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8339169: Remove NaiveHuffman coder
Reviewed-by: djelinski, dfuchs
This commit is contained in:
Aleksei Efimov
parent
a136a85b6f
commit
03ba37e60c
@ -1,691 +0,0 @@
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/*
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* Copyright (c) 2014, 2018, Oracle and/or its affiliates. All rights reserved.
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* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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*
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* This code is free software; you can redistribute it and/or modify it
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* under the terms of the GNU General Public License version 2 only, as
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* published by the Free Software Foundation. Oracle designates this
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* particular file as subject to the "Classpath" exception as provided
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* by Oracle in the LICENSE file that accompanied this code.
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*
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* This code is distributed in the hope that it will be useful, but WITHOUT
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* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
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* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
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* version 2 for more details (a copy is included in the LICENSE file that
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* accompanied this code).
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*
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* You should have received a copy of the GNU General Public License version
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* 2 along with this work; if not, write to the Free Software Foundation,
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* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
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*
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* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
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* or visit www.oracle.com if you need additional information or have any
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* questions.
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*/
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package jdk.internal.net.http.hpack;
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import java.io.IOException;
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import java.nio.ByteBuffer;
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import static java.lang.String.format;
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/**
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* Huffman coding table.
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*
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* <p> Instances of this class are safe for use by multiple threads.
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*
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* @since 9
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*/
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public final class NaiveHuffman {
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// TODO: check if reset is done in both reader and writer
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static final class Reader implements Huffman.Reader {
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private Node curr; // position in the trie
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private int len; // length of the path from the root to 'curr'
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private int p; // byte probe
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{
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reset();
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}
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@Override
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public void read(ByteBuffer source,
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Appendable destination,
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boolean isLast) throws IOException {
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read(source, destination, true, isLast);
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}
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// Takes 'isLast' rather than returns whether the reading is done or
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// not, for more informative exceptions.
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void read(ByteBuffer source,
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Appendable destination,
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boolean reportEOS, /* reportEOS is exposed for tests */
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boolean isLast) throws IOException {
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Node c = curr;
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int l = len;
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/*
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Since ByteBuffer is itself stateful, its position is
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remembered here NOT as a part of Reader's state,
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but to set it back in the case of a failure
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*/
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int pos = source.position();
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while (source.hasRemaining()) {
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int d = source.get();
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for (; p != 0; p >>= 1) {
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c = c.getChild(p & d);
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l++;
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if (c.isLeaf()) {
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if (reportEOS && c.isEOSPath) {
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throw new IOException("Encountered EOS");
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}
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char ch;
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try {
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ch = c.getChar();
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} catch (IllegalStateException e) {
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source.position(pos); // do we need this?
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throw new IOException(e);
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}
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try {
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destination.append(ch);
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} catch (IOException e) {
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source.position(pos); // do we need this?
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throw e;
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}
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c = INSTANCE.root;
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l = 0;
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}
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curr = c;
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len = l;
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}
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resetProbe();
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pos++;
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}
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if (!isLast) {
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return; // it's too early to jump to any conclusions, let's wait
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}
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if (c.isLeaf()) {
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return; // it's perfectly ok, no extra padding bits
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}
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if (c.isEOSPath && len <= 7) {
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return; // it's ok, some extra padding bits
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}
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if (c.isEOSPath) {
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throw new IOException(
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"Padding is too long (len=" + len + ") " +
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"or unexpected end of data");
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}
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throw new IOException(
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"Not a EOS prefix padding or unexpected end of data");
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}
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@Override
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public void reset() {
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curr = INSTANCE.root;
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len = 0;
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resetProbe();
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}
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private void resetProbe() {
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p = 0x80;
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}
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}
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static final class Writer implements Huffman.Writer {
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private int pos; // position in 'source'
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private int avail = 8; // number of least significant bits available in 'curr'
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private int curr; // next byte to put to the destination
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private int rem; // number of least significant bits in 'code' yet to be processed
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private int code; // current code being written
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private CharSequence source;
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private int end;
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@Override
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public Writer from(CharSequence input, int start, int end) {
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if (start < 0 || end < 0 || end > input.length() || start > end) {
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throw new IndexOutOfBoundsException(
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String.format("input.length()=%s, start=%s, end=%s",
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input.length(), start, end));
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}
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pos = start;
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this.end = end;
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this.source = input;
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return this;
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}
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@Override
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public boolean write(ByteBuffer destination) {
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for (; pos < end; pos++) {
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if (rem == 0) {
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Code desc = INSTANCE.codeOf(source.charAt(pos));
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rem = desc.length;
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code = desc.code;
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}
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while (rem > 0) {
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if (rem < avail) {
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curr |= (code << (avail - rem));
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avail -= rem;
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rem = 0;
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} else {
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int c = (curr | (code >>> (rem - avail)));
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if (destination.hasRemaining()) {
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destination.put((byte) c);
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} else {
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return false;
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}
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curr = c;
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code <<= (32 - rem + avail); // throw written bits off the cliff (is this Sparta?)
