1.1 --- /dev/null	Thu Jan 01 00:00:00 1970 +0000
     1.2 +++ b/src/ca/randelshofer/SeekableByteArrayOutputStream.java	Wed Oct 26 09:38:27 2011 -0700
     1.3 @@ -0,0 +1,153 @@
     1.4 +/*
     1.5 + * @(#)SeekableByteArrayOutputStream.java  1.0  2010-12-27
     1.6 + * 
     1.7 + * Copyright © 2010 Werner Randelshofer, Immensee, Switzerland.
     1.8 + * All rights reserved.
     1.9 + * 
    1.10 + * You may not use, copy or modify this file, except in compliance with the
    1.11 + * license agreement you entered into with Werner Randelshofer.
    1.12 + * For details see accompanying license terms.
    1.13 + */
    1.14 +
    1.15 +package ca.randelshofer;
    1.16 +
    1.17 +import java.io.ByteArrayOutputStream;
    1.18 +import java.io.IOException;
    1.19 +import java.io.OutputStream;
    1.20 +import java.util.Arrays;
    1.21 +import static java.lang.Math.*;
    1.22 +/**
    1.23 + * {@code SeekableByteArrayOutputStream}.
    1.24 + *
    1.25 + * @author Werner Randelshofer
    1.26 + * @version 1.0 2010-12-27 Created.
    1.27 + */
    1.28 +public class SeekableByteArrayOutputStream extends ByteArrayOutputStream {
    1.29 +
    1.30 +    /**
    1.31 +     * The current stream position.
    1.32 +     */
    1.33 +    private int pos;
    1.34 +
    1.35 +    /**
    1.36 +     * Creates a new byte array output stream. The buffer capacity is
    1.37 +     * initially 32 bytes, though its size increases if necessary.
    1.38 +     */
    1.39 +    public SeekableByteArrayOutputStream() {
    1.40 +	this(32);
    1.41 +    }
    1.42 +
    1.43 +    /**
    1.44 +     * Creates a new byte array output stream, with a buffer capacity of
    1.45 +     * the specified size, in bytes.
    1.46 +     *
    1.47 +     * @param   size   the initial size.
    1.48 +     * @exception  IllegalArgumentException if size is negative.
    1.49 +     */
    1.50 +    public SeekableByteArrayOutputStream(int size) {
    1.51 +        if (size < 0) {
    1.52 +            throw new IllegalArgumentException("Negative initial size: "
    1.53 +                                               + size);
    1.54 +        }
    1.55 +	buf = new byte[size];
    1.56 +    }
    1.57 +
    1.58 +    /**
    1.59 +     * Writes the specified byte to this byte array output stream.
    1.60 +     *
    1.61 +     * @param   b   the byte to be written.
    1.62 +     */
    1.63 +    @Override
    1.64 +    public synchronized void write(int b) {
    1.65 +	int newcount = max(pos + 1, count);
    1.66 +	if (newcount > buf.length) {
    1.67 +            buf = Arrays.copyOf(buf, Math.max(buf.length << 1, newcount));
    1.68 +	}
    1.69 +	buf[pos++] = (byte)b;
    1.70 +	count = newcount;
    1.71 +    }
    1.72 +
    1.73 +    /**
    1.74 +     * Writes <code>len</code> bytes from the specified byte array
    1.75 +     * starting at offset <code>off</code> to this byte array output stream.
    1.76 +     *
    1.77 +     * @param   b     the data.
    1.78 +     * @param   off   the start offset in the data.
    1.79 +     * @param   len   the number of bytes to write.
    1.80 +     */
    1.81 +    @Override
    1.82 +    public synchronized void write(byte b[], int off, int len) {
    1.83 +	if ((off < 0) || (off > b.length) || (len < 0) ||
    1.84 +            ((off + len) > b.length) || ((off + len) < 0)) {
    1.85 +	    throw new IndexOutOfBoundsException();
    1.86 +	} else if (len == 0) {
    1.87 +	    return;
    1.88 +	}
    1.89 +        int newcount = max(pos+len,count);
    1.90 +        if (newcount > buf.length) {
    1.91 +            buf = Arrays.copyOf(buf, Math.max(buf.length << 1, newcount));
    1.92 +        }
    1.93 +        System.arraycopy(b, off, buf, pos, len);
    1.94 +        pos+=len;
    1.95 +        count = newcount;
    1.96 +    }
    1.97 +
    1.98 +    /**
    1.99 +     * Resets the <code>count</code> field of this byte array output
   1.100 +     * stream to zero, so that all currently accumulated output in the
   1.101 +     * output stream is discarded. The output stream can be used again,
   1.102 +     * reusing the already allocated buffer space.
   1.103 +     *
   1.104 +     * @see     java.io.ByteArrayInputStream#count
   1.105 +     */
   1.106 +    @Override
   1.107 +    public synchronized void reset() {
   1.108 +	count = 0;
   1.109 +        pos=0;
   1.110 +    }
   1.111 +
   1.112 +    /**
   1.113 +     * Sets the current stream position to the desired location.  The
   1.114 +     * next read will occur at this location.  The bit offset is set
   1.115 +     * to 0.
   1.116 +     *
   1.117 +     * <p> An <code>IndexOutOfBoundsException</code> will be thrown if
   1.118 +     * <code>pos</code> is smaller than the flushed position (as
   1.119 +     * returned by <code>getflushedPosition</code>).
   1.120 +     *
   1.121 +     * <p> It is legal to seek past the end of the file; an
   1.122 +     * <code>EOFException</code> will be thrown only if a read is
   1.123 +     * performed.
   1.124 +     *
   1.125 +     * @param pos a <code>long</code> containing the desired file
   1.126 +     * pointer position.
   1.127 +     *
   1.128 +     * @exception IndexOutOfBoundsException if <code>pos</code> is smaller
   1.129 +     * than the flushed position.
   1.130 +     * @exception IOException if any other I/O error occurs.
   1.131 +     */
   1.132 +    public void seek(long pos) throws IOException {
   1.133 +        this.pos = (int)pos;
   1.134 +    }
   1.135 +
   1.136 +        /**
   1.137 +     * Returns the current byte position of the stream.  The next write
   1.138 +     * will take place starting at this offset.
   1.139 +     *
   1.140 +     * @return a long containing the position of the stream.
   1.141 +     *
   1.142 +     * @exception IOException if an I/O error occurs.
   1.143 +     */
   1.144 +    public long getStreamPosition() throws IOException {
   1.145 +        return pos;
   1.146 +    }
   1.147 +
   1.148 +    /** Writes the contents of the byte array into the specified output
   1.149 +     * stream.
   1.150 +     * @param out
   1.151 +     */
   1.152 +    public void toOutputStream(OutputStream out) throws IOException {
   1.153 +        out.write(buf, 0, count);
   1.154 +    }
   1.155 +
   1.156 +}