/* TrackerInfo - Holds information returned by a tracker, mainly the peer list.
Copyright (C) 2003 Mark J. Wielaard
This file is part of Snark.
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2, or (at your option)
any later version.
This program 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 for more details.
You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software Foundation,
Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
*/
package org.klomp.snark;
import java.io.IOException;
import java.io.InputStream;
import java.util.HashSet;
import java.util.Collections;
import java.util.List;
import java.util.Map;
import java.util.Set;
import org.klomp.snark.bencode.BDecoder;
import org.klomp.snark.bencode.BEValue;
import org.klomp.snark.bencode.InvalidBEncodingException;
/**
* The data structure for the tracker response.
* Handles both traditional and compact formats.
* Compact format 1 - a list of hashes - early format for testing
* Compact format 2 - One big string of concatenated hashes - official format
*/
class TrackerInfo
{
private final String failure_reason;
private final int interval;
private final Set<Peer> peers;
private int complete;
private int incomplete;
/** @param metainfo may be null */
public TrackerInfo(InputStream in, byte[] my_id, byte[] infohash, MetaInfo metainfo, I2PSnarkUtil util)
throws IOException
{
this(new BDecoder(in), my_id, infohash, metainfo, util);
}
private TrackerInfo(BDecoder be, byte[] my_id, byte[] infohash, MetaInfo metainfo, I2PSnarkUtil util)
throws IOException
{
this(be.bdecodeMap().getMap(), my_id, infohash, metainfo, util);
}
private TrackerInfo(Map<String, BEValue> m, byte[] my_id, byte[] infohash, MetaInfo metainfo, I2PSnarkUtil util)
throws IOException
{
BEValue reason = m.get("failure reason");
if (reason != null)
{
failure_reason = reason.getString();
interval = -1;
peers = null;
}
else
{
failure_reason = null;
BEValue beInterval = m.get("interval");
if (beInterval == null)
throw new InvalidBEncodingException("No interval given");
else
interval = beInterval.getInt();
BEValue bePeers = m.get("peers");
if (bePeers == null) {
peers = Collections.emptySet();
} else {
Set<Peer> p;
try {
// One big string (the official compact format)
p = getPeers(bePeers.getBytes(), my_id, infohash, metainfo, util);
} catch (InvalidBEncodingException ibe) {
// List of Dictionaries or List of Strings
p = getPeers(bePeers.getList(), my_id, infohash, metainfo, util);
}
peers = p;
}
BEValue bev = m.get("complete");
if (bev != null) try {
complete = bev.getInt();
if (complete < 0)
complete = 0;
} catch (InvalidBEncodingException ibe) {}
bev = m.get("incomplete");
if (bev != null) try {
incomplete = bev.getInt();
if (incomplete < 0)
incomplete = 0;
} catch (InvalidBEncodingException ibe) {}
}
}
/******
public static Set<Peer> getPeers(InputStream in, byte[] my_id, MetaInfo metainfo)
throws IOException
{
return getPeers(new BDecoder(in), my_id, metainfo);
}
public static Set<Peer> getPeers(BDecoder be, byte[] my_id, MetaInfo metainfo)
throws IOException
{
return getPeers(be.bdecodeList().getList(), my_id, metainfo);
}
******/
/** List of Dictionaries or List of Strings */
private static Set<Peer> getPeers(List<BEValue> l, byte[] my_id, byte[] infohash, MetaInfo metainfo, I2PSnarkUtil util)
throws IOException
{
Set<Peer> peers = new HashSet<Peer>(l.size());
for (BEValue bev : l) {
PeerID peerID;
try {
// Case 1 - non-compact - A list of dictionaries (maps)
peerID = new PeerID(bev.getMap());
} catch (InvalidBEncodingException ibe) {
try {
// Case 2 - compact - A list of 32-byte binary strings (hashes)
// This was just for testing and is not the official format
peerID = new PeerID(bev.getBytes(), util);
} catch (InvalidBEncodingException ibe2) {
// don't let one bad entry spoil the whole list
//Snark.debug("Discarding peer from list: " + ibe, Snark.ERROR);
continue;
}
}
peers.add(new Peer(peerID, my_id, infohash, metainfo));
}
return peers;
}
private static final int HASH_LENGTH = 32;
/**
* One big string of concatenated 32-byte hashes
* @since 0.8.1
*/
private static Set<Peer> getPeers(byte[] l, byte[] my_id, byte[] infohash, MetaInfo metainfo, I2PSnarkUtil util)
throws IOException
{
int count = l.length / HASH_LENGTH;
Set<Peer> peers = new HashSet<Peer>(count);
for (int i = 0; i < count; i++) {
PeerID peerID;
byte[] hash = new byte[HASH_LENGTH];
System.arraycopy(l, i * HASH_LENGTH, hash, 0, HASH_LENGTH);
try {
peerID = new PeerID(hash, util);
} catch (InvalidBEncodingException ibe) {
// won't happen
continue;
}
peers.add(new Peer(peerID, my_id, infohash, metainfo));
}
return peers;
}
public Set<Peer> getPeers()
{
return peers;
}
public int getPeerCount()
{
int pc = peers == null ? 0 : peers.size();
return Math.max(pc, complete + incomplete - 1);
}
/** @since 0.9.9 */
public int getSeedCount()
{
return complete;
}
/**
* Not HTML escaped.
*/
public String getFailureReason()
{
return failure_reason;
}
/** in seconds */
public int getInterval()
{
return interval;
}
@Override
public String toString()
{
if (failure_reason != null)
return "TrackerInfo[FAILED: " + failure_reason + "]";
else
return "TrackerInfo[interval=" + interval
+ (complete > 0 ? (", complete=" + complete) : "" )
+ (incomplete > 0 ? (", incomplete=" + incomplete) : "" )
+ ", peers=" + peers + "]";
}
}