2006-10-18 Tatsuhiro Tsujikawa <tujikawa at rednoah dot com>

	Request -> RequestHandle:
	
	* src/HttpResponseCommand.h: Request->RequestHandle
	* src/AbstractCommand.cc: Request->RequestHandle
	* src/HttpDownloadCommand.cc: Request->RequestHandle
	* src/HttpRequestCommand.cc: Request->RequestHandle
	* src/FtpInitiateConnectionCommand.h: Request->RequestHandle
	* src/AbstractCommand.h: Request->RequestHandle
	* src/HttpProxyRequestCommand.h: Request->RequestHandle
	* src/HttpResponseCommand.cc: Request->RequestHandle
	* src/HttpInitiateConnectionCommand.h: Request->RequestHandle
	* src/FtpNegotiateCommand.cc: Request->RequestHandle
	* src/FtpTunnelResponseCommand.h: Request->RequestHandle
	* src/HttpConnection.h: Request->RequestHandle
	* src/HttpProxyResponseCommand.cc: Request->RequestHandle
	* src/InitiateConnectionCommandFactory.h: Request->RequestHandle
	* src/FtpTunnelResponseCommand.cc: Request->RequestHandle
	* src/DownloadCommand.h: Request->RequestHandle
	* src/FtpDowndloadCommand.cc: Request->RequestHandle
	* src/HttpInitiateConnectionCommand.cc: Request->RequestHandle
	* src/HttpRequestCommand.h: Request->RequestHandle
	* src/FtpNegotiateCommand.h: Request->RequestHandle
	* src/FtpTunnelResponseCommand.cc: Request->RequestHandle
	* src/FtpInitiateConnectionCommand.cc: Request->RequestHandle
	* src/HttpDownloadCommand.h: Request->RequestHandle
	* src/FtpConnection.cc: Request->RequestHandle
	* src/InitiateConnectionCommandFactory.cc: 
Request->RequestHandle
	* src/UrlRequestInfo.cc: Request->RequestHandle
	* src/HttpProxyResponseCommand.h: Request->RequestHandle
	* src/HttpConnection.h: Request->RequestHandle
	* src/DownloadCommand.cc: Request->RequestHandle
	* src/FtpConnection.h: Request->RequestHandle
	* src/FtpDowndloadCommand.h: Request->RequestHandle
	* src/HttpProxyRequestCommand.cc: Request->RequestHandle
	* src/FtpTunnelRequestCommand.h: Request->RequestHandle
	* src/Request.h
	(SharedHandle.h): New include.
	(RequestHandle): New type definition.
	(Requests): Redefined.
	
	To add MULTITRACKER support:

	* src/TrackerWatcherCommand.h
	(createRequestCommand): New function.
	* src/DownloadEngineFactory.cc
	(newTorrentConsoleEngine): Removed req.
	* src/prefs.h
	(PREF_TRACKER_MAX_TRIES): New definition.
	* src/TorrentMan.cc
	(TorrentMan): Removed req. Added trackerNumTry.
	(~TorrentMan): Removed req.
	(setupInternal1): Added announceList.
	* src/TorrentRequestInfo.cc
	(execute): Set PREF_MAX_TIRES to 1. The max number of tries for
	announces is now specified by PREF_TRACKER_MAX_TRIES.
	* src/main.cc
	(main): Added PREF_TRACKER_MAX_TRIES.
	* src/TorrentMan.h
	(Request.h): Removed.
	(AnnounceList.h): New include.
	(trackerNumTry): New variable.
	(req): Removed.
	(announceList): New variable.
	* src/TrackerWatcherCommand.cc
	(execute): Rewritten.
	(createRequestCommand): New function.
	* src/TrackerUpdateCommand.cc
	(execute): Updated with the use of AnnounceList.
	* src/AnnounceList.cc: New class.
	* src/AnnounceList.h: New class.
	
	To fix typo:

	* src/prefs.h
	(PREF_MAX_TRIES): max_try->max_tries

	To not to decode "+" as space in URL decode:

	* src/Util.cc
	(urldecode): Removed "+"->space decoding rule. Test case was 
updated.

48 files changed, 569 insertions, 146 deletions

diff --git a/src/AbstractCommand.cc b/src/AbstractCommand.cc
index 9ffa549c..fb2cb4c7 100644
--- a/src/AbstractCommand.cc
+++ b/src/AbstractCommand.cc
@@ -41,7 +41,9 @@
 #include "SleepCommand.h"
 #include "prefs.h"
 
-AbstractCommand::AbstractCommand(int cuid, Request* req, DownloadEngine* e,
+AbstractCommand::AbstractCommand(int cuid,
+				 const RequestHandle req,
+				 DownloadEngine* e,
 				 const SocketHandle& s):
   Command(cuid), req(req), e(e), socket(s),
   checkSocketIsReadable(false), checkSocketIsWritable(false),
@@ -125,7 +127,7 @@ bool AbstractCommand::execute() {
 
 void AbstractCommand::tryReserved() {
   if(!e->segmentMan->reserved.empty()) {
-    Request* req = e->segmentMan->reserved.front();
+    RequestHandle req = e->segmentMan->reserved.front();
     e->segmentMan->reserved.pop_front();
     Command* command = InitiateConnectionCommandFactory::createInitiateConnectionCommand(cuid, req, e);
     e->commands.push_back(command);
diff --git a/src/AbstractCommand.h b/src/AbstractCommand.h
index fba4997f..c4f115cc 100644
--- a/src/AbstractCommand.h
+++ b/src/AbstractCommand.h
@@ -46,7 +46,7 @@ private:
   Time checkPoint;
   int timeout;
 protected:
-  Request* req;
+  RequestHandle req;
   DownloadEngine* e;
   SocketHandle socket;
 
