001/**
002 * Licensed to the Apache Software Foundation (ASF) under one or more
003 * contributor license agreements.  See the NOTICE file distributed with
004 * this work for additional information regarding copyright ownership.
005 * The ASF licenses this file to You under the Apache License, Version 2.0
006 * (the "License"); you may not use this file except in compliance with
007 * the License.  You may obtain a copy of the License at
008 *
009 *      http://www.apache.org/licenses/LICENSE-2.0
010 *
011 * Unless required by applicable law or agreed to in writing, software
012 * distributed under the License is distributed on an "AS IS" BASIS,
013 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
014 * See the License for the specific language governing permissions and
015 * limitations under the License.
016 */
017package org.apache.activemq.util;
018
019import java.io.DataOutput;
020import java.io.IOException;
021import java.io.OutputStream;
022import java.io.UTFDataFormatException;
023
024/**
025 * Optimized ByteArrayOutputStream
026 * 
027 * 
028 */
029public final class DataByteArrayOutputStream extends OutputStream implements DataOutput {
030    private static final int DEFAULT_SIZE = 2048;
031    private byte buf[];
032    private int pos;
033
034    /**
035     * Creates a new byte array output stream, with a buffer capacity of the
036     * specified size, in bytes.
037     * 
038     * @param size the initial size.
039     * @exception IllegalArgumentException if size is negative.
040     */
041    public DataByteArrayOutputStream(int size) {
042        if (size < 0) {
043            throw new IllegalArgumentException("Invalid size: " + size);
044        }
045        buf = new byte[size];
046    }
047
048    /**
049     * Creates a new byte array output stream.
050     */
051    public DataByteArrayOutputStream() {
052        this(DEFAULT_SIZE);
053    }
054
055    /**
056     * start using a fresh byte array
057     * 
058     * @param size
059     */
060    public void restart(int size) {
061        buf = new byte[size];
062        pos = 0;
063    }
064
065    /**
066     * start using a fresh byte array
067     */
068    public void restart() {
069        restart(DEFAULT_SIZE);
070    }
071
072    /**
073     * Get a ByteSequence from the stream
074     * 
075     * @return the byte sequence
076     */
077    public ByteSequence toByteSequence() {
078        return new ByteSequence(buf, 0, pos);
079    }
080
081    /**
082     * Writes the specified byte to this byte array output stream.
083     * 
084     * @param b the byte to be written.
085     */
086    public void write(int b) {
087        int newcount = pos + 1;
088        ensureEnoughBuffer(newcount);
089        buf[pos] = (byte)b;
090        pos = newcount;
091    }
092
093    /**
094     * Writes <code>len</code> bytes from the specified byte array starting at
095     * offset <code>off</code> to this byte array output stream.
096     * 
097     * @param b the data.
098     * @param off the start offset in the data.
099     * @param len the number of bytes to write.
