jdk/src/jdk.jartool/share/classes/sun/tools/jar/FingerPrint.java
changeset 40251 481b890e50a3
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/jdk/src/jdk.jartool/share/classes/sun/tools/jar/FingerPrint.java	Fri Jul 29 09:58:28 2016 -0700
@@ -0,0 +1,324 @@
+/*
+ * Copyright (c) 2016, Oracle and/or its affiliates. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.  Oracle designates this
+ * particular file as subject to the "Classpath" exception as provided
+ * by Oracle in the LICENSE file that accompanied this code.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ */
+
+package sun.tools.jar;
+
+import jdk.internal.org.objectweb.asm.*;
+
+import java.io.IOException;
+import java.io.InputStream;
+import java.security.MessageDigest;
+import java.security.NoSuchAlgorithmException;
+import java.util.HashMap;
+import java.util.HashSet;
+import java.util.Map;
+import java.util.Set;
+
+/**
+ * A FingerPrint is an abstract representation of a JarFile entry that contains
+ * information to determine if the entry represents a class or a
+ * resource, and whether two entries are identical.  If the FingerPrint represents
+ * a class, it also contains information to (1) describe the public API;
+ * (2) compare the public API of this class with another class;  (3) determine
+ * whether or not it's a nested class and, if so, the name of the associated
+ * top level class; and (4) for an canonically ordered set of classes determine
+ * if the class versions are compatible.  A set of classes is canonically
+ * ordered if the classes in the set have the same name, and the base class
+ * precedes the versioned classes and if each versioned class with version
+ * {@code n} precedes classes with versions {@code > n} for all versions
+ * {@code n}.
+ */
+final class FingerPrint {
+    private static final MessageDigest MD;
+
+    private final byte[] sha1;
+    private final ClassAttributes attrs;
+    private final boolean isClassEntry;
+    private final String entryName;
+
+    static {
+        try {
+            MD = MessageDigest.getInstance("SHA-1");
+        } catch (NoSuchAlgorithmException x) {
+            // log big problem?
+            throw new RuntimeException(x);
+        }
+    }
+
+    public FingerPrint(String entryName,byte[] bytes) throws IOException {
+        this.entryName = entryName;
+        if (entryName.endsWith(".class") && isCafeBabe(bytes)) {
+            isClassEntry = true;
+            sha1 = sha1(bytes, 8);  // skip magic number and major/minor version
+            attrs = getClassAttributes(bytes);
+        } else {
+            isClassEntry = false;
+            sha1 = sha1(bytes);
+            attrs = new ClassAttributes();   // empty class
+        }
+    }
+
+    public boolean isClass() {
+        return isClassEntry;
+    }
+
+    public boolean isNestedClass() {
+        return attrs.nestedClass;
+    }
+
+    public boolean isPublicClass() {
+        return attrs.publicClass;
+    }
+
+    public boolean isIdentical(FingerPrint that) {
+        if (that == null) return false;
+        if (this == that) return true;
+        return isEqual(this.sha1, that.sha1);
+    }
+
+    public boolean isCompatibleVersion(FingerPrint that) {
+        return attrs.version >= that.attrs.version;
+    }
+
+    public boolean isSameAPI(FingerPrint that) {
+        if (that == null) return false;
+        return attrs.equals(that.attrs);
+    }
+
+    public String name() {
+        String name = attrs.name;
+        return name == null ? entryName : name;
+    }
+
+    public String topLevelName() {
+        String name = attrs.topLevelName;
+        return name == null ? name() : name;
+    }
+
+    private byte[] sha1(byte[] entry) {
+        MD.update(entry);
+        return MD.digest();
+    }
+
+    private byte[] sha1(byte[] entry, int offset) {
+        MD.update(entry, offset, entry.length - offset);
+        return MD.digest();
+    }
+
+    private boolean isEqual(byte[] sha1_1, byte[] sha1_2) {
+        return MessageDigest.isEqual(sha1_1, sha1_2);
+    }
+
+    private static final byte[] cafeBabe = {(byte)0xca, (byte)0xfe, (byte)0xba, (byte)0xbe};
+
+    private boolean isCafeBabe(byte[] bytes) {
+        if (bytes.length < 4) return false;
+        for (int i = 0; i < 4; i++) {
+            if (bytes[i] != cafeBabe[i]) {
+                return false;
+            }
+        }
+        return true;
+    }
+
+    private ClassAttributes getClassAttributes(byte[] bytes) {
+        ClassReader rdr = new ClassReader(bytes);
+        ClassAttributes attrs = new ClassAttributes();
+        rdr.accept(attrs, 0);
+        return attrs;
+    }
+
+    private static final class Field {
+        private final int access;
+        private final String name;
+        private final String desc;
+
+        Field(int access, String name, String desc) {
+            this.access = access;
+            this.name = name;
+            this.desc = desc;
+        }
+
+        @Override
+        public boolean equals(Object that) {
+            if (that == null) return false;
+            if (this == that) return true;
+            if (!(that instanceof Field)) return false;
+            Field field = (Field)that;
+            return (access == field.access) && name.equals(field.name)
+                    && desc.equals(field.desc);
+        }
+
+        @Override
+        public int hashCode() {
+            int result = 17;
+            result = 37 * result + access;
