result.java

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                            .data, order, way) > 0) {
                        n       = source1;
                        source1 = source1.next;

                        n1--;
                    } else {
                        n       = source0;
                        source0 = source0.next;

                        n0--;
                    }

                    if (target[dest] == null) {
                        target[dest] = n;
                    } else {
                        targetlast[dest].next = n;
                    }

                    targetlast[dest] = n;
                    n.next           = null;
                }
            }
        }

        rRoot = target[0];
        rTail = targetlast[0];
    }

    /**
     *  Method declaration
     *
     * @param  a
     * @param  b
     * @param  order
     * @param  way
     * @return -1, 0, +1
     * @throws  HsqlException
     */
    private int compareRecord(Session session, Object[] a, final Object[] b,
                              final int[] order,
                              int[] way) throws HsqlException {

        int i = Column.compare(session.database.collation, a[order[0]],
                               b[order[0]], metaData.colTypes[order[0]]);

        if (i == 0) {
            for (int j = 1; j < order.length; j++) {
                i = Column.compare(session.database.collation, a[order[j]],
                                   b[order[j]], metaData.colTypes[order[j]]);

                if (i != 0) {
                    return i * way[j];
                }
            }
        }

        return i * way[0];
    }

    /**
     *  Method declaration
     *
     * @param  a
     * @param  b
     * @param  len
     * @return -1, 0, +1
     * @throws  HsqlException
     */
    private int compareRecord(Session session, Object[] a, Object[] b,
                              int len) throws HsqlException {

        for (int j = 0; j < len; j++) {
            int i = Column.compare(session.database.collation, a[j], b[j],
                                   metaData.colTypes[j]);

            if (i != 0) {
                return i;
            }
        }

        return 0;
    }

    /**
     * Result structure used for set/get session attributes
     */
    static Result newSessionAttributesResult() {

        Result r = new Result(ResultConstants.DATA, 7);

        r.metaData.colNames = r.metaData.colLabels = r.metaData.tableNames =
            new String[] {
            "", "", "", "", "", "", ""
        };
        r.metaData.colTypes = new int[] {
            Types.VARCHAR, Types.VARCHAR, Types.INTEGER, Types.INTEGER,
            Types.BOOLEAN, Types.BOOLEAN, Types.BOOLEAN
        };

        return r;
    }

    void write(RowOutputBinary out) throws IOException, HsqlException {

        if (mode == ResultConstants.MULTI) {
            writeMulti(out);

            return;
        }

        int startPos = out.size();

        out.writeSize(0);
        out.writeIntData(mode);
        out.writeIntData(databaseID);
        out.writeIntData(sessionID);

        switch (mode) {

            case ResultConstants.GETSESSIONATTR :
            case ResultConstants.SQLDISCONNECT :
            case ResultConstants.SQLSTARTTRAN :
            case ResultConstants.HSQLRESETSESSION :
                break;

            case ResultConstants.SQLPREPARE :

                // Allows the engine side to fast-fail prepare of non-CALL
                // statement against a CallableStatement object and CALL
                // statement against PreparedStatement.
                //
                // May be useful in the future for other things
                out.writeIntData(getStatementType());
                out.writeString(mainString);
                break;

            case ResultConstants.PREPARE_ACK :
            case ResultConstants.SQLFREESTMT :
                out.writeIntData(statementID);
                break;

            case ResultConstants.SQLEXECDIRECT :
                out.writeIntData(updateCount);
                out.writeIntData(statementID);          // currently unused
                out.writeString(mainString);
                break;

            case ResultConstants.ERROR :
            case ResultConstants.SQLCONNECT :
                out.writeString(mainString);
                out.writeString(subString);
                out.writeString(subSubString);
                out.writeIntData(statementID);
                break;

            case ResultConstants.UPDATECOUNT :
                out.writeIntData(updateCount);
                break;

            case ResultConstants.SQLENDTRAN : {
                int type = getEndTranType();

                out.writeIntData(type);                 // endtran type

                switch (type) {

                    case ResultConstants.SAVEPOINT_NAME_RELEASE :
                    case ResultConstants.SAVEPOINT_NAME_ROLLBACK :
                        out.writeString(mainString);    // savepoint name

                    // default; // do nothing
                }

                break;
            }
            case ResultConstants.BATCHEXECUTE :
            case ResultConstants.BATCHEXECDIRECT :
            case ResultConstants.SQLEXECUTE :
            case ResultConstants.SETSESSIONATTR : {
                out.writeIntData(updateCount);
                out.writeIntData(statementID);

                int l = significantColumns;

                out.writeIntData(l);

                for (int i = 0; i < l; i++) {
                    out.writeType(metaData.colTypes[i]);
                }

                out.writeIntData(size);

                Record n = rRoot;

                while (n != null) {
                    out.writeData(l, metaData.colTypes, n.data, null, null);

                    n = n.next;
                }

                break;
            }
            case ResultConstants.DATA :
            case ResultConstants.PARAM_META_DATA : {
                metaData.write(out, significantColumns);
                out.writeIntData(size);

                Record n = rRoot;

                while (n != null) {
                    out.writeData(significantColumns, metaData.colTypes,
                                  n.data, null, null);

                    n = n.next;
                }

                break;
            }
            case ResultConstants.SQLSETCONNECTATTR : {
                int type = getConnectionAttrType();

                out.writeIntData(type);                 // attr type

                switch (type) {

                    case ResultConstants.SQL_ATTR_SAVEPOINT_NAME :
                        out.writeString(mainString);    // savepoint name

