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.ArrayList; 025import java.util.Calendar; 026import java.util.List; 027 028import org.apache.commons.logging.Log; 029import org.apache.commons.logging.LogFactory; 030import org.nuxeo.ecm.core.api.Blob; 031import org.nuxeo.ecm.core.api.DocumentModel; 032import org.nuxeo.ecm.core.api.NuxeoException; 033import org.nuxeo.ecm.core.api.impl.blob.StringBlob; 034import org.nuxeo.ecm.core.transientstore.api.TransientStore; 035import org.nuxeo.ecm.core.transientstore.api.TransientStoreService; 036import org.nuxeo.ecm.core.work.api.Work; 037import org.nuxeo.ecm.core.work.api.Work.State; 038import org.nuxeo.ecm.core.work.api.WorkManager; 039import org.nuxeo.ecm.platform.rendition.Rendition; 040import org.nuxeo.ecm.platform.rendition.extension.AutomationRenderer; 041import org.nuxeo.ecm.platform.rendition.extension.RenditionProvider; 042import org.nuxeo.ecm.platform.rendition.impl.LazyRendition; 043import org.nuxeo.ecm.platform.rendition.service.RenditionDefinition; 044import org.nuxeo.runtime.api.Framework; 045 046/** 047 * Default implementation of an asynchronous {@link RenditionProvider} 048 * 049 * @author <a href="mailto:tdelprat@nuxeo.com">Tiry</a> 050 * @since 7.2 051 */ 052public abstract class AbstractLazyCachableRenditionProvider implements RenditionProvider { 053 054 public static final String WORKERID_KEY = "workerid"; 055 056 public static final String CACHE_NAME = "LazyRenditionCache"; 057 058 protected static Log log = LogFactory.getLog(AbstractLazyCachableRenditionProvider.class); 059 060 @Override 061 public List<Blob> render(DocumentModel doc, RenditionDefinition def) { 062 063 // build the key 064 String key = buildRenditionKey(doc, def); 065 066 // see if rendition is already in process 067 068 TransientStoreService tss = Framework.getService(TransientStoreService.class); 069 070 TransientStore ts = tss.getStore(CACHE_NAME); 071 072 if (ts == null) { 073 throw new NuxeoException("Unable to find Transient Store " + CACHE_NAME); 074 } 075 076 if (!ts.exists(key)) { 077 Work work = getRenditionWork(key, doc, def); 078 WorkManager wm = Framework.getService(WorkManager.class); 079 ts.putParameter(key, WORKERID_KEY, work.getId()); 080 wm.schedule(work); 081 } else { 082 if (ts.isCompleted(key)) { 083 List<Blob> blobs = ts.getBlobs(key); 084 ts.release(key); 085 return blobs; 086 } else { 087 WorkManager wm = Framework.getService(WorkManager.class); 088 String workId = (String) ts.getParameter(key, WORKERID_KEY); 089 Work work = wm.find(workId, State.COMPLETED); 090 if (work == null) { 091 work = wm.find(workId, State.FAILED); 092 } 093 if (work != null) { 094 State state = work.getWorkInstanceState(); 095 if (state == State.FAILED) { 096 // return an empty Blob 097 List<Blob> blobs = new ArrayList<Blob>(); 098 StringBlob emptyBlob = new StringBlob(""); 099 emptyBlob.setFilename("error"); 100 emptyBlob.setMimeType("text/plain;" + LazyRendition.ERROR_MARKER); 101 blobs.add(emptyBlob); 102 ts.release(key); 103 return blobs; 104 } 105 } 106 } 107 } 108 // return an empty Blob 109 List<Blob> blobs = new ArrayList<Blob>(); 110 StringBlob emptyBlob = new StringBlob(""); 111 emptyBlob.setFilename("inprogress"); 112 emptyBlob.setMimeType("text/plain;" + LazyRendition.EMPTY_MARKER); 113 blobs.add(emptyBlob); 114 return blobs; 115 } 116 117 @Override 118 public String getVariant(DocumentModel doc, RenditionDefinition definition) { 119 return AutomationRenderer.getVariant(doc, definition); 120 } 121 122 protected String buildRenditionKey(DocumentModel doc, RenditionDefinition def) { 123 124 StringBuffer sb = new StringBuffer(doc.getId()); 125 sb.append("::"); 126 String modificationDatePropertyName = def.getSourceDocumentModificationDatePropertyName(); 127 Calendar modif = (Calendar) doc.getPropertyValue(modificationDatePropertyName); 128 if (modif != null) { 129 sb.append(modif.getTimeInMillis()); 130 sb.append("::"); 131 } 132 String variant = getVariant(doc, def); 133 if (variant != null) { 134 sb.append(variant); 135 sb.append("::"); 136 } 137 sb.append(def.getName()); 138 139 return getDigest(sb.toString()); 140 } 141 142 protected String getDigest(String key) { 143 MessageDigest digest; 144 try { 145 digest = MessageDigest.getInstance("MD5"); 146 } catch (NoSuchAlgorithmException e) { 147 return key; 148 } 149 byte[] buf = digest.digest(key.getBytes()); 150 return toHexString(buf); 151 } 152 153 private static final char[] HEX_DIGITS = "0123456789abcdef".toCharArray(); 154 155 protected String toHexString(byte[] data) { 156 StringBuilder buf = new StringBuilder(2 * data.length); 157 for (byte b : data) { 158 buf.append(HEX_DIGITS[(0xF0 & b) >> 4]); 159 buf.append(HEX_DIGITS[0x0F & b]); 160 } 161 return buf.toString(); 162 } 163 164 /** 165 * Return the {@link Work} that will compute the {@link Rendition}. {@link AbstractRenditionBuilderWork} can be used 166 * as a base class 167 * 168 * @param key the key used to rendition 169 * @param doc the target {@link DocumentModel} 170 * @param def the {@link RenditionDefinition} 171 * @return 172 */ 173 protected abstract Work getRenditionWork(final String key, final DocumentModel doc, final RenditionDefinition def); 174 175}