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.logging.log4j.LogManager;
025import org.apache.logging.log4j.Logger;
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.impl.blob.StringBlob;
031import org.nuxeo.ecm.core.transientstore.api.TransientStore;
032import org.nuxeo.ecm.core.transientstore.api.TransientStoreService;
033import org.nuxeo.ecm.core.transientstore.work.TransientStoreWork;
034import org.nuxeo.ecm.platform.rendition.extension.RenditionProvider;
035import org.nuxeo.ecm.platform.rendition.impl.LazyRendition;
036import org.nuxeo.ecm.platform.rendition.service.RenditionDefinition;
037import org.nuxeo.ecm.platform.rendition.service.RenditionService;
038import org.nuxeo.runtime.api.Framework;
039
040/**
041 * @author <a href="mailto:tdelprat@nuxeo.com">Tiry</a>
042 * @since 7.2
043 */
044public abstract class AbstractRenditionBuilderWork extends TransientStoreWork {
045
046    private static final long serialVersionUID = 1L;
047
048    protected final String key;
049
050    protected final DocumentRef docRef;
051
052    protected final String renditionName;
053
054    private static final Logger log = LogManager.getLogger(AbstractRenditionBuilderWork.class);
055
056    public static final String CATEGORY = "renditionBuilder";
057
058    public AbstractRenditionBuilderWork(String key, DocumentModel doc, RenditionDefinition def) {
059        super();
060        this.key = key;
061        docRef = doc.getRef();
062        repositoryName = doc.getRepositoryName();
063        renditionName = def.getName();
064        setOriginatingUsername(doc.getPrincipal().getName());
065        this.id = buildId(doc, def);
066    }
067
068    protected String buildId(DocumentModel doc, RenditionDefinition def) {
069        StringBuilder sb = new StringBuilder("rendition:");
070        sb.append(doc.getId());
071        String variant = def.getProvider().getVariant(doc, def);
072        if (variant != null) {
073            sb.append("::");
074            sb.append(variant);
075        }
076        sb.append("::");
077        sb.append(def.getName());
078        return sb.toString();
079    }
080
081    @Override
082    public String getTitle() {
083        return "Lazy Rendition for " + renditionName + " on " + docRef.toString() + " on behalf of "
084                + originatingUsername;
085    }
086
087    @Override
088    public String getCategory() {
089        return CATEGORY;
090    }
091
092    protected String getTransientStoreName() {
093        return AbstractLazyCachableRenditionProvider.CACHE_NAME;
094    }
095
096    @Override
097    public boolean isIdempotent() {
098        // The same rendering can be executed multiple times because the result is transient.
099        return false;
100    }
101
102    @Override
103    public boolean isCoalescing() {
104        // The same rendering has no reason to be executed more than once if schedulled multiple times
105        // The last schedulled work will build the wanted rendition
106        return true;
107    }
108
109    @Override
110    public void work() {
111        log.debug("Starting work: {} with id: {} for transient store key: {} and document: {}",
112                getClass().getSimpleName(), id, key, docRef);
113        openUserSession();
114        DocumentModel doc = session.getDocument(docRef);
115
116        RenditionService rs = Framework.getService(RenditionService.class);
117        RenditionDefinition def = rs.getAvailableRenditionDefinition(doc, renditionName);
118
119        log.debug("Starting rendition computation.");
120        List<Blob> blobs = doComputeRendition(session, doc, def);
121        updateAndCompleteStoreEntry(getSourceDocumentModificationDate(doc), blobs);
122    }
123
124    @Override
125    public void cleanUp(boolean ok, Exception e) {
126        try {
127            if (!ok) {
128                storeAnErrorRendition();
129            }
130        } finally {
131            super.cleanUp(ok, e);
132        }
133    }
134
135    protected void storeAnErrorRendition() {
136        if (session == null) {
137            log.info("No session, unable to clean work: {} with id: {} for transient store key: {} and document: {}",
138                    getClass().getSimpleName(), id, key, docRef);
139            return;
140        }
141        DocumentModel doc = session.getDocument(docRef);
142        String sourceDocumentModificationDate = getSourceDocumentModificationDate(doc);
143        List<Blob> blobs = new ArrayList<>();
144        StringBlob emptyBlob = new StringBlob("");
145        emptyBlob.setFilename("error");
146        emptyBlob.setMimeType("text/plain;" + LazyRendition.ERROR_MARKER);
147        blobs.add(emptyBlob);
148        updateAndCompleteStoreEntry(sourceDocumentModificationDate, blobs);
149    }
150
151    void updateAndCompleteStoreEntry(String sourceDocumentModificationDate, List<Blob> blobs) {
152        log.debug("Updating and completing transient store entry with key: {} (workId: {}, document: {})", key, id,
153                docRef);
154        TransientStoreService tss = Framework.getService(TransientStoreService.class);
155        TransientStore ts = tss.getStore(getTransientStoreName());
156
157        log.debug("BEGIN - Putting blobs for transient store entry with key: {}", key);
158        ts.putBlobs(key, blobs);
159        log.debug("END - Putting blobs for transient store entry with key: {}", key);
160
161        if (sourceDocumentModificationDate != null) {
162            log.debug(
163                    "Updating source document modification date parameter to: {} for transient store entry with key: {}",
164                    sourceDocumentModificationDate, key);
165            ts.putParameter(key, AbstractLazyCachableRenditionProvider.SOURCE_DOCUMENT_MODIFICATION_DATE_KEY,
166                    sourceDocumentModificationDate);
167        }
168        ts.setCompleted(key, true);
169    }
170
171    protected String getSourceDocumentModificationDate(DocumentModel doc) {
172        RenditionService rs = Framework.getService(RenditionService.class);
173        RenditionDefinition definition = rs.getAvailableRenditionDefinition(doc, renditionName);
174        RenditionProvider provider = definition.getProvider();
175        if (provider instanceof AbstractLazyCachableRenditionProvider) {
176            return ((AbstractLazyCachableRenditionProvider) provider).getSourceDocumentModificationDate(doc,
177                    definition);
178        }
179        return null;
180    }
181
182    /**
183     * Does the actual Rendition Computation: this code will be called from inside an Asynchronous Work
184     */
185    protected abstract List<Blob> doComputeRendition(CoreSession session, DocumentModel doc, RenditionDefinition def);
186
187}