J. Duke | 319a3b9 | 2007-12-01 00:00:00 +0000 | [diff] [blame^] | 1 | /* |
| 2 | * Copyright 1994-2004 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 | |
| 26 | package sun.net.www; |
| 27 | |
| 28 | import java.net.URL; |
| 29 | import java.util.*; |
| 30 | import java.io.*; |
| 31 | import sun.net.ProgressSource; |
| 32 | import sun.net.www.http.ChunkedInputStream; |
| 33 | |
| 34 | |
| 35 | public class MeteredStream extends FilterInputStream { |
| 36 | |
| 37 | // Instance variables. |
| 38 | /* if expected != -1, after we've read >= expected, we're "closed" and return -1 |
| 39 | * from subsequest read() 's |
| 40 | */ |
| 41 | protected boolean closed = false; |
| 42 | protected long expected; |
| 43 | protected long count = 0; |
| 44 | protected long markedCount = 0; |
| 45 | protected int markLimit = -1; |
| 46 | protected ProgressSource pi; |
| 47 | |
| 48 | public MeteredStream(InputStream is, ProgressSource pi, long expected) |
| 49 | { |
| 50 | super(is); |
| 51 | |
| 52 | this.pi = pi; |
| 53 | this.expected = expected; |
| 54 | |
| 55 | if (pi != null) { |
| 56 | pi.updateProgress(0, expected); |
| 57 | } |
| 58 | } |
| 59 | |
| 60 | private final void justRead(long n) throws IOException { |
| 61 | if (n == -1) { |
| 62 | |
| 63 | /* |
| 64 | * don't close automatically when mark is set and is valid; |
| 65 | * cannot reset() after close() |
| 66 | */ |
| 67 | if (!isMarked()) { |
| 68 | close(); |
| 69 | } |
| 70 | return; |
| 71 | } |
| 72 | |
| 73 | count += n; |
| 74 | |
| 75 | /** |
| 76 | * If read beyond the markLimit, invalidate the mark |
| 77 | */ |
| 78 | if (count - markedCount > markLimit) { |
| 79 | markLimit = -1; |
| 80 | } |
| 81 | |
| 82 | if (pi != null) |
| 83 | pi.updateProgress(count, expected); |
| 84 | |
| 85 | if (isMarked()) { |
| 86 | return; |
| 87 | } |
| 88 | |
| 89 | // if expected length is known, we could determine if |
| 90 | // read overrun. |
| 91 | if (expected > 0) { |
| 92 | if (count >= expected) { |
| 93 | close(); |
| 94 | } |
| 95 | } |
| 96 | } |
| 97 | |
| 98 | /** |
| 99 | * Returns true if the mark is valid, false otherwise |
| 100 | */ |
| 101 | private boolean isMarked() { |
| 102 | |
| 103 | if (markLimit < 0) { |
| 104 | return false; |
| 105 | } |
| 106 | |
| 107 | // mark is set, but is not valid anymore |
| 108 | if (count - markedCount > markLimit) { |
| 109 | return false; |
| 110 | } |
| 111 | |
| 112 | // mark still holds |
| 113 | return true; |
| 114 | } |
| 115 | |
| 116 | public synchronized int read() throws java.io.IOException { |
| 117 | if (closed) { |
| 118 | return -1; |
| 119 | } |
| 120 | int c = in.read(); |
| 121 | if (c != -1) { |
| 122 | justRead(1); |
| 123 | } else { |
| 124 | justRead(c); |
| 125 | } |
| 126 | return c; |
| 127 | } |
| 128 | |
| 129 | public synchronized int read(byte b[], int off, int len) |
| 130 | throws java.io.IOException { |
| 131 | if (closed) { |
| 132 | return -1; |
| 133 | } |
| 134 | int n = in.read(b, off, len); |
| 135 | justRead(n); |
| 136 | return n; |
| 137 | } |
| 138 | |
| 139 | public synchronized long skip(long n) throws IOException { |
| 140 | |
| 141 | // REMIND: what does skip do on EOF???? |
| 142 | if (closed) { |
| 143 | return 0; |
| 144 | } |
| 145 | |
| 146 | if (in instanceof ChunkedInputStream) { |
| 147 | n = in.skip(n); |
| 148 | } |
| 149 | else { |
| 150 | // just skip min(n, num_bytes_left) |
| 151 | long min = (n > expected - count) ? expected - count: n; |
| 152 | n = in.skip(min); |
| 153 | } |
| 154 | justRead(n); |
| 155 | return n; |
| 156 | } |
| 157 | |
| 158 | public void close() throws IOException { |
| 159 | if (closed) { |
| 160 | return; |
| 161 | } |
| 162 | if (pi != null) |
| 163 | pi.finishTracking(); |
| 164 | |
| 165 | closed = true; |
| 166 | in.close(); |
| 167 | } |
| 168 | |
| 169 | public synchronized int available() throws IOException { |
| 170 | return closed ? 0: in.available(); |
| 171 | } |
| 172 | |
| 173 | public synchronized void mark(int readLimit) { |
| 174 | if (closed) { |
| 175 | return; |
| 176 | } |
| 177 | super.mark(readLimit); |
| 178 | |
| 179 | /* |
| 180 | * mark the count to restore upon reset |
| 181 | */ |
| 182 | markedCount = count; |
| 183 | markLimit = readLimit; |
| 184 | } |
| 185 | |
| 186 | public synchronized void reset() throws IOException { |
| 187 | if (closed) { |
| 188 | return; |
| 189 | } |
| 190 | |
| 191 | if (!isMarked()) { |
| 192 | throw new IOException ("Resetting to an invalid mark"); |
| 193 | } |
| 194 | |
| 195 | count = markedCount; |
| 196 | super.reset(); |
| 197 | } |
| 198 | |
| 199 | public boolean markSupported() { |
| 200 | if (closed) { |
| 201 | return false; |
| 202 | } |
| 203 | return super.markSupported(); |
| 204 | } |
| 205 | |
| 206 | protected void finalize() throws Throwable { |
| 207 | try { |
| 208 | close(); |
| 209 | if (pi != null) |
| 210 | pi.close(); |
| 211 | } |
| 212 | finally { |
| 213 | // Call super class |
| 214 | super.finalize(); |
| 215 | } |
| 216 | } |
| 217 | } |