286N/A

286N/Apackage com.sun.org.apache.xalan.internal.xsltc.dom;

286N/A

286N/Aimport java.io.File;

286N/Aimport java.io.PrintWriter;

286N/Aimport java.net.URL;

286N/Aimport java.net.URLConnection;

286N/Aimport java.net.URLDecoder;

286N/Aimport java.util.Date;

286N/Aimport java.util.Hashtable;

286N/A

286N/Aimport javax.xml.parsers.ParserConfigurationException;

286N/Aimport javax.xml.parsers.SAXParser;

286N/Aimport javax.xml.parsers.SAXParserFactory;

286N/Aimport javax.xml.transform.TransformerException;

286N/Aimport javax.xml.transform.sax.SAXSource;

286N/A

286N/Aimport com.sun.org.apache.xalan.internal.xsltc.DOM;

286N/Aimport com.sun.org.apache.xalan.internal.xsltc.DOMCache;

286N/Aimport com.sun.org.apache.xalan.internal.xsltc.DOMEnhancedForDTM;

286N/Aimport com.sun.org.apache.xalan.internal.xsltc.Translet;

286N/Aimport com.sun.org.apache.xalan.internal.xsltc.runtime.AbstractTranslet;

286N/Aimport com.sun.org.apache.xalan.internal.xsltc.runtime.BasisLibrary;

286N/Aimport com.sun.org.apache.xalan.internal.xsltc.runtime.Constants;

286N/Aimport com.sun.org.apache.xml.internal.utils.SystemIDResolver;

286N/A

286N/Aimport org.xml.sax.InputSource;

286N/Aimport org.xml.sax.SAXException;

286N/Aimport org.xml.sax.XMLReader;

286N/A

286N/Apublic final class DocumentCache implements DOMCache {

286N/A

286N/A private int _size;

286N/A private Hashtable _references;

286N/A private String[] _URIs;

286N/A private int _count;

286N/A private int _current;

286N/A private SAXParser _parser;

286N/A private XMLReader _reader;

286N/A private XSLTCDTMManager _dtmManager;

286N/A

286N/A private static final int REFRESH_INTERVAL = 1000;

286N/A

286N/A /*

286N/A public final class CachedDocument {

286N/A

286N/A // Statistics data

286N/A private long _firstReferenced;

286N/A private long _lastReferenced;

286N/A private long _accessCount;

286N/A private long _lastModified;

286N/A private long _lastChecked;

286N/A private long _buildTime;

286N/A

286N/A // DOM and DTD handler references

286N/A private DOMEnhancedForDTM _dom = null;

286N/A

286N/A /**

286N/A public CachedDocument(String uri) {

286N/A // Initialise statistics variables

286N/A final long stamp = System.currentTimeMillis();

286N/A _firstReferenced = stamp;

286N/A _lastReferenced = stamp;

286N/A _accessCount = 0;

286N/A loadDocument(uri);

286N/A

286N/A _buildTime = System.currentTimeMillis() - stamp;

286N/A }

286N/A

286N/A /**

286N/A public void loadDocument(String uri) {

286N/A

286N/A try {

286N/A final long stamp = System.currentTimeMillis();

286N/A _dom = (DOMEnhancedForDTM)_dtmManager.getDTM(

286N/A new SAXSource(_reader, new InputSource(uri)),

286N/A false, null, true, false);

286N/A _dom.setDocumentURI(uri);

286N/A

286N/A // The build time can be used for statistics for a better

286N/A // priority algorithm (currently round robin).