@@ -73,7 +73,7 @@ private:
   SocketHandle writeCheckTarget;
   bool nameResolverCheck;
 public:
-  AbstractCommand(int cuid, Request* req, DownloadEngine* e, const SocketHandle& s = SocketHandle());
+  AbstractCommand(int cuid, const RequestHandle req, DownloadEngine* e, const SocketHandle& s = SocketHandle());
   virtual ~AbstractCommand();
   bool execute();
 };
diff --git a/src/AnnounceList.cc b/src/AnnounceList.cc
new file mode 100644
index 00000000..43d0daa7
--- /dev/null
+++ b/src/AnnounceList.cc
@@ -0,0 +1,225 @@
+/* <!-- copyright */
+/*
+ * aria2 - The high speed download utility
+ *
+ * Copyright (C) 2006 Tatsuhiro Tsujikawa
+ *
+ * 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 of the License, 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., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
+ *
+ * In addition, as a special exception, the copyright holders give
+ * permission to link the code of portions of this program with the
+ * OpenSSL library under certain conditions as described in each
+ * individual source file, and distribute linked combinations
+ * including the two.
+ * You must obey the GNU General Public License in all respects
+ * for all of the code used other than OpenSSL.  If you modify
+ * file(s) with this exception, you may extend this exception to your
+ * version of the file(s), but you are not obligated to do so.  If you
+ * do not wish to do so, delete this exception statement from your
+ * version.  If you delete this exception statement from all source
+ * files in the program, then also delete it here.
+ */
+/* copyright --> */
+#include "AnnounceList.h"
+#include "List.h"
+#include "Data.h"
+
+AnnounceList::AnnounceList(const MetaEntry* announceListEntry):
+  currentTrackerInitialized(false) {
+  reconfigure(announceListEntry);
+}
+
+AnnounceList::AnnounceList(const AnnounceTiers& announceTiers):
+  tiers(announceTiers), currentTrackerInitialized(false)  {
+  resetIterator();
+}
+
+void AnnounceList::reconfigure(const MetaEntry* announceListEntry) {
+  const List* l = dynamic_cast<const List*>(announceListEntry);
+  if(l) {
+    for(MetaList::const_iterator itr = l->getList().begin();
+	itr != l->getList().end(); itr++) {
+      const List* elem = (List*)*itr;
+      Strings urls;
+      for(MetaList::const_iterator elemItr = elem->getList().begin();
+	  elemItr != elem->getList().end(); elemItr++) {
+	const Data* data = (Data*)*elemItr;
+	urls.push_back(data->toString());
+      }
+      if(urls.size()) {
+	AnnounceTier tier(urls);
+	tiers.push_back(tier);
+      }
+    }
+    resetIterator();
+  }
+}
+
+void AnnounceList::reconfigure(const string& url) {
+  Strings urls;
+  urls.push_back(url);
+  tiers.push_back(AnnounceTier(urls));
+  resetIterator();
+}
+
+void AnnounceList::resetIterator() {
+  currentTier = tiers.begin();
+  if(currentTier != tiers.end() && currentTier->urls.size()) {
+    currentTracker = currentTier->urls.begin();
+    currentTrackerInitialized = true;
+  } else {
+    currentTrackerInitialized = false;
+  }
+}
+
+string AnnounceList::getAnnounce() const {
+  if(currentTrackerInitialized) {
+    return *currentTracker;
+  } else {
+    return "";
+  }
+}
+
+void AnnounceList::announceSuccess() {
+  if(currentTrackerInitialized) {
+    currentTier->nextEvent();
+    string url = *currentTracker;
+    currentTier->urls.erase(currentTracker);
+    currentTier->urls.push_front(url);
+    currentTier = tiers.begin();
+    currentTracker = currentTier->urls.begin();
+  }
+}
+
+void AnnounceList::announceFailure() {
+  if(currentTrackerInitialized) {
+    currentTracker++;
+    if(currentTracker == currentTier->urls.end()) {
+      currentTier++;
+      if(currentTier == tiers.end()) {
+	currentTier = tiers.begin();
+      }
+      currentTracker = currentTier->urls.begin();
+    }
+  }
+}
+
+AnnounceTier::AnnounceEvent AnnounceList::getEvent() const {
+  if(currentTrackerInitialized) {
+    return currentTier->event;
+  } else {
+    return AnnounceTier::STARTED;
+  }
+}
+
+void AnnounceList::setEvent(AnnounceTier::AnnounceEvent event) {
+  if(currentTrackerInitialized) {
+    currentTier->event = event;
+  }
+}
+
+string AnnounceList::getEventString() const {
+  if(currentTrackerInitialized) {
+    switch(currentTier->event) {
+    case AnnounceTier::STARTED:
+    case AnnounceTier::STARTED_AFTER_COMPLETION:
+      return "started";
+    case AnnounceTier::STOPPED:
+      return "stopped";
+    case AnnounceTier::COMPLETED:
+      return "completed";
+    default:
+      return "";
+    }
+  } else {
+    return "";
+  }
+}
+
+class FindStoppedAllowedTier {
+public:
+  bool operator()(const AnnounceTier& tier) const {
+    switch(tier.event) {
+    case AnnounceTier::DOWNLOADING:
+    case AnnounceTier::STOPPED:
+    case AnnounceTier::COMPLETED:
+    case AnnounceTier::SEEDING:
+      return true;
+    default:
+      return false;
+    }
+  }
+};
+
+class FindCompletedAllowedTier {
+public:
+  bool operator()(const AnnounceTier& tier) const {
+    switch(tier.event) {
+    case AnnounceTier::DOWNLOADING:
+    case AnnounceTier::COMPLETED:
+      return true;
+    default:
+      return false;
+    }
+  }
+};
+
+int AnnounceList::countStoppedAllowedTier() const {
+  return count_if(tiers.begin(), tiers.end(), FindStoppedAllowedTier());
+}
+
+int AnnounceList::countCompletedAllowedTier() const {
+  return count_if(tiers.begin(), tiers.end(), FindCompletedAllowedTier());
+}
+
+void AnnounceList::setCurrentTier(const AnnounceTiers::iterator& itr) {
+  if(itr != tiers.end()) {
+    currentTier = itr;
+    currentTracker = currentTier->urls.begin();
+  }
+}
+
+template<class InputIterator, class Predicate>
+InputIterator
+find_wrap_if(InputIterator first, InputIterator last,
+	     InputIterator current, Predicate pred) {
+  InputIterator itr = find_if(current, last,
+			      pred);
+  if(itr == last) {
+    itr = find_if(first, current, pred);
+  }
+  return itr;
+}
+
+void AnnounceList::moveToStoppedAllowedTier() {
+  AnnounceTiers::iterator itr = find_wrap_if(tiers.begin(), tiers.end(),
+					     currentTier,
+					     FindStoppedAllowedTier());
+  setCurrentTier(itr);
+}
+
+void AnnounceList::moveToCompletedAllowedTier() {
+  AnnounceTiers::iterator itr = find_wrap_if(tiers.begin(), tiers.end(),
+					     currentTier,
+					     FindCompletedAllowedTier());
+  setCurrentTier(itr);
+}
+
+void AnnounceList::shuffle() {
+  for(AnnounceTiers::iterator itr = tiers.begin();
+      itr != tiers.end(); itr++) {
+    random_shuffle(itr->urls.begin(), itr->urls.end());
+  }
+}
diff --git a/src/AnnounceList.h b/src/AnnounceList.h
new file mode 100644
index 00000000..d2ecb3d8
--- /dev/null
+++ b/src/AnnounceList.h
@@ -0,0 +1,158 @@
+/* <!-- copyright */
+/*
+ * aria2 - The high speed download utility
+ *
+ * Copyright (C) 2006 Tatsuhiro Tsujikawa
+ *
+ * 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 of the License, 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., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
+ *
+ * In addition, as a special exception, the copyright holders give
+ * permission to link the code of portions of this program with the
+ * OpenSSL library under certain conditions as described in each
+ * individual source file, and distribute linked combinations
+ * including the two.
+ * You must obey the GNU General Public License in all respects
+ * for all of the code used other than OpenSSL.  If you modify
+ * file(s) with this exception, you may extend this exception to your
+ * version of the file(s), but you are not obligated to do so.  If you
+ * do not wish to do so, delete this exception statement from your
+ * version.  If you delete this exception statement from all source
+ * files in the program, then also delete it here.
+ */
+/* copyright --> */
+#ifndef _D_ANNOUNCE_LIST_H_
+#define _D_ANNOUNCE_LIST_H_
+
+#include "common.h"
+#include "MetaEntry.h"
+
+class AnnounceTier {
+public:
+  enum AnnounceEvent {
+    STARTED,
+    STARTED_AFTER_COMPLETION,
+    DOWNLOADING,
+    STOPPED,
+    COMPLETED,
+    SEEDING,
+    HALTED
+  };
+
+  AnnounceEvent event;
+  Strings urls;
+
+  AnnounceTier(const Strings& urls):event(STARTED), urls(urls) {}
+
+  void nextEvent() {
+    switch(event) {
+    case STARTED:
+      event = DOWNLOADING;
+      break;
+    case STARTED_AFTER_COMPLETION:
+      event = SEEDING;
+      break;
+    case STOPPED:
+      event = HALTED;
+      break;
+    case COMPLETED:
+      event = SEEDING;
+      break;
+    default:
+      break;
+    }
+  }
+};
+
+typedef deque<AnnounceTier> AnnounceTiers;
+
+class AnnounceList {
+public:
+private:
+  AnnounceTiers tiers;
+  AnnounceTiers::iterator currentTier;
+  Strings::iterator currentTracker;
+  bool currentTrackerInitialized;
+
+  void resetIterator();
+  void setCurrentTier(const AnnounceTiers::iterator& itr);
+public:
+  AnnounceList():currentTrackerInitialized(false) {}
+  AnnounceList(const MetaEntry* announceListEntry);
+  AnnounceList(const AnnounceTiers& tiers);
+
+  void reconfigure(const MetaEntry* announceListEntry);
+  void reconfigure(const string& url);
+
+  int countTier() const {
+    return tiers.size();
+  }
+
+  /**
+   * Shuffles all the URLs in each group.
+   */
+  void shuffle();
+
+  /**
+   * Returns announce URL.
+   */
+  string getAnnounce() const;
+
+  /**
+   * Returns announce event, such as started, stopped, completed, etc.
+   */
+  string getEventString() const;
+
+  AnnounceTier::AnnounceEvent getEvent() const;
+
+  void setEvent(AnnounceTier::AnnounceEvent event);
+
+  /**
+   * Removes current announce URL from its group and inserts it before the
+   * first element of the group.
+   * The internal announce group pointer points to the first element of the
+   * first group after this call.
+   */
+  void announceSuccess();
+
+  /**
+   * The internal announce URL pointer points to next URL.
+   * If the current URL is the last element of its group, then the first
+   * element of the next group is pointed.
+   */
+  void announceFailure();
+
+  /**
+   * Counts the number of tiers to which the "stopped" event can be sent.
+   */
+  int countStoppedAllowedTier() const;
+
+  /**
+   * Counts the number of tiers to which the "completed" event can be sent.
+   */
+  int countCompletedAllowedTier() const;
+
+  /**
+   * Moves current tier pointer to the tier to which the "stopped" event can
+   * be sent.
+   * 2-stage search operation is made.
+   * The first search operation is performed from current pointer position
+   * to the end. If no such tier is found, the second search is performed from
+   * the first to the current pointer position.
+   */
+  void moveToStoppedAllowedTier();
+  void moveToCompletedAllowedTier();
+};
+
+#endif // _D_ANNOUNCE_LIST_H_
diff --git a/src/DownloadCommand.cc b/src/DownloadCommand.cc
index 691e9f62..3c9cc8e3 100644
--- a/src/DownloadCommand.cc
+++ b/src/DownloadCommand.cc
@@ -42,7 +42,9 @@
 #include "prefs.h"
 #include <sys/time.h>
 