                    // case ResultConstants.SQL_ATTR_AUTO_IPD // always true
                    // default: // throw, but case never happens
                }

                break;
            }
            default :
                throw new HsqlException(
                    Trace.getMessage(
                        Trace.Result_Result, true, new Object[]{
                            new Integer(mode) }), null, 0);
        }

        out.writeIntData(out.size(), startPos);
    }

    void readMultiResult(RowInputBinary in)
    throws HsqlException, IOException {

        mode       = ResultConstants.MULTI;
        databaseID = in.readIntData();
        sessionID  = in.readIntData();

        int count = in.readIntData();

        for (int i = 0; i < count; i++) {

            // Currently required for the outer result, but can simply
            // be ignored for sub-results
            in.readIntData();
            add(new Object[]{ new Result(in) });
        }
    }

    private void writeMulti(RowOutputBinary out)
    throws IOException, HsqlException {

        int startPos = out.size();

        out.writeSize(0);
        out.writeIntData(mode);
        out.writeIntData(databaseID);
        out.writeIntData(sessionID);
        out.writeIntData(size);

        Record n = rRoot;

        while (n != null) {
            ((Result) n.data[0]).write(out);

            n = n.next;
        }

        out.writeIntData(out.size(), startPos);
    }

    /**
     * Convenience method for writing, shared by Server side.
     */
    public static void write(Result r, RowOutputBinary rowout,
                             OutputStream dataout)
                             throws IOException, HsqlException {

        rowout.reset();
        r.write(rowout);
        dataout.write(rowout.getOutputStream().getBuffer(), 0,
                      rowout.getOutputStream().size());
        dataout.flush();
    }

    /**
     * Convenience method for reading, shared by Server side.
     */
    public static Result read(RowInputBinary rowin,
                              DataInput datain)
                              throws IOException, HsqlException {

        int length = datain.readInt();

        rowin.resetRow(0, length);

        byte[] byteArray = rowin.getBuffer();
        int    offset    = 4;

        datain.readFully(byteArray, offset, length - offset);

        return new Result(rowin);
    }

/** @todo fredt - move the messages to Trace.java */
    public Result(Throwable t, String statement) {

        mode      = ResultConstants.ERROR;
        exception = t;

        if (t instanceof HsqlException) {
            HsqlException he = (HsqlException) t;

            subString  = he.getSQLState();
            mainString = he.getMessage();

            if (statement != null) {
                mainString += " in statement [" + statement + "]";
            }

            statementID = he.getErrorCode();
        } else if (t instanceof OutOfMemoryError) {

            // At this point, we've nothing to lose by doing this
            System.gc();

            subString   = "S1000";
            mainString  = "out of memory";
            statementID = Trace.OUT_OF_MEMORY;
        } else {
            subString  = "S1000";
            mainString = Trace.getMessage(Trace.GENERAL_ERROR) + " " + t;

            if (statement != null) {
                mainString += " in statement [" + statement + "]";
            }

            statementID = Trace.GENERAL_ERROR;
        }

        subSubString = "";
    }

    public Throwable getException() {
        return exception;
    }

    public int getStatementID() {
        return statementID;
    }

    void setStatementID(int id) {
        statementID = id;
    }

    public String getMainString() {
        return mainString;
    }

    public void setMainString(String sql) {
        mainString = sql;
    }

    public String getSubString() {
        return subString;
    }

    public void setMaxRows(int count) {
        updateCount = count;
    }

    public int getUpdateCount() {
        return updateCount;
    }

    int getConnectionAttrType() {
        return updateCount;
    }

    void setConnectionAttrType(int type) {
        updateCount = type;
    }

    int getEndTranType() {
        return updateCount;
    }

    void setEndTranType(int type) {
        updateCount = type;
    }

    /** @todo fred - check this repurposing */
    public int[] getUpdateCounts() {
        return metaData.colTypes;
    }

    Object[] getParameterData() {
        return (rRoot == null) ? null
                               : rRoot.data;
    }

    public void setParameterData(Object[] data) {

        if (rRoot == null) {
            rRoot = new Record();
        }

        rRoot.data = data;
        rRoot.next = null;
        rTail      = rRoot;
        size       = 1;
    }

    public void setResultType(int type) {
        mode = type;
    }

    public void setStatementType(int type) {
        updateCount = type;
    }

    public int getStatementType() {
        return updateCount;
    }

    public int getType() {
        return mode;
    }

    public boolean isData() {
        return mode == ResultConstants.DATA;
    }

    public boolean isError() {
        return mode == ResultConstants.ERROR;
    }

    public boolean isUpdateCount() {
        return mode == ResultConstants.UPDATECOUNT;
    }

    public Iterator iterator() {
        return new ResultIterator();
    }

    private class ResultIterator implements Iterator {

        boolean removed;
        int     counter;
        Record  current = rRoot;
        Record  last;

        public boolean hasNext() {
            return counter < size;
        }

        public Object next() {

            if (hasNext()) {
                removed = false;

                if (counter != 0) {
                    last    = current;
                    current = current.next;
                }

                counter++;

                return current.data;
            }

            throw new NoSuchElementException();
        }

        public int nextInt() {
            throw new NoSuchElementException();
        }

        public long nextLong() {
            throw new NoSuchElementException();
        }

        public void remove() {

            if (counter <= size && counter != 0 &&!removed) {
                removed = true;

                if (current == rTail) {
                    rTail = last;
                }

                if (current == rRoot) {
                    current = rRoot = rRoot.next;
                } else {
                    current      = last;
                    last         = null;
                    current.next = current.next.next;
                }

                size--;
                counter--;

                return;
            }

            throw new NoSuchElementException();
        }
    }
}