/*
* Copyright (C) 2014 The Android Open Source Project
* Copyright (c) 1996, 2021, 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 java.util.zip;
import java.io.FilterInputStream;
import java.io.InputStream;
import java.io.IOException;
import java.io.EOFException;
/**
* This class implements a stream filter for uncompressing data in the
* "deflate" compression format. It is also used as the basis for other
* decompression filters, such as GZIPInputStream.
*
* @see Inflater
* @author David Connelly
* @since 1.1
*/
public class InflaterInputStream extends FilterInputStream {
/**
* Decompressor for this stream.
*/
protected Inflater inf;
/**
* Input buffer for decompression.
*/
protected byte[] buf;
/**
* Length of input buffer.
*/
protected int len;
// Android-changed: Make closed accessible to subclasses.
// This was made protected because it needed to be accessed by
// StrictJarFile.ZipInflaterInputStream. Unfortunately, it was not marked as @hide and so it
// inadvertently became part of the public API. It will be marked as @removed to remove it from
// the public API in a future release of Android. See http://b/111592689 for more information.
// private boolean closed = false;
/**
* Indicates whether the {@link #close()} method has been called, internal use only.
*
* @deprecated This field will be removed from a future version of Android and should not be
* used. Subclasses that access this field need to be modified to keep track of their own
* closed state by overriding close().
*/
@Deprecated
protected boolean closed = false;
// this flag is set to true after EOF has reached
private boolean reachEOF = false;
/**
* Check to make sure that this stream has not been closed
*/
private void ensureOpen() throws IOException {
if (closed) {
throw new IOException("Stream closed");
}
}
// Android-added: constructor which explicitly sets whether Inflater is owned by this stream.
/**
* Creates a new input stream with the specified decompressor and
* buffer size.
* @param in the input stream
* @param inf the decompressor ("inflater")
* @param size the input buffer size
* @param ownsInflater whether this {@code InflaterInputStream} controls its inflater
* lifetime and should call {@link Inflater#end} when it is closed.
* @throws IllegalArgumentException if {@code size <= 0}
* @hide
*/
InflaterInputStream(InputStream in, Inflater inf, int size, boolean ownsInflater) {
super(in);
if (in == null || inf == null) {
throw new NullPointerException();
} else if (size <= 0) {
throw new IllegalArgumentException("buffer size <= 0");
}
this.inf = inf;
buf = new byte[size];
this.ownsInflater = ownsInflater;
}
/**
* Creates a new input stream with the specified decompressor and
* buffer size.
* @param in the input stream
* @param inf the decompressor ("inflater")
* @param size the input buffer size
* @throws IllegalArgumentException if {@code size <= 0}
*/
public InflaterInputStream(InputStream in, Inflater inf, int size) {
// Android-changed: refer initialization to constructor which specifies ownInflater.
/*
super(in);
if (in == null || inf == null) {
throw new NullPointerException();
} else if (size <= 0) {
throw new IllegalArgumentException("buffer size <= 0");
}
this.inf = inf;
buf = new byte[size];
*/
this(in, inf, size, /* ownsInflater= */ true);
}
/**
* Creates a new input stream with the specified decompressor and a
* default buffer size.
* @param in the input stream
* @param inf the decompressor ("inflater")
*/
public InflaterInputStream(InputStream in, Inflater inf) {
this(in, inf, 512);
}
// Android-changed: Unconditionally close external inflaters (b/26462400)
// See http://b/111630946 for more details.
// boolean usesDefaultInflater = false;
// Android-added: functionally this is identical to usesDefaultInflater, but re-using
// it will be confusing. Setting it to true keeps old Android behaviour.
// This is added just for ZipFileInflaterInputStream - moving to usesDefaultInflater
// is trickier.
private final boolean ownsInflater;
/**
* Creates a new input stream with a default decompressor and buffer size.
* @param in the input stream
*/
public InflaterInputStream(InputStream in) {
this(in, in != null ? new Inflater() : null);
// Android-changed: Unconditionally close external inflaters (b/26462400)
// usesDefaultInflater = true;
}
private byte[] singleByteBuf = new byte[1];
/**
* Reads a byte of uncompressed data. This method will block until
* enough input is available for decompression.
* @return the byte read, or -1 if end of compressed input is reached
* @throws IOException if an I/O error has occurred
*/
public int read() throws IOException {
ensureOpen();
return read(singleByteBuf, 0, 1) == -1 ? -1 : Byte.toUnsignedInt(singleByteBuf[0]);
}
/**
* Reads uncompressed data into an array of bytes. If {@code len} is not
* zero, the method will block until some input can be decompressed; otherwise,
* no bytes are read and {@code 0} is returned.