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code >>>= (32 - rem + avail); // return to the position
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rem -= avail;
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curr = 0;
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avail = 8;
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}
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}
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}
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if (avail < 8) { // have to pad
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if (destination.hasRemaining()) {
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destination.put((byte) (curr | (INSTANCE.EOS.code >>> (INSTANCE.EOS.length - avail))));
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avail = 8;
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} else {
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return false;
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}
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}
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return true;
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}
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@Override
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public Writer reset() {
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source = null;
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end = -1;
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pos = -1;
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avail = 8;
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curr = 0;
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code = 0;
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return this;
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}
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@Override
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public int lengthOf(CharSequence value, int start, int end) {
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return INSTANCE.lengthOf(value, start, end);
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}
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}
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/**
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* Shared instance.
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*/
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public static final NaiveHuffman INSTANCE = new NaiveHuffman();
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private final Code EOS = new Code(0x3fffffff, 30);
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private final Code[] codes = new Code[257];
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private final Node root = new Node() {
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@Override
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public String toString() { return "root"; }
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};
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// TODO: consider builder and immutable trie
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private NaiveHuffman() {
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// @formatter:off
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addChar(0, 0x1ff8, 13);
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addChar(1, 0x7fffd8, 23);
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addChar(2, 0xfffffe2, 28);
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addChar(3, 0xfffffe3, 28);
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addChar(4, 0xfffffe4, 28);
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addChar(5, 0xfffffe5, 28);
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addChar(6, 0xfffffe6, 28);
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addChar(7, 0xfffffe7, 28);
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addChar(8, 0xfffffe8, 28);
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addChar(9, 0xffffea, 24);
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addChar(10, 0x3ffffffc, 30);
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addChar(11, 0xfffffe9, 28);
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addChar(12, 0xfffffea, 28);
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addChar(13, 0x3ffffffd, 30);
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addChar(14, 0xfffffeb, 28);
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addChar(15, 0xfffffec, 28);
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addChar(16, 0xfffffed, 28);
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addChar(17, 0xfffffee, 28);
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addChar(18, 0xfffffef, 28);
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addChar(19, 0xffffff0, 28);
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addChar(20, 0xffffff1, 28);
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addChar(21, 0xffffff2, 28);
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addChar(22, 0x3ffffffe, 30);
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addChar(23, 0xffffff3, 28);
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addChar(24, 0xffffff4, 28);
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addChar(25, 0xffffff5, 28);