-DownloadCommand::DownloadCommand(int cuid, Request* req, DownloadEngine* e,
+DownloadCommand::DownloadCommand(int cuid,
+				 const RequestHandle req,
+				 DownloadEngine* e,
 				 const SocketHandle& s):
   AbstractCommand(cuid, req, e, s), lastSize(0) {
   PeerStatHandle peerStat = PeerStatHandle(new PeerStat(cuid));
diff --git a/src/DownloadCommand.h b/src/DownloadCommand.h
index 1b6b29fc..dc1f68c4 100644
--- a/src/DownloadCommand.h
+++ b/src/DownloadCommand.h
@@ -49,7 +49,7 @@ protected:
 
   virtual bool prepareForNextSegment(const Segment& currentSegment);
 public:
-  DownloadCommand(int cuid, Request* req, DownloadEngine* e,
+  DownloadCommand(int cuid, const RequestHandle req, DownloadEngine* e,
 		  const SocketHandle& s);
   virtual ~DownloadCommand();
 
diff --git a/src/DownloadEngineFactory.cc b/src/DownloadEngineFactory.cc
index 1aebc1a6..4adc6d2f 100644
--- a/src/DownloadEngineFactory.cc
+++ b/src/DownloadEngineFactory.cc
@@ -80,9 +80,6 @@ DownloadEngineFactory::newTorrentConsoleEngine(const Option* op,
 					       const string& torrentFile,
 					       const Strings& targetFiles)
 {
-  Request* req = new Request();
-  req->isTorrent = true;
-  req->setTrackerEvent(Request::STARTED);
   TorrentConsoleDownloadEngine* te = new TorrentConsoleDownloadEngine();
   te->option = op;
   ByteArrayDiskWriter* byteArrayDiskWriter = new ByteArrayDiskWriter();
@@ -92,7 +89,6 @@ DownloadEngineFactory::newTorrentConsoleEngine(const Option* op,
   te->torrentMan = new TorrentMan();
   te->torrentMan->setStoreDir(op->get(PREF_DIR));
   te->torrentMan->option = op;
-  te->torrentMan->req = req;
   Integers selectIndexes;
   Util::unfoldRange(op->get(PREF_SELECT_FILE), selectIndexes);
   if(selectIndexes.size()) {
diff --git a/src/FtpConnection.cc b/src/FtpConnection.cc
index 36ddb971..57de9a06 100644
--- a/src/FtpConnection.cc
+++ b/src/FtpConnection.cc
@@ -41,7 +41,7 @@
 #include "LogFactory.h"
 
 FtpConnection::FtpConnection(int cuid, const SocketHandle& socket,
-			     const Request* req, const Option* op)
+			     const RequestHandle req, const Option* op)
   :cuid(cuid), socket(socket), req(req), option(op) {
   logger = LogFactory::getInstance();
 }
diff --git a/src/FtpConnection.h b/src/FtpConnection.h
index bdef42a8..9a6c6be4 100644
--- a/src/FtpConnection.h
+++ b/src/FtpConnection.h
@@ -49,7 +49,7 @@ class FtpConnection {
 private:
   int cuid;
   SocketHandle socket;
-  const Request* req;
+  RequestHandle req;
   const Option* option;
   const Logger* logger;
 
@@ -60,7 +60,7 @@ private:
   bool bulkReceiveResponse(pair<int, string>& response);
 public:
   FtpConnection(int cuid, const SocketHandle& socket,
-		const Request* req, const Option* op);
+		const RequestHandle req, const Option* op);
   ~FtpConnection();
   void sendUser() const;
   void sendPass() const;
diff --git a/src/FtpDownloadCommand.cc b/src/FtpDownloadCommand.cc
index 16e2e41a..c5377a0b 100644
--- a/src/FtpDownloadCommand.cc
+++ b/src/FtpDownloadCommand.cc
@@ -34,7 +34,8 @@
 /* copyright --> */
 #include "FtpDownloadCommand.h"
 
-FtpDownloadCommand::FtpDownloadCommand(int cuid, Request* req,
+FtpDownloadCommand::FtpDownloadCommand(int cuid,
+				       const RequestHandle req,
 				       DownloadEngine* e,
 				       const SocketHandle& dataSocket,
 				       const SocketHandle& ctrlSocket)
diff --git a/src/FtpDownloadCommand.h b/src/FtpDownloadCommand.h
index 91d5caa3..6e969ef4 100644
--- a/src/FtpDownloadCommand.h
+++ b/src/FtpDownloadCommand.h
@@ -41,7 +41,7 @@ class FtpDownloadCommand : public DownloadCommand {
 private:
   SocketHandle ctrlSocket;
 public:
-  FtpDownloadCommand(int cuid, Request* req, DownloadEngine* e,
+  FtpDownloadCommand(int cuid, const RequestHandle req, DownloadEngine* e,
 		     const SocketHandle& dataSocket,
 		     const SocketHandle& ctrlSocket);
   ~FtpDownloadCommand();
diff --git a/src/FtpInitiateConnectionCommand.cc b/src/FtpInitiateConnectionCommand.cc
index 2be27d53..456c369c 100644
--- a/src/FtpInitiateConnectionCommand.cc
+++ b/src/FtpInitiateConnectionCommand.cc
@@ -42,7 +42,7 @@
 #include "Util.h"
 
 FtpInitiateConnectionCommand::FtpInitiateConnectionCommand(int cuid,
-							   Request* req,
+							   const RequestHandle req,
 							   DownloadEngine* e)
   :AbstractCommand(cuid, req, e)
 {
diff --git a/src/FtpInitiateConnectionCommand.h b/src/FtpInitiateConnectionCommand.h
index 48f0adc2..52a3fc02 100644
--- a/src/FtpInitiateConnectionCommand.h
+++ b/src/FtpInitiateConnectionCommand.h
@@ -54,7 +54,7 @@ private:
 protected:
   bool executeInternal(Segment& segment);
 public:
-  FtpInitiateConnectionCommand(int cuid, Request* req, DownloadEngine* e);
+  FtpInitiateConnectionCommand(int cuid, const RequestHandle req, DownloadEngine* e);
   ~FtpInitiateConnectionCommand();
 };
 
diff --git a/src/FtpNegotiationCommand.cc b/src/FtpNegotiationCommand.cc
index f4fae85c..407aa438 100644
--- a/src/FtpNegotiationCommand.cc
+++ b/src/FtpNegotiationCommand.cc
@@ -39,7 +39,7 @@
 #include "message.h"
 #include "prefs.h"
 
