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321 lines
10 KiB
321 lines
10 KiB
// BDecoder.java
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// -----------------------
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// part of YaCy
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// (C) by Michael Peter Christen; mc@yacy.net
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// first published on http://www.anomic.de
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// Frankfurt, Germany, 2010
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// Created 03.01.2010
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//
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// $LastChangedDate$
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// $LastChangedRevision$
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// $LastChangedBy$
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//
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// this is an BDecoder implementation according to http://wiki.theory.org/BitTorrentSpecification
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//
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// This program is free software; you can redistribute it and/or modify
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// it under the terms of the GNU General Public License as published by
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// the Free Software Foundation; either version 2 of the License, or
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// (at your option) any later version.
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//
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// This program is distributed in the hope that it will be useful,
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// but WITHOUT ANY WARRANTY; without even the implied warranty of
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// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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// GNU General Public License for more details.
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//
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// You should have received a copy of the GNU General Public License
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// along with this program; if not, write to the Free Software
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// Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
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package net.yacy.kelondro.util;
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import java.io.File;
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import java.io.IOException;
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import java.io.OutputStream;
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import java.util.ArrayList;
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import java.util.LinkedHashMap;
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import java.util.List;
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import java.util.Map;
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import net.yacy.cora.document.UTF8;
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public class BDecoder {
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final static byte[] _e = "e".getBytes();
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final static byte[] _i = "i".getBytes();
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final static byte[] _d = "d".getBytes();
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final static byte[] _l = "l".getBytes();
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final static byte[] _p = ":".getBytes();
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private final byte[] b;
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private int pos;
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public BDecoder(byte[] b) {
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this.b = b;
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this.pos = 0;
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}
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public static enum BType {
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string, integer, list, dictionary;
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}
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public static interface BObject {
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public BType getType();
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public byte[] getString();
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public long getInteger();
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public List<BObject> getList();
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public Map<String, BObject> getMap();
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@Override
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public String toString();
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public void toStream(OutputStream os) throws IOException;
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}
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public static abstract class BDfltObject implements BObject {
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public long getInteger() {
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throw new UnsupportedOperationException();
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}
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public List<BObject> getList() {
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throw new UnsupportedOperationException();
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}
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public Map<String, BObject> getMap() {
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throw new UnsupportedOperationException();
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}
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public byte[] getString() {
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throw new UnsupportedOperationException();
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}
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public BType getType() {
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throw new UnsupportedOperationException();
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}
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@Override
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public String toString() {
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throw new UnsupportedOperationException();
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}
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}
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public static class BStringObject extends BDfltObject implements BObject {
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private byte[] b;
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public BStringObject(byte[] b) {
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this.b = b;
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}
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@Override
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public BType getType() {
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return BType.string;
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}
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@Override
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public byte[] getString() {
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return this.b;
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}
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@Override
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public String toString() {
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return UTF8.String(this.b);
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}
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public void toStream(OutputStream os) throws IOException {
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os.write(UTF8.getBytes(Integer.toString(this.b.length)));
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os.write(_p);
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os.write(this.b);
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}
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public static void toStream(OutputStream os, byte[] b) throws IOException {
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os.write(UTF8.getBytes(Integer.toString(b.length)));
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os.write(_p);
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os.write(b);
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}
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public static void toStream(OutputStream os, String s) throws IOException {
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os.write(UTF8.getBytes(Integer.toString(s.length())));
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os.write(_p);
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os.write(UTF8.getBytes(s));
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}
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}
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public static class BListObject extends BDfltObject implements BObject {
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private List<BObject> l;
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public BListObject(List<BObject> l) {
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this.l = l;
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}
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@Override
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public BType getType() {
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return BType.list;
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}
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@Override
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public List<BObject> getList() {
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return this.l;
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}
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@Override
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public String toString() {
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StringBuilder s = new StringBuilder(l.size() * 40 + 1);
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s.append("[");
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for (final BObject o: l) s.append(o.toString()).append(",");
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s.setLength(s.length() - 1);
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s.append("]");
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return s.toString();
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}
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public void toStream(OutputStream os) throws IOException {
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os.write(_l);
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for (final BObject bo: this.l) bo.toStream(os);
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os.write(_e);
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}
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}
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public static class BDictionaryObject extends BDfltObject implements BObject {
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private Map<String, BObject> m;
