2006-09-19 Tatsuhiro Tsujikawa <tujikawa at rednoah dot com>

To rewrite segment download mechanism for HTTP/FTP download. Use BitfieldMan to manage segment download. * src/HttpResponseCommand.h (executeInternal): Pass the reference of segment. * src/AbstractCommand.cc (prepareForRetry): Call segmentMan->cancelSegment here. (onAbort): Call segmentMan->cancelSegment here. * src/HttpDownloadCommand.cc (prepareForNextSegment): New function. * src/DownloadEngineFactory.cc (newConsoleEngine): Removed splitter. (newTorrentConsoleEngine): Removed splitter. * src/Request.h (segment): Renamed from seg. * src/FtpInitiateConnectionCommand.h (executeInternal): Pass the reference of segment. * src/AbstractCommand.h (executeInternal): Pass the reference of segment. * src/pref.h (PREF_SEGMENT_SIZE): New definition. * src/HttpProxyRequestCommand.h (executeInternal): Pass the reference of segment. * src/HttpResponseCommand.cc (checkResponse): Allowed status 206 when a request range starts 0. (handleDefaultEncoding): Rewritten the code related to Segment. (handleOtherEncoding): Rewritten the code related to Segment. * src/SegmentMan.h (SegmentEntry): New class. (SegmentEntries): New type definition. (bitfield): New variable. (usedSegmentEntries): New variable. (onNullBitfield): New function. (checkoutSegment): New function. (segments): Removed. (splitter): Removed. (unregisterId): Removed. (getSegment): New function(overload) (getDownloadedSize): Removed. (cancelSegment): New function. (completeSegment): New function. (initBitfield): New function. (hasSegment): New function. (getDownloadLength): New function. * src/BitfieldMan.h (getStartIndex): New function. (getEndIndex): New function. (getMissingUnusedIndex): New function(overload). (getSparseMissingUnusedIndex): New function. * src/BitfieldMan.cc (getMissingIndexRandomly): Handle the last byte of bitfield properly. (getMissingUnusedIndex): New function(overload). (Range): New class. (getStartIndex): New function. (getEndIndex): New function. (getSparseMissingUnusedIndex): New function. (isBitSetInternal): Return false if the given index is less than 0. * src/HttpInitiateConnectionCommand.h (executeInternal): Pass the reference of segment. * src/FtpNegotiateCommand.h (executeInternal): Pass the reference of segment. * src/FtpNegotiateCommand.cc (recvSize): Initialize bitfield here. * src/FtpTunnelResponseCommand.h (executeInternal): Pass the reference of segment. * src/HttpConnection.cc (createRequest): Rewritten range header processing. * src/DownloadCommand.h (executeInternal): Pass the reference of segment. (prepareForRetry): Removed. (prepareForNextSegment): Added an argument segment. Made it a virtual function. * src/main.cc (main): Set the initial value of PREF_SEGMENT_SIZE to 1MB. * src/SegmentMan.cc (SegmentMan): Added bitfield. Removed splitter. (~SegmentMan): Added bitfield. Removed splitter. (unregisterId): Removed. (getSegment): Rewritten. (updateSegment): Rewritten. (save): Rewritten. (read): Rewritten. (finished): Rewritten. (getDownloadedSize): Removed. (initBitfield): New function. (FindSegmentEntryByIndex): New function object. (FindSegmentEntryByCuid): New function object. (checkoutSegment): New function. (onNullBitfield): New function. (getSegment): New function(overload). (CancelSegment): New function object. (cancelSegment): New function. (completeSegment): New function. (hasSegment): New function. (getDownloadLength): New function. * src/FtpInitiateConnectionCommand.cc (executeInternal): Load .aria2 file after hostname resolution finishes. * src/Segment.h: Rewritten. * src/Segment.cc (operator<<): New function. * src/HttpDownloadCommand.h (prepareForNextSegment): New function. * src/Request.cc (resetUrl): Made segment null. * src/DownloadEngine.cc (~DownloadEngine): Call cleanQueue before deleting segmentMan. * src/HttpProxyRequestCommand.h (executeInternal): Pass the reference of segment. * src/DownloadCommand.cc (executeInternal): Rewritten the code related to Segment. (prepareForRetry): Removed. (prepareForNextSegment): Rewritten. * src/FtpTunnelResponseCommand.h (executeInternal): Pass the reference of segment. To add HTTP 1.1 persistent connection support(experimental) * src/HttpRequestCommand.cc (executeInternal): Disable keep alive if it is disabled by configuration. * src/Request.h (keepAlive): New variable. (isKeepAlive): New function. (setKeepAlive): New function. * src/pref.h (PREF_HTTP_KEEP_ALIVE): New definition. * src/HttpResponseCommand.cc (executeInternal): Check the remote server supports keep alive. * src/HttpConnection.cc (createRequest): Send "Connection: close" only if keep alive is disabled. * src/main.cc (main): Set the initial value(false) of PREF_KEEP_ALIVE to false. To add max download speed limit: * src/pref.h (PREF_MAX_SPEED_LIMIT): New definition. * src/PeerInteractionCommand.cc (executeInternal): Added max download speed limit. Not tested yet. * src/SegmentMan.h (PeerStats): New type definition. (peerStats): New variable. (registerPeerStat): New function. (FindPeerStat): New function object. (getPeerStat): New function. (calculateDownloadSpeed): New function. * src/SpeedCalc.h: New class. * src/SpeedCalc.cc: New class. * src/main.cc (main): Set the initial value of PREF_MAX_SPEED_LIMIT to 0(which means the download speed is not restricted). * src/PeerStat.h: New class. * src/SegmentMan.cc (registerPeerStat): New function. (calculateDownloadSpeed): New function. * src/DownloadCommand.cc (STARTUP_IDLE_TIME): New definition. (DownloadCommand): Register peerStat to segmentMan. Call peerStat-> downloadStart. (~DownloadCommand): Call peerStat->downloadStop. (executeInternal): Added download speed limitter. Rewritten lowest speed limitter. * src/HttpConnection.cc (receiveResponse): Fixed: eohIndex[headerBuf] -> headerBuf[eohIndex]. * src/AbstractCommand.cc (resolveHostname): Throw DlAbortEx if a name resolution failes. Added hostname to the error message. * src/ConsoleDownloadEngine.cc (calculateStatistics): Initialize psize with dlSize. * src/PieceMessage.cc (receivedAction): Do not call peerInteraction->abortPiece here. (onGotWrongPiece): Call peerInteraction->abortPiece here. * src/BitfieldMan.h (clearAllUseBit): New function. (setAllUseBit): New function. * src/BitfieldMan.cc (clearAllBit): Do not clear useBitfield here. (clearAllUseBit): New function. (setAllUseBit): New function. * src/Piece.cc (clearAllBlock): Call bitfield->clearAllUseBit().
author: Tatsuhiro Tsujikawa <tatsuhiro.t@gmail.com> 2006-09-19 14:52:59 +0000
committer: Tatsuhiro Tsujikawa <tatsuhiro.t@gmail.com> 2006-09-19 14:52:59 +0000
commit: 2fb9b5be9705560fd77b4244636bc2515e81f32c (patch)
tree: 0532a3d2a40d51e0d56490dedc744b0feaa56e33 /src
parent: 1d52ba244ee360a36db245988a797c7fa143c0f5 (diff)
48 files changed, 1024 insertions, 319 deletions
diff --git a/src/AbstractCommand.cc b/src/AbstractCommand.cc
index 907c7ee9..6a471277 100644
--- a/src/AbstractCommand.cc
+++ b/src/AbstractCommand.cc
@@ -48,16 +48,18 @@ bool AbstractCommand::execute() {
        checkSocketIsWritable && writeCheckTarget->isWritable(0) ||
        !checkSocketIsReadable && !checkSocketIsWritable) {
       checkPoint.reset();
-      Segment seg = { 0, 0, 0, false };
+      if(e->segmentMan->finished()) {
+	logger->debug("CUID#%d - finished.", cuid);
+	return true;
+      }
+      Segment segment;
       if(e->segmentMan->downloadStarted) {
-	// get segment information in order to set Range header.
-	if(!e->segmentMan->getSegment(seg, cuid)) {
-	  // no segment available
+	if(!e->segmentMan->getSegment(segment, cuid)) {
 	  logger->info(MSG_NO_SEGMENT_AVAILABLE, cuid);
 	  return true;
 	}
       }
-      return executeInternal(seg);
+      return executeInternal(segment);
     } else {
       if(checkPoint.elapsed(timeout)) {
 	throw new DlRetryEx(EX_TIME_OUT);
@@ -103,6 +105,7 @@ void AbstractCommand::tryReserved() {
 }
 
 bool AbstractCommand::prepareForRetry(int wait) {
+  e->segmentMan->cancelSegment(cuid);
   Command* command = InitiateConnectionCommandFactory::createInitiateConnectionCommand(cuid, req, e);
   if(wait == 0) {
     e->commands.push_back(command);
@@ -115,7 +118,8 @@ bool AbstractCommand::prepareForRetry(int wait) {
 
 void AbstractCommand::onAbort(Exception* ex) {
   logger->debug(MSG_UNREGISTER_CUID, cuid);
-  e->segmentMan->unregisterId(cuid);
+  //e->segmentMan->unregisterId(cuid);
+  e->segmentMan->cancelSegment(cuid);
 }
 
 void AbstractCommand::disableReadCheckSocket() {
@@ -193,7 +197,8 @@ bool AbstractCommand::resolveHostname(const string& hostname,
     return true;
     break;
   case NameResolver::STATUS_ERROR:
-    throw new DlRetryEx("CUID#%d - Name resolution failed:%s", cuid,
+    throw new DlAbortEx("CUID#%d - Name resolution for %s failed:%s", cuid,
+			hostname.c_str(),
 			resolver->getError().c_str());
   default:
     return false;
diff --git a/src/AbstractCommand.h b/src/AbstractCommand.h
index 3fbea81e..7ac5cd2c 100644
--- a/src/AbstractCommand.h
+++ b/src/AbstractCommand.h
@@ -40,7 +40,7 @@ protected:
   void tryReserved();
   virtual bool prepareForRetry(int wait);
   virtual void onAbort(Exception* ex);
-  virtual bool executeInternal(Segment segment) = 0;
+  virtual bool executeInternal(Segment& segment) = 0;
 
   void setReadCheckSocket(const SocketHandle& socket);
   void setWriteCheckSocket(const SocketHandle& socket);
diff --git a/src/BitfieldMan.cc b/src/BitfieldMan.cc
index 54519c48..e7013e46 100644
--- a/src/BitfieldMan.cc
+++ b/src/BitfieldMan.cc
@@ -95,8 +95,20 @@ BitfieldMan::getMissingIndexRandomly(const unsigned char* bitfield,
 {
   int byte = (int)(((double)bitfieldLength)*random()/(RAND_MAX+1.0));
 
+  unsigned char lastMask = 0;
+  int lastByteLength = totalLength%(blockLength*8);
+  int lastBlockCount = DIV_FLOOR(lastByteLength, blockLength);
+  for(int i = 0; i < lastBlockCount; i++) {
+    lastMask >>= 1;
+    lastMask |= 0x80;
+  }
   for(int i = 0; i < bitfieldLength; i++) {
-    unsigned char mask = 0xff;
+    unsigned char mask;
+    if(byte == bitfieldLength-1) {
+      mask = lastMask;
+    } else {
+      mask = 0xff;
+    }
     if(bitfield[byte]&mask) {
       int index = byte*8+getNthBitIndex(bitfield[byte], 1);
       return index;
@@ -207,6 +219,82 @@ int BitfieldMan::getMissingIndex() const {
   return index;
 }
 