-FtpNegotiationCommand::FtpNegotiationCommand(int cuid, Request* req,
+FtpNegotiationCommand::FtpNegotiationCommand(int cuid, const RequestHandle req,
 					     DownloadEngine* e,
 					     const SocketHandle& s):
   AbstractCommand(cuid, req, e, s), sequence(SEQ_RECV_GREETING)
diff --git a/src/FtpNegotiationCommand.h b/src/FtpNegotiationCommand.h
index e1814559..87b66a27 100644
--- a/src/FtpNegotiationCommand.h
+++ b/src/FtpNegotiationCommand.h
@@ -93,7 +93,7 @@ private:
 protected:
   bool executeInternal(Segment& segment);
 public:
-  FtpNegotiationCommand(int cuid, Request* req, DownloadEngine* e,
+  FtpNegotiationCommand(int cuid, const RequestHandle req, DownloadEngine* e,
 			const SocketHandle& s);
   ~FtpNegotiationCommand();
 };
diff --git a/src/FtpTunnelRequestCommand.cc b/src/FtpTunnelRequestCommand.cc
index 2a34bf0a..c1051d20 100644
--- a/src/FtpTunnelRequestCommand.cc
+++ b/src/FtpTunnelRequestCommand.cc
@@ -36,7 +36,8 @@
 #include "FtpTunnelResponseCommand.h"
 #include "HttpConnection.h"
 
-FtpTunnelRequestCommand::FtpTunnelRequestCommand(int cuid, Request* req,
+FtpTunnelRequestCommand::FtpTunnelRequestCommand(int cuid,
+						 const RequestHandle req,
 						 DownloadEngine* e,
 						 const SocketHandle& s)
   :AbstractCommand(cuid, req, e, s) {
diff --git a/src/FtpTunnelRequestCommand.h b/src/FtpTunnelRequestCommand.h
index beb6a49b..92126597 100644
--- a/src/FtpTunnelRequestCommand.h
+++ b/src/FtpTunnelRequestCommand.h
@@ -41,7 +41,7 @@ class FtpTunnelRequestCommand : public AbstractCommand {
 protected:
   bool executeInternal(Segment& segment);
 public:
-  FtpTunnelRequestCommand(int cuid, Request* req, DownloadEngine* e,
+  FtpTunnelRequestCommand(int cuid, const RequestHandle req, DownloadEngine* e,
 			  const SocketHandle& s);
   ~FtpTunnelRequestCommand();
 };
diff --git a/src/FtpTunnelResponseCommand.cc b/src/FtpTunnelResponseCommand.cc
index 45dc56be..4f09a649 100644
--- a/src/FtpTunnelResponseCommand.cc
+++ b/src/FtpTunnelResponseCommand.cc
@@ -37,7 +37,8 @@
 #include "DlRetryEx.h"
 #include "message.h"
 
-FtpTunnelResponseCommand::FtpTunnelResponseCommand(int cuid, Request* req,
+FtpTunnelResponseCommand::FtpTunnelResponseCommand(int cuid,
+						   const RequestHandle req,
 						   DownloadEngine* e,
 						   const SocketHandle& s)
   :AbstractCommand(cuid, req, e, s) {
diff --git a/src/FtpTunnelResponseCommand.h b/src/FtpTunnelResponseCommand.h
index 1a972082..3dc19d0f 100644
--- a/src/FtpTunnelResponseCommand.h
+++ b/src/FtpTunnelResponseCommand.h
@@ -44,7 +44,7 @@ private:
 protected:
     bool executeInternal(Segment& segment);
 public:
-  FtpTunnelResponseCommand(int cuid, Request* req, DownloadEngine* e,
+  FtpTunnelResponseCommand(int cuid, const RequestHandle req, DownloadEngine* e,
 			   const SocketHandle& s);
   ~FtpTunnelResponseCommand();
 };
diff --git a/src/HttpConnection.cc b/src/HttpConnection.cc
index 1096e452..7c080864 100644
--- a/src/HttpConnection.cc
+++ b/src/HttpConnection.cc
@@ -41,7 +41,7 @@
 #include "LogFactory.h"
 
 HttpConnection::HttpConnection(int cuid, const SocketHandle& socket,
-			       const Request* req, const Option* op):
+			       const RequestHandle req, const Option* op):
   cuid(cuid), socket(socket), req(req), option(op), headerBufLength(0) {
   logger = LogFactory::getInstance();
 }
diff --git a/src/HttpConnection.h b/src/HttpConnection.h
index 925cf63d..e01f6b22 100644
--- a/src/HttpConnection.h
+++ b/src/HttpConnection.h
@@ -60,13 +60,13 @@ private:
   string getProxyAuthString() const;
   int cuid;
   SocketHandle socket;
-  const Request* req;
+  RequestHandle req;
   const Option* option;
   const Logger* logger;
   char headerBuf[HEADERBUF_SIZE+1];
   int headerBufLength;
 public:
-  HttpConnection(int cuid, const SocketHandle& socket, const Request* req,
+  HttpConnection(int cuid, const SocketHandle& socket, const RequestHandle req,
 		 const Option* op);
 
   /**
diff --git a/src/HttpDownloadCommand.cc b/src/HttpDownloadCommand.cc
index fbd019ab..9ea89ef4 100644
--- a/src/HttpDownloadCommand.cc
+++ b/src/HttpDownloadCommand.cc
@@ -45,7 +45,7 @@
 
 using namespace std;
 
-HttpDownloadCommand::HttpDownloadCommand(int cuid, Request* req,
+HttpDownloadCommand::HttpDownloadCommand(int cuid, const RequestHandle req,
 					 DownloadEngine* e,
 					 const SocketHandle& socket)
   :DownloadCommand(cuid, req, e, socket)
diff --git a/src/HttpDownloadCommand.h b/src/HttpDownloadCommand.h
index 8e2408aa..ecb2e398 100644
--- a/src/HttpDownloadCommand.h
+++ b/src/HttpDownloadCommand.h
@@ -52,7 +52,7 @@ private:
 protected:
   virtual bool prepareForNextSegment(const Segment& currentSegment);
 public:
-  HttpDownloadCommand(int cuid, Request* req, DownloadEngine* e,
+  HttpDownloadCommand(int cuid, const RequestHandle req, DownloadEngine* e,
 		      const SocketHandle& s);
   ~HttpDownloadCommand();
 
diff --git a/src/HttpInitiateConnectionCommand.cc b/src/HttpInitiateConnectionCommand.cc
index 297ef4dd..4d1492f2 100644
--- a/src/HttpInitiateConnectionCommand.cc
+++ b/src/HttpInitiateConnectionCommand.cc
@@ -42,7 +42,7 @@
 #include "prefs.h"
 
 HttpInitiateConnectionCommand::HttpInitiateConnectionCommand(int cuid,
-							     Request* req,
+							     const RequestHandle req,
 							     DownloadEngine* e):
   AbstractCommand(cuid, req, e)
 {
diff --git a/src/HttpInitiateConnectionCommand.h b/src/HttpInitiateConnectionCommand.h
index 8eecbbcc..8f9b32e4 100644
--- a/src/HttpInitiateConnectionCommand.h
+++ b/src/HttpInitiateConnectionCommand.h
@@ -62,7 +62,7 @@ protected:
   }
 #endif // ENABLE_ASYNC_DNS
 public:
-  HttpInitiateConnectionCommand(int cuid, Request* req, DownloadEngine* e);
+  HttpInitiateConnectionCommand(int cuid, const RequestHandle req, DownloadEngine* e);
   ~HttpInitiateConnectionCommand();
 };
 
diff --git a/src/HttpProxyRequestCommand.cc b/src/HttpProxyRequestCommand.cc
index 37717b0b..6f6f486e 100644
--- a/src/HttpProxyRequestCommand.cc
+++ b/src/HttpProxyRequestCommand.cc
@@ -36,7 +36,8 @@
 #include "HttpConnection.h"
 #include "HttpProxyResponseCommand.h"
 
