| 1 | /* |
| 2 | Copyright (C) 2002-2004 MySQL AB |
| 3 | |
| 4 | This program is free software; you can redistribute it and/or modify |
| 5 | it under the terms of version 2 of the GNU General Public License as |
| 6 | published by the Free Software Foundation. |
| 7 | |
| 8 | There are special exceptions to the terms and conditions of the GPL |
| 9 | as it is applied to this software. View the full text of the |
| 10 | exception in file EXCEPTIONS-CONNECTOR-J in the directory of this |
| 11 | software distribution. |
| 12 | |
| 13 | This program is distributed in the hope that it will be useful, |
| 14 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 15 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 16 | GNU General Public License for more details. |
| 17 | |
| 18 | You should have received a copy of the GNU General Public License |
| 19 | along with this program; if not, write to the Free Software |
| 20 | Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA |
| 21 | |
| 22 | |
| 23 | |
| 24 | */ |
| 25 | package com.mysql.jdbc; |
| 26 | |
| 27 | import java.io.EOFException; |
| 28 | import java.io.IOException; |
| 29 | import java.io.InputStream; |
| 30 | |
| 31 | import java.sql.SQLException; |
| 32 | |
| 33 | import java.util.zip.DataFormatException; |
| 34 | import java.util.zip.Inflater; |
| 35 | |
| 36 | /** |
| 37 | * Used to de-compress packets from the MySQL server when protocol-level |
| 38 | * compression is turned on. |
| 39 | * |
| 40 | * @author Mark Matthews |
| 41 | * |
| 42 | * @version $Id: CompressedInputStream.java,v 1.1.2.1 2005/05/13 18:58:37 |
| 43 | * mmatthews Exp $ |
| 44 | */ |
| 45 | class CompressedInputStream extends InputStream { |
| 46 | /** The packet data after it has been un-compressed */ |
| 47 | private byte[] buffer; |
| 48 | |
| 49 | /** The connection that is using us (used to read config values) */ |
| 50 | private Connection connection; |
| 51 | |
| 52 | /** The stream we are reading from the server */ |
| 53 | private InputStream in; |
| 54 | |
| 55 | /** The ZIP inflater used to un-compress packets */ |
| 56 | private Inflater inflater; |
| 57 | |
| 58 | /** |
| 59 | * The buffer to read packet headers into |
| 60 | */ |
| 61 | private byte[] packetHeaderBuffer = new byte[7]; |
| 62 | |
| 63 | /** The position we are reading from */ |
| 64 | private int pos = 0; |
| 65 | |
| 66 | /** |
| 67 | * Creates a new CompressedInputStream that reads the given stream from the |
| 68 | * server. |
| 69 | * |
| 70 | * @param conn |
| 71 | * DOCUMENT ME! |
| 72 | * @param streamFromServer |
| 73 | */ |
| 74 | public CompressedInputStream(Connection conn, InputStream streamFromServer) { |
| 75 | this.connection = conn; |
| 76 | this.in = streamFromServer; |
| 77 | this.inflater = new Inflater(); |
| 78 | } |
| 79 | |
| 80 | /** |
| 81 | * @see java.io.InputStream#available() |
| 82 | */ |
| 83 | public int available() throws IOException { |
| 84 | if (this.buffer == null) { |
| 85 | return this.in.available(); |
| 86 | } |
| 87 | |
| 88 | return this.buffer.length - this.pos + this.in.available(); |
| 89 | } |
| 90 | |
| 91 | /** |
| 92 | * @see java.io.InputStream#close() |
| 93 | */ |
| 94 | public void close() throws IOException { |
| 95 | this.in.close(); |
| 96 | this.buffer = null; |
| 97 | this.inflater = null; |
| 98 | } |
| 99 | |
| 100 | /** |
| 101 | * Retrieves and un-compressed (if necessary) the next packet from the |