100     */
101    public void write(byte b[], int off, int len) {
102        if (len == 0) {
103            return;
104        }
105        int newcount = pos + len;
106        ensureEnoughBuffer(newcount);
107        System.arraycopy(b, off, buf, pos, len);
108        pos = newcount;
109    }
110
111    /**
112     * @return the underlying byte[] buffer
113     */
114    public byte[] getData() {
115        return buf;
116    }
117
118    /**
119     * reset the output stream
120     */
121    public void reset() {
122        pos = 0;
123    }
124
125    /**
126     * Set the current position for writing
127     * 
128     * @param offset
129     */
130    public void position(int offset) {
131        ensureEnoughBuffer(offset);
132        pos = offset;
133    }
134
135    public int size() {
136        return pos;
137    }
138
139    public void writeBoolean(boolean v) {
140        ensureEnoughBuffer(pos + 1);
141        buf[pos++] = (byte)(v ? 1 : 0);
142    }
143
144    public void writeByte(int v) {
145        ensureEnoughBuffer(pos + 1);
146        buf[pos++] = (byte)(v >>> 0);
147    }
148
149    public void writeShort(int v) {
150        ensureEnoughBuffer(pos + 2);
151        buf[pos++] = (byte)(v >>> 8);
152        buf[pos++] = (byte)(v >>> 0);
153    }
154
155    public void writeChar(int v) {
156        ensureEnoughBuffer(pos + 2);
157        buf[pos++] = (byte)(v >>> 8);
158        buf[pos++] = (byte)(v >>> 0);
159    }
160
161    public void writeInt(int v) {
162        ensureEnoughBuffer(pos + 4);
163        buf[pos++] = (byte)(v >>> 24);
164        buf[pos++] = (byte)(v >>> 16);
165        buf[pos++] = (byte)(v >>> 8);
166        buf[pos++] = (byte)(v >>> 0);
167    }
168
169    public void writeLong(long v) {
170        ensureEnoughBuffer(pos + 8);
171        buf[pos++] = (byte)(v >>> 56);
172        buf[pos++] = (byte)(v >>> 48);
173        buf[pos++] = (byte)(v >>> 40);
174        buf[pos++] = (byte)(v >>> 32);
175        buf[pos++] = (byte)(v >>> 24);
176        buf[pos++] = (byte)(v >>> 16);
177        buf[pos++] = (byte)(v >>> 8);
178        buf[pos++] = (byte)(v >>> 0);
179    }
180
181    public void writeFloat(float v) throws IOException {
182        writeInt(Float.floatToIntBits(v));
183    }
184
185    public void writeDouble(double v) throws IOException {
186        writeLong(Double.doubleToLongBits(v));
187    }
188
189    public void writeBytes(String s) {
190        int length = s.length();
191        for (int i = 0; i < length; i++) {
192            write((byte)s.charAt(i));
193        }
194    }
195
196    public void writeChars(String s) {
197        int length = s.length();
198        for (int i = 0; i < length; i++) {
199            int c = s.charAt(i);
200            write((c >>> 8) & 0xFF);
201            write((c >>> 0) & 0xFF);
202        }
203    }
204
205    public void writeUTF(String str) throws IOException {
206        int strlen = str.length();
207        int encodedsize = 0;
208        int c;
209        for (int i = 0; i < strlen; i++) {
210            c = str.charAt(i);
211            if ((c >= 0x0001) && (c <= 0x007F)) {
212                encodedsize++;
213            } else if (c > 0x07FF) {
214                encodedsize += 3;
215            } else {
216                encodedsize += 2;
217            }
218        }
219        if (encodedsize > 65535) {
220            throw new UTFDataFormatException("encoded string too long: " + encodedsize + " bytes");
221        }
222        ensureEnoughBuffer(pos + encodedsize + 2);
223        writeShort(encodedsize);
224        int i = 0;
225        for (i = 0; i < strlen; i++) {
226            c = str.charAt(i);
227            if (!((c >= 0x0001) && (c <= 0x007F))) {
228                break;
229            }
230            buf[pos++] = (byte)c;
231        }
232        for (; i < strlen; i++) {
233            c = str.charAt(i);
234            if ((c >= 0x0001) && (c <= 0x007F)) {
235                buf[pos++] = (byte)c;
236            } else if (c > 0x07FF) {
237                buf[pos++] = (byte)(0xE0 | ((c >> 12) & 0x0F));
238                buf[pos++] = (byte)(0x80 | ((c >> 6) & 0x3F));
239                buf[pos++] = (byte)(0x80 | ((c >> 0) & 0x3F));
240            } else {
241                buf[pos++] = (byte)(0xC0 | ((c >> 6) & 0x1F));
242                buf[pos++] = (byte)(0x80 | ((c >> 0) & 0x3F));
243            }
244        }
245    }
246
247    private void ensureEnoughBuffer(int newcount) {
248        if (newcount > buf.length) {
249            byte newbuf[] = new byte[Math.max(buf.length << 1, newcount)];
250            System.arraycopy(buf, 0, newbuf, 0, pos);
251            buf = newbuf;
252        }
253    }
254}