pset_triplestore_rdb.java

Jena推理机

/*
  (c) Copyright 2003, 2004, 2005, 2006, 2007 Hewlett-Packard Development Company, LP
  [See end of file]
  $Id: PSet_TripleStore_RDB.java,v 1.57 2007/01/02 11:50:42 andy_seaborne Exp $
*/

package com.hp.hpl.jena.db.impl;

import java.sql.BatchUpdateException;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.util.*;

import com.hp.hpl.jena.db.RDFRDBException;
import com.hp.hpl.jena.db.impl.DriverRDB;
import com.hp.hpl.jena.graph.*;
import com.hp.hpl.jena.shared.*;
import com.hp.hpl.jena.util.iterator.ExtendedIterator;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;

//=======================================================================
/**
* Handles Physical storage for implementing SpecializedGraphs.
* Different PSet classes are needed for different databases and different
* layout schemes.
* <p>
* This class is a base implemention from which database-specific
* drivers can inherit. It is not generic in the sense that it will work
* on any minimal SQL store and so should be treated as if it were
* an abstract class.
* <p>The SQL statements which implement each of the functions are
* loaded in a separate file etc/[layout]_[database].sql from the classpath.
* See {@link SQLCache SQLCache documentation} for more information on the
* format of this file.
* 
* Based on Driver* classes by Dave Reynolds.
*
* @author <a href="mailto:[e-mail]">Harumi Kuno</a>
* @version $Revision: 1.57 $ on $Date: 2007/01/02 11:50:42 $
*/

public  class PSet_TripleStore_RDB implements IPSet {

//=======================================================================
// Cutomization variables

   /**
	* Holds name of AssertedStatement table (defaults to JENA_SYS_AssStatements).
	* Every triple store has at least one tables for AssertedStatements.
	*/
   public String m_tblName = null;
   
    /** The SQL type to use for storing ids (compatible with wrapDBID) */
    protected String ID_SQL_TYPE = null;

    /** Set to true if the insert operations already check for duplications */
    protected boolean SKIP_DUPLICATE_CHECK = false;

    /** Set to true to enable cache of pre-prepared statements */
    protected boolean CACHE_PREPARED_STATEMENTS = true;

	/** The table of sql driver statements */
	protected SQLCache m_sql = null;
	
//=======================================================================
// Internal variables

    /** default size for literal and resource caches */
    protected final static int DEFAULT_CACHE = 1000;

    /** Cache of literals */
    protected ICache literalCache = new SimpleCache(DEFAULT_CACHE);

    /** Cache of resources */
    protected ICache resourceCache = new SimpleCache(DEFAULT_CACHE);
	
	/** 
	 * The IRDBDriver for the database.	 
	 */
	protected IRDBDriver m_driver = null;
	
//=======================================================================
// Constructors and accessors

    /**
     * Constructor.
     */
    public PSet_TripleStore_RDB(){
    }
    	    
	/**
	 * Link an existing instance of the IPSet to a specific driver
	 */
	public void setDriver(IRDBDriver driver) throws RDFRDBException {
		m_driver = driver;
	}

    protected static Log logger = LogFactory.getLog(PSet_TripleStore_RDB.class);
    
	public void setSQLType(String value) { ID_SQL_TYPE = value; }
	public void setSkipDuplicateCheck(boolean value) { SKIP_DUPLICATE_CHECK = value;}
	public void setSQLCache(SQLCache cache ) { m_sql = cache; }
	public SQLCache getSQLCache() { return m_sql; }
	public void setCachePreparedStatements(boolean value) { CACHE_PREPARED_STATEMENTS = value; }
	
	
	/**
	 * Sets m_tblName variable.
	 * @param tblName the name of the Statement Table
	 */
	public void setTblName(String tblName){
		m_tblName = tblName;
	}
	
	/**
	 * Accessor for m_tblName.
	 * @return name of the Statement table.
	 */
	public String getTblName() {
		return m_tblName;
	}
	

	/**
	 * Close this PSet
	 */
	public void close() {
		// no need to do anything here for now
	}
	
	/**
	 * @return the database driver.
	 */

	public IRDBDriver driver() {
		return m_driver;
	}

    
    /**
     * Remove all RDF information about this pset from a database.
     */
    public void cleanDB() {
    	
    	// drop my own table(s)
    	try {
    		m_sql.runSQLGroup("dropStatementTable",getTblName());
    	} catch (SQLException e) {
			logger.warn( "Problem dropping table " + getTblName(), e );
			throw new RDFRDBException("Failed to drop table ", e);
		}
    		        
    }

     /**
      * Printable name for the driver configuration
      */
     public String toString() {
        return this.getClass().getPackage().getName();
     }
     
	/**
	 * Fetch a literal from the cache just knowing its literal rdb-id.
	 * If it is not in the cache, do not attempt to retrieve it from the database.
	 */
	public Node_Literal getLiteralFromCache(IDBID id) {
		return (Node_Literal) literalCache.get(id);
	}

