+
−/*
+
− * This Source Code Form is subject to the terms of the Mozilla Public
+
− * License, v. 2.0.  If a copy of the MPL was not distributed with this
+
− * file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
− *
+
− * Copyright 2016 MonetDB B.V.
+
− */
+
−
+
−package nl.cwi.monetdb.embedded;
+
−
+
−import java.util.Arrays;
+
−import java.util.ListIterator;
+
−
+
−/**
+
− * Embedded MonetDB query result.
+
− * The query result columns are not eagerly copied from the native code to Java.
+
− * Instead, they are kept around at MonetDB native C-level, materialised in Java 
+
− * on demand and freed on {@code super.close()}.
+
− *
+
− * @author <a href="mailto:pedro.ferreira@monetdbsolutions.com">Pedro Ferreira</a>
+
− */
+
−public class QueryResultSet extends AbstractQueryResultSet {
+
−
+
−	/**
+
−	 * The query result set columns listing
+
−	 */
+
−    private final QueryResultSetColumn<?>[] columns;
+
−
+
−	protected QueryResultSet(MonetDBEmbeddedConnection connection, long resultPointer,
+
−                             QueryResultSetColumn<?>[] columns, int numberOfRows) {
+
−        super(connection, resultPointer, columns.length, numberOfRows);
+
−        this.columns = columns;
+
−		this.resultPointer = resultPointer;
+
−	}
+
−
+
−    /**
+
−     * Get the query set column values as an Iterable.
+
−     *
+
−     * @return An Iterable over the columns
+
−     */
+
−    @Override
+
−    protected Iterable<AbstractColumn<?>> getIterable() {
+
−        return Arrays.asList(columns);
+
−    }
+
−
+
−    /**
+
−     * Get a columns' values from the result set by index.
+
−     *
+
−     * @param index QueryResultSetColumn index (starting from 0)
+
−     * @return The columns, {@code null} if index not in bounds
+
−     */
+
−    @Override
+
−    @SuppressWarnings("unchecked")
+
−    public <T> QueryResultSetColumn<T> getColumn(int index) {
+
−        return (QueryResultSetColumn<T>) columns[index];
+
−    }
+
−
+
−    /**
+
−     * Fetches rows from the result set.
+
−     *
+
−     * @param startIndex The first row index to retrieve
+
−     * @param endIndex The last row index to retrieve
+
−     * @return The rows as {@code QueryRowsResultSet}
+
−     * @throws MonetDBEmbeddedException If an error in the database occurred
+
−     */
+
−	public QueryRowsResultSet fetchResultSetRows(int startIndex, int endIndex) throws MonetDBEmbeddedException {
+
−        if(endIndex < startIndex) {
+
−            int aux = startIndex;
+
−            startIndex = endIndex;
+
−            endIndex = aux;
+
−        }
+
−        if (startIndex < 0) {
+
−            throw new ArrayIndexOutOfBoundsException("The start index must be larger than 0!");
+
−        } else if (endIndex > this.numberOfRows) {
+
−            throw new ArrayIndexOutOfBoundsException("The index must be smaller than the number of elements in the columns!");
+
−        } else if(startIndex == endIndex) {
+
−            throw new ArrayIndexOutOfBoundsException("Retrieving 0 rows?");
+
−        }
+
−        int numberOfRowsToRetrieve = endIndex - startIndex;
+
−        Object[][] temp = new Object[numberOfRowsToRetrieve][this.numberOfColumns];
+
−		for (int i = 0 ; i < this.numberOfColumns; i++) {
+
−            Object[] nextColumn = this.columns[i].fetchColumnValues(startIndex, endIndex);
+
−            for(int j = 0; j < numberOfRowsToRetrieve ; j++) {
+
−                temp[j][i] = nextColumn[j];
+
−			}
+
−		}
+
−        return new QueryRowsResultSet(this, this.getMappings(), temp);
+
−	}
+
−
+
−    /**
+
−     * Fetches rows from the result set asynchronously.
+
−     *
+
−     * @param startIndex The first row index to retrieve
+
−     * @param endIndex The last row index to retrieve
+
−     * @return The rows as {@code QueryRowsResultSet}
+
−     * @throws MonetDBEmbeddedException If an error in the database occurred
+
−     */
+
−    public QueryRowsResultSet fetchResultSetRowsAsync(int startIndex, int endIndex) throws MonetDBEmbeddedException {
+
−        /* CompletableFuture.supplyAsync(() -> this.fetchResultSetRows(startIndex, endIndex)); */
+
−        throw new UnsupportedOperationException("Must wait for Java 8 :(");
+
−    }
+
−
+
−    /**
+
−     * Fetches the first N rows from the result set.
+
−     *
+
−     * @param n The last row index to retrieve
+
−     * @return The rows as {@code QueryRowsResultSet}
+
−     * @throws MonetDBEmbeddedException If an error in the database occurred
+
−     */
+
−    public QueryRowsResultSet fetchFirstNRowValues(int n) throws MonetDBEmbeddedException {
+
−        return this.fetchResultSetRows(0, n);
+
−    }
+
−
+
−    /**
+
−     * Fetches the first N rows from the result set asynchronously.
+
−     *
+
−     * @param n The last row index to retrieve
+
−     * @return The rows as {@code QueryRowsResultSet}
+
−     * @throws MonetDBEmbeddedException If an error in the database occurred
+
−     */
+
−    public QueryRowsResultSet fetchFirstNRowValuesAsync(int n) throws MonetDBEmbeddedException {
+
−        return this.fetchResultSetRowsAsync(0, n);
+
−    }
+
−
+
−    /**
+
−     * Fetches all rows from the result set.
+
−     *
+
−     * @return The rows as {@code QueryRowsResultSet}
+
−     * @throws MonetDBEmbeddedException If an error in the database occurred
+
−     */
+
−    public QueryRowsResultSet fetchAllRowValues() throws MonetDBEmbeddedException {
+
−        return this.fetchResultSetRows(0, this.numberOfRows);
+
−    }
+
−
+
−    /**
+
−     * Fetches all rows from the result set asynchronously.
+
−     *
+
−     * @return The rows as {@code QueryRowsResultSet}
+
−     * @throws MonetDBEmbeddedException If an error in the database occurred
+
−     */
+
−    public QueryRowsResultSet fetchAllRowValuesAsync() throws MonetDBEmbeddedException {
+
−        return this.fetchResultSetRowsAsync(0, this.numberOfRows);
+
−    }
+
−
+
−    @Override
+
−    public ListIterator<QueryRowsResultSet.QueryResulSetSingleRow> iterator() {
+
−        try {
+
−            return Arrays.asList(this.fetchAllRowValues().getAllRows()).listIterator();
+
−        } catch (MonetDBEmbeddedException ex) {
+
−            return null;
+
−        }
+
−    }
+
−}