* @param b the buffer into which the data is read
* @param off the start offset in the destination array {@code b}
* @param len the maximum number of bytes read
* @return the actual number of bytes read, or -1 if the end of the
* compressed input is reached or a preset dictionary is needed
* @throws NullPointerException If {@code b} is {@code null}.
* @throws IndexOutOfBoundsException If {@code off} is negative,
* {@code len} is negative, or {@code len} is greater than
* {@code b.length - off}
* @throws ZipException if a ZIP format error has occurred
* @throws IOException if an I/O error has occurred
*/
public int read(byte[] b, int off, int len) throws IOException {
ensureOpen();
if (b == null) {
throw new NullPointerException();
} else if (off < 0 || len < 0 || len > b.length - off) {
throw new IndexOutOfBoundsException();
} else if (len == 0) {
return 0;
}
try {
int n;
while ((n = inf.inflate(b, off, len)) == 0) {
if (inf.finished() || inf.needsDictionary()) {
reachEOF = true;
return -1;
}
if (inf.needsInput()) {
fill();
}
}
return n;
} catch (DataFormatException e) {
String s = e.getMessage();
throw new ZipException(s != null ? s : "Invalid ZLIB data format");
}
}
/**
* Returns 0 after EOF has been reached, otherwise always return 1.
*
* Programs should not count on this method to return the actual number
* of bytes that could be read without blocking.
*
* @return 1 before EOF and 0 after EOF.
* @throws IOException if an I/O error occurs.
*
*/
public int available() throws IOException {
ensureOpen();
if (reachEOF) {
return 0;
} else if (inf.finished()) {
// the end of the compressed data stream has been reached
reachEOF = true;
return 0;
} else {
return 1;
}
}
private byte[] b = new byte[512];
/**
* Skips specified number of bytes of uncompressed data.
* @param n the number of bytes to skip
* @return the actual number of bytes skipped.
* @throws IOException if an I/O error has occurred
* @throws IllegalArgumentException if {@code n < 0}
*/
public long skip(long n) throws IOException {
if (n < 0) {
throw new IllegalArgumentException("negative skip length");
}
ensureOpen();
int max = (int)Math.min(n, Integer.MAX_VALUE);
int total = 0;
while (total < max) {
int len = max - total;
if (len > b.length) {
len = b.length;
}
len = read(b, 0, len);
if (len == -1) {
reachEOF = true;
break;
}
total += len;
}
return total;
}
/**
* Closes this input stream and releases any system resources associated
* with the stream.
* @throws IOException if an I/O error has occurred
*/
public void close() throws IOException {
if (!closed) {
// BEGIN Android-changed: close inflater only if it is owned by this
// InflaterInputStream. (b/26462400)
/*
if (usesDefaultInflater)
inf.end();
*/
if (ownsInflater) {
inf.end();
}
// END Android-changed: close inflater only if it is owned by this
// InflaterInputStream. (b/26462400)
in.close();
closed = true;
}
}
/**
* Fills input buffer with more data to decompress.
* @throws IOException if an I/O error has occurred
*/
protected void fill() throws IOException {
ensureOpen();
len = in.read(buf, 0, buf.length);
if (len == -1) {
throw new EOFException("Unexpected end of ZLIB input stream");
}
inf.setInput(buf, 0, len);
}
/**
* Tests if this input stream supports the {@code mark} and
* {@code reset} methods. The {@code markSupported}
* method of {@code InflaterInputStream} returns
* {@code false}.
*
* @return a {@code boolean} indicating if this stream type supports
* the {@code mark} and {@code reset} methods.
* @see java.io.InputStream#mark(int)
* @see java.io.InputStream#reset()
*/
public boolean markSupported() {
return false;
}
/**
* Marks the current position in this input stream.
*
*
The {@code mark} method of {@code InflaterInputStream}
* does nothing.
*
* @param readlimit the maximum limit of bytes that can be read before
* the mark position becomes invalid.
* @see java.io.InputStream#reset()
*/
public synchronized void mark(int readlimit) {
}
/**
* Repositions this stream to the position at the time the
* {@code mark} method was last called on this input stream.
*
*
The method {@code reset} for class
* {@code InflaterInputStream} does nothing except throw an
* {@code IOException}.
*
* @throws IOException if this method is invoked.
* @see java.io.InputStream#mark(int)
* @see java.io.IOException
*/
public synchronized void reset() throws IOException {
throw new IOException("mark/reset not supported");
}
}