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 * Nuxeo - initial API and implementation 018 */ 019 020package org.nuxeo.ecm.platform.rendition.lazy; 021 022import java.security.MessageDigest; 023import java.security.NoSuchAlgorithmException; 024import java.util.Calendar; 025import java.util.Collections; 026import java.util.List; 027import java.util.Objects; 028import java.util.stream.Collectors; 029 030import org.apache.logging.log4j.LogManager; 031import org.apache.logging.log4j.Logger; 032import org.nuxeo.ecm.core.api.Blob; 033import org.nuxeo.ecm.core.api.DocumentModel; 034import org.nuxeo.ecm.core.api.NuxeoException; 035import org.nuxeo.ecm.core.api.impl.blob.StringBlob; 036import org.nuxeo.ecm.core.transientstore.api.TransientStore; 037import org.nuxeo.ecm.core.transientstore.api.TransientStoreService; 038import org.nuxeo.ecm.core.work.api.Work; 039import org.nuxeo.ecm.core.work.api.WorkManager; 040import org.nuxeo.ecm.platform.rendition.Rendition; 041import org.nuxeo.ecm.platform.rendition.extension.DefaultAutomationRenditionProvider; 042import org.nuxeo.ecm.platform.rendition.extension.RenditionProvider; 043import org.nuxeo.ecm.platform.rendition.impl.LazyRendition; 044import org.nuxeo.ecm.platform.rendition.service.RenditionDefinition; 045import org.nuxeo.runtime.api.Framework; 046 047/** 048 * Default implementation of an asynchronous {@link RenditionProvider} 049 * 050 * @author <a href="mailto:tdelprat@nuxeo.com">Tiry</a> 051 * @since 7.2 052 */ 053public abstract class AbstractLazyCachableRenditionProvider extends DefaultAutomationRenditionProvider { 054 055 public static final String SOURCE_DOCUMENT_MODIFICATION_DATE_KEY = "sourceDocumentModificationDate"; 056 057 public static final String CACHE_NAME = "LazyRenditionCache"; 058 059 protected static Logger log = LogManager.getLogger(AbstractLazyCachableRenditionProvider.class); 060 061 @Override 062 public List<Blob> render(DocumentModel doc, RenditionDefinition definition) { 063 log.debug("Asking \"{}\" rendition lazy rendering for document {} (id={}).", definition::getName, 064 doc::getPathAsString, doc::getId); 065 066 // Build the rendition key and get the current source document modification date 067 String key = buildRenditionKey(doc, definition); 068 String sourceDocumentModificationDate = getSourceDocumentModificationDate(doc, definition); 069 070 // If rendition is not already in progress schedule it 071 List<Blob> blobs; 072 TransientStore ts = getTransientStore(); 073 if (!ts.exists(key)) { 074 blobs = handleNewRendition(key, doc, definition, sourceDocumentModificationDate); 075 } else { 076 String tsSourceDocumentModificationDate = (String) ts.getParameter(key, 077 SOURCE_DOCUMENT_MODIFICATION_DATE_KEY); 078 blobs = ts.getBlobs(key); 079 if (ts.isCompleted(key)) { 080 handleCompletedRendition(key, doc, definition, sourceDocumentModificationDate, 081 tsSourceDocumentModificationDate, blobs); 082 } else { 083 handleIncompleteRendition(key, doc, definition, sourceDocumentModificationDate, 084 tsSourceDocumentModificationDate); 085 } 086 } 087 final List<Blob> finalBlobs = blobs; 088 log.debug("Returning blobs: {}.", () -> getBlobInfo(finalBlobs)); 089 return blobs; 090 } 091 092 /** 093 * @since 11.1 094 */ 095 protected String getBlobInfo(List<Blob> blobs) { 096 if (blobs == null) { 097 return null; 098 } 099 return blobs.stream() 100 .map(blob -> String.format("{filename=%s, MIME type=%s}", blob.getFilename(), blob.getMimeType())) 101 .collect(Collectors.joining(",", "[", "]")); 102 } 103 104 public String buildRenditionKey(DocumentModel doc, RenditionDefinition def) { 105 StringBuilder sb = new StringBuilder(doc.getId()); 106 sb.append("::"); 107 String variant = getVariant(doc, def); 108 if (variant != null) { 109 sb.append(variant); 110 sb.append("::"); 111 } 112 sb.append(def.getName()); 113 114 String key = getDigest(sb.toString()); 115 log.debug("Built rendition key for document {} (id={}): {}.", doc::getPathAsString, doc::getId, () -> key); 116 return key; 117 } 118 119 public String getSourceDocumentModificationDate(DocumentModel doc, RenditionDefinition definition) { 120 String modificationDatePropertyName = definition.getSourceDocumentModificationDatePropertyName(); 121 Calendar modificationDate = (Calendar) doc.getPropertyValue(modificationDatePropertyName); 122 if (modificationDate == null) { 123 return null; 124 } 125 long millis = modificationDate.getTimeInMillis(); 126 // the date may have been rounded by the storage layer, normalize it to the second 127 millis -= millis % 1000; 128 return String.valueOf(millis); 129 } 130 131 protected String getDigest(String key) { 132 MessageDigest digest; 133 try { 134 digest = MessageDigest.getInstance("MD5"); 135 } catch (NoSuchAlgorithmException e) { 136 return key; 137 } 138 byte[] buf = digest.digest(key.getBytes()); 139 return toHexString(buf); 140 } 141 142 private static final char[] HEX_DIGITS = "0123456789abcdef".toCharArray(); 143 144 protected String toHexString(byte[] data) { 145 StringBuilder sb = new StringBuilder(2 * data.length); 146 for (byte b : data) { 147 sb.append(HEX_DIGITS[(0xF0 & b) >> 4]); 148 sb.append(HEX_DIGITS[0x0F & b]); 149 } 150 return sb.toString(); 151 } 152 153 protected TransientStore getTransientStore() { 154 