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public BDictionaryObject(Map<String, BObject> m) {
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this.m = m;
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}
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@Override
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public BType getType() {
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return BType.dictionary;
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}
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@Override
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public Map<String, BObject> getMap() {
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return this.m;
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}
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@Override
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public String toString() {
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StringBuilder s = new StringBuilder(m.size() * 40 + 1);
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s.append('{');
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for (final Map.Entry<String, BObject> e: m.entrySet()) s.append(e.getKey()).append(':').append(e.getValue().toString()).append(',');
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s.setLength(s.length() - 1);
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s.append('}');
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return s.toString();
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}
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public void toStream(OutputStream os) throws IOException {
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os.write(_d);
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for (final Map.Entry<String, BObject> e: this.m.entrySet()) {
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BStringObject.toStream(os, e.getKey());
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e.getValue().toStream(os);
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}
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os.write(_e);
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}
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public static void toStream(OutputStream os, String key, byte[] value) throws IOException {
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os.write(_d);
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BStringObject.toStream(os, key);
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BStringObject.toStream(os, value);
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os.write(_e);
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}
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}
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public static class BIntegerObject extends BDfltObject implements BObject {
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private long i;
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public BIntegerObject(long i) {
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this.i = i;
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}
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@Override
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public BType getType() {
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return BType.integer;
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}
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@Override
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public long getInteger() {
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return this.i;
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}
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@Override
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public String toString() {
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return Long.toString(this.i);
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}
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public void toStream(OutputStream os) throws IOException {
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os.write(_i);
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os.write(UTF8.getBytes(Long.toString(this.i)));
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os.write(_e);
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}
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}
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private Map<String, BObject> convertToMap(final List<BObject> list) {
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final Map<String, BObject> m = new LinkedHashMap<String, BObject>();
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final int length = list.size();
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byte[] key;
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BObject value;
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for (int i = 0; i < length; i += 2) {
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key = list.get(i).getString();
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value = null;
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if (i + 1 < length) {
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value = list.get(i + 1);
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}
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m.put(UTF8.String(key), value);
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}
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return m;
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}
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private List<BObject> readList() {
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final List<BObject> list = new ArrayList<BObject>();
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char ch = (char) b[pos];
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BObject bo;
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while (ch != 'e') {
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bo = parse();
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if (bo == null) {pos++; break;}
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list.add(bo);
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ch = (char) b[pos];
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}
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pos++;
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return list;
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}
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public BObject parse() {
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if (pos >= b.length) return null;
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char ch = (char) b[pos];
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if ((ch >= '0') && (ch <= '9')) {
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int end = pos;
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end++;
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while (b[end] != ':') ++end;
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final int len = Integer.parseInt(UTF8.String(b, pos, end - pos));
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final byte[] s = new byte[len];
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System.arraycopy(b, end + 1, s, 0, len);
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pos = end + len + 1;
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return new BStringObject(s);
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} else if (ch == 'l') {
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pos++;
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return new BListObject(readList());
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} else if (ch == 'd') {
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pos++;
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return new BDictionaryObject(convertToMap(readList()));
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} else if (ch == 'i') {
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pos++;
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int end = pos;
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while (b[end] != 'e') ++end;
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BIntegerObject io = new BIntegerObject(Long.parseLong(UTF8.String(b, pos, end - pos)));
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pos = end + 1;
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return io;
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} else {
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return null;
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}
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}
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public static void print(BObject bo, int t) {
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for (int i = 0; i < t; i++) System.out.print(" ");
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if (bo.getType() == BType.integer) System.out.println(bo.getInteger());
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if (bo.getType() == BType.string) System.out.println(bo.getString());
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if (bo.getType() == BType.list) {
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System.out.println("[");
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//for (int i = 0; i < t + 1; i++) System.out.print(" ");
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for (final BObject o: bo.getList()) print(o, t + 1);
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for (int i = 0; i < t; i++) System.out.print(" ");
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System.out.println("]");
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}
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if (bo.getType() == BType.dictionary) {
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System.out.println("{");
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for (final Map.Entry<String, BObject> e: bo.getMap().entrySet()) {
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for (int i = 0; i < t + 1; i++) System.out.print(" ");
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System.out.print(e.getKey());
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System.out.println(":");
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print(e.getValue(), t + 2);
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}
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for (int i = 0; i < t; i++) System.out.print(" ");
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System.out.println("}");
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}
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}
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public static void main(String[] args) {
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try {
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byte[] b = FileUtils.read(new File(args[0]));
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BDecoder bdecoder = new BDecoder(b);
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BObject o = bdecoder.parse();
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print(o, 0);
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System.out.println("Object: " + o.toString());
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} catch (IOException e) {
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e.printStackTrace();
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}
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}
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} |