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1
5 package com.tc.object.bytecode;
6
7 import com.tc.asm.ClassAdapter;
8 import com.tc.asm.ClassVisitor;
9 import com.tc.asm.MethodAdapter;
10 import com.tc.asm.MethodVisitor;
11 import com.tc.asm.Opcodes;
12 import com.tc.object.bytecode.hook.impl.JavaLangArrayHelpers;
13 import com.tc.util.Assert;
14 import com.tc.util.runtime.Vm;
15 import com.tc.util.runtime.Vm.Version;
16
17 public class JavaLangStringAdapter extends ClassAdapter implements Opcodes {
18
19 private final Version vmVersion;
20 private final boolean portableStringBuffer;
21
22 public JavaLangStringAdapter(ClassVisitor cv, Version vmVersion, boolean portableStringBuffer) {
23 super(cv);
24 this.vmVersion = vmVersion;
25 this.portableStringBuffer = portableStringBuffer;
26 }
27
28 public MethodVisitor visitMethod(int access, String  name, String desc, String signature, String [] exceptions) {
29 MethodVisitor mv = super.visitMethod(access, name, desc, signature, exceptions);
30 if ("getBytes".equals(name) && "(II[BI)V".equals(desc)) {
31 return rewriteGetBytes(mv);
32 } else if ("<init>".equals(name) && "(Ljava/lang/StringBuffer;)V".equals(desc)) {
33 if (vmVersion.isJDK14() && portableStringBuffer) { return rewriteStringBufferConstructor(mv); }
34 } else if ("getChars".equals(name) && "(II[CI)V".equals(desc)) {
35 return new GetCharsAdapter(mv);
37 } else if ("getChars".equals(name) && "([CI)V".equals(desc)) {
38 return new GetCharsAdapter(mv);
40 }
41
42 return new RewriteGetCharsCallsAdapter(mv);
43 }
44
45 public void visitEnd() {
46 addFastGetChars();
47 super.visitEnd();
48 }
49
50 private void addFastGetChars() {
51 MethodVisitor mv = super.visitMethod(ACC_SYNTHETIC | ACC_PUBLIC, "getCharsFast", "(II[CI)V", null, null);
54 mv.visitCode();
55 mv.visitVarInsn(ALOAD, 0);
56 mv.visitFieldInsn(GETFIELD, "java/lang/String", "value", "[C");
57 mv.visitVarInsn(ALOAD, 0);
58 mv.visitFieldInsn(GETFIELD, "java/lang/String", "offset", "I");
59 mv.visitVarInsn(ILOAD, 1);
60 mv.visitInsn(IADD);
61 mv.visitVarInsn(ALOAD, 3);
62 mv.visitVarInsn(ILOAD, 4);
63 mv.visitVarInsn(ILOAD, 2);
64 mv.visitVarInsn(ILOAD, 1);
65 mv.visitInsn(ISUB);
66 mv.visitMethodInsn(INVOKESTATIC, "java/lang/System", "arraycopy", "(Ljava/lang/Object;ILjava/lang/Object;II)V");
67 mv.visitInsn(RETURN);
68 mv.visitMaxs(0, 0);
69 mv.visitEnd();
70
71 mv = super.visitMethod(ACC_SYNTHETIC, "getCharsFast", "([CI)V", null, null);
73 mv.visitCode();
74 mv.visitVarInsn(ALOAD, 0);
75 mv.visitFieldInsn(GETFIELD, "java/lang/String", "value", "[C");
76 mv.visitVarInsn(ALOAD, 0);
77 mv.visitFieldInsn(GETFIELD, "java/lang/String", "offset", "I");
78 mv.visitVarInsn(ALOAD, 1);
79 mv.visitVarInsn(ILOAD, 2);
80 mv.visitVarInsn(ALOAD, 0);
81 mv.visitFieldInsn(GETFIELD, "java/lang/String", "count", "I");
82 mv.visitMethodInsn(INVOKESTATIC, "java/lang/System", "arraycopy", "(Ljava/lang/Object;ILjava/lang/Object;II)V");
