+
−/*
+
− * 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.AbstractColumn;
+
−import nl.cwi.monetdb.embedded.mapping.AbstractResultTable;
+
−import nl.cwi.monetdb.embedded.env.MonetDBEmbeddedConnection;
+
−import nl.cwi.monetdb.embedded.env.MonetDBEmbeddedException;
+
−
+
−import java.util.Arrays;
+
−import java.util.ListIterator;
+
−
+
−/**
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− * Embedded MonetDB query result.
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− * The query result columns are not eagerly copied from the native code to Java.
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− * Instead, they are kept around at MonetDB native C-level, materialised in Java 
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− * on demand and freed on {@code super.close()}.
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− *
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− * @author <a href="mailto:pedro.ferreira@monetdbsolutions.com">Pedro Ferreira</a>
+
− */
+
−public class QueryResultSet extends AbstractResultTable implements Iterable {
+
−
+
−    /**
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−     * Pointer to the native result set.
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−     * We need to keep it around for getting columns.
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−     * The native result set is kept until the the close method is called.
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−     */
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−    protected long resultPointer;
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−
+
−    /**
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−     * The query result set columns listing.
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−     */
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−    private final QueryResultSetColumn<?>[] columns;
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−
+
−    /**
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−     * The number of rows in the query result.
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−     */
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−    protected final int numberOfRows;
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−
+
−	protected QueryResultSet(MonetDBEmbeddedConnection connection, long resultPointer,
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−                             QueryResultSetColumn<?>[] columns, int numberOfRows) {
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−        super(connection);
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−        this.resultPointer = resultPointer;
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−        this.numberOfRows = numberOfRows;
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−        this.columns = columns;
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−	}
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−
+
−    /**
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−     * Close the query data so no more new results can be retrieved.
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−     */
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−    @Override
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−    public void closeImplementation() {
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−        this.cleanupResultInternal(this.resultPointer);
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−        this.resultPointer = 0;
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−    }
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−
+
−    @Override
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−    protected AbstractColumn<?>[] getColumns() { return columns; }
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−
+
−    @Override
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−    public int getNumberOfRows() {
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−        return this.numberOfRows;
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−    }
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−
+
−    @Override
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−    public int getNumberOfColumns() { return this.columns.length; }
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−
+
−    /**
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−     * Tells if the connection of this statement result has been closed or not.
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−     *
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−     * @return A boolean indicating if the statement result has been cleaned or not
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−     */
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−    public boolean isStatementClosed() { return this.resultPointer == 0; }
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−
+
−    /**
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−     * Get a columns' values from the result set by index.
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−     *
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−     * @param index QueryResultSetColumn index (starting from 0)
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−     * @return The columns, {@code null} if index not in bounds
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−     */
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−    @SuppressWarnings("unchecked")
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−    public <T> QueryResultSetColumn<T> getColumn(int index) {
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−        return (QueryResultSetColumn<T>) columns[index];
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−    }
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−
+
−    /**
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−     * Get a columns from the result set by name.
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−     *
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−     * @param name QueryResultSetColumn name
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−     * @return The columns
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−     */
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−    public <T> QueryResultSetColumn<T> getColumn(String name) {
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−        int index = 0;
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−        for (AbstractColumn col : this.columns) {
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−            if (col.getColumnName().equals(name)) {
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−                return this.getColumn(index);
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−            }
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−            index++;
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−        }
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−        throw new ArrayIndexOutOfBoundsException("The columns is not present in the result set!");
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−    }
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−
+
−    /**
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−     * Fetches rows from the result set.