    /**
     * Convert the raw SQL object used to store a database identifier into a java object
     * which meets the IDBID interface.
     */
    public IDBID wrapDBID(Object id) throws RDFRDBException {
        if (id instanceof Number) {
            return new DBIDInt(((Number)id).intValue());
        } else if (id == null) {
            return null;
        } else {
            throw new RDFRDBException("Unexpected DB identifier type: " + id);
            //return null;
        }
    }
    
	/** 
	 * Compute the number of rows in a table.
	 * 
	 * @return int count.
	 */
	public int rowCount(int gid) {
	String tName = getTblName();
	int result = 0;
	ResultSet rs=null;

	try {
		 String op = "getRowCount"; 
		 PreparedStatement ps = m_sql.getPreparedSQLStatement(op,tName);
		 ps.setInt(1, gid);
		 rs = ps.executeQuery();
	     while ( rs.next() ) result = rs.getInt(1); 
		m_sql.returnPreparedSQLStatement(ps);
	} catch (SQLException e) {
	   logger.debug("tried to count rows in " + tName);
	   logger.debug("Caught exception: ", e);
           throw new JenaException("Exception during database access", e);    // Rethrow in case there is a recovery option
	} finally {
		if (rs != null)
				try {
					rs.close();
				} catch (SQLException e1) {
					throw new RDFRDBException("Failed to get last inserted ID: " + e1);
				}
	}
	return result;
	}

	//=======================================================================
// Patched functions to adapt to oracle jdbc driver expectations

	/**
	 * Convert the current row of a result set from a ResultSet
	 * to a Triple.
	 * Expects row to contain:
	 *    S.SubjRes, S.PropRes, S.ObjRes, S.ObjStr, S.ObjLiteral
	 * @param rs the resultSet to be processed.
	 */
	public Triple extractTripleFromRowData(
		String subj,
		String pred,
		String obj) {
		
		Node subjNode = subj == null ? null : m_driver.RDBStringToNode(subj);
		Node predNode = pred == null ? null : m_driver.RDBStringToNode(pred);
		Node objNode = obj == null ? null : m_driver.RDBStringToNode(obj);

		return ( Triple.create(subjNode, predNode, objNode) );
	}



    /**
     * Wrap up a boolean flag as a object which the jdbc driver can assert into a boolean/short column.
     */
    public Object wrapFlag(boolean flag) {
        return  flag ? new Short((short)1) : new Short((short)0);
    }
    
	/**
	 *
	 * Attempt to remove a statement from an Asserted_Statement table,
	 * if it is present.  Return without error if the statement is not
	 * present.
	 *
	 * @param subj_uri is the URI of the subject
	 * @param pred_uri is the URI of the predicate (property)
	 * @param obj_node is the URI of the object (can be URI or literal)
	 * @param graphID is the ID of the graph
	 * @param complete is true if this handler is capable of adding this triple.
	 *
	 **/
  public void deleteTriple(Triple t, IDBID graphID) {
  	deleteTriple(t, graphID, false, null);
  }
  	
  /**
   *
   * Attempt to remove a statement from an Asserted_Statement table,
   * if it is present.  Return without error if the statement is not
   * present.
   *
   * @param subj_uri is the URI of the subject
   * @param pred_uri is the URI of the predicate (property)
   * @param obj_node is the URI of the object (can be URI or literal)
   * @param graphID is the ID of the graph
   * @param complete is true if this handler is capable of adding this triple.
   *
   **/
	public void deleteTriple(Triple t, IDBID graphID, boolean isBatch,
		Hashtable batchedPreparedStatements) {
			deleteTripleAR(t,graphID,null,isBatch,batchedPreparedStatements);
		}
	/**
	 *
	 * Attempt to remove a statement from an Asserted_Statement table,
	 * if it is present.  Return without error if the statement is not
	 * present.
	 *
	 * @param subj_uri is the URI of the subject
	 * @param pred_uri is the URI of the predicate (property)
	 * @param obj_node is the URI of the object (can be URI or literal)
	 * @param stmtURI is the URI of the statement if reified, null for asserted
	 * @param graphID is the ID of the graph
	 * @param complete is true if this handler is capable of adding this triple.
	 *
	 **/
public void deleteTripleAR(
	Triple t,
	IDBID graphID,
	Node reifNode,
	boolean isBatch,
	Hashtable batchedPreparedStatements) {
	boolean isReif = reifNode != null;