+int BitfieldMan::getMissingUnusedIndex() const {
+  unsigned char* tempBitfield = new unsigned char[bitfieldLength];
+  memset(tempBitfield, 0xff, bitfieldLength);
+  int index = getMissingUnusedIndex(tempBitfield, bitfieldLength);
+  delete [] tempBitfield;
+  return index;
+}
+
+// [startIndex, endIndex)
+class Range {
+public:
+  int startIndex;
+  int endIndex;
+  Range(int startIndex = 0, int endIndex = 0):startIndex(startIndex),
+					      endIndex(endIndex) {}
+  
+  int getSize() const {
+    return endIndex-startIndex;
+  }
+
+  int getMidIndex() const {
+    return (endIndex-startIndex)/2+startIndex;
+  }
+
+  bool operator<(const Range& range) const {
+    return getSize() < range.getSize();
+  }
+};
+
+int BitfieldMan::getStartIndex(int index) const {
+  while(index < blocks &&
+	(isUseBitSet(index) || isBitSet(index))) {
+    index++;
+  }
+  if(blocks <= index) {
+    return -1;
+  } else {
+    return index;
+  }
+}
+
+int BitfieldMan::getEndIndex(int index) const {
+  while(index < blocks &&
+	(!isUseBitSet(index) && !isBitSet(index))) {
+    index++;
+  }
+  return index;
+}
+
+int BitfieldMan::getSparseMissingUnusedIndex() const {
+  Range maxRange;
+  int index = 0;
+  int blocks = countBlock();
+  Range currentRange;
+  while(index < blocks) {
+    currentRange.startIndex = getStartIndex(index);
+    if(currentRange.startIndex == -1) {
+      break;
+    }
+    currentRange.endIndex = getEndIndex(currentRange.startIndex);
+    if(maxRange < currentRange) {
+      maxRange = currentRange;
+    }
+    index = currentRange.endIndex;
+  }
+  if(maxRange.getSize()) {
+    if(maxRange.startIndex == 0) {
+      return 0;
+    } else {
+      return maxRange.getMidIndex();
+    }
+  } else {
+    return -1;
+  }
+}
+
 BlockIndexes BitfieldMan::getAllMissingIndexes() const {
   BlockIndexes missingIndexes;
   for(int i = 0; i < bitfieldLength; i++) {
@@ -317,7 +405,7 @@ bool BitfieldMan::isAllBitSet() const {
 }
 
 bool BitfieldMan::isBitSetInternal(const unsigned char* bitfield, int index) const {
-  if(blocks <= index) { return false; }
+  if(index < 0 || blocks <= index) { return false; }
   unsigned char mask = 128 >> index%8;
   return (bitfield[index/8] & mask) != 0;
 }
@@ -340,7 +428,6 @@ void BitfieldMan::setBitfield(const unsigned char* bitfield, int bitfieldLength)
 
 void BitfieldMan::clearAllBit() {
   memset(this->bitfield, 0, this->bitfieldLength);
-  memset(this->useBitfield, 0, this->bitfieldLength);
 }
 
 void BitfieldMan::setAllBit() {
@@ -349,6 +436,16 @@ void BitfieldMan::setAllBit() {
   }
 }
 
+void BitfieldMan::clearAllUseBit() {
+  memset(this->useBitfield, 0, this->bitfieldLength);
+}
+
+void BitfieldMan::setAllUseBit() {
+  for(int i = 0; i < blocks; i++) {
+    setUseBit(i);
+  }
+}
+
 bool BitfieldMan::setFilterBit(int index) {
   return setBitInternal(filterBitfield, index, true);
 }
diff --git a/src/BitfieldMan.h b/src/BitfieldMan.h
index 369c3fd8..dfaf4020 100644
--- a/src/BitfieldMan.h
+++ b/src/BitfieldMan.h
@@ -43,6 +43,9 @@ private:
   bool isBitSetInternal(const unsigned char* bitfield, int index) const;
   bool setBitInternal(unsigned char* bitfield, int index, bool on);
   bool setFilterBit(int index);
+
+  int getStartIndex(int index) const;
+  int getEndIndex(int index) const;
 public:
   BitfieldMan(int blockLength, long long int totalLength);
   BitfieldMan(const BitfieldMan& bitfieldMan);
@@ -119,6 +122,14 @@ public:
   /**
    * affected by filter
    */
+  int getMissingUnusedIndex() const;
+  /**
+   * affected by filter
+   */
+  int getSparseMissingUnusedIndex() const;
+  /**
+   * affected by filter
+   */
   BlockIndexes getAllMissingIndexes() const;
   /**
    * affected by filter
@@ -155,6 +166,9 @@ public:
   void clearAllBit();
   void setAllBit();
 
+  void clearAllUseBit();
+  void setAllUseBit();
+
   void addFilter(long long int offset, long long int length);
   /**
    * Clears filter and disables filter
diff --git a/src/ConsoleDownloadEngine.cc b/src/ConsoleDownloadEngine.cc
index fb2c1bc8..61c1919f 100644
--- a/src/ConsoleDownloadEngine.cc
+++ b/src/ConsoleDownloadEngine.cc
@@ -51,9 +51,10 @@ void ConsoleDownloadEngine::initStatistics() {
 }
 
 void ConsoleDownloadEngine::calculateStatistics() {
-  long long int dlSize = segmentMan->getDownloadedSize();
+  long long int dlSize = segmentMan->getDownloadLength();
   if(!isStartupLengthSet && dlSize > 0) {
     startupLength = dlSize;
+    psize = dlSize;
     isStartupLengthSet = true;
   }
   int elapsed = cp.difference();
diff --git a/src/DownloadCommand.cc b/src/DownloadCommand.cc
index 4e948f53..5ae452dd 100644
--- a/src/DownloadCommand.cc
+++ b/src/DownloadCommand.cc
@@ -29,14 +29,30 @@
 #include "prefs.h"
 #include <sys/time.h>
 
+#define STARTUP_IDLE_TIME 10
+
 DownloadCommand::DownloadCommand(int cuid, Request* req, DownloadEngine* e,
 				 const SocketHandle& s):
   AbstractCommand(cuid, req, e, s), lastSize(0) {
+  PeerStatHandle peerStat = PeerStatHandle(new PeerStat(cuid));
+  peerStat->downloadStart();
+  this->e->segmentMan->registerPeerStat(peerStat);
 }
 
-DownloadCommand::~DownloadCommand() {}
+DownloadCommand::~DownloadCommand() {
+  PeerStatHandle peerStat = e->segmentMan->getPeerStat(cuid);
+  assert(peerStat.get());
+  peerStat->downloadStop();
+}
 
-bool DownloadCommand::executeInternal(Segment seg) {
+bool DownloadCommand::executeInternal(Segment& segment) {
+  int maxSpeedLimit = e->option->getAsInt(PREF_MAX_SPEED_LIMIT);
+  if(maxSpeedLimit > 0 &&
+     maxSpeedLimit < e->segmentMan->calculateDownloadSpeed()) {
+    usleep(1);
+    e->commands.push_back(this);
+    return false;
+  }
   TransferEncoding* te = NULL;
   if(transferEncoding.size()) {
     te = getTransferEncoding(transferEncoding);
@@ -45,61 +61,78 @@ bool DownloadCommand::executeInternal(Segment seg) {
   int bufSize = 4096;
   char buf[bufSize];
   socket->readData(buf, bufSize);
+  PeerStatHandle peerStat = e->segmentMan->getPeerStat(cuid);
+  assert(peerStat.get());
   if(te != NULL) {
     int infbufSize = 4096;
     char infbuf[infbufSize];
     te->inflate(infbuf, infbufSize, buf, bufSize);
-    e->segmentMan->diskWriter->writeData(infbuf, infbufSize, seg.sp+seg.ds);
-    seg.ds += infbufSize;
+    e->segmentMan->diskWriter->writeData(infbuf, infbufSize,
+					 segment.getPosition()+segment.writtenLength);
+    segment.writtenLength += infbufSize;
+    peerStat->updateDownloadLength(infbufSize);
   } else {
-    e->segmentMan->diskWriter->writeData(buf, bufSize, seg.sp+seg.ds);
-    seg.ds += bufSize;
+    e->segmentMan->diskWriter->writeData(buf, bufSize,
+					 segment.getPosition()+segment.writtenLength);
+    segment.writtenLength += bufSize;
+    peerStat->updateDownloadLength(bufSize);
   }
   // calculate downloading speed
-  int diff = sw.difference();
-  if(diff >= 1) {
-    seg.speed = (int)((seg.ds-lastSize)/(diff*1.0));
-    sw.reset();
-    lastSize = seg.ds;
+  if(/*sw.elapsed(1) >= 1 && */peerStat->getDownloadStartTime().elapsed(STARTUP_IDLE_TIME)) {
     int lowestLimit = e->option->getAsInt(PREF_LOWEST_SPEED_LIMIT);
-    if(lowestLimit > 0 && seg.speed <= lowestLimit) {
+    int nowSpeed = peerStat->calculateDownloadSpeed();
+    if(lowestLimit > 0 &&  nowSpeed <= lowestLimit) {
       throw new DlAbortEx("CUID#%d - Too slow Downloading speed: %d <= %d(B/s)",
 			  cuid,
-			  seg.speed,
+			  nowSpeed,
 			  lowestLimit);
     }
+    //sw.reset();
   }
   if(e->segmentMan->totalSize != 0 && bufSize == 0) {
     throw new DlRetryEx(EX_GOT_EOF);
   }
   if(te != NULL && te->finished()
-     || te == NULL && seg.ds >= seg.ep-seg.sp+1
+     || te == NULL && segment.complete()
      || bufSize == 0) {
     if(te != NULL) te->end();
     logger->info(MSG_DOWNLOAD_COMPLETED, cuid);
-    seg.ds = seg.ep-seg.sp+1;
-    seg.finish = true;
-    e->segmentMan->updateSegment(seg);
+    e->segmentMan->completeSegment(cuid, segment);
     // this unit is going to download another segment.
-    return prepareForNextSegment();
+    return prepareForNextSegment(segment);
   } else {
-    e->segmentMan->updateSegment(seg);
+    e->segmentMan->updateSegment(cuid, segment);
     e->commands.push_back(this);
     return false;
   }
   
 }
 
-bool DownloadCommand::prepareForRetry(int wait) {
-  //req->resetUrl();
-  return AbstractCommand::prepareForRetry(wait);
-}
-
-bool DownloadCommand::prepareForNextSegment() {
-  req->resetUrl();
-  if(!e->segmentMan->finished()) {
-    return AbstractCommand::prepareForRetry(0);
-  } else {
+bool DownloadCommand::prepareForNextSegment(const Segment& currentSegment) {
+  if(e->segmentMan->finished()) {
     return true;
+  } else {
+    // Merge segment with next segment, if segment.index+1 == nextSegment.index
+    Segment tempSegment = currentSegment;
+    while(1) {
+      Segment nextSegment;
+      if(e->segmentMan->getSegment(nextSegment, cuid, tempSegment.index+1)) {
+	if(nextSegment.writtenLength > 0) {
+	  return prepareForRetry(0);
+	}
+	nextSegment.writtenLength = tempSegment.writtenLength-tempSegment.length;
+	if(nextSegment.complete()) {
+	  e->segmentMan->completeSegment(cuid, nextSegment);
+	  tempSegment = nextSegment;
+	} else {
+	  e->segmentMan->updateSegment(cuid, nextSegment);
+	  e->commands.push_back(this);
+	  return false;
+	}
+      } else {
+	break;
+      }
+    }
+    return prepareForRetry(0);
   }
 }
diff --git a/src/DownloadCommand.h b/src/DownloadCommand.h
index 60403adf..68c6b291 100644
--- a/src/DownloadCommand.h
+++ b/src/DownloadCommand.h
@@ -33,10 +33,9 @@ private:
   Time sw;
   long long int lastSize;
 protected:
-  bool executeInternal(Segment segment);
+  bool executeInternal(Segment& segment);
 
-  bool prepareForRetry(int wait);
-  bool prepareForNextSegment();
+  virtual bool prepareForNextSegment(const Segment& currentSegment);
 public:
   DownloadCommand(int cuid, Request* req, DownloadEngine* e,
 		  const SocketHandle& s);
diff --git a/src/DownloadEngine.cc b/src/DownloadEngine.cc
index e1dafe5e..90fa8899 100644
--- a/src/DownloadEngine.cc
+++ b/src/DownloadEngine.cc
@@ -37,8 +37,8 @@ DownloadEngine::DownloadEngine():noWait(false), segmentMan(0) {
 }
 
