org.apache.commons.compress.archivers.sevenz.SevenZFile Maven / Gradle / Ivy
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/*
* 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.commons.compress.archivers.sevenz;
import java.io.ByteArrayInputStream;
import java.io.Closeable;
import java.io.DataInput;
import java.io.DataInputStream;
import java.io.File;
import java.io.IOException;
import java.io.InputStream;
import java.io.RandomAccessFile;
import java.util.Arrays;
import java.util.BitSet;
import java.util.zip.CRC32;
import org.apache.commons.compress.utils.BoundedInputStream;
import org.apache.commons.compress.utils.CRC32VerifyingInputStream;
import org.apache.commons.compress.utils.CharsetNames;
import org.apache.commons.compress.utils.IOUtils;
/**
* Reads a 7z file, using RandomAccessFile under
* the covers.
*
* The 7z file format is a flexible container
* that can contain many compression and
* encryption types, but at the moment only
* only Copy, LZMA, LZMA2, BZIP2, Deflate and AES-256 + SHA-256
* are supported.
*
* The format is very Windows/Intel specific,
* so it uses little-endian byte order,
* doesn't store user/group or permission bits,
* and represents times using NTFS timestamps
* (100 nanosecond units since 1 January 1601).
* Hence the official tools recommend against
* using it for backup purposes on *nix, and
* recommend .tar.7z or .tar.lzma or .tar.xz
* instead.
*
* Both the header and file contents may be
* compressed and/or encrypted. With both
* encrypted, neither file names nor file
* contents can be read, but the use of
* encryption isn't plausibly deniable.
*
* @NotThreadSafe
* @since 1.6
*/
public class SevenZFile implements Closeable {
static final int SIGNATURE_HEADER_SIZE = 32;
private RandomAccessFile file;
private final Archive archive;
private int currentEntryIndex = -1;
private int currentFolderIndex = -1;
private InputStream currentFolderInputStream = null;
private InputStream currentEntryInputStream = null;
private byte[] password;
static final byte[] sevenZSignature = {
(byte)'7', (byte)'z', (byte)0xBC, (byte)0xAF, (byte)0x27, (byte)0x1C
};
/**
* Reads a file as 7z archive
*
* @param filename the file to read
* @param password optional password if the archive is encrypted -
* the byte array is supposed to be the UTF16-LE encoded
* representation of the password.
* @throws IOException if reading the archive fails
*/
public SevenZFile(final File filename, final byte[] password) throws IOException {
boolean succeeded = false;
this.file = new RandomAccessFile(filename, "r");
try {
archive = readHeaders(password);
if (password != null) {
this.password = new byte[password.length];
System.arraycopy(password, 0, this.password, 0, password.length);
} else {
this.password = null;
}
succeeded = true;
} finally {
if (!succeeded) {
this.file.close();
}
}
}
/**
* Reads a file as unecrypted 7z archive
*
* @param filename the file to read
* @throws IOException if reading the archive fails
*/
public SevenZFile(final File filename) throws IOException {
this(filename, null);
}
/**
* Closes the archive.
* @throws IOException if closing the file fails
*/
public void close() throws IOException {
if (file != null) {
try {
file.close();
} finally {
file = null;
if (password != null) {
Arrays.fill(password, (byte) 0);
}
password = null;
}
}
}
/**
* Returns the next Archive Entry in this archive.