-HttpProxyRequestCommand::HttpProxyRequestCommand(int cuid, Request* req,
+HttpProxyRequestCommand::HttpProxyRequestCommand(int cuid,
+						 const RequestHandle req,
 						 DownloadEngine* e,
 						 const SocketHandle& s)
   :AbstractCommand(cuid, req, e, s) {
diff --git a/src/HttpProxyRequestCommand.h b/src/HttpProxyRequestCommand.h
index 9c87c5cb..ffec1746 100644
--- a/src/HttpProxyRequestCommand.h
+++ b/src/HttpProxyRequestCommand.h
@@ -41,7 +41,7 @@ class HttpProxyRequestCommand : public AbstractCommand {
 protected:
   bool executeInternal(Segment& segment);
 public:
-  HttpProxyRequestCommand(int cuid, Request* req, DownloadEngine* e,
+  HttpProxyRequestCommand(int cuid, const RequestHandle req, DownloadEngine* e,
 			  const SocketHandle& s);
   ~HttpProxyRequestCommand();
 };
diff --git a/src/HttpProxyResponseCommand.cc b/src/HttpProxyResponseCommand.cc
index 373887d9..e611acc0 100644
--- a/src/HttpProxyResponseCommand.cc
+++ b/src/HttpProxyResponseCommand.cc
@@ -37,7 +37,8 @@
 #include "DlRetryEx.h"
 #include "message.h"
 
-HttpProxyResponseCommand::HttpProxyResponseCommand(int cuid, Request* req,
+HttpProxyResponseCommand::HttpProxyResponseCommand(int cuid,
+						   const RequestHandle req,
 						   DownloadEngine* e,
 						   const SocketHandle& s)
   :AbstractCommand(cuid, req, e, s) {
diff --git a/src/HttpProxyResponseCommand.h b/src/HttpProxyResponseCommand.h
index e26bee14..f5b11af6 100644
--- a/src/HttpProxyResponseCommand.h
+++ b/src/HttpProxyResponseCommand.h
@@ -44,7 +44,7 @@ private:
 protected:
   bool executeInternal(Segment& segment);
 public:
-  HttpProxyResponseCommand(int cuid, Request* req, DownloadEngine* e,
+  HttpProxyResponseCommand(int cuid, const RequestHandle req, DownloadEngine* e,
 			   const SocketHandle& s);
   ~HttpProxyResponseCommand();
 };
diff --git a/src/HttpRequestCommand.cc b/src/HttpRequestCommand.cc
index 1230fe0d..7775fc30 100644
--- a/src/HttpRequestCommand.cc
+++ b/src/HttpRequestCommand.cc
@@ -37,7 +37,8 @@
 #include "HttpConnection.h"
 #include "prefs.h"
 
-HttpRequestCommand::HttpRequestCommand(int cuid, Request* req,
+HttpRequestCommand::HttpRequestCommand(int cuid,
+				       const RequestHandle req,
 				       DownloadEngine* e,
 				       const SocketHandle& s)
   :AbstractCommand(cuid, req, e, s) {
diff --git a/src/HttpRequestCommand.h b/src/HttpRequestCommand.h
index ef2253e9..41a17099 100644
--- a/src/HttpRequestCommand.h
+++ b/src/HttpRequestCommand.h
@@ -42,7 +42,7 @@ protected:
   bool executeInternal(Segment& segment);
   Command* getNextCommand() const;
 public:
-  HttpRequestCommand(int cuid, Request* req, DownloadEngine* e,
+  HttpRequestCommand(int cuid, const RequestHandle req, DownloadEngine* e,
 		     const SocketHandle& s);
   ~HttpRequestCommand();
 };
diff --git a/src/HttpResponseCommand.cc b/src/HttpResponseCommand.cc
index baeda574..618cbbbf 100644
--- a/src/HttpResponseCommand.cc
+++ b/src/HttpResponseCommand.cc
@@ -43,7 +43,8 @@
 #include <sys/types.h>
 #include <unistd.h>
 
-HttpResponseCommand::HttpResponseCommand(int cuid, Request* req,
+HttpResponseCommand::HttpResponseCommand(int cuid,
+					 const RequestHandle req,
 					 DownloadEngine* e,
 					 const SocketHandle& s)
   :AbstractCommand(cuid, req, e, s) {
diff --git a/src/HttpResponseCommand.h b/src/HttpResponseCommand.h
index bf5f1ace..35b99697 100644
--- a/src/HttpResponseCommand.h
+++ b/src/HttpResponseCommand.h
@@ -54,7 +54,7 @@ private:
 protected:
   bool executeInternal(Segment& segment);
 public:
-  HttpResponseCommand(int cuid, Request* req, DownloadEngine* e,
+  HttpResponseCommand(int cuid, const RequestHandle req, DownloadEngine* e,
 		      const SocketHandle& s);
   ~HttpResponseCommand();
 };
diff --git a/src/InitiateConnectionCommandFactory.cc b/src/InitiateConnectionCommandFactory.cc
index 827e2ce8..536cea0b 100644
--- a/src/InitiateConnectionCommandFactory.cc
+++ b/src/InitiateConnectionCommandFactory.cc
@@ -37,7 +37,7 @@
 #include "FtpInitiateConnectionCommand.h"
 #include "DlAbortEx.h"
 
-Command* InitiateConnectionCommandFactory::createInitiateConnectionCommand(int cuid, Request* req, DownloadEngine* e) {
+Command* InitiateConnectionCommandFactory::createInitiateConnectionCommand(int cuid, const RequestHandle req, DownloadEngine* e) {
   if(req->getProtocol() == "http"
 #ifdef ENABLE_SSL
      // for SSL
diff --git a/src/InitiateConnectionCommandFactory.h b/src/InitiateConnectionCommandFactory.h
index 952252e2..820d38bf 100644
--- a/src/InitiateConnectionCommandFactory.h
+++ b/src/InitiateConnectionCommandFactory.h
@@ -41,7 +41,8 @@
 
 class InitiateConnectionCommandFactory {
 public:
-  static Command* createInitiateConnectionCommand(int cuid, Request* req, 
+  static Command* createInitiateConnectionCommand(int cuid,
+						  const RequestHandle req, 
 						  DownloadEngine* e);
 };
 
diff --git a/src/Makefile.am b/src/Makefile.am
index cc0f408d..3807881e 100644
--- a/src/Makefile.am
+++ b/src/Makefile.am
@@ -124,7 +124,8 @@ SRCS += MetaEntry.h\
 	PeerListProcessor.h\
 	DefaultPeerListProcessor.cc DefaultPeerListProcessor.h\
 	CompactPeerListProcessor.cc CompactPeerListProcessor.h\
-	DelegatingPeerListProcessor.cc DelegatingPeerListProcessor.h
+	DelegatingPeerListProcessor.cc DelegatingPeerListProcessor.h\
+	AnnounceList.h AnnounceList.cc
 endif # ENABLE_BITTORRENT
 
 if ENABLE_METALINK
diff --git a/src/Makefile.in b/src/Makefile.in
index 5670f7e6..f52fe022 100644
--- a/src/Makefile.in
+++ b/src/Makefile.in
@@ -101,7 +101,8 @@ bin_PROGRAMS = aria2c$(EXEEXT)
 @ENABLE_BITTORRENT_TRUE@	PeerListProcessor.h\
 @ENABLE_BITTORRENT_TRUE@	DefaultPeerListProcessor.cc DefaultPeerListProcessor.h\
 @ENABLE_BITTORRENT_TRUE@	CompactPeerListProcessor.cc CompactPeerListProcessor.h\
-@ENABLE_BITTORRENT_TRUE@	DelegatingPeerListProcessor.cc DelegatingPeerListProcessor.h
+@ENABLE_BITTORRENT_TRUE@	DelegatingPeerListProcessor.cc DelegatingPeerListProcessor.h\
+@ENABLE_BITTORRENT_TRUE@	AnnounceList.h AnnounceList.cc
 
