+
−package nl.cwi.monetdb.responses;
+
−
+
−import nl.cwi.monetdb.mcl.io.AbstractMCLReader;
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−
+
−import java.sql.SQLException;
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−
+
−/**
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− * The DataBlockResponse is tabular data belonging to a
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− * ResultSetResponse.  Tabular data from the server typically looks
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− * like:
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− * <pre>
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− * [ "value",	56	]
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− * </pre>
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− * where each column is separated by ",\t" and each tuple surrounded
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− * by brackets ("[" and "]").  A DataBlockResponse object holds the
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− * raw data as read from the server, in a parsed manner, ready for
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− * easy retrieval.
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− *
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− * This object is not intended to be queried by multiple threads
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− * synchronously. It is designed to work for one thread retrieving
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− * rows from it.  When multiple threads will retrieve rows from this
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− * object, it is possible for threads to get the same data.
+
− */
+
−public class DataBlockResponse implements IResponse {
+
−
+
−    /** The String array to keep the data in */
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−    private final String[] data;
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−    /** The counter which keeps the current position in the data array */
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−    private int pos;
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−    /** Whether we can discard lines as soon as we have read them */
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−    private boolean forwardOnly;
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−
+
−    /**
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−     * Constructs a DataBlockResponse object
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−     * @param size the size of the data array to create
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−     * @param forward whether this is a forward only result
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−     */
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−    DataBlockResponse(int size, boolean forward) {
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−        this.pos = -1;
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−        this.data = new String[size];
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−        this.forwardOnly = forward;
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−    }
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−
+
−    /**
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−     * addLine adds a String of data to this object's data array.
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−     * Note that an IndexOutOfBoundsException can be thrown when an
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−     * attempt is made to add more than the original construction size
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−     * specified.
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−     *
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−     * @param line the header line as String
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−     * @param linetype the line type according to the MAPI protocol
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−     * @return a non-null String if the line is invalid,
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−     *         or additional lines are not allowed.
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−     */
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−    @Override
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−    public String addLine(String line, int linetype) {
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−        if (linetype != AbstractMCLReader.RESULT)
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−            return "protocol violation: unexpected line in data block: " + line;
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−        // add to the backing array
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−        data[++pos] = line;
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−
+
−        // all is well
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−        return null;
+
−    }
+
−
+
−    /**
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−     * Returns whether this Reponse expects more lines to be added
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−     * to it.
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−     *
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−     * @return true if a next line should be added, false otherwise
+
−     */
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−    @Override
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−    public boolean wantsMore() {
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−        // remember: pos is the value already stored
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−        return pos + 1 < data.length;
+
−    }
+
−
+
−    /**
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−     * Indicates that no more header lines will be added to this
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−     * Response implementation.  In most cases this is a redundant
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−     * operation because the data array is full.  However... it can
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−     * happen that this is NOT the case!
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−     *
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−     * @throws SQLException if not all rows are filled
+
−     */
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−    @Override
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−    public void complete() throws SQLException {
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−        if ((pos + 1) != data.length)
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−            throw new SQLException("Inconsistent state detected!  Current block capacity: " + data.length +
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−                    ", block usage: " + (pos + 1) + ".  Did MonetDB send what it promised to?", "M0M10");
+
−    }
+
−
+
−    /**
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−     * Instructs the Response implementation to close and do the
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−     * necessary clean up procedures.
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−     *
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−     */
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−    @Override
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−    public void close() {
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−        // feed all rows to the garbage collector
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−        for (int i = 0; i < data.length; i++) {
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−            data[i] = null;
+
−        }
+
−    }
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−
+
−    /**
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−     * Retrieves the required row.  Warning: if the requested rows
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−     * is out of bounds, an IndexOutOfBoundsException will be
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−     * thrown.
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−     *
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−     * @param line the row to retrieve
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−     * @return the requested row as String
+
−     */
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−    String getRow(int line) {
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−        if (forwardOnly) {
+
−            String ret = data[line];
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−            data[line] = null;
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−            return ret;
+
−        } else {
+
−            return data[line];
+
−        }
+
−    }
+
−}