*
* @return the next entry,
* or {@code null} if there are no more entries
* @throws IOException if the next entry could not be read
*/
public SevenZArchiveEntry getNextEntry() throws IOException {
if (currentEntryIndex >= archive.files.length - 1) {
return null;
}
++currentEntryIndex;
final SevenZArchiveEntry entry = archive.files[currentEntryIndex];
buildDecodingStream();
return entry;
}
private Archive readHeaders(byte[] password) throws IOException {
final byte[] signature = new byte[6];
file.readFully(signature);
if (!Arrays.equals(signature, sevenZSignature)) {
throw new IOException("Bad 7z signature");
}
// 7zFormat.txt has it wrong - it's first major then minor
final byte archiveVersionMajor = file.readByte();
final byte archiveVersionMinor = file.readByte();
if (archiveVersionMajor != 0) {
throw new IOException(String.format("Unsupported 7z version (%d,%d)",
Byte.valueOf(archiveVersionMajor), Byte.valueOf(archiveVersionMinor)));
}
final long startHeaderCrc = 0xffffFFFFL & Integer.reverseBytes(file.readInt());
final StartHeader startHeader = readStartHeader(startHeaderCrc);
final int nextHeaderSizeInt = (int) startHeader.nextHeaderSize;
if (nextHeaderSizeInt != startHeader.nextHeaderSize) {
throw new IOException("cannot handle nextHeaderSize " + startHeader.nextHeaderSize);
}
file.seek(SIGNATURE_HEADER_SIZE + startHeader.nextHeaderOffset);
final byte[] nextHeader = new byte[nextHeaderSizeInt];
file.readFully(nextHeader);
final CRC32 crc = new CRC32();
crc.update(nextHeader);
if (startHeader.nextHeaderCrc != crc.getValue()) {
throw new IOException("NextHeader CRC mismatch");
}
final ByteArrayInputStream byteStream = new ByteArrayInputStream(nextHeader);
DataInputStream nextHeaderInputStream = new DataInputStream(
byteStream);
Archive archive = new Archive();
int nid = nextHeaderInputStream.readUnsignedByte();
if (nid == NID.kEncodedHeader) {
nextHeaderInputStream =
readEncodedHeader(nextHeaderInputStream, archive, password);
// Archive gets rebuilt with the new header
archive = new Archive();
nid = nextHeaderInputStream.readUnsignedByte();
}
if (nid == NID.kHeader) {
readHeader(nextHeaderInputStream, archive);
nextHeaderInputStream.close();
} else {
throw new IOException("Broken or unsupported archive: no Header");
}
return archive;
}
private StartHeader readStartHeader(final long startHeaderCrc) throws IOException {
final StartHeader startHeader = new StartHeader();
DataInputStream dataInputStream = null;
try {
dataInputStream = new DataInputStream(new CRC32VerifyingInputStream(
new BoundedRandomAccessFileInputStream(file, 20), 20, startHeaderCrc));
startHeader.nextHeaderOffset = Long.reverseBytes(dataInputStream.readLong());
startHeader.nextHeaderSize = Long.reverseBytes(dataInputStream.readLong());
startHeader.nextHeaderCrc = 0xffffFFFFL & Integer.reverseBytes(dataInputStream.readInt());
return startHeader;
} finally {
if (dataInputStream != null) {
dataInputStream.close();
}
}
}
private void readHeader(final DataInput header, final Archive archive) throws IOException {
int nid = header.readUnsignedByte();
if (nid == NID.kArchiveProperties) {
readArchiveProperties(header);
nid = header.readUnsignedByte();
}
if (nid == NID.kAdditionalStreamsInfo) {
throw new IOException("Additional streams unsupported");
//nid = header.readUnsignedByte();
}
if (nid == NID.kMainStreamsInfo) {
readStreamsInfo(header, archive);
nid = header.readUnsignedByte();
}
if (nid == NID.kFilesInfo) {
readFilesInfo(header, archive);
nid = header.readUnsignedByte();
}
if (nid != NID.kEnd) {
throw new IOException("Badly terminated header");
}
}
private void readArchiveProperties(final DataInput input) throws IOException {
// FIXME: the reference implementation just throws them away?
int nid = input.readUnsignedByte();
while (nid != NID.kEnd) {
final long propertySize = readUint64(input);
final byte[] property = new byte[(int)propertySize];
input.readFully(property);
nid = input.readUnsignedByte();
}
}
private DataInputStream readEncodedHeader(final DataInputStream header, final Archive archive,
byte[] password) throws IOException {
readStreamsInfo(header, archive);
// FIXME: merge with buildDecodingStream()/buildDecoderStack() at some stage?