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addChar(26, 0xffffff6, 28);
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addChar(27, 0xffffff7, 28);
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addChar(28, 0xffffff8, 28);
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addChar(29, 0xffffff9, 28);
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addChar(30, 0xffffffa, 28);
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addChar(31, 0xffffffb, 28);
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addChar(32, 0x14, 6);
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addChar(33, 0x3f8, 10);
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addChar(34, 0x3f9, 10);
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addChar(35, 0xffa, 12);
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addChar(36, 0x1ff9, 13);
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addChar(37, 0x15, 6);
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addChar(38, 0xf8, 8);
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addChar(39, 0x7fa, 11);
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addChar(40, 0x3fa, 10);
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addChar(41, 0x3fb, 10);
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addChar(42, 0xf9, 8);
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addChar(43, 0x7fb, 11);
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addChar(44, 0xfa, 8);
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addChar(45, 0x16, 6);
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addChar(46, 0x17, 6);
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addChar(47, 0x18, 6);
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addChar(48, 0x0, 5);
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addChar(49, 0x1, 5);
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addChar(50, 0x2, 5);
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addChar(51, 0x19, 6);
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addChar(52, 0x1a, 6);
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addChar(53, 0x1b, 6);
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addChar(54, 0x1c, 6);
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addChar(55, 0x1d, 6);
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addChar(56, 0x1e, 6);
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addChar(57, 0x1f, 6);
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addChar(58, 0x5c, 7);
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addChar(59, 0xfb, 8);
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addChar(60, 0x7ffc, 15);
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addChar(61, 0x20, 6);
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addChar(62, 0xffb, 12);
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addChar(63, 0x3fc, 10);
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addChar(64, 0x1ffa, 13);
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addChar(65, 0x21, 6);
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addChar(66, 0x5d, 7);
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addChar(67, 0x5e, 7);
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addChar(68, 0x5f, 7);
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addChar(69, 0x60, 7);
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addChar(70, 0x61, 7);
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addChar(71, 0x62, 7);
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addChar(72, 0x63, 7);
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addChar(73, 0x64, 7);
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addChar(74, 0x65, 7);
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addChar(75, 0x66, 7);
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addChar(76, 0x67, 7);
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addChar(77, 0x68, 7);
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addChar(78, 0x69, 7);
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addChar(79, 0x6a, 7);
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addChar(80, 0x6b, 7);
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addChar(81, 0x6c, 7);
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addChar(82, 0x6d, 7);
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addChar(83, 0x6e, 7);
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addChar(84, 0x6f, 7);
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addChar(85, 0x70, 7);
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addChar(86, 0x71, 7);
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addChar(87, 0x72, 7);
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addChar(88, 0xfc, 8);
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addChar(89, 0x73, 7);
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addChar(90, 0xfd, 8);
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addChar(91, 0x1ffb, 13);
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addChar(92, 0x7fff0, 19);
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addChar(93, 0x1ffc, 13);
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addChar(94, 0x3ffc, 14);
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addChar(95, 0x22, 6);
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addChar(96, 0x7ffd, 15);