286N/A final long thisTime = System.currentTimeMillis() - stamp;

286N/A if (_buildTime > 0)

286N/A _buildTime = (_buildTime + thisTime) >>> 1;

286N/A else

286N/A _buildTime = thisTime;

286N/A }

286N/A catch (Exception e) {

286N/A _dom = null;

286N/A }

286N/A }

286N/A

286N/A public DOM getDocument() { return(_dom); }

286N/A

286N/A public long getFirstReferenced() { return(_firstReferenced); }

286N/A

286N/A public long getLastReferenced() { return(_lastReferenced); }

286N/A

286N/A public long getAccessCount() { return(_accessCount); }

286N/A

286N/A public void incAccessCount() { _accessCount++; }

286N/A

286N/A public long getLastModified() { return(_lastModified); }

286N/A

286N/A public void setLastModified(long t){ _lastModified = t; }

286N/A

286N/A public long getLatency() { return(_buildTime); }

286N/A

286N/A public long getLastChecked() { return(_lastChecked); }

286N/A

286N/A public void setLastChecked(long t) { _lastChecked = t; }

286N/A

286N/A public long getEstimatedSize() {

286N/A if (_dom != null)

286N/A return(_dom.getSize() << 5); // ???

286N/A else

286N/A return(0);

286N/A }

286N/A

286N/A }

286N/A

286N/A /**

286N/A public DocumentCache(int size) throws SAXException {

286N/A this(size, null);

286N/A try {

286N/A _dtmManager = (XSLTCDTMManager)XSLTCDTMManager.getDTMManagerClass()

286N/A .newInstance();

286N/A } catch (Exception e) {

286N/A throw new SAXException(e);

286N/A }

286N/A }

286N/A

286N/A /**

286N/A public DocumentCache(int size, XSLTCDTMManager dtmManager) throws SAXException {

286N/A _dtmManager = dtmManager;

286N/A _count = 0;

286N/A _current = 0;

286N/A _size = size;

286N/A _references = new Hashtable(_size+2);

286N/A _URIs = new String[_size];

286N/A

286N/A try {

286N/A // Create a SAX parser and get the XMLReader object it uses

286N/A final SAXParserFactory factory = SAXParserFactory.newInstance();

286N/A try {

286N/A factory.setFeature(Constants.NAMESPACE_FEATURE,true);

286N/A }

286N/A catch (Exception e) {

286N/A factory.setNamespaceAware(true);

286N/A }

286N/A _parser = factory.newSAXParser();

286N/A _reader = _parser.getXMLReader();

286N/A }

286N/A catch (ParserConfigurationException e) {

286N/A BasisLibrary.runTimeError(BasisLibrary.NAMESPACES_SUPPORT_ERR);

286N/A }

286N/A }

286N/A

286N/A /**

286N/A private final long getLastModified(String uri) {

286N/A try {

286N/A URL url = new URL(uri);

286N/A URLConnection connection = url.openConnection();

286N/A long timestamp = connection.getLastModified();

286N/A // Check for a "file:" URI (courtesy of Brian Ewins)

286N/A if (timestamp == 0){ // get 0 for local URI

286N/A if ("file".equals(url.getProtocol())){

286N/A File localfile = new File(URLDecoder.decode(url.getFile()));

286N/A timestamp = localfile.lastModified();

286N/A }

286N/A }

286N/A return(timestamp);

286N/A }

286N/A // Brutal handling of all exceptions

286N/A catch (Exception e) {

286N/A return(System.currentTimeMillis());

286N/A }

286N/A }

286N/A

286N/A /**

286N/A private CachedDocument lookupDocument(String uri) {

286N/A return((CachedDocument)_references.get(uri));

286N/A }

286N/A

286N/A /**

286N/A private synchronized void insertDocument(String uri, CachedDocument doc) {

286N/A if (_count < _size) {

286N/A // Insert out URI in circular buffer

286N/A _URIs[_count++] = uri;

286N/A _current = 0;

286N/A }

286N/A else {

286N/A // Remove oldest URI from reference Hashtable

286N/A _references.remove(_URIs[_current]);

286N/A // Insert our URI in circular buffer

286N/A _URIs[_current] = uri;

286N/A if (++_current >= _size) _current = 0;

286N/A }

286N/A _references.put(uri, doc);