final Folder folder = archive.folders[0];
final int firstPackStreamIndex = 0;
final long folderOffset = SIGNATURE_HEADER_SIZE + archive.packPos +
0;
file.seek(folderOffset);
InputStream inputStreamStack = new BoundedRandomAccessFileInputStream(file,
archive.packSizes[firstPackStreamIndex]);
for (final Coder coder : folder.coders) {
if (coder.numInStreams != 1 || coder.numOutStreams != 1) {
throw new IOException("Multi input/output stream coders are not yet supported");
}
inputStreamStack = Coders.addDecoder(inputStreamStack, coder, password);
}
if (folder.hasCrc) {
inputStreamStack = new CRC32VerifyingInputStream(inputStreamStack,
folder.getUnpackSize(), folder.crc);
}
final byte[] nextHeader = new byte[(int)folder.getUnpackSize()];
final DataInputStream nextHeaderInputStream = new DataInputStream(inputStreamStack);
try {
nextHeaderInputStream.readFully(nextHeader);
} finally {
nextHeaderInputStream.close();
}
return new DataInputStream(new ByteArrayInputStream(nextHeader));
}
private void readStreamsInfo(final DataInput header, final Archive archive) throws IOException {
int nid = header.readUnsignedByte();
if (nid == NID.kPackInfo) {
readPackInfo(header, archive);
nid = header.readUnsignedByte();
}
if (nid == NID.kUnpackInfo) {
readUnpackInfo(header, archive);
nid = header.readUnsignedByte();
} else {
// archive without unpack/coders info
archive.folders = new Folder[0];
}
if (nid == NID.kSubStreamsInfo) {
readSubStreamsInfo(header, archive);
nid = header.readUnsignedByte();
}
if (nid != NID.kEnd) {
throw new IOException("Badly terminated StreamsInfo");
}
}
private void readPackInfo(final DataInput header, final Archive archive) throws IOException {
archive.packPos = readUint64(header);
final long numPackStreams = readUint64(header);
int nid = header.readUnsignedByte();
if (nid == NID.kSize) {
archive.packSizes = new long[(int)numPackStreams];
for (int i = 0; i < archive.packSizes.length; i++) {
archive.packSizes[i] = readUint64(header);
}
nid = header.readUnsignedByte();
}
if (nid == NID.kCRC) {
archive.packCrcsDefined = readAllOrBits(header, (int)numPackStreams);
archive.packCrcs = new long[(int)numPackStreams];
for (int i = 0; i < (int)numPackStreams; i++) {
if (archive.packCrcsDefined.get(i)) {
archive.packCrcs[i] = 0xffffFFFFL & Integer.reverseBytes(header.readInt());
}
}
nid = header.readUnsignedByte();
}
if (nid != NID.kEnd) {
throw new IOException("Badly terminated PackInfo (" + nid + ")");
}
}
private void readUnpackInfo(final DataInput header, final Archive archive) throws IOException {
int nid = header.readUnsignedByte();
if (nid != NID.kFolder) {
throw new IOException("Expected kFolder, got " + nid);
}
final long numFolders = readUint64(header);
final Folder[] folders = new Folder[(int)numFolders];
archive.folders = folders;
final int external = header.readUnsignedByte();
if (external != 0) {
throw new IOException("External unsupported");
} else {
for (int i = 0; i < (int)numFolders; i++) {
folders[i] = readFolder(header);
}
}
nid = header.readUnsignedByte();
if (nid != NID.kCodersUnpackSize) {
throw new IOException("Expected kCodersUnpackSize, got " + nid);
}
for (final Folder folder : folders) {
folder.unpackSizes = new long[(int)folder.totalOutputStreams];
for (int i = 0; i < folder.totalOutputStreams; i++) {
folder.unpackSizes[i] = readUint64(header);
}
}
nid = header.readUnsignedByte();
if (nid == NID.kCRC) {
final BitSet crcsDefined = readAllOrBits(header, (int)numFolders);
for (int i = 0; i < (int)numFolders; i++) {
if (crcsDefined.get(i)) {
folders[i].hasCrc = true;
folders[i].crc = 0xffffFFFFL & Integer.reverseBytes(header.readInt());
} else {
folders[i].hasCrc = false;
}
}
nid = header.readUnsignedByte();
}
if (nid != NID.kEnd) {
throw new IOException("Badly terminated UnpackInfo");
}
}