| 102 | * server. |
| 103 | * |
| 104 | * @throws IOException |
| 105 | * if an I/O error occurs |
| 106 | */ |
| 107 | private void getNextPacketFromServer() throws IOException { |
| 108 | byte[] uncompressedData = null; |
| 109 | |
| 110 | int lengthRead = readFully(this.packetHeaderBuffer, 0, 7); |
| 111 | |
| 112 | if (lengthRead < 7) { |
| 113 | throw new IOException("Unexpected end of input stream"); |
| 114 | } |
| 115 | |
| 116 | int compressedPacketLength = ((this.packetHeaderBuffer[0] & 0xff)) |
| 117 | + (((this.packetHeaderBuffer[1] & 0xff)) << 8) |
| 118 | + (((this.packetHeaderBuffer[2] & 0xff)) << 16); |
| 119 | |
| 120 | int uncompressedLength = ((this.packetHeaderBuffer[4] & 0xff)) |
| 121 | + (((this.packetHeaderBuffer[5] & 0xff)) << 8) |
| 122 | + (((this.packetHeaderBuffer[6] & 0xff)) << 16); |
| 123 | |
| 124 | if (this.connection.getTraceProtocol()) { |
| 125 | try { |
| 126 | this.connection.getLog().logTrace( |
| 127 | "Reading compressed packet of length " |
| 128 | + compressedPacketLength + " uncompressed to " |
| 129 | + uncompressedLength); |
| 130 | } catch (SQLException sqlEx) { |
| 131 | throw new IOException(sqlEx.toString()); // should never |
| 132 | // happen |
| 133 | } |
| 134 | } |
| 135 | |
| 136 | if (uncompressedLength > 0) { |
| 137 | uncompressedData = new byte[uncompressedLength]; |
| 138 | |
| 139 | byte[] compressedBuffer = new byte[compressedPacketLength]; |
| 140 | |
| 141 | readFully(compressedBuffer, 0, compressedPacketLength); |
| 142 | |
| 143 | try { |
| 144 | this.inflater.reset(); |
| 145 | } catch (NullPointerException npe) { |
| 146 | this.inflater = new Inflater(); |
| 147 | } |
| 148 | |
| 149 | this.inflater.setInput(compressedBuffer); |
| 150 | |
| 151 | try { |
| 152 | this.inflater.inflate(uncompressedData); |
| 153 | } catch (DataFormatException dfe) { |
| 154 | throw new IOException( |
| 155 | "Error while uncompressing packet from server."); |
| 156 | } |
| 157 | |
| 158 | this.inflater.end(); |
| 159 | } else { |
| 160 | if (this.connection.getTraceProtocol()) { |
| 161 | try { |
| 162 | this.connection |
| 163 | .getLog() |
| 164 | .logTrace( |
| 165 | "Packet didn't meet compression threshold, not uncompressing..."); |
| 166 | } catch (SQLException sqlEx) { |
| 167 | throw new IOException(sqlEx.toString()); // should never |
| 168 | // happen |
| 169 | } |
| 170 | } |
| 171 | |
| 172 | // |
| 173 | // Read data, note this this code is reached when using |
| 174 | // compressed packets that have not been compressed, as well |
| 175 | // |
| 176 | uncompressedData = new byte[compressedPacketLength]; |
| 177 | readFully(uncompressedData, 0, compressedPacketLength); |
| 178 | } |
| 179 | |
| 180 | if (this.connection.getTraceProtocol()) { |
| 181 | try { |
| 182 | this.connection.getLog().logTrace( |
| 183 | "Uncompressed packet: \n" |
| 184 | + StringUtils.dumpAsHex(uncompressedData, |
| 185 | compressedPacketLength)); |
| 186 | } catch (SQLException sqlEx) { |
| 187 | throw new IOException(sqlEx.toString()); // should never |
| 188 | // happen |
| 189 | } |
| 190 | } |
| 191 | |
| 192 | if ((this.buffer != null) && (this.pos < this.buffer.length)) { |
| 193 | if (this.connection.getTraceProtocol()) { |
| 194 | try { |
| 195 | this.connection.getLog().logTrace( |
| 196 | "Combining remaining packet with new: "); |
| 197 | } catch (SQLException sqlEx) { |
| 198 | throw new IOException(sqlEx.toString()); // should never |
