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16 package org.outerj.daisy.frontend.components.reading;
17
18 import org.apache.cocoon.reading.Reader;
19 import org.apache.cocoon.ProcessingException;
20 import org.apache.cocoon.caching.Cache;
21 import org.apache.cocoon.caching.CachedResponse;
22 import org.apache.cocoon.environment.SourceResolver;
23 import org.apache.cocoon.environment.Request;
24 import org.apache.cocoon.environment.ObjectModelHelper;
25 import org.apache.avalon.framework.parameters.Parameters;
26 import org.apache.avalon.framework.parameters.ParameterException;
27 import org.apache.avalon.framework.service.Serviceable;
28 import org.apache.avalon.framework.service.ServiceManager;
29 import org.apache.avalon.framework.service.ServiceException;
30 import org.apache.excalibur.source.Source;
31 import org.apache.excalibur.source.SourceValidity;
32 import org.apache.excalibur.source.SourceParameters;
33 import org.apache.excalibur.source.impl.validity.ExpiresValidity;
34 import org.xml.sax.SAXException  ;
35
36 import java.io.IOException ;
37 import java.io.OutputStream ;
38 import java.io.InputStream ;
39 import java.io.ByteArrayOutputStream ;
40 import java.util.Map ;
41
42
46 public class CachingReader implements Reader, Serviceable {
47 private ServiceManager serviceManager;
48 private MyCachedResponse cachedResponse;
49 private OutputStream outputStream;
50
51 public void service(ServiceManager serviceManager) throws ServiceException {
52 this.serviceManager = serviceManager;
53 }
54
55 public void generate() throws IOException , SAXException , ProcessingException {
56 outputStream.write(cachedResponse.getResponse());
57 outputStream.flush();
58 }
59
60 public long getLastModified() {
61 return System.currentTimeMillis();
62 }
63
64 public void setup(SourceResolver sourceResolver, Map objectModel, String src, Parameters parameters) throws ProcessingException, SAXException , IOException {
65 Request request = ObjectModelHelper.getRequest(objectModel);
66 SourceParameters sourceParameters = new SourceParameters(request.getQueryString());
67 long expires;
68 try {
69 expires = parameters.getParameterAsLong("expires") * 1000;
70 } catch (ParameterException e) {
71 throw new ProcessingException(e);
72 }
73
74 String cacheKey = "----DAISY-CACHING-READER----" + request.getRequestURI() + "?" + sourceParameters.getQueryString() + "~~" + src;
76
77 Cache cache;
78 try {
79 cache = (Cache) this.serviceManager.lookup(Cache.ROLE);
80 } catch (ServiceException e) {
81 throw new ProcessingException(e);
82 }
83 try {
84 cachedResponse = (MyCachedResponse)cache.get(cacheKey);
85
86 if (cachedResponse != null) {
87 SourceValidity[] validities = cachedResponse.getValidityObjects();
88 ExpiresValidity validity = (ExpiresValidity)validities[0];
89 if (validity.isValid() != SourceValidity.VALID)
90 cachedResponse = null;
91 }
92
93 if (cachedResponse == null) {
94 ExpiresValidity validity = new ExpiresValidity(expires);
95 Source source = sourceResolver.resolveURI(src);
96 byte[] data = readSource(source);
97 cachedResponse = new MyCachedResponse(new SourceValidity[] { validity }, data, source.getMimeType());
98 cache.store(cacheKey, cachedResponse);
99 }
100 } finally {
101 serviceManager.release(cache);
102 }
103 }
104
105 private byte[] readSource(Source source) throws IOException {
106 ByteArrayOutputStream os = new ByteArrayOutputStream ();
107 byte[] buffer = new byte[4096];
108 InputStream inputStream = source.getInputStream();
109 int length;
110 while ((length = inputStream.read(buffer)) > -1) {
111 os.write(buffer, 0, length);
112 }
113 inputStream.close();
114 return os.toByteArray();
115 }
116
117
118 public void setOutputStream(OutputStream outputStream) throws IOException {
119 this.outputStream = outputStream;
120 }
121
122 public String getMimeType() {
123 return cachedResponse.getMimeType();
124 }
125
126 public boolean shouldSetContentLength() {
127 return false;
128 }
129
130 static class MyCachedResponse extends CachedResponse {
131 private String mimeType;
132 public MyCachedResponse(SourceValidity[] sourceValidities, byte[] bytes, String mimeType) {
133 super(sourceValidities, bytes);
134 this.mimeType = mimeType;
135 }
136
137 public String getMimeType() {
138 return mimeType;
139 }
140 }
141 }
142 |
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