J. Duke | 319a3b9 | 2007-12-01 00:00:00 +0000 | [diff] [blame^] | 1 | /* |
| 2 | * Copyright 2004-2007 Sun Microsystems, Inc. All Rights Reserved. |
| 3 | * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. |
| 4 | * |
| 5 | * This code is free software; you can redistribute it and/or modify it |
| 6 | * under the terms of the GNU General Public License version 2 only, as |
| 7 | * published by the Free Software Foundation. Sun designates this |
| 8 | * particular file as subject to the "Classpath" exception as provided |
| 9 | * by Sun in the LICENSE file that accompanied this code. |
| 10 | * |
| 11 | * This code is distributed in the hope that it will be useful, but WITHOUT |
| 12 | * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
| 13 | * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
| 14 | * version 2 for more details (a copy is included in the LICENSE file that |
| 15 | * accompanied this code). |
| 16 | * |
| 17 | * You should have received a copy of the GNU General Public License version |
| 18 | * 2 along with this work; if not, write to the Free Software Foundation, |
| 19 | * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. |
| 20 | * |
| 21 | * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara, |
| 22 | * CA 95054 USA or visit www.sun.com if you need additional information or |
| 23 | * have any questions. |
| 24 | */ |
| 25 | package sun.net.www.http; |
| 26 | |
| 27 | import java.io.*; |
| 28 | |
| 29 | /** |
| 30 | * OutputStream that sends the output to the underlying stream using chunked |
| 31 | * encoding as specified in RFC 2068. |
| 32 | * |
| 33 | * @author Alan Bateman |
| 34 | */ |
| 35 | public class ChunkedOutputStream extends PrintStream { |
| 36 | |
| 37 | /* Default chunk size (including chunk header) if not specified */ |
| 38 | static final int DEFAULT_CHUNK_SIZE = 4096; |
| 39 | |
| 40 | /* internal buffer */ |
| 41 | private byte buf[]; |
| 42 | private int count; |
| 43 | |
| 44 | /* underlying stream */ |
| 45 | private PrintStream out; |
| 46 | |
| 47 | /* the chunk size we use */ |
| 48 | private int preferredChunkSize; |
| 49 | |
| 50 | /* if the users write buffer is bigger than this size, we |
| 51 | * write direct from the users buffer instead of copying |
| 52 | */ |
| 53 | static final int MAX_BUF_SIZE = 10 * 1024; |
| 54 | |
| 55 | /* return the size of the header for a particular chunk size */ |
| 56 | private int headerSize(int size) { |
| 57 | return 2 + (Integer.toHexString(size)).length(); |
| 58 | } |
| 59 | |
| 60 | public ChunkedOutputStream(PrintStream o) { |
| 61 | this(o, DEFAULT_CHUNK_SIZE); |
| 62 | } |
| 63 | |
| 64 | public ChunkedOutputStream(PrintStream o, int size) { |
| 65 | super(o); |
| 66 | |
| 67 | out = o; |
| 68 | |
| 69 | if (size <= 0) { |
| 70 | size = DEFAULT_CHUNK_SIZE; |
| 71 | } |
| 72 | /* Adjust the size to cater for the chunk header - eg: if the |
| 73 | * preferred chunk size is 1k this means the chunk size should |
| 74 | * be 1019 bytes (differs by 5 from preferred size because of |
| 75 | * 3 bytes for chunk size in hex and CRLF). |
| 76 | */ |
| 77 | if (size > 0) { |
| 78 | int adjusted_size = size - headerSize(size); |
| 79 | if (adjusted_size + headerSize(adjusted_size) < size) { |
| 80 | adjusted_size++; |
| 81 | } |
| 82 | size = adjusted_size; |
| 83 | } |
| 84 | |
| 85 | if (size > 0) { |
| 86 | preferredChunkSize = size; |
| 87 | } else { |
| 88 | preferredChunkSize = DEFAULT_CHUNK_SIZE - headerSize(DEFAULT_CHUNK_SIZE); |
| 89 | } |
| 90 | |
| 91 | /* start with an initial buffer */ |
| 92 | buf = new byte[preferredChunkSize + 32]; |
| 93 | } |
| 94 | |
| 95 | /* |
| 96 | * If flushAll is true, then all data is flushed in one chunk. |
| 97 | * |
| 98 | * If false and the size of the buffer data exceeds the preferred |
| 99 | * chunk size then chunks are flushed to the output stream. |
| 100 | * If there isn't enough data to make up a complete chunk, |
| 101 | * then the method returns. |
| 102 | */ |
| 103 | private void flush(byte[] buf, boolean flushAll) { |
| 104 | flush (buf, flushAll, 0); |