private void readSubStreamsInfo(final DataInput header, final Archive archive) throws IOException {
for (final Folder folder : archive.folders) {
folder.numUnpackSubStreams = 1;
}
int totalUnpackStreams = archive.folders.length;
int nid = header.readUnsignedByte();
if (nid == NID.kNumUnpackStream) {
totalUnpackStreams = 0;
for (final Folder folder : archive.folders) {
final long numStreams = readUint64(header);
folder.numUnpackSubStreams = (int)numStreams;
totalUnpackStreams += numStreams;
}
nid = header.readUnsignedByte();
}
final SubStreamsInfo subStreamsInfo = new SubStreamsInfo();
subStreamsInfo.unpackSizes = new long[totalUnpackStreams];
subStreamsInfo.hasCrc = new BitSet(totalUnpackStreams);
subStreamsInfo.crcs = new long[totalUnpackStreams];
int nextUnpackStream = 0;
for (final Folder folder : archive.folders) {
if (folder.numUnpackSubStreams == 0) {
continue;
}
long sum = 0;
if (nid == NID.kSize) {
for (int i = 0; i < folder.numUnpackSubStreams - 1; i++) {
final long size = readUint64(header);
subStreamsInfo.unpackSizes[nextUnpackStream++] = size;
sum += size;
}
}
subStreamsInfo.unpackSizes[nextUnpackStream++] = folder.getUnpackSize() - sum;
}
if (nid == NID.kSize) {
nid = header.readUnsignedByte();
}
int numDigests = 0;
for (final Folder folder : archive.folders) {
if (folder.numUnpackSubStreams != 1 || !folder.hasCrc) {
numDigests += folder.numUnpackSubStreams;
}
}
if (nid == NID.kCRC) {
final BitSet hasMissingCrc = readAllOrBits(header, numDigests);
final long[] missingCrcs = new long[numDigests];
for (int i = 0; i < numDigests; i++) {
if (hasMissingCrc.get(i)) {
missingCrcs[i] = 0xffffFFFFL & Integer.reverseBytes(header.readInt());
}
}
int nextCrc = 0;
int nextMissingCrc = 0;
for (final Folder folder: archive.folders) {
if (folder.numUnpackSubStreams == 1 && folder.hasCrc) {
subStreamsInfo.hasCrc.set(nextCrc, true);
subStreamsInfo.crcs[nextCrc] = folder.crc;
++nextCrc;
} else {
for (int i = 0; i < folder.numUnpackSubStreams; i++) {
subStreamsInfo.hasCrc.set(nextCrc, hasMissingCrc.get(nextMissingCrc));
subStreamsInfo.crcs[nextCrc] = missingCrcs[nextMissingCrc];
++nextCrc;
++nextMissingCrc;
}
}
}
nid = header.readUnsignedByte();
}
if (nid != NID.kEnd) {
throw new IOException("Badly terminated SubStreamsInfo");
}
archive.subStreamsInfo = subStreamsInfo;
}
private Folder readFolder(final DataInput header) throws IOException {
final Folder folder = new Folder();
final long numCoders = readUint64(header);
final Coder[] coders = new Coder[(int)numCoders];
long totalInStreams = 0;
long totalOutStreams = 0;
for (int i = 0; i < coders.length; i++) {
coders[i] = new Coder();
int bits = header.readUnsignedByte();
final int idSize = bits & 0xf;
final boolean isSimple = (bits & 0x10) == 0;
final boolean hasAttributes = (bits & 0x20) != 0;
final boolean moreAlternativeMethods = (bits & 0x80) != 0;
coders[i].decompressionMethodId = new byte[idSize];
header.readFully(coders[i].decompressionMethodId);
if (isSimple) {
coders[i].numInStreams = 1;
coders[i].numOutStreams = 1;
} else {
coders[i].numInStreams = readUint64(header);
coders[i].numOutStreams = readUint64(header);
}
totalInStreams += coders[i].numInStreams;
totalOutStreams += coders[i].numOutStreams;
if (hasAttributes) {
final long propertiesSize = readUint64(header);
coders[i].properties = new byte[(int)propertiesSize];
header.readFully(coders[i].properties);
}
// would need to keep looping as above:
while (moreAlternativeMethods) {
throw new IOException("Alternative methods are unsupported, please report. " +
"The reference implementation doesn't support them either.");
}
}
folder.coders = coders;
folder.totalInputStreams = totalInStreams;
folder.totalOutputStreams = totalOutStreams;
if (totalOutStreams == 0) {
throw new IOException("Total output streams can't be 0");
}
final long numBindPairs = totalOutStreams - 1;