 @ENABLE_METALINK_TRUE@am__append_3 = Metalinker.cc Metalinker.h\
 @ENABLE_METALINK_TRUE@	MetalinkEntry.cc MetalinkEntry.h\
@@ -117,14 +118,14 @@ am__aclocal_m4_deps = $(top_srcdir)/m4/codeset.m4 \
 	$(top_srcdir)/m4/gettext.m4 $(top_srcdir)/m4/glibc21.m4 \
 	$(top_srcdir)/m4/iconv.m4 $(top_srcdir)/m4/intdiv0.m4 \
 	$(top_srcdir)/m4/inttypes-pri.m4 $(top_srcdir)/m4/inttypes.m4 \
-	$(top_srcdir)/m4/inttypes_h.m4 $(top_srcdir)/m4/lcmessage.m4 \
-	$(top_srcdir)/m4/lib-ld.m4 $(top_srcdir)/m4/lib-link.m4 \
-	$(top_srcdir)/m4/lib-prefix.m4 $(top_srcdir)/m4/libares.m4 \
-	$(top_srcdir)/m4/libcares.m4 $(top_srcdir)/m4/nls.m4 \
-	$(top_srcdir)/m4/openssl.m4 $(top_srcdir)/m4/po.m4 \
-	$(top_srcdir)/m4/progtest.m4 $(top_srcdir)/m4/stdint_h.m4 \
-	$(top_srcdir)/m4/uintmax_t.m4 $(top_srcdir)/m4/ulonglong.m4 \
-	$(top_srcdir)/configure.ac
+	$(top_srcdir)/m4/inttypes_h.m4 $(top_srcdir)/m4/isc-posix.m4 \
+	$(top_srcdir)/m4/lcmessage.m4 $(top_srcdir)/m4/lib-ld.m4 \
+	$(top_srcdir)/m4/lib-link.m4 $(top_srcdir)/m4/lib-prefix.m4 \
+	$(top_srcdir)/m4/libares.m4 $(top_srcdir)/m4/libcares.m4 \
+	$(top_srcdir)/m4/nls.m4 $(top_srcdir)/m4/openssl.m4 \
+	$(top_srcdir)/m4/po.m4 $(top_srcdir)/m4/progtest.m4 \
+	$(top_srcdir)/m4/stdint_h.m4 $(top_srcdir)/m4/uintmax_t.m4 \
+	$(top_srcdir)/m4/ulonglong.m4 $(top_srcdir)/configure.ac
 am__configure_deps = $(am__aclocal_m4_deps) $(CONFIGURE_DEPENDENCIES) \
 	$(ACLOCAL_M4)
 mkinstalldirs = $(SHELL) $(top_srcdir)/mkinstalldirs
@@ -210,9 +211,9 @@ am__libaria2c_a_SOURCES_DIST = Socket.h SocketCore.cc SocketCore.h \
 	PeerListProcessor.h DefaultPeerListProcessor.cc \
 	DefaultPeerListProcessor.h CompactPeerListProcessor.cc \
 	CompactPeerListProcessor.h DelegatingPeerListProcessor.cc \
-	DelegatingPeerListProcessor.h Metalinker.cc Metalinker.h \
-	MetalinkEntry.cc MetalinkEntry.h MetalinkResource.cc \
-	MetalinkResource.h MetalinkProcessor.h \
+	DelegatingPeerListProcessor.h AnnounceList.h AnnounceList.cc \
+	Metalinker.cc Metalinker.h MetalinkEntry.cc MetalinkEntry.h \
+	MetalinkResource.cc MetalinkResource.h MetalinkProcessor.h \
 	Xml2MetalinkProcessor.cc Xml2MetalinkProcessor.h \
 	MetalinkRequestInfo.cc MetalinkRequestInfo.h
 @ENABLE_ASYNC_DNS_TRUE@am__objects_1 = NameResolver.$(OBJEXT)
@@ -268,7 +269,8 @@ am__libaria2c_a_SOURCES_DIST = Socket.h SocketCore.cc SocketCore.h \
 @ENABLE_BITTORRENT_TRUE@	SeedCheckCommand.$(OBJEXT) \
 @ENABLE_BITTORRENT_TRUE@	DefaultPeerListProcessor.$(OBJEXT) \
 @ENABLE_BITTORRENT_TRUE@	CompactPeerListProcessor.$(OBJEXT) \
-@ENABLE_BITTORRENT_TRUE@	DelegatingPeerListProcessor.$(OBJEXT)
+@ENABLE_BITTORRENT_TRUE@	DelegatingPeerListProcessor.$(OBJEXT) \
+@ENABLE_BITTORRENT_TRUE@	AnnounceList.$(OBJEXT)
 @ENABLE_METALINK_TRUE@am__objects_3 = Metalinker.$(OBJEXT) \
 @ENABLE_METALINK_TRUE@	MetalinkEntry.$(OBJEXT) \
 @ENABLE_METALINK_TRUE@	MetalinkResource.$(OBJEXT) \
@@ -364,6 +366,7 @@ EXEEXT = @EXEEXT@
 GENCAT = @GENCAT@
 GLIBC21 = @GLIBC21@
 GMSGFMT = @GMSGFMT@
+GREP = @GREP@
 INSTALL_DATA = @INSTALL_DATA@
 INSTALL_PROGRAM = @INSTALL_PROGRAM@
 INSTALL_SCRIPT = @INSTALL_SCRIPT@
@@ -418,10 +421,9 @@ XML2_CONFIG = @XML2_CONFIG@
 XML_CPPFLAGS = @XML_CPPFLAGS@
 XML_LIBS = @XML_LIBS@
 YACC = @YACC@
+YFLAGS = @YFLAGS@
 ac_ct_CC = @ac_ct_CC@
 ac_ct_CXX = @ac_ct_CXX@
-ac_ct_RANLIB = @ac_ct_RANLIB@
-ac_ct_STRIP = @ac_ct_STRIP@
 am__fastdepCC_FALSE = @am__fastdepCC_FALSE@
 am__fastdepCC_TRUE = @am__fastdepCC_TRUE@
 am__fastdepCXX_FALSE = @am__fastdepCXX_FALSE@
@@ -438,12 +440,16 @@ build_cpu = @build_cpu@
 build_os = @build_os@
 build_vendor = @build_vendor@
 datadir = @datadir@
+datarootdir = @datarootdir@
+docdir = @docdir@
+dvidir = @dvidir@
 exec_prefix = @exec_prefix@
 host = @host@
 host_alias = @host_alias@
 host_cpu = @host_cpu@
 host_os = @host_os@
 host_vendor = @host_vendor@
+htmldir = @htmldir@
 includedir = @includedir@
 infodir = @infodir@
 install_sh = @install_sh@
@@ -454,8 +460,10 @@ localstatedir = @localstatedir@
 mandir = @mandir@
 mkdir_p = @mkdir_p@
 oldincludedir = @oldincludedir@
+pdfdir = @pdfdir@
 prefix = @prefix@
 program_transform_name = @program_transform_name@
+psdir = @psdir@
 sbindir = @sbindir@
 sharedstatedir = @sharedstatedir@
 sysconfdir = @sysconfdir@
@@ -586,6 +594,7 @@ distclean-compile:
 @AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/AbstractCommand.Po@am__quote@
 @AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/AbstractDiskWriter.Po@am__quote@
 @AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/AllowedFastMessage.Po@am__quote@
+@AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/AnnounceList.Po@am__quote@
 @AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/Base64.Po@am__quote@
 @AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/BitfieldMan.Po@am__quote@
 @AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/BitfieldMessage.Po@am__quote@
diff --git a/src/Request.h b/src/Request.h
index fc0bfd8c..7b998d4a 100644
--- a/src/Request.h
+++ b/src/Request.h
@@ -39,6 +39,7 @@
 #include "CookieBox.h"
 #include "Segment.h"
 #include "common.h"
+#include "SharedHandle.h"
 
 using namespace std;
 
@@ -120,6 +121,7 @@ public:
 
 };
 
-typedef deque<Request*> Requests;
+typedef SharedHandle<Request> RequestHandle;
+typedef deque<RequestHandle> Requests;
 
