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315 lines (285 loc) · 10.8 KB
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/*
* Copyright (c) 2009, 2025, 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.nio.ByteBuffer;
import java.nio.CharBuffer;
import java.nio.charset.Charset;
import java.nio.charset.CharsetDecoder;
import java.nio.charset.CharsetEncoder;
import java.nio.charset.CharacterCodingException;
import java.nio.charset.CodingErrorAction;
import java.nio.charset.StandardCharsets;
import java.util.Arrays;
import jdk.internal.util.ArraysSupport;
import sun.nio.cs.UTF_8;
/**
* Utility class for ZIP file entry name and comment decoding and encoding.
* <p>
* The {@code ZipCoder} for UTF-8 charset is thread safe, {@code ZipCoder}
* for other charsets require external synchronization.
*/
class ZipCoder {
private static final jdk.internal.access.JavaLangAccess JLA =
jdk.internal.access.SharedSecrets.getJavaLangAccess();
// Encoding/decoding is stateless, so make it singleton.
static final UTF8ZipCoder UTF8 = new UTF8ZipCoder(UTF_8.INSTANCE);
public static ZipCoder get(Charset charset) {
if (charset == UTF_8.INSTANCE) {
return UTF8;
}
return new ZipCoder(charset);
}
/**
* Constants representing the three possible return values for
* {@link #compare(String, byte[], int, int, boolean)} when
* this method compares a lookup name to a string encoded in the
* CEN byte array.
*/
static final byte
/*
* The lookup string is exactly equal
* to the encoded string.
*/
EXACT_MATCH = 0,
/*
* The lookup string and the encoded string differs only
* by the encoded string having a trailing '/' character.
*/
DIRECTORY_MATCH = 1,
/*
* The lookup string and the encoded string do not match.
* (They are neither an exact match or a directory match.)
*/
NO_MATCH = 2;
String toString(byte[] ba, int off, int length) {
try {
return decoder().decode(ByteBuffer.wrap(ba, off, length)).toString();
} catch (CharacterCodingException x) {
throw new IllegalArgumentException(x);
}
}
String toString(byte[] ba, int length) {
return toString(ba, 0, length);
}
String toString(byte[] ba) {
return toString(ba, 0, ba.length);
}
byte[] getBytes(String s) {
try {
ByteBuffer bb = encoder().encode(CharBuffer.wrap(s));
int pos = bb.position();
int limit = bb.limit();
if (bb.hasArray() && pos == 0 && limit == bb.capacity()) {
return bb.array();
}
byte[] bytes = new byte[bb.limit() - bb.position()];
bb.get(bytes);
return bytes;
} catch (CharacterCodingException x) {
throw new IllegalArgumentException(x);
}
}
static String toStringUTF8(byte[] ba, int len) {
return UTF8.toString(ba, 0, len);
}
boolean isUTF8() {
return false;
}
// Hash code functions for ZipFile entry names. We generate the hash as-if
// we first decoded the byte sequence to a String, then appended '/' if no
// trailing slash was found, then called String.hashCode(). This
// normalization ensures we can simplify and speed up lookups.
//
// Does encoding error checking and hashing in a single pass for efficiency.
// On an error, this function will throw CharacterCodingException while the
// UTF8ZipCoder override will throw IllegalArgumentException, so we declare
// throws Exception to keep things simple.
int checkedHash(byte[] a, int off, int len) throws Exception {
if (len == 0) {
return 0;
}
int h = 0;
// cb will be a newly allocated CharBuffer with pos == 0,
// arrayOffset == 0, backed by an array.
CharBuffer cb = decoder().decode(ByteBuffer.wrap(a, off, len));
int limit = cb.limit();
char[] decoded = cb.array();
for (int i = 0; i < limit; i++) {
h = 31 * h + decoded[i];
}
if (limit > 0 && decoded[limit - 1] != '/') {
h = 31 * h + '/';
}
return h;
}
// Hash function equivalent of checkedHash for String inputs
static int hash(String name) {
int hsh = name.hashCode();
int len = name.length();
if (len > 0 && name.charAt(len - 1) != '/') {
hsh = hsh * 31 + '/';
}
return hsh;
}
private final Charset cs;
protected CharsetDecoder dec;
private CharsetEncoder enc;
private ZipCoder(Charset cs) {
this.cs = cs;
}
protected CharsetDecoder decoder() {
if (dec == null) {
dec = cs.newDecoder()
.onMalformedInput(CodingErrorAction.REPORT)
.onUnmappableCharacter(CodingErrorAction.REPORT);
}
return dec;
}
/**
* {@return the {@link Charset} used by this {@code ZipCoder}}
*/
final Charset charset() {
return this.cs;
}
private CharsetEncoder encoder() {
if (enc == null) {
enc = cs.newEncoder()
.onMalformedInput(CodingErrorAction.REPORT)
.onUnmappableCharacter(CodingErrorAction.REPORT);
}
return enc;
}
/**
* This method is used by ZipFile.Source.getEntryPos when comparing the
* name being looked up to candidate names encoded in the CEN byte
* array.
