/src/edu/ucsb/nceas/metacat/DBSAXHandler.java - Diff - Metacat - Ecoinformatics Redmine

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Revision 471

Added by bojilova over 23 years ago

Separate thread used for writing into xml_index table.
This cut the time of the response on insert almost in half.
The tread is started afterwards
(on end of document parsing and inserting into xml_nodes) from
DBSAXHandler and uses new(separate) db connection.
But I did not find a good way to show the work done of that thread.

     import java.sql.*;
     import java.util.Stack;
     import java.util.Vector;
     import java.util.Enumeration;
     import java.util.EmptyStackException;
     import org.xml.sax.Attributes;
-...
      * call when processing the XML stream and generating events
      */
     public class DBSAXHandler extends DefaultHandler
                               implements LexicalHandler, DeclHandler {
                               implements LexicalHandler, DeclHandler, Runnable {
        private boolean	atFirstElement;
        private boolean	processingDTD;
-...
        private String 	doctype;
        private String 	systemid;
        private boolean 	stackCreated = false;
        private Stack 	nodeStack;
        private Connection	conn = null;
        private Stack 	  nodeStack;
        private Vector   nodeIndex;
        private Connection	  conn = null;
        private DocumentImpl currentDocument;
        private DBSAXNode    rootNode;
        private String       action = null;
        private String       docid = null;
        private String       user = null;
        private String   action = null;
        private String   docid = null;
        private String   user = null;
        private Thread   xmlIndex;
        private boolean endDocument = false;
        private static final int MAXDATACHARS = 4000;
        private static final int MAXTITLELEN = 1000;
-...
          // if it doesn't already exist
          if (!stackCreated) {
            nodeStack = new Stack();
            nodeIndex = new Vector();
            stackCreated = true;
+         }
+       }
-...
          this.action = action;
          this.docid = docid;
          this.user = user;
          this.xmlIndex = new Thread(this);
          //this.xmlIndex.setPriority(Thread.MIN_PRIORITY);
+       }
        /** SAX Handler that receives notification of beginning of the document */
-...
        /** SAX Handler that receives notification of end of the document */
        public void endDocument() throws SAXException {
     // NOT NEEDED ANY MORE - use currentDocument.setTitle() from characters(cbuf,start,end)
     //     currentDocument.setTitleFromChildElement();
          MetaCatUtil.debugMessage("end Document");
     // NOT NEEDED ANY MORE - Accession# is generated at the very beginning before the parsing
     //     if ((docid != null) && (!docid.equals(currentDocument.getDocID()))) {
     //       throw (new SAXException("New document ID generated:",
     //           new AccessionNumberGeneratedException(currentDocument.getDocID())));
     //     } else {
     //       throw (new SAXException("New document ID generated:",
     //           new AccessionNumberGeneratedException(currentDocument.getDocID())));
     //     }
          // Starting new thread for writing XML Index.
          // It calls the run method of the thread.
          try {
            xmlIndex.start();
          } catch (NullPointerException e) {
            xmlIndex = null;
            throw new
            SAXException("Problem with starting thread for writing XML Index. " +
                         e.getMessage());
+         }
+       }
        /** SAX Handler that is called at the start of each XML element */
-...
          currentNode = new DBSAXNode(conn, localName, parentNode,
                                      currentDocument.getRootNodeID(),docid,
                                      currentDocument.getDoctype());
          // Add all of the attributes
          for (int i=0; i<atts.getLength(); i++) {
            currentNode.setAttribute(atts.getLocalName(i), atts.getValue(i), docid);
-...
          // Add the node to the stack, so that any text data can be
          // added as it is encountered
          nodeStack.push(currentNode);
          // Add the node to the vector used by thread for writing XML Index
          nodeIndex.addElement(currentNode);
+      }
       // The run method of xmlIndex thread. It writes XML Index for the document.
       public void run () {
         DBSAXNode currNode = null;
         DBSAXNode prevNode = null;
         int step = 0;
         int counter = 0;
         try {
           // Opening separate db connection for writing XML Index
           MetaCatUtil util = new MetaCatUtil();
           Connection conn = util.getConnection();
           conn.setAutoCommit(false);
           // Going through the elements of the document and writing its Index
           Enumeration nodes = nodeIndex.elements();
           while ( nodes.hasMoreElements() ) {
             currNode = (DBSAXNode)nodes.nextElement();
             currNode.updateNodeIndex(conn, docid, currentDocument.getDoctype());
+          }
           conn.commit();
           conn.close();
         } catch (Exception e) {
           try {
             conn.rollback();
             conn.close();
           } catch (SQLException sqle) {}
           System.out.println("Error writing XML Index. " + e.getMessage());
+        }
+      }
       /** SAX Handler that is called for each XML text node */
       public void characters(char[] cbuf, int start, int len) throws SAXException {
          MetaCatUtil.debugMessage("CHARACTERS");

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Revision 471

Added by bojilova over 23 years ago