 #endif // _D_REQUEST_H_
diff --git a/src/TorrentMan.cc b/src/TorrentMan.cc
index 82bc254f..fbf9b98c 100644
--- a/src/TorrentMan.cc
+++ b/src/TorrentMan.cc
@@ -72,7 +72,7 @@ TorrentMan::TorrentMan():bitfield(0),
 			 incomplete(0),
 			 connections(0),
 			 trackers(0),
-			 req(0),
+			 trackerNumTry(0),
 			 diskAdaptor(0)
 {
   logger = LogFactory::getInstance();
@@ -81,7 +81,6 @@ TorrentMan::TorrentMan():bitfield(0),
 TorrentMan::~TorrentMan() {
   delete bitfield;
   delete diskAdaptor;
-  delete req;
 }
 
 // TODO do not use this method in application code
@@ -447,7 +446,15 @@ void TorrentMan::setupInternal1(const string& metaInfoFile) {
   Directory* topDir = NULL;
   readFileEntry(fileEntries, &topDir, infoDic, metaInfoFile);
 
-  announce = ((Data*)topDic->get("announce"))->toString();
+  string announce = ((Data*)topDic->get("announce"))->toString();
+  const MetaEntry* announces = topDic->get("announce-list");
+  if(announces) {
+    announceList.reconfigure(announces);
+    announceList.shuffle();
+  }
+  if(!announceList.countTier()) {
+    announceList.reconfigure(announce);
+  }
   pieceLength = ((Data*)infoDic->get("piece length"))->toInt();
   pieces = totalLength/pieceLength+(totalLength%pieceLength ? 1 : 0);
   Data* piecesHashData = (Data*)infoDic->get("pieces");
diff --git a/src/TorrentMan.h b/src/TorrentMan.h
index 54473c12..240fc1c8 100644
--- a/src/TorrentMan.h
+++ b/src/TorrentMan.h
@@ -45,7 +45,7 @@
 #include "Option.h"
 #include "FileEntry.h"
 #include "DiskAdaptor.h"
-#include "Request.h"
+#include "AnnounceList.h"
 #include "TimeA2.h"
 #include "PeerListProcessor.h"
 #include <deque>
@@ -142,8 +142,9 @@ public:
   int connections;
   // The number of tracker request command currently in the command queue.
   int trackers;
+  int trackerNumTry;
   // tracker request
-  Request* req;
+  AnnounceList announceList;
 public:
   TorrentMan();
   ~TorrentMan();
diff --git a/src/TorrentRequestInfo.cc b/src/TorrentRequestInfo.cc
index defcea83..3760da2e 100644
--- a/src/TorrentRequestInfo.cc
+++ b/src/TorrentRequestInfo.cc
@@ -54,6 +54,8 @@ RequestInfo* TorrentRequestInfo::execute() {
   if(!timeoutSpecified) {
     op->put(PREF_TIMEOUT, "180");
   }
+  // set max_tries to 1. AnnounceList handles retries.
+  op->put(PREF_MAX_TRIES, "1");
   e = DownloadEngineFactory::newTorrentConsoleEngine(op,
 						     torrentFile,
 						     targetFiles);
diff --git a/src/TrackerUpdateCommand.cc b/src/TrackerUpdateCommand.cc
index bb39dc86..f32c1238 100644
--- a/src/TrackerUpdateCommand.cc
+++ b/src/TrackerUpdateCommand.cc
@@ -155,21 +155,17 @@ bool TrackerUpdateCommand::execute() {
     if(!peersEntry) {
       logger->info("CUID#%d - No peer list received.", cuid);
     }
-
-    if(e->torrentMan->req->getTrackerEvent() == Request::STARTED) {
-      e->torrentMan->req->setTrackerEvent(Request::AUTO);
-    }
+    e->torrentMan->announceList.announceSuccess();
+    e->torrentMan->trackers = 0;
+    e->segmentMan->init();
   } catch(Exception* err) {
     logger->error("CUID#%d - Error occurred while processing tracker response.", cuid, err);
+    e->segmentMan->errors++;
     delete err;
   }
-  if(trackerResponse != NULL) {
+  if(trackerResponse) {
     delete [] trackerResponse;
   }
-  e->torrentMan->trackers = 0;
-
-  e->segmentMan->init();
-
   if(e->torrentMan->isHalt()) {
     return true;
   } else {
diff --git a/src/TrackerWatcherCommand.cc b/src/TrackerWatcherCommand.cc
index e76701cf..be7ed234 100644
--- a/src/TrackerWatcherCommand.cc
+++ b/src/TrackerWatcherCommand.cc
@@ -49,83 +49,98 @@ TrackerWatcherCommand::TrackerWatcherCommand(int cuid,
 TrackerWatcherCommand::~TrackerWatcherCommand() {}
 