*
* Since ZipCode.getEntry supports looking up a "dir/" entry by
* the name "dir", this method can optionally distinguish an
* exact match from a partial "directory match" (where names only
* differ by the encoded name having an additional trailing '/')
*
* The return values of this method are as follows:
*
* If the lookup name is exactly equal to the encoded string, return
* {@link EXACT_MATCH}.
*
* If the parameter {@code matchDirectory} is {@code true} and the
* two strings differ only by the encoded string having an extra
* trailing '/' character, then return {@link DIRECTORY_MATCH}.
*
* Otherwise, return {@link NO_MATCH}
*
* While a general implementation will need to decode bytes into a
* String for comparison, this can be avoided if the String coder
* and this ZipCoder are known to encode strings to the same bytes.
*
* @param str The lookup string to compare with the encoded string.
* @param b The byte array holding the encoded string
* @param off The offset into the array where the encoded string starts
* @param len The length of the encoded string in bytes
* @param matchDirectory If {@code true} and the strings do not match exactly,
* a directory match will also be tested
*
*/
byte compare(String str, byte[] b, int off, int len, boolean matchDirectory) {
String decoded = toString(b, off, len);
if (decoded.startsWith(str)) {
if (decoded.length() == str.length()) {
return EXACT_MATCH;
} else if (matchDirectory
&& decoded.length() == str.length() + 1
&& decoded.endsWith("/") ) {
return DIRECTORY_MATCH;
}
}
return NO_MATCH;
}
static final class UTF8ZipCoder extends ZipCoder {
private UTF8ZipCoder(Charset utf8) {
super(utf8);
}
@Override
boolean isUTF8() {
return true;
}
@Override
String toString(byte[] ba, int off, int length) {
try {
// Copy subrange for exclusive use by the string being created
byte[] bytes = Arrays.copyOfRange(ba, off, off + length);
return JLA.uncheckedNewStringOrThrow(bytes, StandardCharsets.UTF_8);
} catch (CharacterCodingException cce) {
throw new IllegalArgumentException(cce);
}
}
@Override
byte[] getBytes(String s) {
try {
return JLA.getBytesUTF8OrThrow(s);
} catch (CharacterCodingException cce) {
throw new IllegalArgumentException(cce);
}
}
@Override
int checkedHash(byte[] a, int off, int len) throws Exception {
if (len == 0) {
return 0;
}
int end = off + len;
int asciiLen = JLA.countPositives(a, off, len);
if (asciiLen != len) {
// Non-ASCII, fall back to decoding a String
// We avoid using decoder() here since the UTF8ZipCoder is
// shared and that decoder is not thread safe.
return hash(toString(a, off, len));
}
int h = ArraysSupport.hashCodeOfUnsigned(a, off, len, 0);
if (a[end - 1] != '/') {
h = 31 * h + '/';
}
return h;
}
private boolean hasTrailingSlash(byte[] a, int end) {
return end > 0 && a[end - 1] == '/';
}
@Override
byte compare(String str, byte[] b, int off, int len, boolean matchDirectory) {
try {
byte[] encoded = JLA.uncheckedGetBytesOrThrow(str, UTF_8.INSTANCE);
int mismatch = Arrays.mismatch(encoded, 0, encoded.length, b, off, off+len);
if (mismatch == -1) {
return EXACT_MATCH;
} else if (matchDirectory && len == mismatch + 1 && hasTrailingSlash(b, off + len)) {
return DIRECTORY_MATCH;
} else {
return NO_MATCH;
}
} catch (CharacterCodingException e) {
return NO_MATCH;
}
}
}
}