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−     *
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−     * @param startIndex The first row index to retrieve
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−     * @param endIndex The last row index to retrieve
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−     * @return The rows as {@code QueryResultSetRows}
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−     * @throws MonetDBEmbeddedException If an error in the database occurred
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−     */
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−	public QueryResultSetRows fetchResultSetRows(int startIndex, int endIndex) throws MonetDBEmbeddedException {
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−        if(endIndex < startIndex) {
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−            int aux = startIndex;
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−            startIndex = endIndex;
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−            endIndex = aux;
+
−        }
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−        if (startIndex < 0) {
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−            throw new ArrayIndexOutOfBoundsException("The start index must be larger than 0!");
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−        } else if (endIndex > this.numberOfRows) {
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−            throw new ArrayIndexOutOfBoundsException("The index must be smaller than the number of elements in the columns!");
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−        } else if(startIndex == endIndex) {
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−            throw new ArrayIndexOutOfBoundsException("Retrieving 0 rows?");
+
−        }
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−        int numberOfRowsToRetrieve = endIndex - startIndex;
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−        Object[][] temp = new Object[numberOfRowsToRetrieve][this.getNumberOfColumns()];
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−		for (int i = 0 ; i < this.getNumberOfColumns(); i++) {
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−            Object[] nextColumn = this.columns[i].fetchColumnValues(startIndex, endIndex);
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−            for(int j = 0; j < numberOfRowsToRetrieve ; j++) {
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−                temp[j][i] = nextColumn[j];
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−			}
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−		}
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−        return new QueryResultSetRows(this, this.getMappings(), temp);
+
−	}
+
−
+
−    /**
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−     * Fetches rows from the result set asynchronously.
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−     *
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−     * @param startIndex The first row index to retrieve
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−     * @param endIndex The last row index to retrieve
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−     * @return The rows as {@code QueryResultSetRows}
+
−     * @throws MonetDBEmbeddedException If an error in the database occurred
+
−     */
+
−    /*public QueryResultSetRows fetchResultSetRowsAsync(int startIndex, int endIndex) throws MonetDBEmbeddedException {
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−        CompletableFuture.supplyAsync(() -> this.fetchResultSetRows(startIndex, endIndex));
+
−        throw new UnsupportedOperationException("Must wait for Java 8 :(");
+
−    }*/
+
−
+
−    /**
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−     * Fetches the first N rows from the result set.
+
−     *
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−     * @param n The last row index to retrieve
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−     * @return The rows as {@code QueryResultSetRows}
+
−     * @throws MonetDBEmbeddedException If an error in the database occurred
+
−     */
+
−    public QueryResultSetRows 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 QueryResultSetRows}
+
−     * @throws MonetDBEmbeddedException If an error in the database occurred
+
−     */
+
−    /*public QueryResultSetRows fetchFirstNRowValuesAsync(int n) throws MonetDBEmbeddedException {
+
−        return this.fetchResultSetRowsAsync(0, n);
+
−    }*/
+
−
+
−    /**
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−     * Fetches all rows from the result set.
+
−     *
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−     * @return The rows as {@code QueryResultSetRows}
+
−     * @throws MonetDBEmbeddedException If an error in the database occurred
+
−     */
+
−    public QueryResultSetRows fetchAllRowValues() throws MonetDBEmbeddedException {
+
−        return this.fetchResultSetRows(0, this.numberOfRows);
+
−    }
+
−
+
−    /**
+
−     * Fetches all rows from the result set asynchronously.
+
−     *
+
−     * @return The rows as {@code QueryResultSetRows}
+
−     * @throws MonetDBEmbeddedException If an error in the database occurred
+
−     */
+
−    /*public QueryResultSetRows fetchAllRowValuesAsync() throws MonetDBEmbeddedException {
+
−        return this.fetchResultSetRowsAsync(0, this.numberOfRows);
+
−    }*/
+
−
+
−    @Override
+
−    public ListIterator<QueryResultSetRows.QueryResulSetRow> iterator() {
+
−        try {
+
−            return Arrays.asList(this.fetchAllRowValues().getAllRows()).listIterator();
+
−        } catch (MonetDBEmbeddedException ex) {
+
−            return null;
+
−        }
+
−    }
+
−
+
−    private native void cleanupResultInternal(long resultPointer);
+
−}