 DownloadEngine::~DownloadEngine() {
-  delete segmentMan;
   cleanQueue();
+  delete segmentMan;
 }
 
 void DownloadEngine::cleanQueue() {
diff --git a/src/DownloadEngineFactory.cc b/src/DownloadEngineFactory.cc
index 6c094592..5edd8eed 100644
--- a/src/DownloadEngineFactory.cc
+++ b/src/DownloadEngineFactory.cc
@@ -22,7 +22,6 @@
 #include "DownloadEngineFactory.h"
 #include "prefs.h"
 #include "DefaultDiskWriter.h"
-#include "SplitSlowestSegmentSplitter.h"
 #include "InitiateConnectionCommandFactory.h"
 #include "ByteArrayDiskWriter.h"
 #include "Util.h"
@@ -51,8 +50,6 @@ DownloadEngineFactory::newConsoleEngine(const Option* op,
   e->segmentMan->dir = op->get(PREF_DIR);
   e->segmentMan->ufilename = op->get(PREF_OUT);
   e->segmentMan->option = op;
-  e->segmentMan->splitter = new SplitSlowestSegmentSplitter();
-  e->segmentMan->splitter->setMinSegmentSize(op->getAsLLInt(PREF_MIN_SEGMENT_SIZE));
   e->segmentMan->reserved = reserved;
   
   int cuidCounter = 1;
@@ -79,8 +76,6 @@ DownloadEngineFactory::newTorrentConsoleEngine(const Option* op,
   te->segmentMan = new SegmentMan();
   te->segmentMan->diskWriter = byteArrayDiskWriter;
   te->segmentMan->option = op;
-  te->segmentMan->splitter = new SplitSlowestSegmentSplitter();
-  te->segmentMan->splitter->setMinSegmentSize(op->getAsLLInt(PREF_MIN_SEGMENT_SIZE));
   te->torrentMan = new TorrentMan();
   te->torrentMan->setStoreDir(op->get(PREF_DIR));
   te->torrentMan->option = op;
diff --git a/src/FtpConnection.cc b/src/FtpConnection.cc
index ba8e2000..e425e0bf 100644
--- a/src/FtpConnection.cc
+++ b/src/FtpConnection.cc
@@ -97,7 +97,7 @@ SocketHandle FtpConnection::sendPort() const {
 }
 
 void FtpConnection::sendRest(const Segment& segment) const {
-  string request = "REST "+Util::llitos(segment.sp+segment.ds)+"\r\n";
+  string request = "REST "+Util::llitos(segment.getPosition()+segment.writtenLength)+"\r\n";
   logger->info(MSG_SENDING_REQUEST, cuid, request.c_str());
   socket->writeData(request);
 }
diff --git a/src/FtpDownloadCommand.cc b/src/FtpDownloadCommand.cc
index 25368973..c6167d46 100644
--- a/src/FtpDownloadCommand.cc
+++ b/src/FtpDownloadCommand.cc
@@ -25,7 +25,8 @@ FtpDownloadCommand::FtpDownloadCommand(int cuid, Request* req,
 				       DownloadEngine* e,
 				       const SocketHandle& dataSocket,
 				       const SocketHandle& ctrlSocket)
-  :DownloadCommand(cuid, req, e, dataSocket), ctrlSocket(ctrlSocket) {}
+  :DownloadCommand(cuid, req, e, dataSocket),
+   ctrlSocket(ctrlSocket) {}
 
 FtpDownloadCommand::~FtpDownloadCommand() {}
 
diff --git a/src/FtpInitiateConnectionCommand.cc b/src/FtpInitiateConnectionCommand.cc
index 8a964870..32979488 100644
--- a/src/FtpInitiateConnectionCommand.cc
+++ b/src/FtpInitiateConnectionCommand.cc
@@ -43,18 +43,7 @@ FtpInitiateConnectionCommand::~FtpInitiateConnectionCommand() {
 #endif // ENABLE_ASYNC_DNS
 }
 
-bool FtpInitiateConnectionCommand::executeInternal(Segment segment) {
-  if(!e->segmentMan->downloadStarted) {
-    e->segmentMan->filename = Util::urldecode(req->getFile());
-    bool segFileExists = e->segmentMan->segmentFileExists();
-    if(segFileExists) {
-      e->segmentMan->load();
-      e->segmentMan->diskWriter->openExistingFile(e->segmentMan->getFilePath());
-      e->segmentMan->downloadStarted = true;
-    } else {
-      e->segmentMan->diskWriter->initAndOpenFile(e->segmentMan->getFilePath());
-    }
-  }
+bool FtpInitiateConnectionCommand::executeInternal(Segment& segment) {
   string hostname;
   if(useHttpProxy()) {
     hostname = e->option->get(PREF_HTTP_PROXY_HOST);
@@ -71,6 +60,17 @@ bool FtpInitiateConnectionCommand::executeInternal(Segment segment) {
     }
   }
 #endif // ENABLE_ASYNC_DNS
+  if(!e->segmentMan->downloadStarted) {
+    e->segmentMan->filename = Util::urldecode(req->getFile());
+    bool segFileExists = e->segmentMan->segmentFileExists();
+    if(segFileExists) {
+      e->segmentMan->load();
+      e->segmentMan->diskWriter->openExistingFile(e->segmentMan->getFilePath());
+      e->segmentMan->downloadStarted = true;
+    } else {
+      e->segmentMan->diskWriter->initAndOpenFile(e->segmentMan->getFilePath());
+    }
+  }
   Command* command;
   if(useHttpProxy()) {
     logger->info(MSG_CONNECTING_TO_SERVER, cuid,
diff --git a/src/FtpInitiateConnectionCommand.h b/src/FtpInitiateConnectionCommand.h
index 95bd9df4..7fa82105 100644
--- a/src/FtpInitiateConnectionCommand.h
+++ b/src/FtpInitiateConnectionCommand.h
@@ -33,7 +33,7 @@ private:
   bool useHttpProxyGet() const;
   bool useHttpProxyConnect() const;
 protected:
-  bool executeInternal(Segment segment);
+  bool executeInternal(Segment& segment);
 public:
   FtpInitiateConnectionCommand(int cuid, Request* req, DownloadEngine* e);
   ~FtpInitiateConnectionCommand();
diff --git a/src/FtpNegotiationCommand.cc b/src/FtpNegotiationCommand.cc
index 34641e27..e0248aca 100644
--- a/src/FtpNegotiationCommand.cc
+++ b/src/FtpNegotiationCommand.cc
@@ -40,7 +40,7 @@ FtpNegotiationCommand::~FtpNegotiationCommand() {
   delete ftp;
 }
 
-bool FtpNegotiationCommand::executeInternal(Segment segment) {
+bool FtpNegotiationCommand::executeInternal(Segment& segment) {
   while(processSequence(segment));
   if(sequence == SEQ_RETRY) {
     return prepareForRetry(0);
@@ -170,6 +170,8 @@ bool FtpNegotiationCommand::recvSize() {
   if(!e->segmentMan->downloadStarted) {
     e->segmentMan->downloadStarted = true;
     e->segmentMan->totalSize = size;
+    e->segmentMan->initBitfield(e->option->getAsInt(PREF_SEGMENT_SIZE),
+				e->segmentMan->totalSize);
   } else if(e->segmentMan->totalSize != size) {
     throw new DlAbortEx(EX_SIZE_MISMATCH, e->segmentMan->totalSize, size);
   }
diff --git a/src/FtpNegotiationCommand.h b/src/FtpNegotiationCommand.h
index e89317d6..8df16dc1 100644
--- a/src/FtpNegotiationCommand.h
+++ b/src/FtpNegotiationCommand.h
@@ -78,7 +78,7 @@ private:
   int sequence;
   FtpConnection* ftp;
 protected:
-  bool executeInternal(Segment segment);
+  bool executeInternal(Segment& segment);
 public:
   FtpNegotiationCommand(int cuid, Request* req, DownloadEngine* e,
 			const SocketHandle& s);
diff --git a/src/FtpTunnelRequestCommand.cc b/src/FtpTunnelRequestCommand.cc
index 24a8049b..b3b56fdf 100644
--- a/src/FtpTunnelRequestCommand.cc
+++ b/src/FtpTunnelRequestCommand.cc
@@ -33,7 +33,7 @@ FtpTunnelRequestCommand::FtpTunnelRequestCommand(int cuid, Request* req,
 
 FtpTunnelRequestCommand::~FtpTunnelRequestCommand() {}
 
-bool FtpTunnelRequestCommand::executeInternal(Segment segment) {
+bool FtpTunnelRequestCommand::executeInternal(Segment& segment) {
   socket->setBlockingMode();
   HttpConnection httpConnection(cuid, socket, req, e->option);
   httpConnection.sendProxyRequest();
diff --git a/src/FtpTunnelRequestCommand.h b/src/FtpTunnelRequestCommand.h
index b02d1806..3a40aa13 100644
--- a/src/FtpTunnelRequestCommand.h
+++ b/src/FtpTunnelRequestCommand.h
@@ -26,7 +26,7 @@
 
 class FtpTunnelRequestCommand : public AbstractCommand {
 protected:
-  bool executeInternal(Segment segment);
+  bool executeInternal(Segment& segment);
 public:
   FtpTunnelRequestCommand(int cuid, Request* req, DownloadEngine* e,
 			  const SocketHandle& s);
diff --git a/src/FtpTunnelResponseCommand.cc b/src/FtpTunnelResponseCommand.cc
index d0e63888..ec521f56 100644
--- a/src/FtpTunnelResponseCommand.cc
+++ b/src/FtpTunnelResponseCommand.cc
@@ -35,7 +35,7 @@ FtpTunnelResponseCommand::~FtpTunnelResponseCommand() {
   delete http;
 }
 
-bool FtpTunnelResponseCommand::executeInternal(Segment segment) {
+bool FtpTunnelResponseCommand::executeInternal(Segment& segment) {
   HttpHeader headers;
   int status = http->receiveResponse(headers);
   if(status == 0) {
diff --git a/src/FtpTunnelResponseCommand.h b/src/FtpTunnelResponseCommand.h
index 7d0e19ae..641096f2 100644
--- a/src/FtpTunnelResponseCommand.h
+++ b/src/FtpTunnelResponseCommand.h
@@ -29,7 +29,7 @@ class FtpTunnelResponseCommand : public AbstractCommand {
 private:
   HttpConnection* http;
 protected:
-    bool executeInternal(Segment segment);
+    bool executeInternal(Segment& segment);
 public:
   FtpTunnelResponseCommand(int cuid, Request* req, DownloadEngine* e,
 			   const SocketHandle& s);
diff --git a/src/HttpConnection.cc b/src/HttpConnection.cc
index e63000a2..47c0f6a0 100644
--- a/src/HttpConnection.cc
+++ b/src/HttpConnection.cc
@@ -71,14 +71,23 @@ string HttpConnection::createRequest(const Segment& segment) const {
      ((req->getDir() == "/" ? "/" : req->getDir()+"/")+req->getFile()))+
     string(" HTTP/1.1\r\n")+
     "User-Agent: "+USER_AGENT+"\r\n"+
-    "Connection: close\r\n"+
+    // use persistent connection
+    //"Connection: close\r\n"+
     "Accept: */*\r\n"+        /* */
     "Host: "+getHost(req->getHost(), req->getPort())+"\r\n"+
     "Pragma: no-cache\r\n"+
     "Cache-Control: no-cache\r\n";
-  if(segment.sp+segment.ds > 0) {
+  if(!req->isKeepAlive()) {
+    request += "Connection: close\r\n";
+  }
+  if(segment.length > 0) {
     request += "Range: bytes="+
-      Util::llitos(segment.sp+segment.ds)+"-"+Util::llitos(segment.ep)+"\r\n";
+      Util::llitos(segment.getPosition()+segment.writtenLength);
+    request += "-";
+    if(req->isKeepAlive()) {
+      request += Util::llitos(segment.getPosition()+segment.length-1);
+    }
+    request += "\r\n";
   }
   if(useProxy() && useProxyAuth() && useProxyGet()) {
     request += "Proxy-Connection: close\r\n";
@@ -144,7 +153,7 @@ int HttpConnection::receiveResponse(HttpHeader& headers) {
     socket->readData(headerBuf+headerBufLength, size);
     headerBufLength += size;
   } else {
-    if(eohIndex[headerBuf] == '\n') {
+    if(headerBuf[eohIndex] == '\n') {
       // for crapping non-standard HTTP server
       delimiterSwitch = 1;
     } else {
diff --git a/src/HttpDownloadCommand.cc b/src/HttpDownloadCommand.cc
index 3077ab16..143e1923 100644
--- a/src/HttpDownloadCommand.cc
+++ b/src/HttpDownloadCommand.cc
@@ -20,14 +20,15 @@
  */
 /* copyright --> */
 #include "HttpDownloadCommand.h"
-#include <sys/time.h>
-#include <sys/types.h>
-#include <unistd.h>
-#include <algorithm>
 #include "DlRetryEx.h"
 #include "HttpRequestCommand.h"
 #include "Util.h"
 #include "ChunkedEncoding.h"
+#include "message.h"
+#include <sys/time.h>
+#include <sys/types.h>
+#include <unistd.h>
+#include <algorithm>
 
 using namespace std;
 
