Use fmt instead of using snprintf directly

src/BtHandshakeMessage.cc

@@ -103,13 +103,10 @@ size_t BtHandshakeMessage::getMessageLength() {
 }
 
 std::string BtHandshakeMessage::toString() const {
-  char buf[256];
+  return fmt("%s peerId=%s, reserved=%s",
-  snprintf(buf, sizeof(buf),
-           "%s peerId=%s, reserved=%s",
              NAME.c_str(),
              util::percentEncode(peerId_, PEER_ID_LENGTH).c_str(),
              util::toHex(reserved_, RESERVED_LENGTH).c_str());
-  return buf;
 }
 
 bool BtHandshakeMessage::isFastExtensionSupported() const {

src/BtPieceMessage.cc

@@ -213,13 +213,11 @@ void BtPieceMessage::pushPieceData(off_t offset, size_t length) const
 
 std::string BtPieceMessage::toString() const
 {
-  char buf[256];
+  return fmt("%s index=%lu, begin=%u, length=%lu",
-  snprintf(buf, sizeof(buf), "%s index=%lu, begin=%u, length=%lu",
              NAME.c_str(),
              static_cast<unsigned long>(index_),
              begin_,
              static_cast<unsigned long>(blockLength_));
-  return buf;
 }
 
 bool BtPieceMessage::checkPieceHash(const SharedHandle<Piece>& piece)

src/BtPortMessage.cc

@@ -118,9 +118,7 @@ size_t BtPortMessage::getMessageLength() {
 }
 
 std::string BtPortMessage::toString() const {
-  char buf[256];
+  return fmt("%s port=%u", NAME.c_str(), port_);
-  snprintf(buf, sizeof(buf), "%s port=%u", NAME.c_str(), port_);
-  return buf;
 }
 
 void BtPortMessage::setLocalNode(DHTNode* localNode)

src/DHTAnnouncePeerMessage.cc

@@ -129,13 +129,10 @@ void DHTAnnouncePeerMessage::setTokenTracker(DHTTokenTracker* tokenTracker)
 
 std::string DHTAnnouncePeerMessage::toStringOptional() const
 {
-  char buf[256];
+  return fmt("token=%s, info_hash=%s, tcpPort=%u",
-  snprintf(buf, sizeof(buf),
-           "token=%s, info_hash=%s, tcpPort=%u",
              util::toHex(token_).c_str(),
              util::toHex(infoHash_, INFO_HASH_LENGTH).c_str(),
              tcpPort_);
-  return buf;
 }
 
 } // namespace aria2

src/DHTGetPeersReplyMessage.cc

@@ -158,13 +158,10 @@ void DHTGetPeersReplyMessage::accept(DHTMessageCallback* callback)
 
 std::string DHTGetPeersReplyMessage::toStringOptional() const
 {
-  char buf[256];
+  return fmt("token=%s, values=%lu, nodes=%lu",
-  snprintf(buf, sizeof(buf),
-           "token=%s, values=%lu, nodes=%lu",
              util::toHex(token_).c_str(),
              static_cast<unsigned long>(values_.size()),
              static_cast<unsigned long>(closestKNodes_.size()));
-  return buf;
 }
 
 } // namespace aria2

src/DHTNode.cc

@@ -117,15 +117,12 @@ void DHTNode::timeout()
 
 std::string DHTNode::toString() const
 {
-  char buf[256];
+  return fmt("DHTNode ID=%s, Host=%s(%u), Condition=%u, RTT=%u",
-  snprintf(buf, sizeof(buf),
-           "DHTNode ID=%s, Host=%s(%u), Condition=%u, RTT=%u",
              util::toHex(id_, DHT_ID_LENGTH).c_str(),
              ipaddr_.c_str(),
              port_,
              condition_,
              rtt_);
-  return buf;
 }
 
 void DHTNode::setID(const unsigned char* id)

src/DHTQueryMessage.cc

@@ -68,9 +68,7 @@ bool DHTQueryMessage::isReply() const
 
 std::string DHTQueryMessage::toString() const
 {
-  char buf[256];
+  return fmt("dht query %s TransactionID=%s Remote:%s(%u), id=%s, v=%s, %s",
-  snprintf(buf, sizeof(buf),
-           "dht query %s TransactionID=%s Remote:%s(%u), id=%s, v=%s, %s",
              getMessageType().c_str(),
              util::toHex(getTransactionID()).c_str(),
              getRemoteNode()->getIPAddress().c_str(),
@@ -78,7 +76,6 @@ std::string DHTQueryMessage::toString() const
              util::toHex(getRemoteNode()->getID(), DHT_ID_LENGTH).c_str(),
              util::torrentPercentEncode(getVersion()).c_str(),
              toStringOptional().c_str());
-  return buf;
 }
 