	String subj =
		t.getSubject().equals(Node.NULL) ? null : m_driver.nodeToRDBString(t.getSubject(),false);
	String pred =
		t.getPredicate().equals(Node.NULL) ? null : m_driver.nodeToRDBString(t.getPredicate(),false);
	String obj =
		t.getObject() == Node.ANY ? null : m_driver.nodeToRDBString(t.getObject(),false);
//	String gid = graphID.getID().toString();
	int gid = ((DBIDInt) graphID).getIntID();
	int argc = 1;
	String stmtStr;
	
	if ((subj == null) || (pred == null) || (obj == null)) {
//		throw new JenaException("Attempt to delete triple with missing values");
//		used to think this was an exception. i guess it's not.
		return;
	}

	// get statement string	   	   
	PreparedStatement ps = null;
	stmtStr = isReif ? "deleteReified" : "deleteStatement";
	try {
		ps =
			getPreparedStatement(
				stmtStr,
				getTblName(),
				isBatch,
				batchedPreparedStatements);
		//ps.clearParameters();

	} catch (SQLException e1) {
	    logger.debug( "SQLException caught " + e1.getErrorCode(), e1);
            throw new JenaException("Exception during database access", e1);    // Rethrow in case there is a recovery option
	}

	// now fill in parameters
	try {
		ps.setString(argc++, subj);
		ps.setString(argc++, pred);
		ps.setString(argc++, obj);

		ps.setInt(argc++, gid);

		if (isReif) {
			String stmtURI = m_driver.nodeToRDBString(reifNode,false);
			ps.setString(argc++, stmtURI);
			ps.setString(argc++,"T");
		}
	} catch (SQLException e1) {
	    logger.debug("(in delete) SQLException caught ", e1);
            throw new JenaException("Exception during database access", e1);    // Rethrow in case there is a recovery option
	}

	try {
		if (isBatch) {
			ps.addBatch();
		} else {
			ps.executeUpdate();
			m_sql.returnPreparedSQLStatement(ps);
		}
	} catch (SQLException e1) {
		logger.error("Exception executing delete: ", e1);
                throw new JenaException("Exception during database access", e1);    // Rethrow in case there is a recovery option
	}
}

		/**
		 *
		 * Attempt to store a statement into an Asserted_Statement table.
		 *
		 * @param subj_uri is the URI of the subject
		 * @param pred_uri is the URI of the predicate (property)
		 * @param obj_node is the URI of the object (can be URI or literal)
		 * @param graphID is the ID of the graph
		 * @param complete is true if this handler is capable of adding this triple.
		 *
		 **/
	  public void storeTriple(Triple t, IDBID graphID) {
	  	storeTriple(t,graphID,false, null);
	  }
	  
	  /**
	   * Given an operation name, a table name, whether or not this operation is part of a batched update, and
	   * a table of batched prepared statements, find or create an appropriate PreparedStatement.
	   * 
	   * @param op
	   * @param tableName
	   * @param isBatch
	   * @param batchedPreparedStatements
	   * @return the prepared statement
	   * @throws SQLException
	   */
	  public PreparedStatement getPreparedStatement(String op, 
	  				String tableName, 
	  				boolean isBatch, 
	  				Hashtable batchedPreparedStatements) throws SQLException {
	  	PreparedStatement ps = null;
		String opname = SQLCache.concatOpName(op,tableName);
		if (isBatch) {
			ps = (PreparedStatement) batchedPreparedStatements.get(opname);
			if (ps == null) {
				ps = m_sql.getPreparedSQLStatement(op,tableName);
				batchedPreparedStatements.put(opname,ps);
			}
		} else {
			ps = m_sql.getPreparedSQLStatement(op,tableName);
		}
	 	 
		if (ps == null) {
			logger.error("prepared statement not found for " + opname);
		}
		return ps;
	  }


		/**
		 *
		 * Attempt to store a statement into an Asserted_Statement table.
		 *
		 * @param subj_uri is the URI of the subject
		 * @param pred_uri is the URI of the predicate (property)
		 * @param obj_node is the URI of the object (can be URI or literal)
		 * @param graphID is the ID of the graph
		 * @param isBatch is true if this request is part of a batch operation.
		 *
		 **/
	  public void storeTriple(Triple t, 
	  						IDBID graphID,
	  						boolean isBatch, 
	  						Hashtable batchedPreparedStatements) {
	  		 storeTripleAR(t,graphID,null,false,isBatch,batchedPreparedStatements);
	  }
	  
		/**
		 *
		 * Attempt to store a statement into an Asserted_Statement table.
		 *
		 * @param subj_uri is the URI of the subject
		 * @param pred_uri is the URI of the predicate (property)
		 * @param obj_node is the URI of the object (can be URI or literal)
		 * @param stmtURI is the URI of the statement if reified, null for asserted
		 * @param hasType is true if the hasType flag should be set for a reified stmt 
		 * @param graphID is the ID of the graph
		 * @param isBatch is true if this request is part of a batch operation.
		 *
		 **/
	public void storeTripleAR(
		Triple t,
		IDBID graphID,
		Node reifNode,
		boolean hasType,
		boolean isBatch,
		Hashtable batchedPreparedStatements) {