+
−/*
+
− * 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.env.MonetDBEmbeddedException;
+
−import nl.cwi.monetdb.embedded.mapping.AbstractColumn;
+
−
+
−/**
+
− * An abstract class for accessing materialised (Java-level) query result columns.
+
− *
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− * @param <A> An array of a Java primitive mapped from a MonetDB column !! Must be a Java array !!
+
− * @author <a href="mailto:pedro.ferreira@monetdbsolutions.com">Pedro Ferreira</a>
+
− */
+
−public abstract class AbstractQueryResultSetColumn<A> extends AbstractColumn {
+
−
+
−    /**
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−     * Internal C pointer of the column,
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−     */
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−    protected long tablePointer;
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−
+
−    /**
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−     * The index of the column.
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−     */
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−    final int resultSetIndex;
+
−
+
−    /**
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−     * The number of rows in this column.
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−     */
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−    protected final int numberOfRows;
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−
+
−    /**
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−     * The index of the first value mapped to a Java class.
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−     */
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−    private int firstRetrievedIndex;
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−
+
−    /**
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−     * The index of the last value mapped to a Java class.
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−     */
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−    private int lastRetrievedIndex;
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−
+
−    /**
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−     * The null values mapping
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−     */
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−    final boolean[] nullValues;
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−
+
−	protected AbstractQueryResultSetColumn(String columnType, long tablePointer, int resultSetIndex, String columnName,
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−                                           int columnDigits, int columnScale, int numberOfRows) {
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−        super(columnType, columnName, columnDigits, columnScale);
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−        this.tablePointer = tablePointer;
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−        this.resultSetIndex = resultSetIndex;
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−        this.numberOfRows = numberOfRows;
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−        this.firstRetrievedIndex = numberOfRows;
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−        this.lastRetrievedIndex = 0;
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−        this.nullValues = new boolean[numberOfRows];
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− 	}
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−
+
−    /**
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−     * Gets the result set index of the column.
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−     *
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−     * @return The result set index of the column
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−     */
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−    public int getResultSetIndex() {
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−        return resultSetIndex;
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−    }
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−
+
−    /**
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−     * Gets the number of rows in this column.
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−     *
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−     * @return The number of rows
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−     */
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−    public int getNumberOfRows() { return this.numberOfRows; }
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−
+
−    protected abstract void fetchMoreData(int startIndex, int endIndex) throws MonetDBEmbeddedException;
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−
+
−    protected abstract A storeNewDataAndGetResult(int startIndex, int numberOfRowsToRetrieve);
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−
+
−    protected abstract Object[] mapValuesToObjectArrayImplementation(int startIndex, int numberOfRowsToRetrieve);
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−
+
−    private int checkBoundsAndFetch(int startIndex, int endIndex) throws MonetDBEmbeddedException {
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−        if(endIndex < startIndex) {
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−            throw new ArrayIndexOutOfBoundsException("The endIndex cannot be smaller than the startIndex!");
+
−        } else 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 set!");
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−        } else if(startIndex == endIndex) {
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−            throw new ArrayIndexOutOfBoundsException("Retrieving 0 values?");
+
−        }
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−        boolean hasToFetch = false;
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−        int numberOfRowsToRetrieve = endIndex - startIndex;
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−        int firstIndexToFetch = Math.min(startIndex, this.firstRetrievedIndex);
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−        int lastIndexToFetch = Math.max(endIndex, this.lastRetrievedIndex);
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−        if(startIndex < this.firstRetrievedIndex) {
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−            this.firstRetrievedIndex = startIndex;
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−            hasToFetch = true;
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−        }
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−        if(endIndex > this.lastRetrievedIndex) {
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−            this.lastRetrievedIndex = endIndex;
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−            hasToFetch = true;
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−        }
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−        if(hasToFetch) {
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−            if(this.tablePointer == 0) {
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−                throw new MonetDBEmbeddedException("Connection closed!");
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−            }
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−            this.fetchMoreData(firstIndexToFetch, lastIndexToFetch);
+
−        }
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−        return numberOfRowsToRetrieve;
+
−    }
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−
+
−    /**
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−     * Maps columns values using the provided Java representation by the query.
