1 /* 2 * Copyright (c) 1997, Oracle and/or its affiliates. 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. 8 * 9 * This code is distributed in the hope that it will be useful, but WITHOUT 10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 12 * version 2 for more details (a copy is included in the LICENSE file that 13 * accompanied this code). 14 * 15 * You should have received a copy of the GNU General Public License version 16 * 2 along with this work; if not, write to the Free Software Foundation, 17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 18 * 19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 20 * or visit www.oracle.com if you need additional information or have any 21 * questions. 22 */ 23 24 25 /* @test 26 @bug 4016710 27 @summary check for correct implementation of InputStream.skip 28 */ 29 30 import java.io.*; 31 32 33 public class Skip{ 34 35 private static void dotest(InputStream in , int curpos , 36 long total , long toskip , long expected) 37 throws Exception 38 { 39 40 try { 41 42 System.err.println("\n\nCurrently at pos = " + curpos + 43 "\nTotal bytes in the Stream = " + total + 44 "\nNumber of bytes to skip = " + toskip + 45 "\nNumber of bytes that should be skipped = " + 46 expected); 47 48 long skipped = in.skip(toskip); 49 50 System.err.println("actual number skipped: "+ skipped); 51 52 if ((skipped < 0) || (skipped > expected)) { 53 throw new RuntimeException("Unexpected number of bytes skipped"); 54 } 55 56 } catch (IOException e) { 57 System.err.println("IOException is thrown - possible result"); 58 } catch (Throwable e) { 59 throw new RuntimeException("Unexpected "+e+" is thrown!"); 60 } 61 62 } 63 64 public static void main( String argv[] ) throws Exception { 65 66 MyInputStream in = new MyInputStream(11); 67 68 /* test for negative skip */ 69 dotest(in, 0, 11, -23, 0); 70 71 /* check for skip beyond EOF starting from before EOF */ 72 dotest(in, 0, 11, 20, 11); 73 74 /* check for skip after EOF */ 75 dotest(in, -1, 11, 20, 0); 76 77 in = new MyInputStream(9000); 78 /* check for skip equal to the read chunk size in InputStream.java */ 79 dotest(in, 0, 9000, 2048, 2048); 80 81 /* check for skip greater than the read chunk size in InputStream.java */ 82 dotest(in, 2048, 9000, 5000, 5000); 83 84 /* check for skip beyond EOF starting from before EOF */ 85 dotest(in, 7048, 9000, 5000, 1952); 86 87 in = new MyInputStream(5000); 88 89 /* check for multiple chunk reads */ 90 dotest(in, 0, 5000, 6000, 5000); 91 92 /* 93 * check for skip larger than Integer.MAX_VALUE 94 * (Takes about 2 hrs on a sparc ultra-1) 95 * long total = (long)Integer.MAX_VALUE + (long)10; 96 * long toskip = total - (long)6; 97 * in = new MyInputStream(total); 98 * dotest(in, 0, total, toskip, toskip); 99 */ 100 101 } 102 103 } 104 105 class MyInputStream extends InputStream { 106 107 private int readctr = 0; 108 private long endoffile; 109 110 public MyInputStream(long endoffile) { 111 this.endoffile = endoffile; 112 } 113 114 public int read() { 115 116 if (readctr == endoffile) { 117 return -1; 118 } 119 else { 120 readctr++; 121 return 0; 122 } 123 } 124 125 public int available() { return 0; } 126 } | 1 /* 2 * Copyright (c) 1997, 2018 Oracle and/or its affiliates. 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. 8 * 9 * This code is distributed in the hope that it will be useful, but WITHOUT 10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 12 * version 2 for more details (a copy is included in the LICENSE file that 13 * accompanied this code). 14 * 15 * You should have received a copy of the GNU General Public License version 16 * 2 along with this work; if not, write to the Free Software Foundation, 17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 18 * 19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 20 * or visit www.oracle.com if you need additional information or have any 21 * questions. 22 */ 23 24 /** 25 * @test 26 * @bug 4016710 6516099 27 * @summary check for correct implementation of InputStream.skip{NBytes} 28 */ 29 30 import java.io.EOFException; 31 import java.io.InputStream; 32 import java.io.IOException; 33 34 public class Skip { 35 private static final int EOF = -1; 36 37 private static void dotest(InputStream in, int curpos, long total, 38 long toskip, long expected) throws Exception { 39 try { 40 System.err.println("\n\nCurrently at pos = " + curpos + 41 "\nTotal bytes in the Stream = " + total + 42 "\nNumber of bytes to skip = " + toskip + 43 "\nNumber of bytes that should be skipped = " + 44 expected); 45 46 long skipped = in.skip(toskip); 47 48 System.err.println("actual number skipped: "+ skipped); 49 50 if ((skipped < 0) || (skipped > expected)) { 51 throw new RuntimeException("Unexpected byte count skipped"); 52 } 53 } catch (IOException e) { 54 System.err.println("IOException is thrown: " + e); 55 } catch (Throwable e) { 56 throw new RuntimeException("Unexpected " + e + " is thrown!"); 57 } 58 } 59 60 private static void dotestExact(MyInputStream in, long curpos, long total, 61 long toskip, boolean expectIOE, boolean expectEOFE) { 62 63 System.err.println("\n\nCurrently at pos = " + curpos + 64 "\nTotal bytes in the Stream = " + total + 65 "\nNumber of bytes to skip = " + toskip); 66 67 try { 68 long pos = in.position(); 69 assert pos == curpos : pos + " != " + curpos; 70 in.skipNBytes(toskip); 71 if (in.position() != pos + (toskip < 0 ? 