@@ -49,3 +50,17 @@ HttpDownloadCommand::~HttpDownloadCommand() {
 TransferEncoding* HttpDownloadCommand::getTransferEncoding(const string& name) {
   return transferEncodings[name];
 }
+
+bool HttpDownloadCommand::prepareForNextSegment(const Segment& currentSegment) {
+  if(e->segmentMan->finished()) {
+    return true;
+  } else {
+    if(req->isKeepAlive()) {
+      Command* command = new HttpRequestCommand(cuid, req, e, socket);
+      e->commands.push_back(command);
+      return true;
+    } else {
+      return DownloadCommand::prepareForNextSegment(currentSegment);
+    }
+  }
+}
diff --git a/src/HttpDownloadCommand.h b/src/HttpDownloadCommand.h
index 440fa9ec..8141d7ed 100644
--- a/src/HttpDownloadCommand.h
+++ b/src/HttpDownloadCommand.h
@@ -36,6 +36,8 @@ using namespace std;
 class HttpDownloadCommand:public DownloadCommand {
 private:
   map<string, TransferEncoding*> transferEncodings;
+protected:
+  virtual bool prepareForNextSegment(const Segment& currentSegment);
 public:
   HttpDownloadCommand(int cuid, Request* req, DownloadEngine* e,
 		      const SocketHandle& s);
diff --git a/src/HttpInitiateConnectionCommand.cc b/src/HttpInitiateConnectionCommand.cc
index 57bca089..33fd74a9 100644
--- a/src/HttpInitiateConnectionCommand.cc
+++ b/src/HttpInitiateConnectionCommand.cc
@@ -43,7 +43,7 @@ HttpInitiateConnectionCommand::~HttpInitiateConnectionCommand() {
 #endif // ENABLE_ASYNC_DNS
 }
 
-bool HttpInitiateConnectionCommand::executeInternal(Segment segment) {
+bool HttpInitiateConnectionCommand::executeInternal(Segment& segment) {
   string hostname;
   if(useProxy()) {
     hostname = e->option->get(PREF_HTTP_PROXY_HOST);
diff --git a/src/HttpInitiateConnectionCommand.h b/src/HttpInitiateConnectionCommand.h
index 8a3839b4..fbaecfb5 100644
--- a/src/HttpInitiateConnectionCommand.h
+++ b/src/HttpInitiateConnectionCommand.h
@@ -41,7 +41,7 @@ protected:
    * Whether or not the connection is established successfully is
    * evaluated by RequestCommand.
    */
-  bool executeInternal(Segment segment);
+  bool executeInternal(Segment& segment);
 public:
   HttpInitiateConnectionCommand(int cuid, Request* req, DownloadEngine* e);
   ~HttpInitiateConnectionCommand();
diff --git a/src/HttpProxyRequestCommand.cc b/src/HttpProxyRequestCommand.cc
index 0bf66558..b9f660d8 100644
--- a/src/HttpProxyRequestCommand.cc
+++ b/src/HttpProxyRequestCommand.cc
@@ -33,7 +33,7 @@ HttpProxyRequestCommand::HttpProxyRequestCommand(int cuid, Request* req,
 
 HttpProxyRequestCommand::~HttpProxyRequestCommand() {}
 
-bool HttpProxyRequestCommand::executeInternal(Segment segment) {
+bool HttpProxyRequestCommand::executeInternal(Segment& segment) {
   socket->setBlockingMode();
   HttpConnection httpConnection(cuid, socket, req, e->option);
   httpConnection.sendProxyRequest();
diff --git a/src/HttpProxyRequestCommand.h b/src/HttpProxyRequestCommand.h
index 2b5a646a..0d873cc3 100644
--- a/src/HttpProxyRequestCommand.h
+++ b/src/HttpProxyRequestCommand.h
@@ -26,7 +26,7 @@
 
 class HttpProxyRequestCommand : public AbstractCommand {
 protected:
-  bool executeInternal(Segment segment);
+  bool executeInternal(Segment& segment);
 public:
   HttpProxyRequestCommand(int cuid, Request* req, DownloadEngine* e,
 			  const SocketHandle& s);
diff --git a/src/HttpProxyResponseCommand.cc b/src/HttpProxyResponseCommand.cc
index 51cb6580..17d16097 100644
--- a/src/HttpProxyResponseCommand.cc
+++ b/src/HttpProxyResponseCommand.cc
@@ -35,7 +35,7 @@ HttpProxyResponseCommand::~HttpProxyResponseCommand() {
   delete http;
 }
 
-bool HttpProxyResponseCommand::executeInternal(Segment segment) {
+bool HttpProxyResponseCommand::executeInternal(Segment& segment) {
   HttpHeader headers;
   int status = http->receiveResponse(headers);
   if(status == 0) {
diff --git a/src/HttpProxyResponseCommand.h b/src/HttpProxyResponseCommand.h
index ad938cf0..5f800e84 100644
--- a/src/HttpProxyResponseCommand.h
+++ b/src/HttpProxyResponseCommand.h
@@ -29,7 +29,7 @@ class HttpProxyResponseCommand : public AbstractCommand {
 private:
   HttpConnection* http;
 protected:
-  bool executeInternal(Segment segment);
+  bool executeInternal(Segment& segment);
 public:
   HttpProxyResponseCommand(int cuid, Request* req, DownloadEngine* e,
 			   const SocketHandle& s);
diff --git a/src/HttpRequestCommand.cc b/src/HttpRequestCommand.cc
index 9f5ba45a..522c6a1b 100644
--- a/src/HttpRequestCommand.cc
+++ b/src/HttpRequestCommand.cc
@@ -22,6 +22,7 @@
 #include "HttpRequestCommand.h"
 #include "HttpResponseCommand.h"
 #include "HttpConnection.h"
+#include "prefs.h"
 
 HttpRequestCommand::HttpRequestCommand(int cuid, Request* req,
 				       DownloadEngine* e,
@@ -33,15 +34,17 @@ HttpRequestCommand::HttpRequestCommand(int cuid, Request* req,
 
 HttpRequestCommand::~HttpRequestCommand() {}
 
-bool HttpRequestCommand::executeInternal(Segment seg) {
+bool HttpRequestCommand::executeInternal(Segment& segment) {
   socket->setBlockingMode();
   if(req->getProtocol() == "https") {
     socket->initiateSecureConnection();
   }
+  if(!e->option->getAsBool(PREF_HTTP_KEEP_ALIVE)) {
+    req->setKeepAlive(false);
+  }
   HttpConnection http(cuid, socket, req, e->option);
-  // set seg to request in order to remember the request range
-  req->seg = seg;
-  http.sendRequest(seg);
+  req->segment = segment;
+  http.sendRequest(segment);
 
   Command* command = getNextCommand();
   e->commands.push_back(command);
diff --git a/src/HttpRequestCommand.h b/src/HttpRequestCommand.h
index d3fa923b..2834ebb0 100644
--- a/src/HttpRequestCommand.h
+++ b/src/HttpRequestCommand.h
@@ -26,7 +26,7 @@
 
 class HttpRequestCommand:public AbstractCommand {
 protected:
-  bool executeInternal(Segment segment);
+  bool executeInternal(Segment& segment);
   Command* getNextCommand() const;
 public:
   HttpRequestCommand(int cuid, Request* req, DownloadEngine* e,
diff --git a/src/HttpResponseCommand.cc b/src/HttpResponseCommand.cc
index feea4a06..b95070e8 100644
--- a/src/HttpResponseCommand.cc
+++ b/src/HttpResponseCommand.cc
@@ -26,6 +26,7 @@
 #include "HttpInitiateConnectionCommand.h"
 #include "message.h"
 #include "Util.h"
+#include "prefs.h"
 #include <sys/types.h>
 #include <unistd.h>
 
@@ -40,8 +41,8 @@ HttpResponseCommand::~HttpResponseCommand() {
   delete http;
 }
 
-bool HttpResponseCommand::executeInternal(Segment seg) {
-  if(req->seg.sp != seg.sp) {
+bool HttpResponseCommand::executeInternal(Segment& segment) {
+  if(req->segment != segment) {
     logger->info(MSG_SEGMENT_CHANGED, cuid);
     return prepareForRetry(0);
   }
@@ -53,8 +54,12 @@ bool HttpResponseCommand::executeInternal(Segment seg) {
     return false;
   }
   // check HTTP status number
-  checkResponse(status, seg);
+  checkResponse(status, segment);
   retrieveCookie(headers);
+  // check whether the server supports persistent connections.
+  if(Util::toLower(headers.getFirst("Connection")).find("close") != string::npos) {
+    req->setKeepAlive(false);
+  }
   // check whether Location header exists. If it does, update request object
   // with redirected URL.
   // then establish a connection to the new host and port
@@ -64,7 +69,8 @@ bool HttpResponseCommand::executeInternal(Segment seg) {
   if(!e->segmentMan->downloadStarted) {
     string transferEncoding;
     if(headers.defined("Transfer-Encoding")) {
-      return handleOtherEncoding(headers.getFirst("Transfer-Encoding"), headers);
+      return handleOtherEncoding(headers.getFirst("Transfer-Encoding"),
+				 headers);
     } else {
       return handleDefaultEncoding(headers);
     }
@@ -82,8 +88,8 @@ void HttpResponseCommand::checkResponse(int status, const Segment& segment) {
     throw new DlAbortEx(EX_AUTH_FAILED);
   }
   if(!(300 <= status && status < 400 ||
-       (segment.sp+segment.ds == 0 && status == 200)
-       || (segment.sp+segment.ds > 0 &&  status == 206))) {
+       (segment.getPosition()+segment.writtenLength == 0 && (status == 200 || status == 206)) ||
+       (segment.getPosition()+segment.writtenLength > 0 &&  status == 206))) {
     throw new DlRetryEx(EX_BAD_STATUS, status);
   }
 }
@@ -112,6 +118,8 @@ bool HttpResponseCommand::handleDefaultEncoding(const HttpHeader& headers) {
   if(req->isTorrent) {
     long long int size = headers.getFirstAsLLInt("Content-Length");
     e->segmentMan->totalSize = size;
+    e->segmentMan->initBitfield(e->option->getAsInt(PREF_SEGMENT_SIZE),
+				e->segmentMan->totalSize);
     e->segmentMan->isSplittable = false;
     e->segmentMan->downloadStarted = true;
     e->segmentMan->diskWriter->initAndOpenFile("/tmp/aria2"+Util::itos(getpid()));
@@ -134,11 +142,10 @@ bool HttpResponseCommand::handleDefaultEncoding(const HttpHeader& headers) {
     return prepareForRetry(0);
   } else {
     e->segmentMan->totalSize = size;
-    Segment seg;
-    e->segmentMan->getSegment(seg, cuid);	
+    e->segmentMan->initBitfield(e->option->getAsInt(PREF_SEGMENT_SIZE),
+				e->segmentMan->totalSize);
     e->segmentMan->diskWriter->initAndOpenFile(e->segmentMan->getFilePath());
-    createHttpDownloadCommand();
-    return true;
+    return prepareForRetry(0);
   }
 }
 