TransientStoreService tss = Framework.getService(TransientStoreService.class); 155 TransientStore ts = tss.getStore(CACHE_NAME); 156 if (ts == null) { 157 throw new NuxeoException("Unable to find Transient Store " + CACHE_NAME); 158 } 159 return ts; 160 } 161 162 protected List<Blob> handleNewRendition(String key, DocumentModel doc, RenditionDefinition definition, 163 String sourceDocumentModificationDate) { 164 Work work = getRenditionWork(key, doc, definition); 165 log.debug( 166 "No entry found for key {} in the {} transient store, scheduling rendition work with id {} and storing" 167 + " an empty blob for now.", 168 () -> key, () -> CACHE_NAME, work::getId); 169 if (sourceDocumentModificationDate != null) { 170 getTransientStore().putParameter(key, SOURCE_DOCUMENT_MODIFICATION_DATE_KEY, 171 sourceDocumentModificationDate); 172 } 173 StringBlob emptyBlob = new StringBlob(""); 174 emptyBlob.setFilename(LazyRendition.IN_PROGRESS_MARKER); 175 emptyBlob.setMimeType("text/plain;" + LazyRendition.EMPTY_MARKER); 176 getTransientStore().putBlobs(key, Collections.singletonList(emptyBlob)); 177 Framework.getService(WorkManager.class).schedule(work); 178 return Collections.singletonList(emptyBlob); 179 } 180 181 protected void handleCompletedRendition(String key, DocumentModel doc, RenditionDefinition definition, 182 String sourceDocumentModificationDate, String tsSourceDocumentModificationDate, List<Blob> blobs) { 183 log.debug("Completed entry found for key {} in the {} transient store.", key, CACHE_NAME); 184 185 // No or more than one blob 186 if (blobs == null || blobs.size() != 1) { 187 log.debug("No (or more than one) rendition blob for key {}, releasing entry from the transient store.", 188 key); 189 getTransientStore().release(key); 190 return; 191 } 192 193 // Blob in error 194 Blob blob = blobs.get(0); 195 String mimeType = blob.getMimeType(); 196 if (mimeType != null && mimeType.contains(LazyRendition.ERROR_MARKER)) { 197 log.debug("Rendition blob is in error for key {}.", key); 198 // Check if rendition is up-to-date 199 if (Objects.equals(tsSourceDocumentModificationDate, sourceDocumentModificationDate)) { 200 log.debug("Removing entry from the transient store."); 201 getTransientStore().remove(key); 202 return; 203 } 204 Work work = getRenditionWork(key, doc, definition); 205 log.debug( 206 "Source document modification date {} is different from the corresponding transient store parameter" 207 + " {}, scheduling rendition work with id {} and returning an error/stale rendition.", 208 () -> sourceDocumentModificationDate, () -> tsSourceDocumentModificationDate, work::getId); 209 Framework.getService(WorkManager.class).schedule(work); 210 blob.setMimeType(blob.getMimeType() + ";" + LazyRendition.STALE_MARKER); 211 return; 212 } 213 214 // Check if rendition is up-to-date 215 if (Objects.equals(tsSourceDocumentModificationDate, sourceDocumentModificationDate)) { 216 log.debug("Rendition blob is up-to-date for key {}, returning it and releasing entry from the transient" 217 + " store.", key); 218 getTransientStore().release(key); 219 return; 220 } 221 222 // Stale rendition 223 Work work = getRenditionWork(key, doc, definition); 224 log.debug( 225 "Source document modification date {} is different from the corresponding transient store parameter {}," 226 + " scheduling rendition work with id {} and returning a stale rendition.", 227 () -> sourceDocumentModificationDate, () -> tsSourceDocumentModificationDate, work::getId); 228 Framework.getService(WorkManager.class).schedule(work); 229 blob.setMimeType(blob.getMimeType() + ";" + LazyRendition.STALE_MARKER); 230 } 231 232 protected void handleIncompleteRendition(String key, DocumentModel doc, RenditionDefinition definition, 233 String sourceDocumentModificationDate, String tsSourceDocumentModificationDate) { 234 log.debug("Incomplete entry found for key {} in the {} transient store.", key, CACHE_NAME); 235 WorkManager workManager = Framework.getService(WorkManager.class); 236 Work work = getRenditionWork(key, doc, definition); 237 String workId = work.getId(); 238 boolean scheduleWork = false; 239 if (Objects.equals(tsSourceDocumentModificationDate, sourceDocumentModificationDate)) { 240 Work.State workState = workManager.getWorkState(workId); 241 if (workState == null) { 242 log.debug("Found no existing work with id {}.", workId); 243 scheduleWork = true; 244 } else { 245 log.debug("Found an existing work with id {} in sate {}.", workId, workState); 246 } 247 } else { 248 log.debug("Source document modification date {} is different from the corresponding transient store" 249 + " parameter {}.", sourceDocumentModificationDate, tsSourceDocumentModificationDate); 250 scheduleWork = true; 251 } 252 if (scheduleWork) { 253 log.debug("Scheduling rendition work with id {}.", workId); 254 workManager.schedule(work); 255 } 256 } 257 258 /** 259 * Return the {@link Work} that will compute the {@link Rendition}. {@link AbstractRenditionBuilderWork} can be used 260 * as a base class 261 * 262 * @param key the key used to rendition 263 * @param doc the target {@link DocumentModel} 264 * @param def the {@link RenditionDefinition} 265 */ 266 protected abstract Work getRenditionWork(final String key, final DocumentModel doc, final RenditionDefinition def); 267 268}