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addChar(97, 0x3, 5);
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addChar(98, 0x23, 6);
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addChar(99, 0x4, 5);
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addChar(100, 0x24, 6);
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addChar(101, 0x5, 5);
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addChar(102, 0x25, 6);
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addChar(103, 0x26, 6);
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addChar(104, 0x27, 6);
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addChar(105, 0x6, 5);
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addChar(106, 0x74, 7);
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addChar(107, 0x75, 7);
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addChar(108, 0x28, 6);
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addChar(109, 0x29, 6);
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addChar(110, 0x2a, 6);
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addChar(111, 0x7, 5);
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addChar(112, 0x2b, 6);
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addChar(113, 0x76, 7);
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addChar(114, 0x2c, 6);
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addChar(115, 0x8, 5);
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addChar(116, 0x9, 5);
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addChar(117, 0x2d, 6);
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addChar(118, 0x77, 7);
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addChar(119, 0x78, 7);
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addChar(120, 0x79, 7);
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addChar(121, 0x7a, 7);
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addChar(122, 0x7b, 7);
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addChar(123, 0x7ffe, 15);
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addChar(124, 0x7fc, 11);
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addChar(125, 0x3ffd, 14);
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addChar(126, 0x1ffd, 13);
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addChar(127, 0xffffffc, 28);
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addChar(128, 0xfffe6, 20);
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addChar(129, 0x3fffd2, 22);
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addChar(130, 0xfffe7, 20);
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addChar(131, 0xfffe8, 20);
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addChar(132, 0x3fffd3, 22);
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addChar(133, 0x3fffd4, 22);
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addChar(134, 0x3fffd5, 22);
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addChar(135, 0x7fffd9, 23);
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addChar(136, 0x3fffd6, 22);
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addChar(137, 0x7fffda, 23);
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addChar(138, 0x7fffdb, 23);
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addChar(139, 0x7fffdc, 23);
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addChar(140, 0x7fffdd, 23);
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addChar(141, 0x7fffde, 23);
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addChar(142, 0xffffeb, 24);
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addChar(143, 0x7fffdf, 23);
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addChar(144, 0xffffec, 24);
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addChar(145, 0xffffed, 24);
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addChar(146, 0x3fffd7, 22);
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addChar(147, 0x7fffe0, 23);
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addChar(148, 0xffffee, 24);
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addChar(149, 0x7fffe1, 23);
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addChar(150, 0x7fffe2, 23);
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addChar(151, 0x7fffe3, 23);
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addChar(152, 0x7fffe4, 23);
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addChar(153, 0x1fffdc, 21);
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addChar(154, 0x3fffd8, 22);
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addChar(155, 0x7fffe5, 23);
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addChar(156, 0x3fffd9, 22);
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addChar(157, 0x7fffe6, 23);
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addChar(158, 0x7fffe7, 23);
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addChar(159, 0xffffef, 24);
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addChar(160, 0x3fffda, 22);
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addChar(161, 0x1fffdd, 21);
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addChar(162, 0xfffe9, 20);
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addChar(163, 0x3fffdb, 22);
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addChar(164, 0x3fffdc, 22);
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addChar(165, 0x7fffe8, 23);
