1 /*
2  * Licensed to the Apache Software Foundation (ASF) under one or more
3  * contributor license agreements.  See the NOTICE file distributed with
4  * this work for additional information regarding copyright ownership.
5  * The ASF licenses this file to You under the Apache License, Version 2.0
6  * (the "License"); you may not use this file except in compliance with
7  * the License.  You may obtain a copy of the License at
8  *
9  *      http://www.apache.org/licenses/LICENSE-2.0
10  *
11  * Unless required by applicable law or agreed to in writing, software
12  * distributed under the License is distributed on an "AS IS" BASIS,
13  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
14  * See the License for the specific language governing permissions and
15  * limitations under the License.
16  */
17 
18 /* $Id: CachedRenderPagesModel.java 1863625 2019-07-23 10:41:07Z ssteiner $ */
19 
20 package org.apache.fop.area;
21 
22 import java.io.BufferedInputStream;
23 import java.io.BufferedOutputStream;
24 import java.io.IOException;
25 import java.io.InputStream;
26 import java.io.ObjectInputStream;
27 import java.io.ObjectOutputStream;
28 import java.io.OutputStream;
29 import java.net.URI;
30 import java.util.HashMap;
31 import java.util.Iterator;
32 import java.util.Map;
33 
34 import org.xml.sax.SAXException;
35 
36 import org.apache.commons.io.IOUtils;
37 
38 import org.apache.xmlgraphics.io.TempResourceURIGenerator;
39 
40 import org.apache.fop.apps.FOPException;
41 import org.apache.fop.apps.FOUserAgent;
42 import org.apache.fop.fonts.FontInfo;
43 
44 /**
45  * A simple cached render pages model.
46  * If the page is prepared for later rendering then this saves
47  * the page contents to a file and once the page is resolved
48  * the contents are reloaded.
49  */
50 public class CachedRenderPagesModel extends RenderPagesModel {
51 
52     private Map<PageViewport, URI> pageMap = new HashMap<PageViewport, URI>();
53 
54     /** Base directory to save temporary file in, typically points to the user's temp dir. */
55     private final URI tempBaseURI;
56     private static final TempResourceURIGenerator TEMP_URI_GENERATOR
57             = new TempResourceURIGenerator("cached-pages");
58 
59     /**
60      * Main Constructor
61      * @param userAgent FOUserAgent object for process
62      * @param outputFormat the MIME type of the output format to use (ex. "application/pdf").
63      * @param fontInfo FontInfo object
64      * @param stream OutputStream
65      * @throws FOPException if the renderer cannot be properly initialized
66      */
CachedRenderPagesModel(FOUserAgent userAgent, String outputFormat, FontInfo fontInfo, OutputStream stream)67     public CachedRenderPagesModel(FOUserAgent userAgent, String outputFormat,
68             FontInfo fontInfo, OutputStream stream) throws FOPException {
69         super(userAgent, outputFormat, fontInfo, stream);
70         tempBaseURI = TEMP_URI_GENERATOR.generate();
71     }
72 
73     /** {@inheritDoc} */
74     @Override
checkPreparedPages(PageViewport newpage, boolean renderUnresolved)75     protected boolean checkPreparedPages(PageViewport newpage, boolean renderUnresolved) {
76         for (Iterator iter = prepared.iterator(); iter.hasNext();) {
77             PageViewport pageViewport = (PageViewport)iter.next();
78             if (pageViewport.isResolved() || renderUnresolved) {
79                 if (pageViewport != newpage) {
80                     try {
81                         // load page from cache
82                         URI tempURI = pageMap.get(pageViewport);
83                         log.debug("Loading page from: " + tempURI);
84                         InputStream inStream = renderer.getUserAgent().getResourceResolver().getResource(tempURI);
85                         ObjectInputStream in = new ObjectInputStream(new BufferedInputStream(inStream));
86                         try {
87                             pageViewport.loadPage(in);
88                         } finally {
89                             IOUtils.closeQuietly(inStream);
90                             IOUtils.closeQuietly(in);
91                         }
92                         pageMap.remove(pageViewport);
93                     } catch (Exception e) {
94                         AreaEventProducer eventProducer = AreaEventProducer.Provider.get(
95                                 renderer.getUserAgent().getEventBroadcaster());
96                         eventProducer.pageLoadError(this, pageViewport.getPageNumberString(), e);
97                     }
98                 }
99 
100                 renderPage(pageViewport);
101                 pageViewport.clear();
102                 iter.remove();
103             } else {
104                 if (!renderer.supportsOutOfOrder()) {
105                     break;
106                 }
107             }
108         }
109         if (newpage != null && newpage.getPage() != null) {
110             savePage(newpage);
111             newpage.clear();
112         }
113         return renderer.supportsOutOfOrder() || prepared.isEmpty();
114     }
115 
116     /**
117      * Save a page.
118      * It saves the contents of the page to a file.
119      *
120      * @param page the page to prepare
121      */
savePage(PageViewport page)122     protected void savePage(PageViewport page) {
123         try {
124             // save page to cache
125             ObjectOutputStream tempstream;
126             String fname = "/fop-page-" + page.getPageIndex() + ".ser";
127             URI tempURI = URI.create(tempBaseURI + fname);
128             OutputStream outStream = renderer.getUserAgent().getResourceResolver().getOutputStream(tempURI);
129             tempstream = new ObjectOutputStream(new BufferedOutputStream(outStream));
130             try {
131                 page.savePage(tempstream);
132             } finally {
133                 IOUtils.closeQuietly(tempstream);
134             }
135             pageMap.put(page, tempURI);
136             if (log.isDebugEnabled()) {
137                 log.debug("Page saved to temporary file: " + tempURI);
138             }
139         } catch (IOException ioe) {
140             AreaEventProducer eventProducer
141                 = AreaEventProducer.Provider.get(
142                     renderer.getUserAgent().getEventBroadcaster());
143             eventProducer.pageSaveError(this, page.getPageNumberString(), ioe);
144         }
145     }
146 
147     /** {@inheritDoc} */
148     @Override
endDocument()149     public void endDocument() throws SAXException {
150         super.endDocument();
151     }
152 }
153 
154