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−     *
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−     * @param startIndex The first column index to retrieve
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−     * @param endIndex The last column index to retrieve
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−     * @return The column values as a Java array
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−     * @throws MonetDBEmbeddedException If an error in the database occurred
+
−     */
+
−    public A fetchColumnValues(int startIndex, int endIndex) throws MonetDBEmbeddedException {
+
−        int numberOfRowsToRetrieve = this.checkBoundsAndFetch(startIndex, endIndex);
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−        return this.storeNewDataAndGetResult(startIndex, numberOfRowsToRetrieve);
+
−    }
+
−
+
−    /**
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−     * Maps columns values using the provided Java representation by the query asynchronously.
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−     *
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−     * @param startIndex The first column index to retrieve
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−     * @param endIndex The last column index to retrieve
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−     * @return The column values as a Java array
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−     * @throws MonetDBEmbeddedException If an error in the database occurred
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−     */
+
−    /*@SuppressWarnings("unchecked")
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−    public CompletableFuture<T[]> fetchColumnValuesAsync(int startIndex, int endIndex) throws MonetDBEmbeddedException {
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−        return this.fetchColumnValuesAsync(startIndex, endIndex, (Class<T>) this.mapping.getJavaClass());
+
−    }*/
+
−
+
−    /**
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−     * Maps the first N column values using the provided Java representation by the query.
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−     *
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−     * @param n The last column index to map
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−     * @return The column values as a Java array
+
−     * @throws MonetDBEmbeddedException If an error in the database occurred
+
−     */
+
−    public A fetchFirstNColumnValues(int n) throws MonetDBEmbeddedException {
+
−        return this.fetchColumnValues(0, n);
+
−    }
+
−
+
−    /**
+
−     * Maps the first N column values using the provided Java representation by the query asynchronously.
+
−     *
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−     * @param n The last column index to map
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−     * @return The column values as a Java array
+
−     * @throws MonetDBEmbeddedException If an error in the database occurred
+
−     */
+
−    /*public CompletableFuture<T[]> fetchFirstNColumnValuesAsync(int n) throws MonetDBEmbeddedException {
+
−        return this.fetchColumnValuesAsync(0, n);
+
−    }*/
+
−
+
−    /**
+
−     * Maps all column values using the provided Java representation by the query.
+
−     *
+
−     * @return The column values as a Java array
+
−     * @throws MonetDBEmbeddedException If an error in the database occurred
+
−     */
+
−    public A fetchAllColumnValues() throws MonetDBEmbeddedException {
+
−        return this.fetchColumnValues(0, this.numberOfRows);
+
−    }
+
−
+
−    /**
+
−     * Maps all column values using the provided Java representation by the query asynchronously.
+
−     *
+
−     * @return The column values as a Java array
+
−     * @throws MonetDBEmbeddedException If an error in the database occurred
+
−     */
+
−    /*public CompletableFuture<T[]> fetchAllColumnValuesAsync() throws MonetDBEmbeddedException {
+
−        return this.fetchColumnValuesAsync(0, this.numberOfRows);
+
−    }*/
+
−
+
−    /**
+
−     * Checks if column indexes are null
+
−     *
+
−     * @param startIndex The first column index to check
+
−     * @param endIndex The last column index to check
+
−     * @return If the index is null or not
+
−     */
+
−    public boolean[] checkIfIndexesAreNull(int startIndex, int endIndex) throws MonetDBEmbeddedException {
+
−        int numberOfRowsToRetrieve = this.checkBoundsAndFetch(startIndex, endIndex);
+
−        boolean[] res = new boolean[numberOfRowsToRetrieve];
+
−        System.arraycopy(this.nullValues, startIndex, res, 0, numberOfRowsToRetrieve);
+
−        return res;
+
−    }
+
−
+
−    /**
+
−     * Maps values to a Java Object array while mapping null values as well.
+
−     *
+
−     * @param startIndex The first column index to map
+
−     * @param endIndex The last column index to map
+
−     * @return The mapped Java array
+
−     */
+
−    public Object[] mapValuesToObjectArray(int startIndex, int endIndex) throws MonetDBEmbeddedException {
+
−        int numberOfRowsToRetrieve = this.checkBoundsAndFetch(startIndex, endIndex);
+
−        return this.mapValuesToObjectArrayImplementation(startIndex, numberOfRowsToRetrieve);
+
−    }
+
−}