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:[email protected]">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.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:[email protected]">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    protected static Log log = LogFactory.getLog(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.getCoreSession().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        if (log.isDebugEnabled()) {
112            log.debug(String.format("Starting %s work with id %s for transient store key %s and document %s.",
113                    getClass().getSimpleName(), id, key, docRef));
114        }
115        openUserSession();
116        DocumentModel doc = session.getDocument(docRef);
117
118        RenditionService rs = Framework.getService(RenditionService.class);
119        RenditionDefinition def = rs.getAvailableRenditionDefinition(doc, renditionName);
120
121        log.debug("Starting rendition computation.");
122        List<Blob> blobs = doComputeRendition(session, doc, def);
123        updateAndCompleteStoreEntry(getSourceDocumentModificationDate(doc), blobs);
124    }
125
126    @Override
127    public void cleanUp(boolean ok, Exception e) {
128        if (ok) {
129            super.cleanUp(ok, e);
130            return;
131        }
132
133        // Fetch document and compute its modification date before cleaning up which closes the session
134        DocumentModel doc = session.getDocument(docRef);
135        String sourceDocumentModificationDate = getSourceDocumentModificationDate(doc);
136
137        super.cleanUp(ok, e);
138
139        List<Blob> blobs = new ArrayList<>();
140        StringBlob emptyBlob = new StringBlob("");
141        emptyBlob.setFilename("error");
142        emptyBlob.setMimeType("text/plain;" + LazyRendition.ERROR_MARKER);
143        blobs.add(emptyBlob);
144        updateAndCompleteStoreEntry(sourceDocumentModificationDate, blobs);
145    }
146
147    void updateAndCompleteStoreEntry(String sourceDocumentModificationDate, List<Blob> blobs) {
148        if (log.isDebugEnabled()) {
149            log.debug(
150                    String.format("Updating and completing transient store entry with key %s (workId=%s, document=%s).",
151                            key, id, docRef));
152        }
153        TransientStoreService tss = Framework.getService(TransientStoreService.class);
154        TransientStore ts = tss.getStore(getTransientStoreName());
155
156        if (sourceDocumentModificationDate != null) {
157            ts.putParameter(key, AbstractLazyCachableRenditionProvider.SOURCE_DOCUMENT_MODIFICATION_DATE_KEY,
158                    sourceDocumentModificationDate);
159        }
160        ts.putBlobs(key, blobs);
161        ts.setCompleted(key, true);
162    }
163
164    protected String getSourceDocumentModificationDate(DocumentModel doc) {
165        RenditionService rs = Framework.getService(RenditionService.class);
166        RenditionDefinition definition = rs.getAvailableRenditionDefinition(doc, renditionName);
167        RenditionProvider provider = definition.getProvider();
168        if (provider instanceof AbstractLazyCachableRenditionProvider) {
169            return ((AbstractLazyCachableRenditionProvider) provider).getSourceDocumentModificationDate(doc,
170                    definition);
171        }
172        return null;
173    }
174
175    /**
176     * Does the actual Rendition Computation : this code will be called from inside an Asynchronous Work
177     *
178     * @param session
179     * @param doc
180     * @param def
181     * @return
182     */
183    protected abstract List<Blob> doComputeRendition(CoreSession session, DocumentModel doc, RenditionDefinition def);
184
185}