final BindPair[] bindPairs = new BindPair[(int)numBindPairs];
for (int i = 0; i < bindPairs.length; i++) {
bindPairs[i] = new BindPair();
bindPairs[i].inIndex = readUint64(header);
bindPairs[i].outIndex = readUint64(header);
}
folder.bindPairs = bindPairs;
if (totalInStreams < numBindPairs) {
throw new IOException("Total input streams can't be less than the number of bind pairs");
}
final long numPackedStreams = totalInStreams - numBindPairs;
final long packedStreams[] = new long[(int)numPackedStreams];
if (numPackedStreams == 1) {
int i;
for (i = 0; i < (int)totalInStreams; i++) {
if (folder.findBindPairForInStream(i) < 0) {
break;
}
}
if (i == (int)totalInStreams) {
throw new IOException("Couldn't find stream's bind pair index");
}
packedStreams[0] = i;
} else {
for (int i = 0; i < (int)numPackedStreams; i++) {
packedStreams[i] = readUint64(header);
}
}
folder.packedStreams = packedStreams;
return folder;
}
private BitSet readAllOrBits(final DataInput header, final int size) throws IOException {
final int areAllDefined = header.readUnsignedByte();
final BitSet bits;
if (areAllDefined != 0) {
bits = new BitSet(size);
for (int i = 0; i < size; i++) {
bits.set(i, true);
}
} else {
bits = readBits(header, size);
}
return bits;
}
private BitSet readBits(final DataInput header, final int size) throws IOException {
final BitSet bits = new BitSet(size);
int mask = 0;
int cache = 0;
for (int i = 0; i < size; i++) {
if (mask == 0) {
mask = 0x80;
cache = header.readUnsignedByte();
}
bits.set(i, (cache & mask) != 0);
mask >>>= 1;
}
return bits;
}
private void readFilesInfo(final DataInput header, final Archive archive) throws IOException {
final long numFiles = readUint64(header);
final SevenZArchiveEntry[] files = new SevenZArchiveEntry[(int)numFiles];
for (int i = 0; i < files.length; i++) {
files[i] = new SevenZArchiveEntry();
}
BitSet isEmptyStream = null;
BitSet isEmptyFile = null;
BitSet isAnti = null;
while (true) {
final int propertyType = header.readUnsignedByte();
if (propertyType == 0) {
break;
}
long size = readUint64(header);
switch (propertyType) {
case NID.kEmptyStream: {
isEmptyStream = readBits(header, files.length);
break;
}
case NID.kEmptyFile: {
if (isEmptyStream == null) { // protect against NPE
throw new IOException("Header format error: kEmptyStream must appear before kEmptyFile");
}
isEmptyFile = readBits(header, isEmptyStream.cardinality());
break;
}
case NID.kAnti: {
if (isEmptyStream == null) { // protect against NPE
throw new IOException("Header format error: kEmptyStream must appear before kAnti");
}
isAnti = readBits(header, isEmptyStream.cardinality());
break;
}
case NID.kName: {
final int external = header.readUnsignedByte();
if (external != 0) {
throw new IOException("Not implemented");
} else {
if (((size - 1) & 1) != 0) {
throw new IOException("File names length invalid");
}
final byte[] names = new byte[(int)(size - 1)];
header.readFully(names);
int nextFile = 0;
int nextName = 0;
for (int i = 0; i < names.length; i += 2) {
if (names[i] == 0 && names[i+1] == 0) {
files[nextFile++].setName(new String(names, nextName, i-nextName, CharsetNames.UTF_16LE));
nextName = i + 2;
}
}
if (nextName != names.length || nextFile != files.length) {
throw new IOException("Error parsing file names");
}
}
break;
}
case NID.kCTime: {
final BitSet timesDefined = readAllOrBits(header, files.length);
final int external = header.readUnsignedByte();
if (external != 0) {
throw new IOException("Unimplemented");
} else {
for (int i = 0; i < files.length; i++) {
files[i].setHasCreationDate(timesDefined.get(i));
if (files[i].getHasCreationDate()) {
files[i].setCreationDate(Long.reverseBytes(header.readLong()));
}
}
}
break;
}
case NID.kATime: {
final BitSet timesDefined = readAllOrBits(header, files.length);
final int external = header.readUnsignedByte();
