/* * The contents of this file are subject to the Mozilla Public License * Version 1.1 (the "License"); you may not use this file except in * compliance with the License. You may obtain a copy of the License at * http://www.mozilla.org/MPL/ * * Software distributed under the License is distributed on an "AS IS" * basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See * the License for the specific language governing rights and limitations * under the License. * * The Original Code is the Kowari Metadata Store. * * The Initial Developer of the Original Code is Plugged In Software Pty * Ltd (http://www.pisoftware.com, mailto:info@pisoftware.com). Portions * created by Plugged In Software Pty Ltd are Copyright (C) 2001,2002 * Plugged In Software Pty Ltd. All Rights Reserved. * * Contributor(s): N/A. * * [NOTE: The text of this Exhibit A may differ slightly from the text * of the notices in the Source Code files of the Original Code. You * should use the text of this Exhibit A rather than the text found in the * Original Code Source Code for Your Modifications.] * */ package org.mulgara.store.tuples; // Java 2 standard packages import java.util.*; // Log4J import org.apache.log4j.Logger; // Locally written packages import org.mulgara.query.Cursor; import org.mulgara.query.TuplesException; /** * Logical disjunction. The append is performed by iterating through the * operands in the order given. It requires that the operands be * union-compatible (i.e. matching variable lists). The result will have no sort * order. * * @created 2003-01-10 * * @author <a href="http://staff.pisoftware.com/raboczi">Simon Raboczi</a> * * @version $Revision: 1.9 $ * * @modified $Date: 2005/01/05 04:59:10 $ * * @maintenanceAuthor $Author: newmana $ * * @company <A href="mailto:info@PIsoftware.com">Plugged In Software</A> * * @copyright © 2003 <A href="http://www.PIsoftware.com/">Plugged In * Software Pty Ltd</A> * * @licence <a href="{@docRoot}/../../LICENCE">Mozilla Public License v1.1</a> */ class UnorderedAppend extends AbstractTuples { /** Logger. */ @SuppressWarnings("unused") private final static Logger logger = Logger.getLogger(UnorderedAppend.class); /** * The propositions to conjoin. */ private final Tuples[] operands; /** * The operand currently being iterated through. */ private int operand; /** * Description of the Field */ private long[] prefix; /** * Description of the Field */ private int suffixTruncation = -1; // initial value is fail-fast /** * Disjoin a list of propositions. * * @param operands PARAMETER TO DO * @throws IllegalArgumentException if <var>operands</var> is <code>null</code> * @throws TuplesException EXCEPTION TO DO */ UnorderedAppend(Tuples[] operands) throws TuplesException { // Validate "operands" parameter if (operands == null) { throw new IllegalArgumentException("Null \"operands\" parameter"); } if (operands.length < 1) { operands = new Tuples[] { TuplesOperations.empty()}; } // Initialize fields this.operands = clone(operands); setVariables(operands[0].getVariables()); for (int i = 1; i < operands.length; i++) { if (!Arrays.equals(getVariables(), operands[i].getVariables())) { throw new TuplesException("Mismatched variables, operand 0 " + Arrays.asList(getVariables()) + " and operand " + i + " " + Arrays.asList(operands[i].getVariables())); } } } /** * CONSTRUCTOR UnorderedAppend TO DO * * @param unorderedAppend PARAMETER TO DO */ private UnorderedAppend(UnorderedAppend unorderedAppend) { setVariables(unorderedAppend.getVariables()); operands = clone(unorderedAppend.operands); operand = unorderedAppend.operand; prefix = unorderedAppend.prefix; suffixTruncation = unorderedAppend.suffixTruncation; } /** * Gets the ColumnValue attribute of the UnorderedAppend object * * @param column PARAMETER TO DO * @return The ColumnValue value * @throws TuplesException EXCEPTION TO DO */ public long getColumnValue(int column) throws TuplesException { assert(operand >= 0) || (operand < operands.length):"No column " + column; return operands[operand].getColumnValue(column); } /** * Gets the RowCount attribute of the UnorderedAppend object * * @return The RowCount value * @throws TuplesException EXCEPTION TO DO */ public long getRowCount() throws TuplesException { rowCount = 0; for (int i = 0; i < operands.length; i++) { rowCount += operands[i].getRowCount(); if (rowCount < 0) return Long.MAX_VALUE; } return rowCount; } public long getRowUpperBound() throws TuplesException { long bound = 0; for (int i = 0; i < operands.length; i++) { bound += operands[i].getRowUpperBound(); if (bound < 0) return Long.MAX_VALUE; } return bound; } public long getRowExpectedCount() throws TuplesException { long bound = 0; for (int i = 0; i < operands.length; i++) { bound += operands[i].getRowExpectedCount(); if (bound < 0) return Long.MAX_VALUE; } return bound; } public int getRowCardinality() throws TuplesException { if (rowCardinality != -1) return rowCardinality; if (rowCount > 1) { rowCardinality = Cursor.MANY; } else { switch ((int) rowCount) { case 0: rowCardinality = Cursor.ZERO; break; case 1: rowCardinality = Cursor.ONE; break; case -1: for (Tuples op: operands) { Tuples temp = (Tuples)op.clone(); int tc = temp.getRowCardinality(); temp.close(); if (tc == Cursor.ZERO) { if (rowCardinality == -1) rowCardinality = Cursor.ZERO; } else if (tc == Cursor.ONE) { if (rowCardinality == Cursor.ONE) { rowCardinality = Cursor.MANY; return rowCardinality; } assert rowCardinality != Cursor.MANY; rowCardinality = Cursor.ONE; } else { assert tc == Cursor.MANY; rowCardinality = tc; return rowCardinality; } } break; default: throw new TuplesException("Illegal rowCount " + rowCount); } } return rowCardinality; } public boolean isEmpty() throws TuplesException { for (Tuples op : operands) { if (!op.isEmpty()) return false; } return true; } public boolean isColumnEverUnbound(int column) throws TuplesException { assert(operand >= 0) || (operand < operands.length):"No column " + column; for (int i = 0; i < operands.length; i++) { if (operands[i].isColumnEverUnbound(column)) { return true; } } return false; } public boolean hasNoDuplicates() { return false; } /** * @return whether any operand is unconstrained * @throws TuplesException EXCEPTION TO DO */ public boolean isUnconstrained() throws TuplesException { for (int i = 0; i < operands.length; i++) { if (operands[i].isUnconstrained()) { return true; } } return false; } public List<Tuples> getOperands() { return Arrays.asList(operands); } // // Methods implementing Tuples // /** * METHOD TO DO * * @param prefix PARAMETER TO DO * @param suffixTruncation PARAMETER TO DO * @throws TuplesException EXCEPTION TO DO */ public void beforeFirst(long[] prefix, int suffixTruncation) throws TuplesException { operands[0].beforeFirst(prefix, suffixTruncation); operand = 0; this.prefix = prefix; this.suffixTruncation = suffixTruncation; } /** * METHOD TO DO * * @return RETURNED VALUE TO DO */ public Object clone() { return new UnorderedAppend(this); } /** * METHOD TO DO * * @throws TuplesException EXCEPTION TO DO */ public void close() throws TuplesException { close(operands); } /** * METHOD TO DO * * @return RETURNED VALUE TO DO * @throws TuplesException EXCEPTION TO DO */ public boolean next() throws TuplesException { if (operand >= operands.length) { return false; } if (!operands[operand].next()) { operand++; if (operand < operands.length) { operands[operand].beforeFirst(prefix, suffixTruncation); } return next(); } else { return true; } } }