0 : toskip)) { 72 throw new RuntimeException((in.position() - pos) + 73 " bytes skipped; expected " + toskip); 74 } 75 } catch (EOFException eofe) { 76 if (!expectEOFE) { 77 throw new RuntimeException("Unexpected EOFException", eofe); 78 } 79 System.err.println("Caught expected EOFException"); 80 } catch (IOException ioe) { 81 if (!expectIOE) { 82 throw new RuntimeException("Unexpected IOException", ioe); 83 } 84 System.err.println("Caught expected IOException"); 85 } 86 } 87 88 public static void main( String argv[] ) throws Exception { 89 MyInputStream in = new MyInputStream(11); 90 91 // test for negative skip 92 dotest(in, 0, 11, -23, 0); 93 94 // check for skip beyond EOF starting from before EOF 95 dotest(in, 0, 11, 20, 11); 96 97 // check for skip after EOF 98 dotest(in, EOF, 11, 20, 0); 99 100 in = new MyInputStream(9000); 101 102 // check for skip equal to the read chunk size in InputStream.java 103 dotest(in, 0, 9000, 2048, 2048); 104 105 // check for skip larger than the read chunk size in InputStream.java 106 dotest(in, 2048, 9000, 5000, 5000); 107 108 // check for skip beyond EOF starting from before EOF 109 dotest(in, 7048, 9000, 5000, 1952); 110 111 in = new MyInputStream(5000); 112 113 // check for multiple chunk reads 114 dotest(in, 0, 5000, 6000, 5000); 115 116 /* 117 * check for skip larger than Integer.MAX_VALUE 118 * (Takes about 2 hrs on a sparc ultra-1) 119 * long total = (long)Integer.MAX_VALUE + (long)10; 120 * long toskip = total - (long)6; 121 * in = new MyInputStream(total); 122 * dotest(in, 0, total, toskip, toskip); 123 */ 124 125 // tests for skipping an exact number of bytes 126 127 final long streamLength = Long.MAX_VALUE; 128 in = new MyInputStream(streamLength); 129 130 // negative skip: OK 131 dotestExact(in, 0, streamLength, -1, false, false); 132 133 // negative skip at EOF: OK 134 in.position(streamLength); 135 dotestExact(in, streamLength, streamLength, -1, false, false); 136 in.position(0); 137 138 // zero skip: OK 139 dotestExact(in, 0, streamLength, 0, false, false); 140 141 // zero skip at EOF: OK 142 in.position(streamLength); 143 dotestExact(in, streamLength, streamLength, 0, false, false); 144 145 // skip(1) at EOF: EOFE 146 dotestExact(in, streamLength, streamLength, 1, false, true); 147 in.position(0); 148 149 final long n = 31; // skip count 150 long pos = 0; 151 152 // skip(n) returns negative value: IOE 153 in.setState(-1, 100); 154 dotestExact(in, pos, streamLength, n, true, false); 155 156 // skip(n) returns n + 1: IOE 157 in.setState(n + 1, 100); 158 dotestExact(in, pos, streamLength, n, true, false); 159 pos += n + 1; 160 161 // skip(n) returns n/2 but only n/4 subsequent reads succeed: EOFE 162 in.setState(n/2, n/2 + n/4); 163 dotestExact(in, pos, streamLength, n, false, true); 164 pos += n/2 + n/4; 165 166 // skip(n) returns n/2 but n - n/2 subsequent reads succeed: OK 167 in.setState(n/2, n); 168 dotestExact(in, pos, streamLength, n, false, false); 169 pos += n; 170 } 171 } 172 173 class MyInputStream extends InputStream { 174 private static final int EOF = -1; 175 176 private final long endoffile; 177 178 private long readctr = 0; 179 180 private boolean isStateSet = false; 181 private long skipReturn; 182 private long readLimit; 183 184 public MyInputStream(long endoffile) { 185 this.endoffile = endoffile; 186 } 187 188 /** 189 * Limits the behavior of skip() and read(). 190 * 191 * @param skipReturn the value to be returned by skip() 192 * @param maxReads the maximum number of reads past the current position 193 * before EOF is reached 194 */ 195 public void setState(long skipReturn, long maxReads) { 196 this.skipReturn = skipReturn; 197 this.readLimit = readctr + maxReads; 198 isStateSet = true; 199 } 200 201 public int read() { 202 if (readctr == endoffile || 203 (isStateSet && readctr >= readLimit)) { 204 return EOF; 205 } 206 else { 207 readctr++; 208 return 0; 209 } 210 } 211 212 public int available() { return 0; } 213 214 public long position() { return readctr; } 215 216 public void position(long pos) { 217 readctr = pos < 0 ? 0 : Math.min(pos, endoffile); 218 } 219 220 public long skip(long n) throws IOException { 221 if (isStateSet) { 222 return skipReturn < 0 ? skipReturn : super.skip(skipReturn); 223 } 224 225 // InputStream skip implementation. 226 return super.skip(n); // readctr is implicitly incremented 227 } 228 } |