@@ -148,8 +155,10 @@ bool HttpResponseCommand::handleOtherEncoding(const string& transferEncoding, co
   e->segmentMan->isSplittable = false;
   e->segmentMan->filename = determinFilename(headers);
   e->segmentMan->totalSize = 0;
-  Segment seg;
-  e->segmentMan->getSegment(seg, cuid);	
+  // disable keep-alive
+  req->setKeepAlive(false);
+  Segment segment;
+  e->segmentMan->getSegment(segment, cuid);	
   e->segmentMan->diskWriter->initAndOpenFile(e->segmentMan->getFilePath());
   createHttpDownloadCommand(transferEncoding);
   return true;
diff --git a/src/HttpResponseCommand.h b/src/HttpResponseCommand.h
index 664fe026..298085b7 100644
--- a/src/HttpResponseCommand.h
+++ b/src/HttpResponseCommand.h
@@ -39,7 +39,7 @@ private:
   string determinFilename(const HttpHeader& headers);
   HttpConnection* http;
 protected:
-  bool executeInternal(Segment segment);
+  bool executeInternal(Segment& segment);
 public:
   HttpResponseCommand(int cuid, Request* req, DownloadEngine* e,
 		      const SocketHandle& s);
diff --git a/src/Makefile.am b/src/Makefile.am
index 3ed2ba80..b4e85973 100644
--- a/src/Makefile.am
+++ b/src/Makefile.am
@@ -23,11 +23,8 @@ SRCS =  Socket.h\
 	SleepCommand.cc SleepCommand.h\
 	DownloadEngine.cc DownloadEngine.h\
 	ConsoleDownloadEngine.cc ConsoleDownloadEngine.h\
-	Segment.h\
+	Segment.cc Segment.h\
 	SegmentMan.cc SegmentMan.h\
-	SegmentSplitter.cc SegmentSplitter.h\
-	SplitFirstSegmentSplitter.cc SplitFirstSegmentSplitter.h\
-	SplitSlowestSegmentSplitter.cc SplitSlowestSegmentSplitter.h\
 	Util.cc Util.h\
 	Request.cc Request.h\
 	common.h\
@@ -55,7 +52,9 @@ SRCS =  Socket.h\
 	FeatureConfig.cc FeatureConfig.h\
 	DownloadEngineFactory.cc DownloadEngineFactory.h\
 	RequestInfo.h\
-	UrlRequestInfo.cc UrlRequestInfo.h
+	UrlRequestInfo.cc UrlRequestInfo.h\
+	SpeedCalc.cc SpeedCalc.h\
+	PeerStat.h
 
 if ENABLE_ASYNC_DNS
 SRCS += NameResolver.cc NameResolver.h
diff --git a/src/Makefile.in b/src/Makefile.in
index e1df1f2e..ec826441 100644
--- a/src/Makefile.in
+++ b/src/Makefile.in
@@ -151,26 +151,24 @@ am__libaria2c_a_SOURCES_DIST = Socket.h SocketCore.cc SocketCore.h \
 	FtpTunnelRequestCommand.h FtpTunnelResponseCommand.cc \
 	FtpTunnelResponseCommand.h SleepCommand.cc SleepCommand.h \
 	DownloadEngine.cc DownloadEngine.h ConsoleDownloadEngine.cc \
-	ConsoleDownloadEngine.h Segment.h SegmentMan.cc SegmentMan.h \
-	SegmentSplitter.cc SegmentSplitter.h \
-	SplitFirstSegmentSplitter.cc SplitFirstSegmentSplitter.h \
-	SplitSlowestSegmentSplitter.cc SplitSlowestSegmentSplitter.h \
-	Util.cc Util.h Request.cc Request.h common.h message.h \
-	Exception.h DlAbortEx.h DlRetryEx.h Logger.h SimpleLogger.cc \
-	SimpleLogger.h TransferEncoding.h ChunkedEncoding.cc \
-	ChunkedEncoding.h DiskWriter.h DefaultDiskWriter.cc \
-	DefaultDiskWriter.h PreAllocationDiskWriter.cc \
-	PreAllocationDiskWriter.h AbstractDiskWriter.cc \
-	AbstractDiskWriter.h File.cc File.h Option.cc Option.h \
-	Base64.cc Base64.h CookieBox.cc CookieBox.h messageDigest.h \
-	LogFactory.cc LogFactory.h NullLogger.h TimeA2.cc TimeA2.h \
-	SharedHandle.h FeatureConfig.cc FeatureConfig.h \
-	DownloadEngineFactory.cc DownloadEngineFactory.h RequestInfo.h \
-	UrlRequestInfo.cc UrlRequestInfo.h NameResolver.cc \
-	NameResolver.h MetaEntry.h Data.cc Data.h Dictionary.cc \
-	Dictionary.h List.cc List.h MetaFileUtil.cc MetaFileUtil.h \
-	MetaEntryVisitor.h ShaVisitor.cc ShaVisitor.h TorrentMan.cc \
-	TorrentMan.h PeerConnection.cc PeerConnection.h \
+	ConsoleDownloadEngine.h Segment.cc Segment.h SegmentMan.cc \
+	SegmentMan.h Util.cc Util.h Request.cc Request.h common.h \
+	message.h Exception.h DlAbortEx.h DlRetryEx.h Logger.h \
+	SimpleLogger.cc SimpleLogger.h TransferEncoding.h \
+	ChunkedEncoding.cc ChunkedEncoding.h DiskWriter.h \
+	DefaultDiskWriter.cc DefaultDiskWriter.h \
+	PreAllocationDiskWriter.cc PreAllocationDiskWriter.h \
+	AbstractDiskWriter.cc AbstractDiskWriter.h File.cc File.h \
+	Option.cc Option.h Base64.cc Base64.h CookieBox.cc CookieBox.h \
+	messageDigest.h LogFactory.cc LogFactory.h NullLogger.h \
+	TimeA2.cc TimeA2.h SharedHandle.h FeatureConfig.cc \
+	FeatureConfig.h DownloadEngineFactory.cc \
+	DownloadEngineFactory.h RequestInfo.h UrlRequestInfo.cc \
+	UrlRequestInfo.h SpeedCalc.cc SpeedCalc.h PeerStat.h \
+	NameResolver.cc NameResolver.h MetaEntry.h Data.cc Data.h \
+	Dictionary.cc Dictionary.h List.cc List.h MetaFileUtil.cc \
+	MetaFileUtil.h MetaEntryVisitor.h ShaVisitor.cc ShaVisitor.h \
+	TorrentMan.cc TorrentMan.h PeerConnection.cc PeerConnection.h \
 	PeerMessageUtil.cc PeerMessageUtil.h PeerAbstractCommand.cc \
 	PeerAbstractCommand.h PeerInitiateConnectionCommand.cc \
 	PeerInitiateConnectionCommand.h PeerInteractionCommand.cc \
@@ -280,17 +278,15 @@ am__objects_4 = SocketCore.$(OBJEXT) Command.$(OBJEXT) \
 	FtpTunnelRequestCommand.$(OBJEXT) \
 	FtpTunnelResponseCommand.$(OBJEXT) SleepCommand.$(OBJEXT) \
 	DownloadEngine.$(OBJEXT) ConsoleDownloadEngine.$(OBJEXT) \
-	SegmentMan.$(OBJEXT) SegmentSplitter.$(OBJEXT) \
-	SplitFirstSegmentSplitter.$(OBJEXT) \
-	SplitSlowestSegmentSplitter.$(OBJEXT) Util.$(OBJEXT) \
+	Segment.$(OBJEXT) SegmentMan.$(OBJEXT) Util.$(OBJEXT) \
 	Request.$(OBJEXT) SimpleLogger.$(OBJEXT) \
 	ChunkedEncoding.$(OBJEXT) DefaultDiskWriter.$(OBJEXT) \
 	PreAllocationDiskWriter.$(OBJEXT) AbstractDiskWriter.$(OBJEXT) \
 	File.$(OBJEXT) Option.$(OBJEXT) Base64.$(OBJEXT) \
 	CookieBox.$(OBJEXT) LogFactory.$(OBJEXT) TimeA2.$(OBJEXT) \
 	FeatureConfig.$(OBJEXT) DownloadEngineFactory.$(OBJEXT) \
-	UrlRequestInfo.$(OBJEXT) $(am__objects_1) $(am__objects_2) \
-	$(am__objects_3)
+	UrlRequestInfo.$(OBJEXT) SpeedCalc.$(OBJEXT) $(am__objects_1) \
+	$(am__objects_2) $(am__objects_3)
 am_libaria2c_a_OBJECTS = $(am__objects_4)
 libaria2c_a_OBJECTS = $(am_libaria2c_a_OBJECTS)
 am__installdirs = "$(DESTDIR)$(bindir)"
@@ -472,23 +468,21 @@ SRCS = Socket.h SocketCore.cc SocketCore.h Command.cc Command.h \
 	FtpTunnelRequestCommand.h FtpTunnelResponseCommand.cc \
 	FtpTunnelResponseCommand.h SleepCommand.cc SleepCommand.h \
 	DownloadEngine.cc DownloadEngine.h ConsoleDownloadEngine.cc \
-	ConsoleDownloadEngine.h Segment.h SegmentMan.cc SegmentMan.h \
-	SegmentSplitter.cc SegmentSplitter.h \
-	SplitFirstSegmentSplitter.cc SplitFirstSegmentSplitter.h \
-	SplitSlowestSegmentSplitter.cc SplitSlowestSegmentSplitter.h \
-	Util.cc Util.h Request.cc Request.h common.h message.h \
-	Exception.h DlAbortEx.h DlRetryEx.h Logger.h SimpleLogger.cc \
-	SimpleLogger.h TransferEncoding.h ChunkedEncoding.cc \
-	ChunkedEncoding.h DiskWriter.h DefaultDiskWriter.cc \
-	DefaultDiskWriter.h PreAllocationDiskWriter.cc \
-	PreAllocationDiskWriter.h AbstractDiskWriter.cc \
-	AbstractDiskWriter.h File.cc File.h Option.cc Option.h \
-	Base64.cc Base64.h CookieBox.cc CookieBox.h messageDigest.h \
-	LogFactory.cc LogFactory.h NullLogger.h TimeA2.cc TimeA2.h \
-	SharedHandle.h FeatureConfig.cc FeatureConfig.h \
-	DownloadEngineFactory.cc DownloadEngineFactory.h RequestInfo.h \
-	UrlRequestInfo.cc UrlRequestInfo.h $(am__append_1) \
-	$(am__append_2) $(am__append_3)
+	ConsoleDownloadEngine.h Segment.cc Segment.h SegmentMan.cc \
+	SegmentMan.h Util.cc Util.h Request.cc Request.h common.h \
+	message.h Exception.h DlAbortEx.h DlRetryEx.h Logger.h \
+	SimpleLogger.cc SimpleLogger.h TransferEncoding.h \
+	ChunkedEncoding.cc ChunkedEncoding.h DiskWriter.h \
+	DefaultDiskWriter.cc DefaultDiskWriter.h \
+	PreAllocationDiskWriter.cc PreAllocationDiskWriter.h \
+	AbstractDiskWriter.cc AbstractDiskWriter.h File.cc File.h \
+	Option.cc Option.h Base64.cc Base64.h CookieBox.cc CookieBox.h \
+	messageDigest.h LogFactory.cc LogFactory.h NullLogger.h \
+	TimeA2.cc TimeA2.h SharedHandle.h FeatureConfig.cc \
+	FeatureConfig.h DownloadEngineFactory.cc \
+	DownloadEngineFactory.h RequestInfo.h UrlRequestInfo.cc \
+	UrlRequestInfo.h SpeedCalc.cc SpeedCalc.h PeerStat.h \
+	$(am__append_1) $(am__append_2) $(am__append_3)
 noinst_LIBRARIES = libaria2c.a
 libaria2c_a_SOURCES = $(SRCS)
 aria2c_LDADD = libaria2c.a @LIBINTL@ @ALLOCA@ @LIBGNUTLS_LIBS@\
@@ -655,15 +649,14 @@ distclean-compile:
 @AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/RequestMessage.Po@am__quote@
 @AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/RequestSlot.Po@am__quote@
 @AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/SeedCheckCommand.Po@am__quote@
+@AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/Segment.Po@am__quote@
 @AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/SegmentMan.Po@am__quote@
-@AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/SegmentSplitter.Po@am__quote@
 @AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/ShaVisitor.Po@am__quote@
 @AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/SimpleLogger.Po@am__quote@
 @AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/SimplePeerMessage.Po@am__quote@
 @AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/SleepCommand.Po@am__quote@
 @AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/SocketCore.Po@am__quote@
-@AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/SplitFirstSegmentSplitter.Po@am__quote@
-@AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/SplitSlowestSegmentSplitter.Po@am__quote@
+@AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/SpeedCalc.Po@am__quote@
 @AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/SuggestPieceMessage.Po@am__quote@
 @AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/TimeA2.Po@am__quote@
 @AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/TorrentAutoSaveCommand.Po@am__quote@
diff --git a/src/PeerInteractionCommand.cc b/src/PeerInteractionCommand.cc
index 1b529264..6f0f1b89 100644
--- a/src/PeerInteractionCommand.cc
+++ b/src/PeerInteractionCommand.cc
@@ -127,7 +127,11 @@ bool PeerInteractionCommand::executeInternal() {
     }
     receiveMessages();
 
