1/*
2 * Copyright (C) 2009 The Android Open Source Project
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 *      http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17package com.android.mkstubs;
18
19import com.android.mkstubs.Main.Logger;
20import com.android.mkstubs.stubber.ClassStubber;
21
22import org.objectweb.asm.ClassReader;
23import org.objectweb.asm.ClassVisitor;
24import org.objectweb.asm.ClassWriter;
25
26import java.io.File;
27import java.io.FileOutputStream;
28import java.io.IOException;
29import java.util.Map;
30import java.util.Map.Entry;
31import java.util.TreeMap;
32import java.util.jar.JarEntry;
33import java.util.jar.JarOutputStream;
34
35/**
36 * Given a set of already filtered classes, this filters out all private members,
37 * stubs the remaining classes and then generates a Jar out of them.
38 * <p/>
39 * This is an helper extracted for convenience. Callers just need to use
40 * {@link #generateStubbedJar(File, Map, Filter)}.
41 */
42class StubGenerator {
43
44    private Logger mLog;
45
46    public StubGenerator(Logger log) {
47        mLog = log;
48    }
49
50    /**
51     * Generate source for the stubbed classes, mostly for debug purposes.
52     * @throws IOException
53     */
54    public void generateStubbedJar(File destJar,
55            Map<String, ClassReader> classes,
56            Filter filter) throws IOException {
57
58        TreeMap<String, byte[]> all = new TreeMap<String, byte[]>();
59
60        for (Entry<String, ClassReader> entry : classes.entrySet()) {
61            ClassReader cr = entry.getValue();
62
63            byte[] b = visitClassStubber(cr, filter);
64            String name = classNameToEntryPath(cr.getClassName());
65            all.put(name, b);
66        }
67
68        createJar(new FileOutputStream(destJar), all);
69
70        mLog.debug("Wrote %s", destJar.getPath());
71    }
72
73    /**
74     * Utility method that converts a fully qualified java name into a JAR entry path
75     * e.g. for the input "android.view.View" it returns "android/view/View.class"
76     */
77    String classNameToEntryPath(String className) {
78        return className.replaceAll("\\.", "/").concat(".class");
79    }
80
81    /**
82     * Writes the JAR file.
83     *
84     * @param outStream The file output stream were to write the JAR.
85     * @param all The map of all classes to output.
86     * @throws IOException if an I/O error has occurred
87     */
88    void createJar(FileOutputStream outStream, Map<String,byte[]> all) throws IOException {
89        JarOutputStream jar = new JarOutputStream(outStream);
90        for (Entry<String, byte[]> entry : all.entrySet()) {
91            String name = entry.getKey();
92            JarEntry jar_entry = new JarEntry(name);
93            jar.putNextEntry(jar_entry);
94            jar.write(entry.getValue());
95            jar.closeEntry();
96        }
97        jar.flush();
98        jar.close();
99    }
100
101    byte[] visitClassStubber(ClassReader cr, Filter filter) {
102        mLog.debug("Stub " + cr.getClassName());
103
104        // Rewrite the new class from scratch, without reusing the constant pool from the
105        // original class reader.
106        ClassWriter cw = new ClassWriter(ClassWriter.COMPUTE_MAXS);
107
108        ClassVisitor stubWriter = new ClassStubber(cw);
109        ClassVisitor classFilter = new FilterClassAdapter(stubWriter, filter, mLog);
110        cr.accept(classFilter, 0 /*flags*/);
111        return cw.toByteArray();
112    }
113}
114