+
−/*
+
− * 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.resultset;
+
−
+
−import nl.cwi.monetdb.embedded.mapping.AbstractResultTable;
+
−import nl.cwi.monetdb.embedded.env.MonetDBEmbeddedConnection;
+
−import nl.cwi.monetdb.embedded.env.MonetDBEmbeddedException;
+
−import nl.cwi.monetdb.embedded.mapping.MonetDBRow;
+
−import nl.cwi.monetdb.embedded.mapping.MonetDBToJavaMapping;
+
−
+
−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 AbstractResultTable implements Iterable {
+
−
+
−    /**
+
−     * The table C pointer.
+
−     */
+
−    protected long tablePointer;
+
−
+
−    /**
+
−     * The query result set columns listing.
+
−     */
+
−    private final QueryResultSetColumn<?>[] columns;
+
−
+
−    /**
+
−     * The number of rows in the query result.
+
−     */
+
−    protected final int numberOfRows;
+
−
+
−	protected QueryResultSet(MonetDBEmbeddedConnection connection, long tablePointer, QueryResultSetColumn<?>[] columns,
+
−                             int numberOfRows) {
+
−        super(connection);
+
−        this.tablePointer = tablePointer;
+
−        this.numberOfRows = numberOfRows;
+
−        this.columns = columns;
+
−	}
+
−
+
−    @Override
+
−    public int getNumberOfRows() { return this.numberOfRows; }
+
−
+
−    @Override
+
−    public int getNumberOfColumns() { return this.columns.length; }
+
−
+
−    @Override
+
−    protected void closeImplementation() { this.cleanResultSet(this.tablePointer); }
+
−
+
−    @Override
+
−    public String[] getColumnNames() {
+
−        int i = 0;
+
−        String[] result = new String[this.getNumberOfColumns()];
+
−        for(QueryResultSetColumn col : this.columns) {
+
−            result[i] = col.getColumnName();
+
−        }
+
−        return result;
+
−    }
+
−
+
−    @Override
+
−    public String[] getColumnTypes() {
+
−        int i = 0;
+
−        String[] result = new String[this.getNumberOfColumns()];
+
−        for(QueryResultSetColumn col : this.columns) {
+
−            result[i] = col.getColumnInternalTypeName();
+
−        }
+
−        return result;
+
−    }
+
−
+
−    @Override
+
−    public MonetDBToJavaMapping[] getMappings() {
+
−        int i = 0;
+
−        MonetDBToJavaMapping[] result = new MonetDBToJavaMapping[this.getNumberOfColumns()];
+
−        for(QueryResultSetColumn col : this.columns) {
+
−            result[i] = col.getMapping();
+
−        }
+
−        return result;
+
−    }
+
−
+
−    @Override
+
−    public int[] getColumnDigits() {
+
−        int i = 0;
+
−        int[] result = new int[this.getNumberOfColumns()];
+
−        for(QueryResultSetColumn col : this.columns) {
+
−            result[i] = col.getColumnDigits();
+
−        }
+
−        return result;
+
−    }
+
−
+
−    @Override
+
−    public int[] getColumnScales() {
+
−        int i = 0;
+
−        int[] result = new int[this.getNumberOfColumns()];
+
−        for(QueryResultSetColumn col : this.columns) {
+
−            result[i] = col.getColumnScale();
+
−        }
+
−        return result;
+
−    }
+
−
+
−    /**
+
−     * Tells if the connection of this statement result has been closed or not.
+
−     *
+
−     * @return A boolean indicating if the statement result has been cleaned or not
+
−     */
+
−    public boolean isStatementClosed() { return this.tablePointer == 0; }
+
−
+
−    /**
+
−     * Gets a column from the result set by index.
+
−     *
+
−     * @param index QueryResultSetColumn index (starting from 0)
+
−     * @return The column
+
−     */
+
−    @SuppressWarnings("unchecked")
+
−    public <T> QueryResultSetColumn<T> getColumnByIndex(int index) { return (QueryResultSetColumn<T>) columns[index]; }
+
−
+
−    /**
+
−     * Gets a column from the result set by name.