-    peerInteraction->addRequests();
+    int maxSpeedLimit = e->option->getAsInt(PREF_MAX_SPEED_LIMIT);
+    if(maxSpeedLimit == 0 ||
+       maxSpeedLimit > 0 && maxSpeedLimit <= e->getDownloadSpeed()) {
+      peerInteraction->addRequests();
+    }
     peerInteraction->sendMessages(e->getUploadSpeed());
     break;
   }
diff --git a/src/PeerStat.h b/src/PeerStat.h
new file mode 100644
index 00000000..a0fe686d
--- /dev/null
+++ b/src/PeerStat.h
@@ -0,0 +1,90 @@
+/* <!-- copyright */
+/*
+ * aria2 - a simple utility for downloading files faster
+ *
+ * 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., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+ */
+/* copyright --> */
+#ifndef _D_PEER_STAT_H_
+#define _D_PEER_STAT_H_
+
+#include "common.h"
+#include "SpeedCalc.h"
+#include "SharedHandle.h"
+
+class PeerStat {
+public:
+  enum STATUS {
+    IDLE,
+    ACTIVE
+  };
+private:
+  int cuid;
+  SpeedCalc downloadSpeed;
+  Time downloadStartTime;
+  STATUS status;
+public:
+
+  PeerStat(int cuid):cuid(cuid), status(IDLE) {}
+
+  ~PeerStat() {}
+
+  /**
+   * Returns current download speed in byte per sec.
+   */
+  int calculateDownloadSpeed() {
+    return downloadSpeed.calculateSpeed();
+  }
+
+  void updateDownloadLength(int bytes) {
+    downloadSpeed.update(bytes);
+  }
+
+  int getMaxSpeed() const {
+    return downloadSpeed.getMaxSpeed();
+  }
+
+  void reset() {
+    downloadSpeed.reset();
+    downloadStartTime.reset();
+  }
+
+  void downloadStart() {
+    reset();
+    status = ACTIVE;
+  }
+
+  void downloadStop() {
+    status = IDLE;
+  }
+
+  const Time& getDownloadStartTime() const {
+    return downloadStartTime;
+  }
+
+  STATUS getStatus() const {
+    return status;
+  }
+
+  int getCuid() const {
+    return cuid;
+  }
+};
+
+typedef SharedHandle<PeerStat> PeerStatHandle;
+
+#endif // _D_PEER_STAT_H_
diff --git a/src/Piece.cc b/src/Piece.cc
index 9f906f58..424157bc 100644
--- a/src/Piece.cc
+++ b/src/Piece.cc
@@ -30,6 +30,7 @@ void Piece::completeBlock(int blockIndex) {
 
 void Piece::clearAllBlock() {
   bitfield->clearAllBit();
+  bitfield->clearAllUseBit();
 }
 
 void Piece::setAllBlock() {
diff --git a/src/PieceMessage.cc b/src/PieceMessage.cc
index 2c1422ed..8101595d 100644
--- a/src/PieceMessage.cc
+++ b/src/PieceMessage.cc
@@ -81,7 +81,6 @@ void PieceMessage::receivedAction() {
 	onGotNewPiece(piece);
       } else {
 	onGotWrongPiece(piece);
-	peerInteraction->abortPiece(piece);
       }
     }
   }
@@ -212,6 +211,7 @@ void PieceMessage::onGotWrongPiece(Piece& piece) {
   erasePieceOnDisk(piece);
   piece.clearAllBlock();
   torrentMan->updatePiece(piece);
+  peerInteraction->abortPiece(piece);
 }
 
 void PieceMessage::erasePieceOnDisk(const Piece& piece) {
diff --git a/src/Request.cc b/src/Request.cc
index e9e30b86..8dcabc16 100644
--- a/src/Request.cc
+++ b/src/Request.cc
@@ -23,11 +23,7 @@
 #include "Util.h"
 #include "FeatureConfig.h"
 
-Request::Request():port(0), tryCount(0), isTorrent(false) {
-  seg.sp = 0;
-  seg.ep = 0;
-  seg.ds = 0;
-  seg.finish = false;
+Request::Request():port(0), tryCount(0), keepAlive(true), isTorrent(false) {
   cookieBox = new CookieBox();
 }
 
@@ -42,6 +38,7 @@ bool Request::setUrl(const string& url) {
 
 bool Request::resetUrl() {
   previousUrl = referer;
+  segment = Segment();
   return setUrl(url);
 }
 
diff --git a/src/Request.h b/src/Request.h
index 5b5b15f1..313044e1 100644
--- a/src/Request.h
+++ b/src/Request.h
@@ -23,8 +23,8 @@
 #define _D_REQUEST_H_
 #include <string>
 #include <map>
-#include <Segment.h>
 #include "CookieBox.h"
+#include "Segment.h"
 #include "common.h"
 
 using namespace std;
@@ -59,9 +59,10 @@ private:
   string file;
   int tryCount;
   int trackerEvent;
+  bool keepAlive;
   bool parseUrl(const string& url);
 public:
-  Segment seg;
+  Segment segment;
   CookieBox* cookieBox;
   bool isTorrent;
 public:
@@ -91,7 +92,8 @@ public:
   int getPort() const { return port; }
   string getDir() const { return dir; }
   string getFile() const { return file;}
-
+  bool isKeepAlive() const { return keepAlive; }
+  void setKeepAlive(bool keepAlive) { this->keepAlive = keepAlive; }
   void setTrackerEvent(int event) { trackerEvent = event; }
   int getTrackerEvent() const { return trackerEvent; }
 
diff --git a/src/Segment.cc b/src/Segment.cc
new file mode 100644
index 00000000..c909f194
--- /dev/null
+++ b/src/Segment.cc
@@ -0,0 +1,31 @@
+/* <!-- copyright */
+/*
+ * aria2 - a simple utility for downloading files faster
+ *
+ * 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., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+ */
+/* copyright --> */
+
+#include "Segment.h"
+
+ostream& operator<<(ostream& o, const Segment& segment) {
+  o << "index = " << segment.index << ", ";
+  o << "length = " << segment.length << ", ";
+  o << "segmentLength = " << segment.segmentLength << ", ";
+  o << "writtenLength = " << segment.writtenLength;
+  return o;
+}
diff --git a/src/Segment.h b/src/Segment.h
index dc2ea084..139a53b4 100644
--- a/src/Segment.h
+++ b/src/Segment.h
@@ -27,27 +27,46 @@
 
 using namespace std;
 
-/**
- * Segment represents a download segment.
- * sp, ep is a offset from a begining of a file.
- * Therefore, if a file size is x, then 0 <= sp <= ep <= x-1.
- * sp, ep is used in Http Range header.
- * e.g. Range: bytes=sp-ep
- * ds is downloaded bytes.
- * If a download of this segement is complete, finish must be set to true.
- */
-typedef struct {
-  int cuid;
-  long long int sp;
-  long long int ep;
-  long long int ds;
-  int speed;
-  bool finish;
-} Segment;
-
-typedef deque<Segment> Segments;
-
-#define SEGMENT_EQUAL(X, Y) (X.cuid == Y.cuid && X.sp == Y.sp && X.ep == Y.ep && X.ds == Y.ds && X.finish == Y.finish ? true : false)
+class Segment {
+public:
+  int index;
+  int length;
+  int segmentLength;
+  int writtenLength;
+
+  Segment(int index, int length, int segmentLength, int writtenLength = 0)
+    :index(index), length(length), segmentLength(segmentLength),
+     writtenLength(writtenLength) {}
+
+  Segment():index(-1), length(0), segmentLength(0), writtenLength(0) {}
+
+  bool complete() const {
+    return length <= writtenLength;
+  }
+
+  bool isNull() const {
+    return index == -1;
+  }
+
+  long long int getPosition() const {
+    return ((long long int)index)*segmentLength;
+  }
+
+  bool operator==(const Segment& segment) const {
+    return index == segment.index &&
+      length == segment.length &&
+      segmentLength == segment.segmentLength &&
+      writtenLength == segment.writtenLength;
+  }
+
+  bool operator!=(const Segment& segment) const {
+    return !(*this == segment);
+  }
+
+  friend ostream& operator<<(ostream& o, const Segment& segment);
+};
+
+ostream& operator<<(ostream& o, const Segment& segment);
 
 #endif // _D_SEGMENT_H_
 
diff --git a/src/SegmentMan.cc b/src/SegmentMan.cc
index 72929270..36602639 100644
--- a/src/SegmentMan.cc
+++ b/src/SegmentMan.cc
@@ -31,88 +31,21 @@
 #include <unistd.h>
 #include <errno.h>
 
-SegmentMan::SegmentMan():totalSize(0),
+SegmentMan::SegmentMan():bitfield(0),
+			 totalSize(0),
 			 isSplittable(true), 
 			 downloadStarted(false),
 			 dir("."),
 			 errors(0),
-			 splitter(NULL),
-			 diskWriter(NULL) {
+			 diskWriter(0) {
   logger = LogFactory::getInstance();
 }
 
 SegmentMan::~SegmentMan() {
-  if(splitter != NULL) {
-    delete splitter;
-  }
-  if(diskWriter != NULL) {
-    delete diskWriter;
-  }
+  delete bitfield;
+  delete diskWriter;
 }
 
