def.getProvider().getVariant(doc, def);
075        if (variant != null) {
076            sb.append("::");
077            sb.append(variant);
078        }
079        sb.append("::");
080        sb.append(def.getName());
081        return sb.toString();
082    }
083
084    @Override
085    public String getTitle() {
086        return "Lazy Rendition for " + renditionName + " on " + docRef.toString()
087                + " on behalf of " + originatingUsername;
088    }
089
090    @Override
091    public String getCategory() {
092        return CATEGORY;
093    }
094
095    protected String getTransientStoreName() {
096        return AbstractLazyCachableRenditionProvider.CACHE_NAME;
097    }
098
099    @Override
100    public void work() {
101        openUserSession();
102        DocumentModel doc = session.getDocument(docRef);
103
104        RenditionService rs = Framework.getService(RenditionService.class);
105        RenditionDefinition def = ((RenditionServiceImpl) rs).getRenditionDefinition(renditionName);
106
107        RenditionProvider renditionProvider = def.getProvider();
108        if (renditionProvider instanceof AbstractLazyCachableRenditionProvider) {
109            String rendKey = ((AbstractLazyCachableRenditionProvider) renditionProvider).buildRenditionKey(doc, def);
110            if (!rendKey.equals(key)) {
111                refreshStoreEntry(rendKey);
112                this.key = rendKey;
113            }
114        }
115
116        List<Blob> blobs = doComputeRendition(session, doc, def);
117        updateAndCompleteStoreEntry(blobs);
118    }
119
120    @Override
121    public void cleanUp(boolean ok, Exception e) {
122        super.cleanUp(ok, e);
123        if (ok) {
124            return;
125        }
126        List<Blob> blobs = new ArrayList<Blob>();
127        StringBlob emptyBlob = new StringBlob("");
128        emptyBlob.setFilename("error");
129        emptyBlob.setMimeType("text/plain;" + LazyRendition.ERROR_MARKER);
130        blobs.add(emptyBlob);
131        updateAndCompleteStoreEntry(blobs);
132    }
133
134    void refreshStoreEntry(String renditionKey) {
135        TransientStoreService tss = Framework.getService(TransientStoreService.class);
136        TransientStore ts = tss.getStore(getTransientStoreName());
137
138        // Release old key
139        if (ts.exists(key)) {
140            ts.release(key);
141        }
142        ts.putParameter(renditionKey, AbstractLazyCachableRenditionProvider.WORKERID_KEY, getId());
143        List<Blob> blobs = new ArrayList<Blob>();
144        StringBlob emptyBlob = new StringBlob("");
145        emptyBlob.setFilename("inprogress");
146        emptyBlob.setMimeType("text/plain;" + LazyRendition.EMPTY_MARKER);
147        blobs.add(emptyBlob);
148        ts.putBlobs(renditionKey, blobs);
149    }
150
151    void updateAndCompleteStoreEntry(List<Blob> blobs) {
152        TransientStoreService tss = Framework.getService(TransientStoreService.class);
153        TransientStore ts = tss.getStore(getTransientStoreName());
154
155        if (!ts.exists(key)) {
156            throw new NuxeoException("Rendition TransientStore entry can not be null");
157        }
158        ts.putBlobs(key, blobs);
159        ts.setCompleted(key, true);
160    }
161
162    /**
163     * Does the actual Rendition Computation : this code will be called from inside an Asynchronous Work
164     *
165     * @param session
166     * @param doc
167     * @param def
168     * @return
169     */
170    protected abstract List<Blob> doComputeRendition(CoreSession session, DocumentModel doc, RenditionDefinition def);
171
172}