83 mv.visitInsn(RETURN);
84 mv.visitMaxs(0, 0);
85 mv.visitEnd();
86 }
87
88 private MethodVisitor rewriteStringBufferConstructor(MethodVisitor mv) {
89 Assert.assertTrue(Vm.isJDK14());
91 mv.visitCode();
92 mv.visitVarInsn(ALOAD, 0);
93 mv.visitMethodInsn(INVOKESPECIAL, "java/lang/Object", "<init>", "()V");
94 mv.visitVarInsn(ALOAD, 1);
95 mv.visitMethodInsn(INVOKEVIRTUAL, "java/lang/StringBuffer", "toString", "()Ljava/lang/String;");
96 mv.visitVarInsn(ASTORE, 2);
97 mv.visitVarInsn(ALOAD, 0);
98 mv.visitVarInsn(ALOAD, 2);
99 mv.visitFieldInsn(GETFIELD, "java/lang/String", "value", "[C");
100 mv.visitFieldInsn(PUTFIELD, "java/lang/String", "value", "[C");
101 mv.visitVarInsn(ALOAD, 0);
102 mv.visitVarInsn(ALOAD, 2);
103 mv.visitFieldInsn(GETFIELD, "java/lang/String", "count", "I");
104 mv.visitFieldInsn(PUTFIELD, "java/lang/String", "count", "I");
105 mv.visitVarInsn(ALOAD, 0);
106 mv.visitVarInsn(ALOAD, 2);
107 mv.visitFieldInsn(GETFIELD, "java/lang/String", "offset", "I");
108 mv.visitFieldInsn(PUTFIELD, "java/lang/String", "offset", "I");
109 mv.visitInsn(RETURN);
110 mv.visitMaxs(0, 0);
111 return null;
112 }
113
114 private MethodVisitor rewriteGetBytes(MethodVisitor mv) {
115 mv.visitCode();
116 mv.visitVarInsn(ILOAD, 1);
117 mv.visitVarInsn(ILOAD, 2);
118 mv.visitVarInsn(ALOAD, 3);
119 mv.visitVarInsn(ILOAD, 4);
120 mv.visitVarInsn(ALOAD, 0);
121 mv.visitFieldInsn(GETFIELD, "java/lang/String", "count", "I");
122 mv.visitVarInsn(ALOAD, 0);
123 mv.visitFieldInsn(GETFIELD, "java/lang/String", "offset", "I");
124 mv.visitVarInsn(ALOAD, 0);
125 mv.visitFieldInsn(GETFIELD, "java/lang/String", "value", "[C");
126 mv.visitMethodInsn(INVOKESTATIC, JavaLangArrayHelpers.CLASS, "javaLangStringGetBytes", "(II[BIII[C)V");
127 mv.visitInsn(RETURN);
128 mv.visitMaxs(0, 0);
129 mv.visitEnd();
130 return null;
131 }
132
133 private static class RewriteGetCharsCallsAdapter extends MethodAdapter {
134
135 public RewriteGetCharsCallsAdapter(MethodVisitor mv) {
136 super(mv);
137 }
138
139 public void visitMethodInsn(int opcode, String owner, String name, String desc) {
140 if ((INVOKEVIRTUAL == opcode) && ("java/lang/String".equals(owner) && "getChars".equals(name))) {
141 super.visitMethodInsn(opcode, owner, "getCharsFast", desc);
142 } else {
143 super.visitMethodInsn(opcode, owner, name, desc);
144 }
145 }
146
147 }
148
149 private static class GetCharsAdapter extends MethodAdapter {
150
151 public GetCharsAdapter(MethodVisitor mv) {
152 super(mv);
153 }
154
155 public void visitMethodInsn(int opcode, String owner, String name, String desc) {
156 if ((opcode == INVOKESTATIC) && "java/lang/System".equals(owner) && "arraycopy".equals(name)) {
157 super.visitMethodInsn(INVOKESTATIC, JavaLangArrayHelpers.CLASS, "charArrayCopy", "([CI[CII)V");
158 } else {
159 super.visitMethodInsn(opcode, owner, name, desc);
160 }
161 }
162
163 }
164
165 }
166 |
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