286N/A }

286N/A

286N/A /**

286N/A private synchronized void replaceDocument(String uri, CachedDocument doc) {

286N/A CachedDocument old = (CachedDocument)_references.get(uri);

286N/A if (doc == null)

286N/A insertDocument(uri, doc);

286N/A else

286N/A _references.put(uri, doc);

286N/A }

286N/A

286N/A /**

286N/A public DOM retrieveDocument(String baseURI, String href, Translet trs) {

286N/A CachedDocument doc;

286N/A

286N/A String uri = href;

286N/A if (baseURI != null && !baseURI.equals("")) {

286N/A try {

286N/A uri = SystemIDResolver.getAbsoluteURI(uri, baseURI);

286N/A } catch (TransformerException te) {

286N/A // ignore

286N/A }

286N/A }

286N/A

286N/A // Try to get the document from the cache first

286N/A if ((doc = lookupDocument(uri)) == null) {

286N/A doc = new CachedDocument(uri);

286N/A if (doc == null) return null; // better error handling needed!!!

286N/A doc.setLastModified(getLastModified(uri));

286N/A insertDocument(uri, doc);

286N/A }

286N/A // If the document is in the cache we must check if it is still valid

286N/A else {

286N/A long now = System.currentTimeMillis();

286N/A long chk = doc.getLastChecked();

286N/A doc.setLastChecked(now);

286N/A // Has the modification time for this file been checked lately?

286N/A if (now > (chk + REFRESH_INTERVAL)) {

286N/A doc.setLastChecked(now);

286N/A long last = getLastModified(uri);

286N/A // Reload document if it has been modified since last download

286N/A if (last > doc.getLastModified()) {

286N/A doc = new CachedDocument(uri);

286N/A if (doc == null) return null;

286N/A doc.setLastModified(getLastModified(uri));

286N/A replaceDocument(uri, doc);

286N/A }

286N/A }

286N/A

286N/A }

286N/A

286N/A // Get the references to the actual DOM and DTD handler

286N/A final DOM dom = doc.getDocument();

286N/A

286N/A // The dom reference may be null if the URL pointed to a

286N/A // non-existing document

286N/A if (dom == null) return null;

286N/A

286N/A doc.incAccessCount(); // For statistics

286N/A

286N/A final AbstractTranslet translet = (AbstractTranslet)trs;

286N/A

286N/A // Give the translet an early opportunity to extract any

286N/A // information from the DOM object that it would like.

286N/A translet.prepassDocument(dom);

286N/A

286N/A return(doc.getDocument());

286N/A }

286N/A

286N/A /**

286N/A public void getStatistics(PrintWriter out) {

286N/A out.println("<h2>DOM cache statistics</h2><center><table border=\"2\">"+

286N/A "<tr><td><b>Document URI</b></td>"+

286N/A "<td><center><b>Build time</b></center></td>"+

286N/A "<td><center><b>Access count</b></center></td>"+

286N/A "<td><center><b>Last accessed</b></center></td>"+

286N/A "<td><center><b>Last modified</b></center></td></tr>");

286N/A

286N/A for (int i=0; i<_count; i++) {

286N/A CachedDocument doc = (CachedDocument)_references.get(_URIs[i]);

286N/A out.print("<tr><td><a href=\""+_URIs[i]+"\">"+

286N/A "<font size=-1>"+_URIs[i]+"</font></a></td>");

286N/A out.print("<td><center>"+doc.getLatency()+"ms</center></td>");

286N/A out.print("<td><center>"+doc.getAccessCount()+"</center></td>");

286N/A out.print("<td><center>"+(new Date(doc.getLastReferenced()))+

286N/A "</center></td>");

286N/A out.print("<td><center>"+(new Date(doc.getLastModified()))+

286N/A "</center></td>");

286N/A out.println("</tr>");

286N/A }

286N/A

286N/A out.println("</table></center>");

286N/A }

286N/A}