| 105 | } |
| 106 | |
| 107 | private void flush(byte[] buf, boolean flushAll, int offset) { |
| 108 | int chunkSize; |
| 109 | |
| 110 | do { |
| 111 | if (count < preferredChunkSize) { |
| 112 | if (!flushAll) { |
| 113 | break; |
| 114 | } |
| 115 | chunkSize = count; |
| 116 | } else { |
| 117 | chunkSize = preferredChunkSize; |
| 118 | } |
| 119 | |
| 120 | byte[] bytes = null; |
| 121 | try { |
| 122 | bytes = (Integer.toHexString(chunkSize)).getBytes("US-ASCII"); |
| 123 | } catch (java.io.UnsupportedEncodingException e) { |
| 124 | //This should never happen. |
| 125 | throw new InternalError(e.getMessage()); |
| 126 | } |
| 127 | |
| 128 | out.write(bytes, 0, bytes.length); |
| 129 | out.write((byte)'\r'); |
| 130 | out.write((byte)'\n'); |
| 131 | if (chunkSize > 0) { |
| 132 | out.write(buf, offset, chunkSize); |
| 133 | out.write((byte)'\r'); |
| 134 | out.write((byte)'\n'); |
| 135 | } |
| 136 | out.flush(); |
| 137 | if (checkError()) { |
| 138 | break; |
| 139 | } |
| 140 | if (chunkSize > 0) { |
| 141 | count -= chunkSize; |
| 142 | offset += chunkSize; |
| 143 | } |
| 144 | } while (count > 0); |
| 145 | |
| 146 | if (!checkError() && count > 0) { |
| 147 | System.arraycopy(buf, offset, this.buf, 0, count); |
| 148 | } |
| 149 | } |
| 150 | |
| 151 | public boolean checkError() { |
| 152 | return out.checkError(); |
| 153 | } |
| 154 | |
| 155 | /* |
| 156 | * Check if we have enough data for a chunk and if so flush to the |
| 157 | * underlying output stream. |
| 158 | */ |
| 159 | private void checkFlush() { |
| 160 | if (count >= preferredChunkSize) { |
| 161 | flush(buf, false); |
| 162 | } |
| 163 | } |
| 164 | |
| 165 | /* Check that the output stream is still open */ |
| 166 | private void ensureOpen() { |
| 167 | if (out == null) |
| 168 | setError(); |
| 169 | } |
| 170 | |
| 171 | public synchronized void write(byte b[], int off, int len) { |
| 172 | ensureOpen(); |
| 173 | if ((off < 0) || (off > b.length) || (len < 0) || |
| 174 | ((off + len) > b.length) || ((off + len) < 0)) { |
| 175 | throw new IndexOutOfBoundsException(); |
| 176 | } else if (len == 0) { |
| 177 | return; |
| 178 | } |
| 179 | |
| 180 | if (len > MAX_BUF_SIZE) { |
| 181 | /* first finish the current chunk */ |
| 182 | int l = preferredChunkSize - count; |
| 183 | if (l > 0) { |
| 184 | System.arraycopy(b, off, buf, count, l); |
| 185 | count = preferredChunkSize; |
| 186 | flush(buf, false); |
| 187 | } |
| 188 | count = len - l; |
| 189 | /* Now write the rest of the data */ |
| 190 | flush (b, false, l+off); |
| 191 | } else { |
| 192 | int newcount = count + len; |
| 193 | |
| 194 | if (newcount > buf.length) { |
| 195 | byte newbuf[] = new byte[Math.max(buf.length << 1, newcount)]; |
| 196 | System.arraycopy(buf, 0, newbuf, 0, count); |
| 197 | buf = newbuf; |
| 198 | } |
| 199 | System.arraycopy(b, off, buf, count, len); |
| 200 | count = newcount; |
| 201 | checkFlush(); |
| 202 | } |
| 203 | } |
| 204 | |
| 205 | public synchronized void write(int b) { |
| 206 | ensureOpen(); |
| 207 | int newcount = count + 1; |
| 208 | if (newcount > buf.length) { |
| 209 | byte newbuf[] = new byte[Math.max(buf.length << 1, newcount)]; |
| 210 | System.arraycopy(buf, 0, newbuf, 0, count); |
| 211 | buf = newbuf; |
| 212 | } |
| 213 | buf[count] = (byte)b; |
| 214 | count = newcount; |
| 215 | checkFlush(); |
| 216 | } |
| 217 | |
| 218 | public synchronized void reset() { |
| 219 | count = 0; |
| 220 | } |
| 221 | |
| 222 | public int size() { |
| 223 | return count; |
| 224 | } |
| 225 | |
| 226 | public synchronized void close() { |
| 227 | ensureOpen(); |
| 228 | |
| 229 | /* if we have buffer a chunked send it */ |
| 230 | if (count > 0) { |
| 231 | flush(buf, true); |
| 232 | } |
| 233 | |
| 234 | /* send a zero length chunk */ |
| 235 | flush(buf, true); |
| 236 | |
| 237 | /* don't close the underlying stream */ |
| 238 | out = null; |
| 239 | } |
| 240 | |
| 241 | public synchronized void flush() { |
| 242 | ensureOpen(); |
| 243 | if (count > 0) { |
| 244 | flush(buf, true); |
| 245 | } |
| 246 | } |
| 247 | |
| 248 | } |