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addChar(166, 0x7fffe9, 23);
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addChar(167, 0x1fffde, 21);
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addChar(168, 0x7fffea, 23);
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addChar(169, 0x3fffdd, 22);
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addChar(170, 0x3fffde, 22);
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addChar(171, 0xfffff0, 24);
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addChar(172, 0x1fffdf, 21);
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addChar(173, 0x3fffdf, 22);
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addChar(174, 0x7fffeb, 23);
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addChar(175, 0x7fffec, 23);
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addChar(176, 0x1fffe0, 21);
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addChar(177, 0x1fffe1, 21);
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addChar(178, 0x3fffe0, 22);
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addChar(179, 0x1fffe2, 21);
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addChar(180, 0x7fffed, 23);
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addChar(181, 0x3fffe1, 22);
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addChar(182, 0x7fffee, 23);
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addChar(183, 0x7fffef, 23);
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addChar(184, 0xfffea, 20);
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addChar(185, 0x3fffe2, 22);
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addChar(186, 0x3fffe3, 22);
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addChar(187, 0x3fffe4, 22);
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addChar(188, 0x7ffff0, 23);
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addChar(189, 0x3fffe5, 22);
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addChar(190, 0x3fffe6, 22);
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addChar(191, 0x7ffff1, 23);
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addChar(192, 0x3ffffe0, 26);
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addChar(193, 0x3ffffe1, 26);
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addChar(194, 0xfffeb, 20);
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addChar(195, 0x7fff1, 19);
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addChar(196, 0x3fffe7, 22);
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addChar(197, 0x7ffff2, 23);
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addChar(198, 0x3fffe8, 22);
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addChar(199, 0x1ffffec, 25);
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addChar(200, 0x3ffffe2, 26);
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addChar(201, 0x3ffffe3, 26);
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addChar(202, 0x3ffffe4, 26);
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addChar(203, 0x7ffffde, 27);
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addChar(204, 0x7ffffdf, 27);
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addChar(205, 0x3ffffe5, 26);
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addChar(206, 0xfffff1, 24);
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addChar(207, 0x1ffffed, 25);
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addChar(208, 0x7fff2, 19);
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addChar(209, 0x1fffe3, 21);
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addChar(210, 0x3ffffe6, 26);
|
||||
addChar(211, 0x7ffffe0, 27);
|
||||
addChar(212, 0x7ffffe1, 27);
|
||||
addChar(213, 0x3ffffe7, 26);
|
||||
addChar(214, 0x7ffffe2, 27);
|
||||
addChar(215, 0xfffff2, 24);
|
||||
addChar(216, 0x1fffe4, 21);
|
||||
addChar(217, 0x1fffe5, 21);
|
||||
addChar(218, 0x3ffffe8, 26);
|
||||
addChar(219, 0x3ffffe9, 26);
|
||||
addChar(220, 0xffffffd, 28);
|
||||
addChar(221, 0x7ffffe3, 27);
|
||||
addChar(222, 0x7ffffe4, 27);
|
||||
addChar(223, 0x7ffffe5, 27);
|
||||
addChar(224, 0xfffec, 20);
|
||||
addChar(225, 0xfffff3, 24);
|
||||
addChar(226, 0xfffed, 20);
|
||||
addChar(227, 0x1fffe6, 21);
|
||||
addChar(228, 0x3fffe9, 22);
|
||||
addChar(229, 0x1fffe7, 21);
|
||||
addChar(230, 0x1fffe8, 21);
|
||||
addChar(231, 0x7ffff3, 23);
|
||||
addChar(232, 0x3fffea, 22);
|
||||
addChar(233, 0x3fffeb, 22);
|
||||
addChar(234, 0x1ffffee, 25);
|
||||
addChar(235, 0x1ffffef, 25);
|
||||
addChar(236, 0xfffff4, 24);
|
||||
addChar(237, 0xfffff5, 24);
|
||||
addChar(238, 0x3ffffea, 26);
|
||||
addChar(239, 0x7ffff4, 23);
|
||||
addChar(240, 0x3ffffeb, 26);
|
||||
addChar(241, 0x7ffffe6, 27);
|
||||
addChar(242, 0x3ffffec, 26);
|
||||
addChar(243, 0x3ffffed, 26);
|
||||
addChar(244, 0x7ffffe7, 27);
|
||||
addChar(245, 0x7ffffe8, 27);
|
||||
addChar(246, 0x7ffffe9, 27);
|
||||
addChar(247, 0x7ffffea, 27);
|
||||
addChar(248, 0x7ffffeb, 27);
|
||||
addChar(249, 0xffffffe, 28);
|
||||
addChar(250, 0x7ffffec, 27);
|
||||
addChar(251, 0x7ffffed, 27);
|
||||
addChar(252, 0x7ffffee, 27);
|
||||
addChar(253, 0x7ffffef, 27);
|
||||
addChar(254, 0x7fffff0, 27);
|
||||
addChar(255, 0x3ffffee, 26);
|
||||
addEOS (256, EOS.code, EOS.length);
|
||||
// @formatter:on
|
||||
}
|
||||
|
||||
|
||||
/**
|
||||
