/*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You under the Apache License, Version 2.0
* (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.apache.harmony.pack200;
import java.io.BufferedInputStream;
import java.io.DataOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.util.jar.JarEntry;
import java.util.jar.JarOutputStream;
import java.util.zip.GZIPInputStream;
import org.apache.harmony.pack200.bytecode.Attribute;
import org.apache.harmony.pack200.bytecode.CPClass;
import org.apache.harmony.pack200.bytecode.CPField;
import org.apache.harmony.pack200.bytecode.CPMethod;
import org.apache.harmony.pack200.bytecode.ClassConstantPool;
import org.apache.harmony.pack200.bytecode.ClassFile;
import org.apache.harmony.pack200.bytecode.ClassFileEntry;
import org.apache.harmony.pack200.bytecode.SourceFileAttribute;
/**
* A Pack200 archive consists of one (or more) segments. Each segment is
* standalone, in the sense that every segment has the magic number header;
* thus, every segment is also a valid archive. However, it is possible to
* combine (non-GZipped) archives into a single large archive by concatenation
* alone. Thus all the hard work in unpacking an archive falls to understanding
* a segment.
*
* This class implements the Pack200 specification by an entry point ({@link #parse(InputStream)})
* which in turn delegates to a variety of other parse methods. Each parse
* method corresponds (roughly) to the name of the bands in the Pack200
* specification.
*
* The first component of a segment is the header; this contains (amongst other
* things) the expected counts of constant pool entries, which in turn defines
* how many values need to be read from the stream. Because values are variable
* width (see {@link Codec}), it is not possible to calculate the start of the
* next segment, although one of the header values does hint at the size of the
* segment if non-zero, which can be used for buffering purposes.
*
* Note that this does not perform any buffering of the input stream; each value
* will be read on a byte-by-byte basis. It does not perform GZip decompression
* automatically; both of these are expected to be done by the caller if the
* stream has the magic header for GZip streams ({@link GZIPInputStream#GZIP_MAGIC}).
* In any case, if GZip decompression is being performed the input stream will
* be buffered at a higher level, and thus this can read on a byte-oriented
* basis.
*/
public class Segment {
/**
* Decode a segment from the given input stream. This does not attempt to
* re-assemble or export any class files, but it contains enough information
* to be able to re-assemble class files by external callers.
*
* @param in
* the input stream to read from TODO At this point, this must be
* a non-GZipped input stream, but this decoding could be done in
* this method in the future (but perhaps more likely on an
* archive as a whole)
* @return a segment parsed from the input stream
* @throws IOException
* if a problem occurs during reading from the underlying stream
* @throws Pack200Exception
* if a problem occurs with an unexpected value or unsupported
* codec
*/
public static Segment parse(InputStream in) throws IOException,
Pack200Exception {
Segment segment = new Segment();
// See if file is GZip compressed
if (!in.markSupported()) {
in = new BufferedInputStream(in);
if (!in.markSupported())
throw new IllegalStateException();
}
in.mark(2);
if (((in.read() & 0xFF) | (in.read() & 0xFF) << 8) == GZIPInputStream.GZIP_MAGIC) {
in.reset();
in = new BufferedInputStream(new GZIPInputStream(in));
} else {
in.reset();
}
segment.parseSegment(in);
return segment;
}
private SegmentHeader header;
private CpBands cpBands;
private AttrDefinitionBands attrDefinitionBands;
private IcBands icBands;
private ClassBands classBands;
private BcBands bcBands;
private FileBands fileBands;
private ClassFile buildClassFile(int classNum) throws Pack200Exception {
ClassFile classFile = new ClassFile();
classFile.major = header.getDefaultClassMajorVersion(); // TODO If
// classVersionMajor[] use
// that instead
classFile.minor = header.getDefaultClassMinorVersion(); // TODO if
// classVersionMinor[] use
// that instead
// build constant pool
ClassConstantPool cp = classFile.pool;
String fullName = classBands.getClassThis()[classNum];
// SourceFile attribute
int i = fullName.lastIndexOf("/") + 1; // if lastIndexOf==-1, then
// -1+1=0, so str.substring(0)
// == str
AttributeLayout SOURCE_FILE = attrDefinitionBands.getAttributeDefinitionMap()
.getAttributeLayout(AttributeLayout.ATTRIBUTE_SOURCE_FILE,
AttributeLayout.CONTEXT_CLASS);
if (SOURCE_FILE.matches(classBands.getClassFlags()[classNum])) {
String fileName = fullName.substring(i) + ".java";
classFile.attributes = new Attribute[] { (Attribute) cp
.add(new SourceFileAttribute(fileName)) };
} else {
classFile.attributes = new Attribute[] {};
}
// this/superclass
ClassFileEntry cfThis = cp.add(new CPClass(fullName));
ClassFileEntry cfSuper = cp.add(new CPClass(classBands.getClassSuper()[classNum]));
// add interfaces
ClassFileEntry cfInterfaces[] = new ClassFileEntry[classBands.getClassInterfaces()[classNum].length];
for (i = 0; i < cfInterfaces.length; i++) {
cfInterfaces[i] = cp.add(new CPClass(classBands.getClassInterfaces()[classNum][i]));
}
// add fields
ClassFileEntry cfFields[] = new ClassFileEntry[classBands.getClassFieldCount()[classNum]];
// fieldDescr and fieldFlags used to create this
for (i = 0; i < cfFields.length; i++) {
cfFields[i] = cp.add(new CPField(classBands.getFieldDescr()[classNum][i],
classBands.getFieldFlags()[classNum][i], classBands.getFieldAttributes()[classNum][i]));
}
// add methods
ClassFileEntry cfMethods[] = new ClassFileEntry[classBands.getClassMethodCount()[classNum]];
// fieldDescr and fieldFlags used to create this
for (i = 0; i < cfMethods.length; i++) {
cfMethods[i] = cp.add(new CPMethod(classBands.getMethodDescr()[classNum][i],
classBands.getMethodFlags()[classNum][i], classBands.getMethodAttributes()[classNum][i]));
}
// sort CP according to cp_All
cp.resolve(this);
// print out entries
debug("Constant pool looks like:");
for (i = 1; i <= cp.size(); i++) {
debug(String.valueOf(i) + ":" + String.valueOf(cp.get(i)));
}
// NOTE the indexOf is only valid after the cp.resolve()
// build up remainder of file
classFile.accessFlags = (int) classBands.getClassFlags()[classNum];
classFile.thisClass = cp.indexOf(cfThis);
classFile.superClass = cp.indexOf(cfSuper);
// TODO placate format of file for writing purposes
classFile.interfaces = new int[cfInterfaces.length];
for (i = 0; i < cfInterfaces.length; i++) {
classFile.interfaces[i] = cp.indexOf(cfInterfaces[i]);
}
classFile.fields = cfFields;
classFile.methods = cfMethods;
return classFile;
}
/**
* This performs the actual work of parsing against a non-static instance of
* Segment.
