1 /* 2 * Copyright (c) 2003, 2019, 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 import java.io.*; 25 26 /* 27 * Copyright 2003 Wily Technology, Inc. 28 */ 29 30 public class NamedBuffer 31 { 32 private final String fName; 33 private final byte[] fBuffer; 34 35 public 36 NamedBuffer( String name, 37 byte[] buffer) 38 { 39 fName = name; 40 fBuffer = buffer; 41 } 42 43 public 44 NamedBuffer( String name, 45 InputStream stream) 46 throws IOException 47 { 48 this( name, 49 loadBufferFromStream(stream)); 50 } 51 52 public String 53 getName() 54 { 55 return fName; 56 } 57 58 public byte[] 59 getBuffer() 60 { 61 return fBuffer; 62 } 63 64 public static byte[] 65 loadBufferFromStream(InputStream stream) 66 throws IOException 67 { 68 // hack for now, just assume the stream will fit in our reasonable size buffer. 69 // if not, panic 70 int bufferLimit = 200 * 1024; 71 byte[] readBuffer = new byte[bufferLimit]; 72 int actualSize = stream.read(readBuffer); 73 if ( actualSize >= bufferLimit ) 74 { 75 // if there might be more bytes, just surrender 76 throw new IOException("too big for buffer"); 77 } 78 79 byte[] resultBuffer = new byte[actualSize]; 80 System.arraycopy( readBuffer, 81 0, 82 resultBuffer, 83 0, 84 actualSize); 85 return resultBuffer; 86 } 87 88 static final String DEST = System.getProperty("test.classes"); 89 static final boolean VERBOSE = false; 90 91 static boolean checkMatch(byte[] buf, byte[] name, int begIdx) { 92 if (buf.length < name.length + begIdx) { 93 return false; 94 } 95 for (int i = 0; i < name.length; i++) { 96 if (buf[i + begIdx] != name[i]) { 97 return false; 98 } 99 } 100 return true; 101 } 102 103 // This function reads a class file from disk and replaces the first character of 104 // the name with the one passed as "replace". Then goes through the bytecodes to 105 // replace all instances of the name of the class with the new name. The 106 // redefinition tests use this to redefine Host$ classes with precompiled class files 107 // Xost.java, Yost.java and Zost.java. 108 static byte[] 109 bytesForHostClass(char replace, String className) throws Throwable { 110 String tail = className.substring(1); 111 String origClassName = "" + replace + tail; 112 File clsfile = new File(DEST + "/" + origClassName + ".class"); 113 114 if (VERBOSE) { 115 System.out.println(" Reading bytes from " + clsfile); 116 } 117 byte[] buf = null; 118 try (FileInputStream str = new FileInputStream(clsfile)) { 119 buf = loadBufferFromStream(str); 120 } 121 122 boolean found = false; 123 int dollarSignIdx = className.indexOf('$'); 124 int ptrnLen = (dollarSignIdx == -1) ? className.length() : dollarSignIdx; 125 byte[] ptrnBytes = origClassName.substring(0, ptrnLen).getBytes(); 126 byte firstByte = className.getBytes()[0]; 127 128 for (int i = 0; i < buf.length - ptrnLen; i++) { 129 if (checkMatch(buf, ptrnBytes, i)) { 130 if (VERBOSE) { 131 System.out.println("Appear to have found " + origClassName + " starting at " + i); 132 } 133 buf[i] = firstByte; 134 found = true; 135 } 136 } 137 if (!found) { 138 throw new Error("Could not locate '" + ptrnBytes + "' name in byte array"); 139 } 140 return buf; 141 } 142 }