 bool TrackerWatcherCommand::execute() {
-  if(e->segmentMan->errors > 0) {
-    if(e->torrentMan->isHalt()) {
+  Command* command = 0;
+  if(e->torrentMan->trackers == 0 && e->torrentMan->isHalt()) {
+    // Download is going to halt.
+    // Check whether there are at least one tracker which can receive
+    // "stopped" event.
+    if(e->torrentMan->announceList.countStoppedAllowedTier()) {
+      e->torrentMan->announceList.moveToStoppedAllowedTier();
+      e->torrentMan->announceList.setEvent(AnnounceTier::STOPPED);
+      command = createRequestCommand();
+    } else {
+      // We don't send "stopped" event since no tracker cares about it.
       return true;
     }
+  } else if(e->torrentMan->trackers == 0 &&
+	    e->torrentMan->downloadComplete() &&
+	    e->torrentMan->announceList.countCompletedAllowedTier()) {
+    // Send "completed" event to all trackers which can accept it.
+    e->torrentMan->announceList.moveToCompletedAllowedTier();
+    e->torrentMan->announceList.setEvent(AnnounceTier::COMPLETED);
+    command = createRequestCommand();
+  } else if(e->torrentMan->trackers == 0 &&
+	    checkPoint.elapsed(interval)) {
+    checkPoint.reset();
+    // If download completed before "started" event is sent to a tracker,
+    // we change the event to something else to prevent us from
+    // sending "completed" event.
+    if(e->torrentMan->downloadComplete() &&
+       e->torrentMan->announceList.getEvent() == AnnounceTier::STARTED) {
+      e->torrentMan->announceList.setEvent(AnnounceTier::STARTED_AFTER_COMPLETION);
+    }
+    command = createRequestCommand();
+  } else if(e->segmentMan->errors > 0) {
+    e->torrentMan->trackerNumTry++;
+    checkPoint.reset();
     // we assume the tracker request has failed.
+    e->torrentMan->announceList.announceFailure();
     e->torrentMan->trackers = 0;
     e->segmentMan->init();
-    // sleep a few seconds.
-    SleepCommand* sleepCommand =
-      new SleepCommand(cuid, e, this, e->option->getAsInt(PREF_RETRY_WAIT));
-    e->commands.push_back(sleepCommand);
-    return false;
-  }
-  if(e->torrentMan->trackers == 0 &&
-     (e->torrentMan->isHalt() ||
-      checkPoint.elapsed(interval))) {
-    checkPoint.reset();
-    e->torrentMan->req->resetTryCount();
-    int numWant = 50;
-    if(e->torrentMan->connections >= MIN_PEERS || e->torrentMan->isHalt()) {
-      numWant = 0;
-    }
-    if(e->torrentMan->isHalt()) {
-      e->torrentMan->req->setTrackerEvent(Request::STOPPED);
-    } else if(e->torrentMan->downloadComplete()) {
-      if(e->torrentMan->req->getTrackerEvent() == Request::COMPLETED) {
-	e->torrentMan->req->setTrackerEvent(Request::AFTER_COMPLETED);
-      } else {
-	if(e->torrentMan->req->getTrackerEvent() == Request::STARTED) {
-	  // in case where download had completed when aria2c started.
-	  e->torrentMan->req->setTrackerEvent(Request::AFTER_COMPLETED);
-	} else if(e->torrentMan->req->getTrackerEvent() != Request::AFTER_COMPLETED) {
-	  e->torrentMan->req->setTrackerEvent(Request::COMPLETED);
-	}
+    if(e->torrentMan->trackerNumTry >= e->option->getAsInt(PREF_TRACKER_MAX_TRIES)) {
+      // abort tracker request
+      e->torrentMan->trackerNumTry = 0;
+      if(e->torrentMan->isHalt()) {
+	return true;
       }
+    } else {
+      // sleep a few seconds.
+      command =
+	new SleepCommand(cuid, e,
+			 createRequestCommand(),
+			 e->option->getAsInt(PREF_RETRY_WAIT));
     }
-    string event;
-    switch(e->torrentMan->req->getTrackerEvent()) {
-    case Request::STARTED:
-      event = "started";
-      break;
-    case Request::STOPPED:
-      event = "stopped";
-      break;
-    case Request::COMPLETED:
-      event = "completed";
-      break;
-    }
-    string url = e->torrentMan->announce+"?"+
-      "info_hash="+Util::torrentUrlencode(e->torrentMan->getInfoHash(), 20)+"&"+
-      "peer_id="+e->torrentMan->peerId+"&"+
-      "port="+Util::itos(e->torrentMan->getPort())+"&"+
-      "uploaded="+Util::llitos(e->torrentMan->getSessionUploadLength())+"&"+
-      "downloaded="+Util::llitos(e->torrentMan->getSessionDownloadLength())+"&"+
-      "left="+(e->torrentMan->getTotalLength()-e->torrentMan->getDownloadLength() <= 0
-	       ? "0" : Util::llitos(e->torrentMan->getTotalLength()-e->torrentMan->getDownloadLength()))+"&"+
-      "compact=1"+"&"+
-      "key="+e->torrentMan->key+"&"+
-      "numwant="+Util::itos(numWant)+"&"+
-      "no_peer_id=1";
-    if(!event.empty()) {
-      url += string("&")+"event="+event;
-    }
-    if(!e->torrentMan->trackerId.empty()) {
-      url += string("&")+"trackerid="+e->torrentMan->trackerId;
-    }
-    e->torrentMan->req->setUrl(url);
-    Command* command = InitiateConnectionCommandFactory::createInitiateConnectionCommand(e->torrentMan->getNewCuid(), e->torrentMan->req, e);
+  }
+
+  if(command) {
     e->commands.push_back(command);
     e->torrentMan->trackers++;
-    logger->info("CUID#%d - Creating new tracker request command #%d", cuid,
-		 command->getCuid());
-    if(e->torrentMan->isHalt()) {
-      return true;
-    }
   }
+  // updates interval with newest minInterval
   interval = e->torrentMan->minInterval;
   e->commands.push_back(this);
   return false;
 }
+
+Command* TrackerWatcherCommand::createRequestCommand() {
+  int numWant = 50;
+  if(e->torrentMan->connections >= MIN_PEERS || e->torrentMan->isHalt()) {
+    numWant = 0;
+  }
+  string url = e->torrentMan->announceList.getAnnounce()+"?"+
+    "info_hash="+Util::torrentUrlencode(e->torrentMan->getInfoHash(), 20)+"&"+
+    "peer_id="+e->torrentMan->peerId+"&"+
+    "port="+Util::itos(e->torrentMan->getPort())+"&"+
+    "uploaded="+Util::llitos(e->torrentMan->getSessionUploadLength())+"&"+
+    "downloaded="+Util::llitos(e->torrentMan->getSessionDownloadLength())+"&"+
+    "left="+(e->torrentMan->getTotalLength()-e->torrentMan->getDownloadLength() <= 0
+	     ? "0" : Util::llitos(e->torrentMan->getTotalLength()-e->torrentMan->getDownloadLength()))+"&"+
+    "compact=1"+"&"+
+    "key="+e->torrentMan->key+"&"+
+    "numwant="+Util::itos(numWant)+"&"+
+    "no_peer_id=1";
+  string event = e->torrentMan->announceList.getEventString();
+  if(!event.empty()) {
+    url += string("&")+"event="+event;
+  }
+  if(!e->torrentMan->trackerId.empty()) {
+    url += string("&")+"trackerid="+e->torrentMan->trackerId;
+  }
+  RequestHandle req;
+  req->setUrl(url);
+  req->isTorrent = true;
+  Command* command = InitiateConnectionCommandFactory::createInitiateConnectionCommand(e->torrentMan->getNewCuid(), req, e);
+  logger->info("CUID#%d - Creating new tracker request command #%d", cuid,
+	       command->getCuid());
+  return command;
+}
diff --git a/src/TrackerWatcherCommand.h b/src/TrackerWatcherCommand.h
index e32efdfa..03d79c94 100644
--- a/src/TrackerWatcherCommand.h
+++ b/src/TrackerWatcherCommand.h
@@ -44,6 +44,8 @@ private:
   TorrentDownloadEngine* e;
   int interval;
   Time checkPoint;
+
+  Command* createRequestCommand();
 public:
   TrackerWatcherCommand(int cuid, TorrentDownloadEngine* e, int interval);
   ~TrackerWatcherCommand();
diff --git a/src/UrlRequestInfo.cc b/src/UrlRequestInfo.cc
index f3645a50..a338430a 100644
--- a/src/UrlRequestInfo.cc
+++ b/src/UrlRequestInfo.cc
@@ -97,14 +97,13 @@ public:
 
   void operator()(const string& url) {
     for(int s = 1; s <= split; s++) {
-      Request* req = new Request();
+      RequestHandle req;
       req->setReferer(referer);
       if(req->setUrl(url)) {
 	requestsPtr->push_back(req);
       } else {
 	fprintf(stderr, _("Unrecognized URL or unsupported protocol: %s\n"),
 		req->getUrl().c_str());
-	delete req;
       }
     }
   }
@@ -146,9 +145,6 @@ RequestInfo* UrlRequestInfo::execute() {
     delete e;
     fail = true;
   }
-  for_each(requests.begin(), requests.end(), Deleter());
-  for_each(reserved.begin(), reserved.end(), Deleter());
-  
   setSignalHander(SIGINT, SIG_DFL, 0);
   setSignalHander(SIGTERM, SIG_DFL, 0);
   
diff --git a/src/Util.cc b/src/Util.cc
index 0f47f8ee..ef2aafd7 100644
--- a/src/Util.cc
+++ b/src/Util.cc
@@ -221,9 +221,7 @@ string Util::urldecode(const string& target) {
   string result;
   for(string::const_iterator itr = target.begin();
       itr != target.end(); itr++) {
-    if(*itr == '+') {
-      result += ' ';
-    } else if(*itr == '%') {
+    if(*itr == '%') {
       if(itr+1 != target.end() && itr+2 != target.end() &&
 	 isxdigit(*(itr+1)) && isxdigit(*(itr+2))) {
 	char temp[3];
diff --git a/src/main.cc b/src/main.cc
index fb60a14e..ca4344c3 100644
--- a/src/main.cc
+++ b/src/main.cc
@@ -332,6 +332,7 @@ int main(int argc, char* argv[]) {
   op->put(PREF_MAX_DOWNLOAD_LIMIT, "0");
   op->put(PREF_MAX_UPLOAD_LIMIT, "0");
   op->put(PREF_STARTUP_IDLE_TIME, "10");
+  op->put(PREF_TRACKER_MAX_TRIES, "10");
   while(1) {
     int optIndex = 0;
     int lopt;
diff --git a/src/prefs.h b/src/prefs.h
index e5e05520..f451edc4 100644
--- a/src/prefs.h
+++ b/src/prefs.h
@@ -53,7 +53,7 @@
 // values: 1*digit
 #define PREF_DNS_TIMEOUT "dns_timeout"
 // values: 1*digit
-#define PREF_MAX_TRIES "max_try"
+#define PREF_MAX_TRIES "max_tries"
 // values: 1*digit
 #define PREF_MIN_SEGMENT_SIZE "min_segment_size"
 // values: 1*digit
@@ -149,6 +149,8 @@
 #define PREF_SEED_TIME "seed_time"
 // values: 1*digit ['.' [ 1*digit ] ]
 #define PREF_SEED_RATIO "seed_ratio"
+// values: 1*digit
+#define PREF_TRACKER_MAX_TRIES "tracker_max_tries"
 
 /**
  * Metalink related preferences