| 199 | // happen |
| 200 | } |
| 201 | } |
| 202 | |
| 203 | int remaining = this.buffer.length - this.pos; |
| 204 | byte[] newBuffer = new byte[remaining + uncompressedData.length]; |
| 205 | |
| 206 | int newIndex = 0; |
| 207 | |
| 208 | for (int i = this.pos; i < this.buffer.length; i++) |
| 209 | newBuffer[newIndex++] = this.buffer[i]; |
| 210 | |
| 211 | System.arraycopy(uncompressedData, 0, newBuffer, newIndex, |
| 212 | uncompressedData.length); |
| 213 | |
| 214 | uncompressedData = newBuffer; |
| 215 | } |
| 216 | |
| 217 | this.pos = 0; |
| 218 | this.buffer = uncompressedData; |
| 219 | |
| 220 | return; |
| 221 | } |
| 222 | |
| 223 | /** |
| 224 | * Determines if another packet needs to be read from the server to be able |
| 225 | * to read numBytes from the stream. |
| 226 | * |
| 227 | * @param numBytes |
| 228 | * the number of bytes to be read |
| 229 | * |
| 230 | * @throws IOException |
| 231 | * if an I/O error occors. |
| 232 | */ |
| 233 | private void getNextPacketIfRequired(int numBytes) throws IOException { |
| 234 | if ((this.buffer == null) |
| 235 | || ((this.pos + numBytes) > this.buffer.length)) { |
| 236 | getNextPacketFromServer(); |
| 237 | } |
| 238 | } |
| 239 | |
| 240 | /** |
| 241 | * @see java.io.InputStream#read() |
| 242 | */ |
| 243 | public int read() throws IOException { |
| 244 | try { |
| 245 | getNextPacketIfRequired(1); |
| 246 | } catch (IOException ioEx) { |
| 247 | return -1; |
| 248 | } |
| 249 | |
| 250 | return this.buffer[this.pos++] & 0xff; |
| 251 | } |
| 252 | |
| 253 | /** |
| 254 | * @see java.io.InputStream#read(byte) |
| 255 | */ |
| 256 | public int read(byte[] b) throws IOException { |
| 257 | return read(b, 0, b.length); |
| 258 | } |
| 259 | |
| 260 | /** |
| 261 | * @see java.io.InputStream#read(byte, int, int) |
| 262 | */ |
| 263 | public int read(byte[] b, int off, int len) throws IOException { |
| 264 | if (b == null) { |
| 265 | throw new NullPointerException(); |
| 266 | } else if ((off < 0) || (off > b.length) || (len < 0) |
| 267 | || ((off + len) > b.length) || ((off + len) < 0)) { |
| 268 | throw new IndexOutOfBoundsException(); |
| 269 | } |
| 270 | |
| 271 | if (len <= 0) { |
| 272 | return 0; |
| 273 | } |
| 274 | |
| 275 | try { |
| 276 | getNextPacketIfRequired(len); |
| 277 | } catch (IOException ioEx) { |
| 278 | return -1; |
| 279 | } |
| 280 | |
| 281 | System.arraycopy(this.buffer, this.pos, b, off, len); |
| 282 | this.pos += len; |
| 283 | |
| 284 | return len; |
| 285 | } |
| 286 | |
| 287 | private final int readFully(byte[] b, int off, int len) throws IOException { |
| 288 | if (len < 0) { |
| 289 | throw new IndexOutOfBoundsException(); |
| 290 | } |
| 291 | |
| 292 | int n = 0; |
| 293 | |
| 294 | while (n < len) { |
| 295 | int count = this.in.read(b, off + n, len - n); |
| 296 | |
| 297 | if (count < 0) { |
| 298 | throw new EOFException(); |
| 299 | } |
| 300 | |
| 301 | n += count; |
| 302 | } |
| 303 | |
| 304 | return n; |
| 305 | } |
| 306 | |
| 307 | /** |
| 308 | * @see java.io.InputStream#skip(long) |
| 309 | */ |
| 310 | public long skip(long n) throws IOException { |
| 311 | long count = 0; |
| 312 | |
| 313 | for (long i = 0; i < n; i++) { |
| 314 | int bytesRead = read(); |
| 315 | |
| 316 | if (bytesRead == -1) { |
| 317 | break; |
| 318 | } |
| 319 | |
| 320 | count++; |
| 321 | } |
| 322 | |
| 323 | return count; |
| 324 | } |
| 325 | } |