if (external != 0) {
throw new IOException("Unimplemented");
} else {
for (int i = 0; i < files.length; i++) {
files[i].setHasAccessDate(timesDefined.get(i));
if (files[i].getHasAccessDate()) {
files[i].setAccessDate(Long.reverseBytes(header.readLong()));
}
}
}
break;
}
case NID.kMTime: {
final BitSet timesDefined = readAllOrBits(header, files.length);
final int external = header.readUnsignedByte();
if (external != 0) {
throw new IOException("Unimplemented");
} else {
for (int i = 0; i < files.length; i++) {
files[i].setHasLastModifiedDate(timesDefined.get(i));
if (files[i].getHasLastModifiedDate()) {
files[i].setLastModifiedDate(Long.reverseBytes(header.readLong()));
}
}
}
break;
}
case NID.kWinAttributes: {
final BitSet attributesDefined = readAllOrBits(header, files.length);
final int external = header.readUnsignedByte();
if (external != 0) {
throw new IOException("Unimplemented");
} else {
for (int i = 0; i < files.length; i++) {
files[i].setHasWindowsAttributes(attributesDefined.get(i));
if (files[i].getHasWindowsAttributes()) {
files[i].setWindowsAttributes(Integer.reverseBytes(header.readInt()));
}
}
}
break;
}
case NID.kStartPos: {
throw new IOException("kStartPos is unsupported, please report");
}
case NID.kDummy: {
throw new IOException("kDummy is unsupported, please report");
}
default: {
throw new IOException("Unknown property " + propertyType);
// FIXME: Should actually:
//header.skipBytes((int)size);
}
}
}
int nonEmptyFileCounter = 0;
int emptyFileCounter = 0;
for (int i = 0; i < files.length; i++) {
files[i].setHasStream(isEmptyStream == null ? true : !isEmptyStream.get(i));
if (files[i].hasStream()) {
files[i].setDirectory(false);
files[i].setAntiItem(false);
files[i].setHasCrc(archive.subStreamsInfo.hasCrc.get(nonEmptyFileCounter));
files[i].setCrcValue(archive.subStreamsInfo.crcs[nonEmptyFileCounter]);
files[i].setSize(archive.subStreamsInfo.unpackSizes[nonEmptyFileCounter]);
++nonEmptyFileCounter;
} else {
files[i].setDirectory(isEmptyFile == null ? true : !isEmptyFile.get(emptyFileCounter));
files[i].setAntiItem(isAnti == null ? false : isAnti.get(emptyFileCounter));
files[i].setHasCrc(false);
files[i].setSize(0);
++emptyFileCounter;
}
}
archive.files = files;
calculateStreamMap(archive);
}
private void calculateStreamMap(final Archive archive) throws IOException {
final StreamMap streamMap = new StreamMap();
int nextFolderPackStreamIndex = 0;
final int numFolders = archive.folders != null ? archive.folders.length : 0;
streamMap.folderFirstPackStreamIndex = new int[numFolders];
for (int i = 0; i < numFolders; i++) {
streamMap.folderFirstPackStreamIndex[i] = nextFolderPackStreamIndex;
nextFolderPackStreamIndex += archive.folders[i].packedStreams.length;
}
long nextPackStreamOffset = 0;
final int numPackSizes = archive.packSizes != null ? archive.packSizes.length : 0;
streamMap.packStreamOffsets = new long[numPackSizes];
for (int i = 0; i < numPackSizes; i++) {
streamMap.packStreamOffsets[i] = nextPackStreamOffset;
nextPackStreamOffset += archive.packSizes[i];
}
streamMap.folderFirstFileIndex = new int[numFolders];
streamMap.fileFolderIndex = new int[archive.files.length];
int nextFolderIndex = 0;
int nextFolderUnpackStreamIndex = 0;
for (int i = 0; i < archive.files.length; i++) {
if (!archive.files[i].hasStream() && nextFolderUnpackStreamIndex == 0) {
streamMap.fileFolderIndex[i] = -1;
continue;
}
if (nextFolderUnpackStreamIndex == 0) {
for (; nextFolderIndex < archive.folders.length; ++nextFolderIndex) {
streamMap.folderFirstFileIndex[nextFolderIndex] = i;
if (archive.folders[nextFolderIndex].numUnpackSubStreams > 0) {
break;
}
}
if (nextFolderIndex >= archive.folders.length) {
throw new IOException("Too few folders in archive");
}
}
streamMap.fileFolderIndex[i] = nextFolderIndex;
if (!archive.files[i].hasStream()) {