+            result = 37 * result + name.hashCode();
+            result = 37 * result + desc.hashCode();
+            return result;
+        }
+    }
+
+    private static final class Method {
+        private final int access;
+        private final String name;
+        private final String desc;
+        private final Set<String> exceptions;
+
+        Method(int access, String name, String desc, Set<String> exceptions) {
+            this.access = access;
+            this.name = name;
+            this.desc = desc;
+            this.exceptions = exceptions;
+        }
+
+        @Override
+        public boolean equals(Object that) {
+            if (that == null) return false;
+            if (this == that) return true;
+            if (!(that instanceof Method)) return false;
+            Method method = (Method)that;
+            return (access == method.access) && name.equals(method.name)
+                    && desc.equals(method.desc)
+                    && exceptions.equals(method.exceptions);
+        }
+
+        @Override
+        public int hashCode() {
+            int result = 17;
+            result = 37 * result + access;
+            result = 37 * result + name.hashCode();
+            result = 37 * result + desc.hashCode();
+            result = 37 * result + exceptions.hashCode();
+            return result;
+        }
+    }
+
+    private static final class ClassAttributes extends ClassVisitor {
+        private String name;
+        private String topLevelName;
+        private String superName;
+        private int version;
+        private int access;
+        private boolean publicClass;
+        private boolean nestedClass;
+        private final Set<Field> fields = new HashSet<>();
+        private final Set<Method> methods = new HashSet<>();
+
+        public ClassAttributes() {
+            super(Opcodes.ASM5);
+        }
+
+        private boolean isPublic(int access) {
+            return ((access & Opcodes.ACC_PUBLIC) == Opcodes.ACC_PUBLIC)
+                    || ((access & Opcodes.ACC_PROTECTED) == Opcodes.ACC_PROTECTED);
+        }
+
+        @Override
+        public void visit(int version, int access, String name, String signature,
+                          String superName, String[] interfaces) {
+            this.version = version;
+            this.access = access;
+            this.name = name;
+            this.nestedClass = name.contains("$");
+            this.superName = superName;
+            this.publicClass = isPublic(access);
+        }
+
+        @Override
+        public void visitOuterClass(String owner, String name, String desc) {
+            if (!this.nestedClass) return;
+            this.topLevelName = owner;
+        }
+
+        @Override
+        public void visitInnerClass(String name, String outerName, String innerName,
+                                    int access) {
+            if (!this.nestedClass) return;
+            if (outerName == null) return;
+            if (!this.name.equals(name)) return;
+            if (this.topLevelName == null) this.topLevelName = outerName;
+        }
+
+        @Override
+        public FieldVisitor visitField(int access, String name, String desc,
+                                       String signature, Object value) {
+            if (isPublic(access)) {
+                fields.add(new Field(access, name, desc));
+            }
+            return null;
+        }
+
+        @Override
+        public MethodVisitor visitMethod(int access, String name, String desc,
+                                         String signature, String[] exceptions) {
+            if (isPublic(access)) {
+                Set<String> exceptionSet = new HashSet<>();
+                if (exceptions != null) {
+                    for (String e : exceptions) {
+                        exceptionSet.add(e);
+                    }
+                }
+                // treat type descriptor as a proxy for signature because signature
+                // is usually null, need to strip off the return type though
+                int n;
+                if (desc != null && (n = desc.lastIndexOf(')')) != -1) {
+                    desc = desc.substring(0, n + 1);
+                    methods.add(new Method(access, name, desc, exceptionSet));
+                }
+            }
+            return null;
+        }
+
+        @Override
+        public void visitEnd() {
+            this.nestedClass = this.topLevelName != null;
+        }
+
+        @Override
+        public boolean equals(Object that) {
+            if (that == null) return false;
+            if (this == that) return true;
+            if (!(that instanceof ClassAttributes)) return false;
+            ClassAttributes clsAttrs = (ClassAttributes)that;
+            boolean superNameOkay = superName != null
+                    ? superName.equals(clsAttrs.superName) : true;
+            return access == clsAttrs.access
+                    && superNameOkay
+                    && fields.equals(clsAttrs.fields)
+                    && methods.equals(clsAttrs.methods);
+        }
+
+        @Override
+        public int hashCode() {
+            int result = 17;
+            result = 37 * result + access;
+            result = 37 * result + superName != null ? superName.hashCode() : 0;
+            result = 37 * result + fields.hashCode();
+            result = 37 * result + methods.hashCode();
+            return result;
+        }
+    }
+}