data/xulugridfile/BufferedHelper.java

package appl.parallel.data.xulugridfile;

import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;
import java.io.EOFException;
import java.io.IOException;
// fuer Doku
import java.io.RandomAccessFile;

/**
 * The methods of this class can be used to efficiently read or write values
 * into a Bytestream (it is e.g. used by the {@link XuluGridFile}).
 *
 * @author Dominik Appl
 *
 */
public class BufferedHelper {

        /**
         * Reads a long value out of the given bytestream Used for buffered reading.
         * Used the code of {@link RandomAccessFile#readInt()}
         *
         * @exception IOException
         *                if an I/O error occurs.
         */
        public static final int readIntFromStream(ByteArrayInputStream input)
                        throws IOException {
                int ch1 = input.read();
                int ch2 = input.read();
                int ch3 = input.read();
                int ch4 = input.read();
                if ((ch1 | ch2 | ch3 | ch4) < 0)
                        throw new EOFException();
                return ((ch1 << 24) + (ch2 << 16) + (ch3 << 8) + (ch4 << 0));
        }

        /**
         * Writes a int value in the the given bytestream Used for buffered writing.
         * Used the code of {@link RandomAccessFile#writeInt(int)}
         *
         * @exception IOException
         *                if an I/O error occurs.
         *
         */
        public static final void writeInt(int v, ByteArrayOutputStream output)
                        throws IOException {
                output.write((v >>> 24) & 0xFF);
                output.write((v >>> 16) & 0xFF);
                output.write((v >>> 8) & 0xFF);
                output.write((v >>> 0) & 0xFF);
                // written += 4;
        }

        /**
         * Writes a <code>long</code> to the stream as eight bytes, high byte
         * first. The write starts at the current position of the file pointer. Used
         * for buffered writing. Used the code of
         * {@link RandomAccessFile#writeLong(long)}
         *
         * @param output the stream to be written to
         * @param v
         *            a <code>long</code> to be written.
         * @exception IOException
         *                if an I/O error occurs.
         */
        public static final void writeLong(long v, ByteArrayOutputStream output)
                        throws IOException {
                output.write((int) (v >>> 56) & 0xFF);
                output.write((int) (v >>> 48) & 0xFF);
                output.write((int) (v >>> 40) & 0xFF);
                output.write((int) (v >>> 32) & 0xFF);
                output.write((int) (v >>> 24) & 0xFF);
                output.write((int) (v >>> 16) & 0xFF);
                output.write((int) (v >>> 8) & 0xFF);
                output.write((int) (v >>> 0) & 0xFF);
                // written += 8;
        }

        /**
         * Reads a long value out of the given {@link ByteArrayInputStream}. Used for buffered
         * reading. Used the code of {@link RandomAccessFile#readLong()} *
         *
         * @exception IOException
         *                if an I/O error occurs.
         */
        public static final long readLongFromStream(ByteArrayInputStream input)
                        throws IOException {
                return ((long) (readIntFromStream(input) << 32) + (readIntFromStream(input) & 0xFFFFFFFFL));
        }

}
1	package appl.parallel.data.xulugridfile;
2
3	import java.io.ByteArrayInputStream;
4	import java.io.ByteArrayOutputStream;
5	import java.io.EOFException;
6	import java.io.IOException;
7	// fuer Doku
8	import java.io.RandomAccessFile;
9
10	/**
11	* The methods of this class can be used to efficiently read or write values
12	* into a Bytestream (it is e.g. used by the {@link XuluGridFile}).
13	*
14	* @author Dominik Appl
15	*
16	*/
17	public class BufferedHelper {
18
19	/**
20	* Reads a long value out of the given bytestream Used for buffered reading.
21	* Used the code of {@link RandomAccessFile#readInt()}
22	*
23	* @exception IOException
24	* if an I/O error occurs.
25	*/
26	public static final int readIntFromStream(ByteArrayInputStream input)
27	throws IOException {
28	int ch1 = input.read();
29	int ch2 = input.read();
30	int ch3 = input.read();
31	int ch4 = input.read();
32	if ((ch1 \| ch2 \| ch3 \| ch4) < 0)
33	throw new EOFException();
34	return ((ch1 << 24) + (ch2 << 16) + (ch3 << 8) + (ch4 << 0));
35	}
36
37	/**
38	* Writes a int value in the the given bytestream Used for buffered writing.
39	* Used the code of {@link RandomAccessFile#writeInt(int)}
40	*
41	* @exception IOException
42	* if an I/O error occurs.
43	*
44	*/
45	public static final void writeInt(int v, ByteArrayOutputStream output)
46	throws IOException {
47	output.write((v >>> 24) & 0xFF);
48	output.write((v >>> 16) & 0xFF);
49	output.write((v >>> 8) & 0xFF);
50	output.write((v >>> 0) & 0xFF);
51	// written += 4;
52	}
53
54	/**
55	* Writes a <code>long</code> to the stream as eight bytes, high byte
56	* first. The write starts at the current position of the file pointer. Used
57	* for buffered writing. Used the code of
58	* {@link RandomAccessFile#writeLong(long)}
59	*
60	* @param output the stream to be written to
61	* @param v
62	* a <code>long</code> to be written.
63	* @exception IOException
64	* if an I/O error occurs.
65	*/
66	public static final void writeLong(long v, ByteArrayOutputStream output)
67	throws IOException {
68	output.write((int) (v >>> 56) & 0xFF);
69	output.write((int) (v >>> 48) & 0xFF);
70	output.write((int) (v >>> 40) & 0xFF);
71	output.write((int) (v >>> 32) & 0xFF);
72	output.write((int) (v >>> 24) & 0xFF);
73	output.write((int) (v >>> 16) & 0xFF);
74	output.write((int) (v >>> 8) & 0xFF);
75	output.write((int) (v >>> 0) & 0xFF);
76	// written += 8;
77	}
78
79	/**
80	* Reads a long value out of the given {@link ByteArrayInputStream}. Used for buffered
81	* reading. Used the code of {@link RandomAccessFile#readLong()} *
82	*
83	* @exception IOException
84	* if an I/O error occurs.
85	*/
86	public static final long readLongFromStream(ByteArrayInputStream input)
87	throws IOException {
88	return ((long) (readIntFromStream(input) << 32) + (readIntFromStream(input) & 0xFFFFFFFFL));
89	}
90
91	}