continue;
}
++nextFolderUnpackStreamIndex;
if (nextFolderUnpackStreamIndex >= archive.folders[nextFolderIndex].numUnpackSubStreams) {
++nextFolderIndex;
nextFolderUnpackStreamIndex = 0;
}
}
archive.streamMap = streamMap;
}
private void buildDecodingStream() throws IOException {
final int folderIndex = archive.streamMap.fileFolderIndex[currentEntryIndex];
if (folderIndex < 0) {
currentEntryInputStream = new BoundedInputStream(
new ByteArrayInputStream(new byte[0]), 0);
return;
}
if (currentFolderIndex == folderIndex) {
// need to advance the folder input stream past the current file
drainPreviousEntry();
} else {
currentFolderIndex = folderIndex;
if (currentFolderInputStream != null) {
currentFolderInputStream.close();
currentFolderInputStream = null;
}
final Folder folder = archive.folders[folderIndex];
final int firstPackStreamIndex = archive.streamMap.folderFirstPackStreamIndex[folderIndex];
final long folderOffset = SIGNATURE_HEADER_SIZE + archive.packPos +
archive.streamMap.packStreamOffsets[firstPackStreamIndex];
currentFolderInputStream = buildDecoderStack(folder, folderOffset, firstPackStreamIndex);
}
final SevenZArchiveEntry file = archive.files[currentEntryIndex];
final InputStream fileStream = new BoundedInputStream(
currentFolderInputStream, file.getSize());
if (file.getHasCrc()) {
currentEntryInputStream = new CRC32VerifyingInputStream(
fileStream, file.getSize(), file.getCrcValue());
} else {
currentEntryInputStream = fileStream;
}
}
private void drainPreviousEntry() throws IOException {
if (currentEntryInputStream != null) {
// return value ignored as IOUtils.skip ensures the stream is drained completely
IOUtils.skip(currentEntryInputStream, Long.MAX_VALUE);
currentEntryInputStream.close();
currentEntryInputStream = null;
}
}
private InputStream buildDecoderStack(final Folder folder, final long folderOffset,
final int firstPackStreamIndex) throws IOException {
file.seek(folderOffset);
InputStream inputStreamStack = new BoundedRandomAccessFileInputStream(file,
archive.packSizes[firstPackStreamIndex]);
for (final Coder coder : folder.coders) {
if (coder.numInStreams != 1 || coder.numOutStreams != 1) {
throw new IOException("Multi input/output stream coders are not yet supported");
}
inputStreamStack = Coders.addDecoder(inputStreamStack, coder, password);
}
if (folder.hasCrc) {
return new CRC32VerifyingInputStream(inputStreamStack,
folder.getUnpackSize(), folder.crc);
} else {
return inputStreamStack;
}
}
/**
* Reads a byte of data.
*
* @return the byte read, or -1 if end of input is reached
* @throws IOException
* if an I/O error has occurred
*/
public int read() throws IOException {
return currentEntryInputStream.read();
}
/**
* Reads data into an array of bytes.
*
* @param b the array to write data to
* @return the number of bytes read, or -1 if end of input is reached
* @throws IOException
* if an I/O error has occurred
*/
public int read(byte[] b) throws IOException {
return read(b, 0, b.length);
}
/**
* Reads data into an array of bytes.
*
* @param b the array to write data to
* @param off offset into the buffer to start filling at
* @param len of bytes to read
* @return the number of bytes read, or -1 if end of input is reached
* @throws IOException
* if an I/O error has occurred
*/
public int read(byte[] b, int off, int len) throws IOException {
return currentEntryInputStream.read(b, off, len);
}
private static long readUint64(final DataInput in) throws IOException {
// long rather than int as it might get shifted beyond the range of an int
long firstByte = in.readUnsignedByte();
int mask = 0x80;
long value = 0;
for (int i = 0; i < 8; i++) {
if ((firstByte & mask) == 0) {
return value | ((firstByte & (mask - 1)) << (8 * i));
}
long nextByte = in.readUnsignedByte();
value |= nextByte << (8 * i);
mask >>>= 1;
}
return value;
}
}