*
* @param in
* the input stream to read from
* @throws IOException
* if a problem occurs during reading from the underlying stream
* @throws Pack200Exception
* if a problem occurs with an unexpected value or unsupported
* codec
*/
private void parseSegment(InputStream in) throws IOException,
Pack200Exception {
debug("-------");
header = new SegmentHeader();
header.unpack(in);
cpBands = new CpBands(this);
cpBands.unpack(in);
attrDefinitionBands = new AttrDefinitionBands(this);
attrDefinitionBands.unpack(in);
icBands = new IcBands(this);
icBands.unpack(in);
classBands = new ClassBands(this);
classBands.unpack(in);
bcBands = new BcBands(this);
bcBands.unpack(in);
fileBands = new FileBands(this);
fileBands.unpack(in);
}
/**
* Unpacks a packed stream (either .pack. or .pack.gz) into a corresponding
* JarOuputStream.
*
* @throws Pack200Exception
* if there is a problem unpacking
* @throws IOException
* if there is a problem with I/O during unpacking
*/
public void unpack(InputStream in, JarOutputStream out) throws IOException,
Pack200Exception {
if (!in.markSupported())
in = new BufferedInputStream(in);
// TODO Can handle multiple concatenated streams, so should deal with
// that possibility
parse(in).unpack(in, out);
}
/**
* This is a local debugging message to aid the developer in writing this
* class. It will be removed before going into production. If the property
* 'debug.pack200' is set, this will generate messages to stderr; otherwise,
* it will be silent.
*
* @param message
* @deprecated this should be removed from production code
*/
protected void debug(String message) {
if (System.getProperty("debug.pack200") != null) {
System.err.println(message);
}
}
/**
* Writes the segment to an output stream. The output stream should be
* pre-buffered for efficiency. Also takes the same input stream for
* reading, since the file bits may not be loaded and thus just copied from
* one stream to another. Doesn't close the output stream when finished, in
* case there are more entries (e.g. further segments) to be written.
*
* @param out
* the JarOutputStream to write data to
* @param in
* the same InputStream that was used to parse the segment
* @throws IOException
* if an error occurs whilst reading or writing to the streams
* @throws Pack200Exception
* if an error occurs whilst unpacking data
*/
public void writeJar(JarOutputStream out, InputStream in)
throws IOException, Pack200Exception {
fileBands.processFileBits(in);
DataOutputStream dos = new DataOutputStream(out);
String[] fileName = fileBands.getFileName();
long[] fileModtime = fileBands.getFileModtime();
long[] fileOptions = fileBands.getFileOptions();
long[] fileSize = fileBands.getFileSize();
byte[][] fileBits = fileBands.getFileBits();
// out.setLevel(JarEntry.DEFLATED)
// now write the files out
int classNum = 0;
int numberOfFiles = header.getNumberOfFiles();
long archiveModtime = header.getArchiveModtime();
SegmentOptions options = header.getOptions();
for (int i = 0; i < numberOfFiles; i++) {
String name = fileName[i];
long modtime = archiveModtime + fileModtime[i];
boolean deflate = (fileOptions[i] & 1) == 1
|| options.shouldDeflate();
boolean isClass = (fileOptions[i] & 2) == 2 || name == null
|| name.equals("");
if (isClass) {
// pull from headers
if (name == null || name.equals(""))
name = classBands.getClassThis()[classNum] + ".class";
}
JarEntry entry = new JarEntry(name);
if (deflate)
entry.setMethod(JarEntry.DEFLATED);
entry.setTime(modtime);
out.putNextEntry(entry);
if (isClass) {
// write to dos
ClassFile classFile = buildClassFile(classNum);
classFile.write(dos);
dos.flush();
classNum++;
} else {
long size = fileSize[i];
entry.setSize(size);
// TODO pull from in
byte[] data = fileBits[i];
out.write(data);
}
}
dos.flush();
out.finish();
out.flush();
}
public SegmentConstantPool getConstantPool() {
return cpBands.getConstantPool();
}
public SegmentHeader getSegmentHeader() {
return header;
}
protected AttrDefinitionBands getAttrDefinitionBands() {
return attrDefinitionBands;
}
protected BcBands getBcBands() {
return bcBands;
}
protected ClassBands getClassBands() {
return classBands;
}
protected CpBands getCpBands() {
return cpBands;
}
protected FileBands getFileBands() {
return fileBands;
}
protected IcBands getIcBands() {
return icBands;
}
}