+
−     *
+
−     * @param name QueryResultSetColumn name
+
−     * @return The column
+
−     */
+
−    @SuppressWarnings("unchecked")
+
−    public <T> QueryResultSetColumn<T> getColumnByName(String name) {
+
−        int index = 0;
+
−        for (QueryResultSetColumn col : this.columns) {
+
−            if (col.getColumnName().equals(name)) {
+
−                return (QueryResultSetColumn<T>) this.columns[index];
+
−            }
+
−            index++;
+
−        }
+
−        throw new ArrayIndexOutOfBoundsException("The column is not present in the result set!");
+
−    }
+
−
+
−    /**
+
−     * 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 AbstractRowSet}
+
−     * @throws MonetDBEmbeddedException If an error in the database occurred
+
−     */
+
−	public QueryResultRowSet 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.getNumberOfColumns()];
+
−		for (int i = 0 ; i < this.getNumberOfColumns(); i++) {
+
−            Object[] nextColumn = this.columns[i].fetchColumnValues(startIndex, endIndex);
+
−            for(int j = 0; j < numberOfRowsToRetrieve ; j++) {
+
−                temp[j][i] = nextColumn[j];
+
−			}
+
−		}
+
−        return new QueryResultRowSet(this.getMappings(), temp, this);
+
−	}
+
−
+
−    /**
+
−     * 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 AbstractRowSet}
+
−     * @throws MonetDBEmbeddedException If an error in the database occurred
+
−     */
+
−    /*public CompletableFuture<AbstractRowSet> fetchResultSetRowsAsync(int startIndex, int endIndex) throws MonetDBEmbeddedException {
+
−        return CompletableFuture.supplyAsync(() -> this.fetchResultSetRows(startIndex, endIndex));
+
−    }*/
+
−
+
−    /**
+
−     * Fetches the first N rows from the result set.
+
−     *
+
−     * @param n The last row index to retrieve
+
−     * @return The rows as {@code AbstractRowSet}
+
−     * @throws MonetDBEmbeddedException If an error in the database occurred
+
−     */
+
−    public QueryResultRowSet 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 AbstractRowSet}
+
−     * @throws MonetDBEmbeddedException If an error in the database occurred
+
−     */
+
−    /*public CompletableFuture<AbstractRowSet> fetchFirstNRowValuesAsync(int n) throws MonetDBEmbeddedException {
+
−        return this.fetchResultSetRowsAsync(0, n);
+
−    }*/
+
−
+
−    /**
+
−     * Fetches all rows from the result set.
+
−     *
+
−     * @return The rows as {@code AbstractRowSet}
+
−     * @throws MonetDBEmbeddedException If an error in the database occurred
+
−     */
+
−    public QueryResultRowSet fetchAllRowValues() throws MonetDBEmbeddedException {
+
−        return this.fetchResultSetRows(0, this.numberOfRows);
+
−    }
+
−
+
−    /**
+
−     * Fetches all rows from the result set asynchronously.
+
−     *
+
−     * @return The rows as {@code AbstractRowSet}
+
−     * @throws MonetDBEmbeddedException If an error in the database occurred
+
−     */
+
−    /*public CompletableFuture<AbstractRowSet> fetchAllRowValuesAsync() throws MonetDBEmbeddedException {
+
−        return this.fetchResultSetRowsAsync(0, this.numberOfRows);
+
−    }*/
+
−
+
−    @Override
+
−    public ListIterator<MonetDBRow> iterator() {
+
−        try {
+
−            return Arrays.asList(this.fetchAllRowValues().getAllRows()).listIterator();
+
−        } catch (MonetDBEmbeddedException ex) {
+
−            return null;
+
−        }
+
−    }
+
−
+
−    private native void cleanResultSet(long tablePointer);
+
−}