-void SegmentMan::unregisterId(int cuid) {
-  for(Segments::iterator itr = segments.begin(); itr != segments.end(); itr++) {
-    if((*itr).cuid == cuid) {
-      cuid = 0;
-    }
-  }
-}
-
-bool SegmentMan::getSegment(Segment& seg, int cuid) {
-  //Segment s = { 0, 0, 0, false };
-
-  if(segments.empty()) {
-    logger->debug(string("assign new segment { sp = 0, ep = "+(totalSize == 0 ? "0" : Util::llitos(totalSize-1))+" } to cuid "+Util::llitos(cuid)).c_str());
-    //seg = { cuid, 0, totalSize == 0 ? 0 : totalSize-1, 0, false };
-    seg.cuid = cuid;
-    seg.sp = 0;
-    seg.ep = totalSize == 0 ? 0 : totalSize-1;
-    seg.ds = 0;
-    seg.speed = 0;
-    seg.finish = false;
-    segments.push_back(seg);
-    return true;
-  }
-  for(Segments::iterator itr = segments.begin(); itr != segments.end(); itr++) {
-    if((*itr).cuid == cuid && !(*itr).finish) {
-//       logger->debug("return an existing segment { "
-// 		    "sp = "+Util::ulitos((*itr).sp)+", "+
-// 		    "ep = "+Util::ulitos((*itr).ep)+", "
-// 		    "ds = "+Util::ulitos((*itr).ds)+" } to "+
-// 		    "cuid "+Util::ulitos((*itr).cuid));
-      seg = *itr;
-      return true;
-    }
-  }
-  if(!isSplittable) {
-    return false;
-  }
-  for(Segments::iterator itr = segments.begin(); itr != segments.end(); itr++) {
-    Segment& s = *itr;
-    if(s.finish) {
-      continue;
-    }
-    if(s.cuid == 0) {
-      s.cuid = cuid;
-      seg = s;
-      return true;
-    }
-  }
-  return splitter->splitSegment(seg, cuid, segments);
-}
-
-void SegmentMan::updateSegment(const Segment& segment) {
-  for(Segments::iterator itr = segments.begin(); itr != segments.end(); itr++) {
-    if((*itr).cuid == segment.cuid && 
-       (*itr).sp == segment.sp &&
-       (*itr).ep == segment.ep) {
-      *itr = segment;
-      break;
-    }
-  } 
-}
-
-
 bool SegmentMan::segmentFileExists() const {
   if(!isSplittable) {
     return false;
@@ -144,10 +77,6 @@ void SegmentMan::load() {
 			segFilename.c_str(), strerror(errno));
   }
   logger->info(MSG_LOADED_SEGMENT_FILE);
-  for(Segments::iterator itr = segments.begin(); itr != segments.end();
-      itr++) {
-    (*itr).cuid = 0;
-  }
 }
 
 void SegmentMan::save() const {
@@ -161,8 +90,32 @@ void SegmentMan::save() const {
     if(fwrite(&totalSize, sizeof(totalSize), 1, segFile) < 1) {
       throw string("writeError");
     }
-    for(Segments::const_iterator itr = segments.begin(); itr != segments.end(); itr++) {
-      if(fwrite(&*itr, sizeof(Segment), 1, segFile) < 1) {
+    int segmentLength = bitfield->getBlockLength();
+    if(fwrite(&segmentLength, sizeof(segmentLength), 1, segFile) < 1) {
+      throw string("writeError");
+    }
+    if(bitfield) {
+      int bitfieldLength = bitfield->getBitfieldLength();
+      if(fwrite(&bitfieldLength, sizeof(bitfieldLength), 1, segFile) < 1) {
+	throw string("writeError");
+      }
+      if(fwrite(bitfield->getBitfield(), bitfield->getBitfieldLength(),
+		1, segFile) < 1) {
+	throw string("writeError");
+      }					 
+    } else {
+      int i = 0;
+      if(fwrite(&i, sizeof(i), 1, segFile) < 1) {
+	throw string("writeError");
+      }
+    }
+    int usedSegmentCount = usedSegmentEntries.size();
+    if(fwrite(&usedSegmentCount, sizeof(usedSegmentCount), 1, segFile) < 1) {
+      throw string("writeError");
+    }
+    for(SegmentEntries::const_iterator itr = usedSegmentEntries.begin();
+	itr != usedSegmentEntries.end(); itr++) {
+      if(fwrite(&itr->segment, sizeof(Segment), 1, segFile) < 1) {
 	throw string("writeError");
       }
     }
@@ -189,16 +142,35 @@ void SegmentMan::read(FILE* file) {
   if(fread(&totalSize, sizeof(totalSize), 1, file) < 1) {
     throw string("readError");
   }
-  while(1) {
+  int segmentSize;
+  if(fread(&segmentSize, sizeof(segmentSize), 1, file) < 1) {
+    throw string("readError");
+  }
+  int bitfieldLength;
+  if(fread(&bitfieldLength, sizeof(bitfieldLength), 1, file) < 1) {
+    throw string("readError");
+  }
+  if(bitfieldLength > 0) {
+    initBitfield(segmentSize, totalSize);
+    unsigned char* savedBitfield = new unsigned char[bitfield->getBitfieldLength()];
+    if(fread(savedBitfield, bitfield->getBitfieldLength(), 1, file) < 1) {
+      delete [] savedBitfield;
+      throw string("readError");
+    } else {
+      bitfield->setBitfield(savedBitfield, bitfield->getBitfieldLength());
+      delete [] savedBitfield;
+    }
+  }
+  int segmentCount;
+  if(fread(&segmentCount, sizeof(segmentCount), 1, file) < 1) {
+    throw string("readError");
+  }
+  while(segmentCount--) {
     Segment seg;
     if(fread(&seg, sizeof(Segment), 1, file) < 1) {
-      if(ferror(file)) {
-	throw string("readError");
-      } else if(feof(file)) {
-	break;
-      }
+      throw string("readError");
     }
-    segments.push_back(seg);
+    usedSegmentEntries.push_back(SegmentEntry(0, seg));
   }
 }
 
@@ -213,15 +185,14 @@ void SegmentMan::remove() const {
 }
 
 bool SegmentMan::finished() const {
-  if(!downloadStarted || segments.size() == 0) {
+  if(!downloadStarted) {
     return false;
   }
-  for(Segments::const_iterator itr = segments.begin(); itr != segments.end(); itr++) {
-    if(!(*itr).finish) {
-      return false;
-    }
+  if(!bitfield) {
+    return false;
   }
-  return true;
+  assert(bitfield);
+  return bitfield->isAllBitSet();
 }
 
 void SegmentMan::removeIfFinished() const {
@@ -230,19 +201,219 @@ void SegmentMan::removeIfFinished() const {
   }
 }
 
-long long int SegmentMan::getDownloadedSize() const {
-  long long int size = 0;
-  for(Segments::const_iterator itr = segments.begin(); itr != segments.end(); itr++) {
-    size += (*itr).ds;
-  }
-  return size;
-}
-
 void SegmentMan::init() {
   totalSize = 0;
   isSplittable = false;
   downloadStarted = false;
   errors = 0;
-  segments.clear();
+  //segments.clear();
+  usedSegmentEntries.clear();
+  delete bitfield;
+  peerStats.clear();
   diskWriter->closeFile();
+  
+}
+
+void SegmentMan::initBitfield(int segmentLength, long long int totalLength) {
+  this->bitfield = new BitfieldMan(segmentLength, totalLength);
+}
+
+class FindSegmentEntryByIndex {
+private:
+  int index;
+public:
+  FindSegmentEntryByIndex(int index):index(index) {}
+  
+  bool operator()(const SegmentEntry& entry) {
+    return entry.segment.index == index;
+  }
+};
+
+class FindSegmentEntryByCuid {
+private:
+  int cuid;
+public:
+  FindSegmentEntryByCuid(int cuid):cuid(cuid) {}
+
+  bool operator()(const SegmentEntry& entry) {
+    return entry.cuid == cuid;
+  }
+};
+
+Segment SegmentMan::checkoutSegment(int cuid, int index) {
+  logger->debug("Attach segment#%d to CUID#%d.", index, cuid);
+  bitfield->setUseBit(index);
+
+  SegmentEntries::iterator itr = find_if(usedSegmentEntries.begin(),
+					 usedSegmentEntries.end(),
+					 FindSegmentEntryByIndex(index));
+  Segment segment;
+  if(itr == usedSegmentEntries.end()) {
+    segment = Segment(index, bitfield->getBlockLength(index),
+		       bitfield->getBlockLength());
+    SegmentEntry entry(cuid, segment);
+    usedSegmentEntries.push_back(entry);
+  } else {
+    (*itr).cuid = cuid;
+    segment = (*itr).segment;
+  }
+
+  logger->debug("index=%d, length=%d, segmentLength=%d, writtenLength=%d",
+		segment.index, segment.length, segment.segmentLength,
+		segment.writtenLength);
+  return segment;
+}
+
+bool SegmentMan::onNullBitfield(Segment& segment, int cuid) {
+  if(usedSegmentEntries.size() == 0) {
+    segment = Segment(0, 0, 0);
+    usedSegmentEntries.push_back(SegmentEntry(cuid, segment));
+    return true;
+  } else {
+    SegmentEntries::iterator uitr = find_if(usedSegmentEntries.begin(),
+					    usedSegmentEntries.end(),
+					    FindSegmentEntryByCuid(cuid));
+    if(uitr == usedSegmentEntries.end()) {
+      return false;
+    } else {
+      segment = uitr->segment;
+      return true;
+    }
+  }
+}
+
+bool SegmentMan::getSegment(Segment& segment, int cuid) {
+  if(!bitfield) {
+    return onNullBitfield(segment, cuid);
+  }
+  SegmentEntries::iterator uitr = find_if(usedSegmentEntries.begin(),
+					  usedSegmentEntries.end(),
+					  FindSegmentEntryByCuid(cuid));
+  if(uitr != usedSegmentEntries.end()) {
+    segment = uitr->segment;
+    return true;
+  }
+  int index = bitfield->getSparseMissingUnusedIndex();
+  if(index == -1) {
+    return false;
+  } else {
+    segment = checkoutSegment(cuid, index);
+    return true;
+  }
+}
+
+bool SegmentMan::getSegment(Segment& segment, int cuid, int index) {
+  if(!bitfield) {
+    return onNullBitfield(segment, cuid);
+  }
+  if(index < 0 || bitfield->countBlock() <= index) {
+    return false;
+  }
+  if(bitfield->isBitSet(index) || bitfield->isUseBitSet(index)) {
+    return false;
+  } else {
+    segment = checkoutSegment(cuid, index);
+    return true;
+  }
+}
+
+bool SegmentMan::updateSegment(int cuid, const Segment& segment) {
+  if(segment.isNull()) {
+    return false;
+  }
+  SegmentEntries::iterator itr = find_if(usedSegmentEntries.begin(),
+					 usedSegmentEntries.end(),
+					 FindSegmentEntryByCuid(cuid));
+  if(itr == usedSegmentEntries.end()) {
+    return false;
+  } else {
+    (*itr).segment = segment;
+    return true;
+  }
+}
+
+class CancelSegment {
+private:
+  int cuid;
+  BitfieldMan* bitfield;
+public:
+  CancelSegment(int cuid, BitfieldMan* bitfield):cuid(cuid),
+						 bitfield(bitfield) {}
+  
+  void operator()(SegmentEntry& entry) {
+    if(entry.cuid == cuid) {
+      bitfield->unsetUseBit(entry.segment.index);
+      entry.cuid = 0;
+    }
+  }
+};
+
+void SegmentMan::cancelSegment(int cuid) {
+  if(bitfield) {
+    for_each(usedSegmentEntries.begin(), usedSegmentEntries.end(),
+	     CancelSegment(cuid, bitfield));
+  } else {
+    usedSegmentEntries.clear();
+  }
+}
+
+bool SegmentMan::completeSegment(int cuid, const Segment& segment) {
+  if(segment.isNull()) {
+    return false;
+  }
+  if(bitfield) {
+    bitfield->unsetUseBit(segment.index);
+    bitfield->setBit(segment.index);
+  } else {
+    initBitfield(option->getAsInt(PREF_SEGMENT_SIZE), segment.writtenLength);
+    bitfield->setAllBit();
+  }
+  SegmentEntries::iterator itr = find_if(usedSegmentEntries.begin(),
+					 usedSegmentEntries.end(),
+					 FindSegmentEntryByCuid(cuid));
+  if(itr == usedSegmentEntries.end()) {
+    return false;
+  } else {
+    usedSegmentEntries.erase(itr);
+    return true;
+  }
+}
+
+bool SegmentMan::hasSegment(int index) const {
+  if(bitfield) {
+    return bitfield->isBitSet(index);
+  } else {
+    return false;
+  }
+}
+
+long long int SegmentMan::getDownloadLength() const {
+  long long int dlLength = 0;
+  if(bitfield) {
+    dlLength += bitfield->getCompletedLength();
+  }
+  for(SegmentEntries::const_iterator itr = usedSegmentEntries.begin();
+      itr != usedSegmentEntries.end(); itr++) {
+    dlLength += itr->segment.writtenLength;
+  }
+  return dlLength;
+}
+
+void SegmentMan::registerPeerStat(const PeerStatHandle& peerStat) {
+  PeerStatHandle temp = getPeerStat(peerStat->getCuid());
+  if(!temp.get()) {
+    peerStats.push_back(peerStat);
+  }
+}
+
+int SegmentMan::calculateDownloadSpeed() const {
+  int speed = 0;
+  for(PeerStats::const_iterator itr = peerStats.begin();
+      itr != peerStats.end(); itr++) {
+    const PeerStatHandle& peerStat = *itr;
+    if(peerStat->getStatus() == PeerStat::ACTIVE) {
+      speed += peerStat->calculateDownloadSpeed();
+    }
+  }
+  return speed;
 }
diff --git a/src/SegmentMan.h b/src/SegmentMan.h
index 53112d6d..6b36c670 100644
--- a/src/SegmentMan.h
+++ b/src/SegmentMan.h
@@ -26,23 +26,42 @@
 #include "Logger.h"
 #include "Segment.h"
 #include "Option.h"
-#include "SegmentSplitter.h"
 #include "DiskWriter.h"
 #include "Request.h"
+#include "BitfieldMan.h"
+#include "PeerStat.h"
 
 using namespace std;
 