* Calculates the number of bytes required to represent the given {@code
|
||||
* CharSequence} with the Huffman coding.
|
||||
*
|
||||
* @param value
|
||||
* characters
|
||||
*
|
||||
* @return number of bytes
|
||||
*
|
||||
* @throws NullPointerException
|
||||
* if the value is null
|
||||
*/
|
||||
public int lengthOf(CharSequence value) {
|
||||
return lengthOf(value, 0, value.length());
|
||||
}
|
||||
|
||||
/**
|
||||
* Calculates the number of bytes required to represent a subsequence of the
|
||||
* given {@code CharSequence} with the Huffman coding.
|
||||
*
|
||||
* @param value
|
||||
* characters
|
||||
* @param start
|
||||
* the start index, inclusive
|
||||
* @param end
|
||||
* the end index, exclusive
|
||||
*
|
||||
* @return number of bytes
|
||||
*
|
||||
* @throws NullPointerException
|
||||
* if the value is null
|
||||
* @throws IndexOutOfBoundsException
|
||||
* if any invocation of {@code value.charAt(i)}, where
|
||||
* {@code start <= i < end} would throw an IndexOutOfBoundsException
|
||||
*/
|
||||
public int lengthOf(CharSequence value, int start, int end) {
|
||||
int len = 0;
|
||||
for (int i = start; i < end; i++) {
|
||||
char c = value.charAt(i);
|
||||
len += INSTANCE.codeOf(c).length;
|
||||
}
|
||||
// Integer division with ceiling, assumption:
|
||||
assert (len / 8 + (len % 8 != 0 ? 1 : 0)) == (len + 7) / 8 : len;
|
||||
return (len + 7) / 8;
|
||||
}
|
||||
|
||||
private void addChar(int c, int code, int bitLength) {
|
||||
addLeaf(c, code, bitLength, false);
|
||||
codes[c] = new Code(code, bitLength);
|
||||
}
|
||||
|
||||
private void addEOS(int c, int code, int bitLength) {
|
||||
addLeaf(c, code, bitLength, true);
|
||||
codes[c] = new Code(code, bitLength);
|
||||
}
|
||||
|
||||
private void addLeaf(int c, int code, int bitLength, boolean isEOS) {
|
||||
if (bitLength < 1) {
|
||||
throw new IllegalArgumentException("bitLength < 1");
|
||||
}
|
||||
Node curr = root;
|
||||
for (int p = 1 << bitLength - 1; p != 0 && !curr.isLeaf(); p = p >> 1) {
|
||||
curr.isEOSPath |= isEOS; // If it's already true, it can't become false
|
||||
curr = curr.addChildIfAbsent(p & code);
|
||||
}
|
||||
curr.isEOSPath |= isEOS; // The last one needs to have this property as well
|
||||
if (curr.isLeaf()) {
|
||||
throw new IllegalStateException("Specified code is already taken");
|
||||
}
|
||||
curr.setChar((char) c);
|
||||
}
|
||||
|
||||
private Code codeOf(char c) {
|
||||
if (c > 255) {
|
||||
throw new IllegalArgumentException("char=" + ((int) c));
|
||||
}
|
||||
return codes[c];
|
||||
}
|
||||
|
||||
//
|
||||
// For debugging/testing purposes
|
||||
//
|
||||
Node getRoot() {
|
||||
return root;
|
||||
}
|
||||
|
||||
//
|
||||
// Guarantees:
|
||||
//
|
||||
// if (isLeaf() == true) => getChar() is a legal call
|
||||
// if (isLeaf() == false) => getChild(i) is a legal call (though it can
|
||||
// return null)
|
||||
//
|
||||
static class Node {
|
||||
|
||||
Node left;
|
||||
Node right;
|
||||
boolean isEOSPath;
|
||||
|
||||
boolean charIsSet;
|
||||
char c;
|
||||
|
||||
Node getChild(int selector) {
|
||||
if (isLeaf()) {
|
||||
throw new IllegalStateException("This is a leaf node");
|
||||
}
|
||||
Node result = selector == 0 ? left : right;
|
||||
if (result == null) {
|
||||
throw new IllegalStateException(format(
|
||||
"Node doesn't have a child (selector=%s)", selector));
|
||||
}
|
||||
return result;
|
||||
}
|
||||
|
||||
boolean isLeaf() {
|
||||
return charIsSet;
|
||||
}
|
||||
|
||||
char getChar() {
|
||||
if (!isLeaf()) {
|
||||
throw new IllegalStateException("This node is not a leaf node");
|
||||
}
|
||||
return c;
|
||||
}
|
||||
|
||||
void setChar(char c) {
|
||||
if (charIsSet) {
|
||||
throw new IllegalStateException(
|
||||
"This node has been taken already");
|
||||
}
|
||||
if (left != null || right != null) {
|
||||
throw new IllegalStateException("The node cannot be made "
|
||||
+ "a leaf as it's already has a child");
|
||||
}
|
||||
this.c = c;
|
||||
charIsSet = true;
|
||||
}
|
||||
|
||||
Node addChildIfAbsent(int i) {
|
||||
if (charIsSet) {
|
||||
throw new IllegalStateException("The node cannot have a child "
|
||||
+ "as it's already a leaf node");
|
||||
}
|
||||
Node child;
|
||||
if (i == 0) {
|
||||
if ((child = left) == null) {
|
||||
child = left = new Node();
|
||||
}
|
||||
} else {
|
||||
if ((child = right) == null) {
|
||||
child = right = new Node();
|
||||
}
|
||||
}
|
||||
return child;
|
||||
}
|
||||
|
||||
@Override
|
||||
public String toString() {
|
||||
if (isLeaf()) {
|
||||
if (isEOSPath) {
|
||||
return "EOS";
|
||||
} else {
|
||||
return format("char: (%3s) '%s'", (int) c, c);
|
||||
}
|
||||
}
|
||||
return "/\\";
|
||||
}
|
||||
}
|
||||
|
||||
// TODO: value-based class?
|
||||
// FIXME: can we re-use Node instead of this class?
|
||||
private static final class Code {
|
||||
|
||||
final int code;
|
||||
final int length;
|
||||
|
||||
private Code(int code, int length) {
|
||||
this.code = code;
|
||||
this.length = length;
|
||||
}
|
||||
|
||||
public int getCode() {
|
||||
return code;
|
||||
}
|
||||
|
||||
public int getLength() {
|
||||
return length;
|
||||
}
|
||||
|
||||
@Override
|
||||
public String toString() {
|
||||
long p = 1 << length;
|
||||
return Long.toBinaryString(code + p).substring(1)
|
||||
+ ", length=" + length;
|
||||
}
|
||||
}
|
||||
}
|
||||
Loading…
x
Reference in New Issue
Block a user