 #define SEGMENT_FILE_EXTENSION ".aria2"
 
+class SegmentEntry {
+public:
+  int cuid;
+  Segment segment;
+public:
+  SegmentEntry(int cuid, const Segment& segment)
+    :cuid(cuid), segment(segment) {}
+  ~SegmentEntry() {}
+};
+
+typedef deque<SegmentEntry> SegmentEntries;
+typedef deque<PeerStatHandle> PeerStats;
+
 /**
  * This class holds the download progress of the one download entry.
  */
 class SegmentMan {
 private:
   const Logger* logger;
+  BitfieldMan* bitfield;
+  SegmentEntries usedSegmentEntries;
+  PeerStats peerStats;
 
   void read(FILE* file);
   FILE* openSegFile(const string& segFilename, const string& mode) const;
+  bool onNullBitfield(Segment& segment, int cuid);
+  Segment checkoutSegment(int cuid, int index);
 public:
   /**
    * The total number of bytes to download.
@@ -66,10 +85,6 @@ public:
    */
   bool downloadStarted;
   /**
-   * Holds segments.
-   */
-  Segments segments;
-  /**
    * Respresents the file name of the downloaded file.
    * If the URL does not contain file name part(http://www.rednoah.com/, for 
    * example), this value may be 0 length string.
@@ -91,7 +106,6 @@ public:
   int errors;
 
   const Option* option;
-  SegmentSplitter* splitter;
   DiskWriter* diskWriter;
   Requests reserved;
 
@@ -117,31 +131,6 @@ public:
   }
 
   /**
-   * Sets the cuid of the holded segments with specified cuid to 0.
-   */
-  void unregisterId(int cuid);
-  /**
-   * There is a segment available for DownloadCommand specified by cuid,
-   * fills segment and returns true.
-   * There is no segment available, then returns false and segment is
-   * undefined in this case.
-   *
-   * @param segment segment to attach for cuid.
-   * @param cuid cuid of DownloadCommand.
-   * @returns true: there is a segment available, false: there is no segment
-   * available.
-   */
-  bool getSegment(Segment& segment, int cuid);
-  /**
-   * Updates the ds value of the specified segment.
-   * Only a segment x is updated where x.sp == sgment.sp &amp;&amp; x.ep ==
-   * segment.ep &amp;&amp; x.ds == segment.ds &amp;&amp;x.cuid == segment.cuid
-   * is true.
-   *
-   * @param segment segment to update
-   */
-  void updateSegment(const Segment& segment);
-  /**
    * Returns true only if the segment data file exists.
    * The file name of the segment data is filename appended by ".aria2".
    * If isSplittable is false, then returns simply false without any operation.
@@ -173,9 +162,84 @@ public:
    */
   void removeIfFinished() const;
   /**
-   * Returns the total number of bytes to be downloaded.
+   * Returns a vacant segment.
+   * If there is no vacant segment, then returns a segment instance whose
+   * isNull call is true.
+   */
+  bool getSegment(Segment& segment, int cuid);
+  /**
+   * Returns a segment whose index is index. 
+   * If it has already assigned
+   * to another cuid or has been downloaded, then returns a segment instance
+   * whose isNull call is true.
+   */
+  bool getSegment(Segment& segment, int cuid, int index);
+  /**
+   * Updates download status.
+   */
+  bool updateSegment(int cuid, const Segment& segment);
+  /**
+   * Cancels all the segment which the command having given cuid
+   * uses.
+   */
+  void cancelSegment(int cuid);
+  /**
+   * Tells SegmentMan that the segment has been downloaded successfully.
+   */
+  bool completeSegment(int cuid, const Segment& segment);
+  /**
+   * Initializes bitfield with the provided length parameters.
+   */
+  void initBitfield(int segmentLength, long long int totalLength);
+  /**
+   * Returns true if the segment whose index is index has been downloaded.
+   */
+  bool hasSegment(int index) const;
+  /**
+   * Returns the length of bytes downloaded.
+   */
+  long long int getDownloadLength() const;
+
+  /**
+   * Registers given peerStat if it has not been registerd.
+   * Otherwise does nothing.
+   */
+  void registerPeerStat(const PeerStatHandle& peerStat);
+
+  class FindPeerStat {
+  private:
+    int cuid;
+  public:
+    FindPeerStat(int cuid):cuid(cuid) {}
+
+    bool operator()(const PeerStatHandle& peerStat) {
+      if(peerStat->getCuid() == cuid) {
+	return true;
+      } else {
+	return false;
+      }
+    }
+  };
+
+  /**
+   * Returns peerStat whose cuid is given cuid. If it is not found, returns
+   * PeerStatHandle(0).
+   */
+  PeerStatHandle getPeerStat(int cuid) const {
+    PeerStats::const_iterator itr = find_if(peerStats.begin(), peerStats.end(),
+					    FindPeerStat(cuid));
+    if(itr == peerStats.end()) {
+      // TODO
+      return PeerStatHandle(0);
+    } else {
+      return *itr;
+    }
+  }
+
+  /**
+   * Returns current download speed in bytes per sec. 
    */
-  long long int getDownloadedSize() const;
+  int calculateDownloadSpeed() const;
 };
 
 #endif // _D_SEGMENT_MAN_H_
diff --git a/src/SpeedCalc.cc b/src/SpeedCalc.cc
new file mode 100644
index 00000000..10750cc2
--- /dev/null
+++ b/src/SpeedCalc.cc
@@ -0,0 +1,82 @@
+/* <!-- copyright */
+/*
+ * aria2 - a simple utility for downloading files faster
+ *
+ * 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., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+ */
+/* copyright --> */
+#include "SpeedCalc.h"
+#include <algorithm>
+#include <ostream>
+#include <iterator>
+
+#define CHANGE_INTERVAL_SEC 15
+
+class Reset {
+public:
+  void operator()(Time& tm) {
+    tm.reset();
+  }
+};
+
+void SpeedCalc::reset() {
+  fill(&lengthArray[0], &lengthArray[2], 0);
+  for_each(&cpArray[0], &cpArray[2], Reset());
+  sw = 0;
+  maxSpeed = 0;
+  prevSpeed = 0;
+}
+
+int SpeedCalc::calculateSpeed() {
+  int milliElapsed = cpArray[sw].differenceInMillis();
+  if(milliElapsed) {
+    int speed = lengthArray[sw]*1000/milliElapsed;
+    prevSpeed = speed;
+    maxSpeed = max<int>(speed, maxSpeed);
+    return speed;
+  } else {
+    return prevSpeed;
+  }
+}
+
+class Plus {
+private:
+  int d;
+public:
+  Plus(int d):d(d) {}
+
+  void operator()(long long int& length) {
+    length += d;
+  }
+};
+
+void SpeedCalc::update(int bytes) {
+  for_each(&lengthArray[0], &lengthArray[2], Plus(bytes));
+  if(isIntervalOver()) {
+    changeSw();
+  }
+}
+
+bool SpeedCalc::isIntervalOver() const {
+  return CHANGE_INTERVAL_SEC <= cpArray[sw].difference();
+}
+
+void SpeedCalc::changeSw() {
+  lengthArray[sw] = 0;
+  cpArray[sw].reset();
+  sw ^= 0x01;
+}
diff --git a/src/SpeedCalc.h b/src/SpeedCalc.h
new file mode 100644
index 00000000..e0ba7d28
--- /dev/null
+++ b/src/SpeedCalc.h
@@ -0,0 +1,59 @@
+/* <!-- copyright */
+/*
+ * aria2 - a simple utility for downloading files faster
+ *
+ * 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., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+ */
+/* copyright --> */
+#ifndef _D_SPEED_CALC_H_
+#define _D_SPEED_CALC_H_
+
+#include "common.h"
+#include "TimeA2.h"
+
+class SpeedCalc {
+private:
+  long long int lengthArray[2];
+  int sw;
+  Time cpArray[2];
+  int maxSpeed;
+  int prevSpeed;
+
+  bool isIntervalOver() const;
+  void changeSw();
+public:
+  SpeedCalc() {
+    reset();
+  }
+
+  ~SpeedCalc() {}
+
+  /**
+   * Returns download/upload speed in byte per sec
+   */
+  int calculateSpeed();
+
+  int getMaxSpeed() const {
+    return maxSpeed;
+  }
+
+  void update(int bytes);
+
+  void reset();
+};
+
+#endif // _D_SPEED_CALC_H_
diff --git a/src/main.cc b/src/main.cc
index 3914d375..c3c4a7e3 100644
--- a/src/main.cc
+++ b/src/main.cc
@@ -22,7 +22,6 @@
 #include "HttpInitiateConnectionCommand.h"
 #include "ConsoleDownloadEngine.h"
 #include "SegmentMan.h"
-#include "SplitSlowestSegmentSplitter.h"
 #include "LogFactory.h"
 #include "common.h"
 #include "DefaultDiskWriter.h"
@@ -272,6 +271,8 @@ int main(int argc, char* argv[]) {
   op->put(PREF_DIR, ".");
   op->put(PREF_SPLIT, "1");
   op->put(PREF_DAEMON, V_FALSE);
+  op->put(PREF_SEGMENT_SIZE, Util::itos(1024*1024));
+  op->put(PREF_HTTP_KEEP_ALIVE, V_FALSE);
   op->put(PREF_LISTEN_PORT, "-1");
   op->put(PREF_METALINK_SERVERS, "15");
   op->put(PREF_FOLLOW_TORRENT,
@@ -303,6 +304,7 @@ int main(int argc, char* argv[]) {
   op->put(PREF_DIRECT_FILE_MAPPING, V_TRUE);
   op->put(PREF_UPLOAD_LIMIT, "0");
   op->put(PREF_LOWEST_SPEED_LIMIT, "0");
+  op->put(PREF_MAX_SPEED_LIMIT, "0");
   while(1) {
     int optIndex = 0;
     int lopt;
diff --git a/src/prefs.h b/src/prefs.h
index 9c3e040a..70fc9207 100644
--- a/src/prefs.h
+++ b/src/prefs.h
@@ -57,8 +57,12 @@
 #define PREF_DAEMON "daemon"
 // value: a string
 #define PREF_REFERER "referer"
-// value' 1*digit
+// value: 1*digit
 #define PREF_LOWEST_SPEED_LIMIT "lowest_speed_limit"
+// value: 1*digit
+#define PREF_SEGMENT_SIZE "segment_size"
+// value: 1*digit
+#define PREF_MAX_SPEED_LIMIT "max_speed_limit"
 
 /**
  * FTP related preferences
@@ -86,6 +90,8 @@
 #  define V_BASIC "basic"
 // values: true | false
 #define PREF_HTTP_AUTH_ENABLED "http_auth_enabled"
+// values: true | false
+#define PREF_HTTP_KEEP_ALIVE "http_keep_alive"
 
 /** 
  * HTTP proxy related preferences
author	Tatsuhiro Tsujikawa <tatsuhiro.t@gmail.com>	2006-09-19 14:52:59 +0000
committer	Tatsuhiro Tsujikawa <tatsuhiro.t@gmail.com>	2006-09-19 14:52:59 +0000
commit	2fb9b5be9705560fd77b4244636bc2515e81f32c (patch)
tree	0532a3d2a40d51e0d56490dedc744b0feaa56e33 /src
parent	1d52ba244ee360a36db245988a797c7fa143c0f5 (diff)