 } // namespace aria2

src/DHTResponseMessage.cc

@@ -65,9 +65,7 @@ bool DHTResponseMessage::isReply() const
 
 std::string DHTResponseMessage::toString() const
 {
-  char buf[256];
+  return fmt("dht response %s TransactionID=%s Remote:%s(%u), id=%s, v=%s, %s",
-  snprintf(buf, sizeof(buf),
-           "dht response %s TransactionID=%s Remote:%s(%u), id=%s, v=%s, %s",
              getMessageType().c_str(),
              util::toHex(getTransactionID()).c_str(),
              getRemoteNode()->getIPAddress().c_str(),
@@ -75,7 +73,6 @@ std::string DHTResponseMessage::toString() const
              util::toHex(getRemoteNode()->getID(), DHT_ID_LENGTH).c_str(),
              util::torrentPercentEncode(getVersion()).c_str(),
              toStringOptional().c_str());
-  return buf;
 }
 
 } // namespace aria2

src/DHTUnknownMessage.cc

@@ -88,14 +88,10 @@ std::string DHTUnknownMessage::toString() const
   if(length_ < sampleLength) {
     sampleLength = length_;
   }
-  std::string sample(&data_[0], &data_[sampleLength]);
+  return fmt("dht unknown Remote:%s(%u) length=%lu, first 8 bytes(hex)=%s",
-  char buf[256];
-  snprintf(buf, sizeof(buf),
-           "dht unknown Remote:%s(%u) length=%lu, first 8 bytes(hex)=%s",
              ipaddr_.c_str(), port_,
              static_cast<unsigned long>(length_),
              util::toHex(data_, sampleLength).c_str());
-  return buf;
 }
 
 } // namespace aria2

src/FtpNegotiationCommand.cc

@@ -724,10 +724,8 @@ bool FtpNegotiationCommand::sendTunnelRequest()
     SharedHandle<Request> req(new Request());
     // Construct fake URI in order to use HttpRequest
     // TODO Handle IPv6 address; it must be enclosed with [].
-    char fakeUriBuf[1024];
+    req->setUri(fmt("ftp://%s:%u",
-    snprintf(fakeUriBuf, sizeof(fakeUriBuf), "ftp://%s:%u",
+                    dataConnAddr_.first.c_str(), dataConnAddr_.second));
-             dataConnAddr_.first.c_str(), dataConnAddr_.second);
-    req->setUri(fakeUriBuf);
     httpRequest->setRequest(req);
     httpRequest->setProxyRequest(createProxyRequest());
     http_->sendProxyRequest(httpRequest);

src/IndexBtMessage.cc

@@ -60,11 +60,9 @@ size_t IndexBtMessage::getMessageLength()
 
 std::string IndexBtMessage::toString() const
 {
-  char buf[256];
+  return fmt("%s index=%lu",
-  snprintf(buf, sizeof(buf), "%s index=%lu",
              getName().c_str(),
              static_cast<unsigned long>(index_));
-  return buf;
 }
 
 } // namespace aria2

src/OptionHandlerImpl.cc

@@ -262,17 +262,13 @@ std::string FloatNumberOptionHandler::createPossibleValuesString() const
   if(min_ < 0) {
     valuesString += "*";
   } else {
-    char buf[11];
+    valuesString += fmt("%.1f", min_);
-    snprintf(buf, sizeof(buf), "%.1f", min_);
-    valuesString += buf;
   }
   valuesString += "-";
   if(max_ < 0) {
     valuesString += "*";
   } else {
-    char buf[11];
+    valuesString += fmt("%.1f", max_);
-    snprintf(buf, sizeof(buf), "%.1f", max_);
-    valuesString += buf;
   }
   return valuesString;
 }

src/Piece.cc

@@ -167,11 +167,9 @@ bool Piece::getAllMissingBlockIndexes
 }
 
 std::string Piece::toString() const {
-  char buf[256];
+  return fmt("piece: index=%lu, length=%lu",
-  snprintf(buf, sizeof(buf), "piece: index=%lu, length=%lu",
              static_cast<unsigned long>(index_),
              static_cast<unsigned long>(length_));
-  return buf;
 }
 
 void Piece::reconfigure(size_t length)

src/RangeBtMessage.cc

@@ -72,14 +72,11 @@ size_t RangeBtMessage::getMessageLength()
 
 std::string RangeBtMessage::toString() const
 {
-  char buf[256];
+  return fmt("%s index=%lu, begin=%u, length=%lu",
-  snprintf(buf, sizeof(buf),
-           "%s index=%lu, begin=%u, length=%lu",
              getName().c_str(),
              static_cast<unsigned long>(index_),
              begin_,
              static_cast<unsigned long>(length_));
-  return buf;
 }
 
 } // namespace aria2

src/UTMetadataDataExtensionMessage.cc

@@ -71,10 +71,8 @@ std::string UTMetadataDataExtensionMessage::getPayload()
 
 std::string UTMetadataDataExtensionMessage::toString() const
 {
-  char buf[256];
+  return fmt("ut_metadata data piece=%lu",
-  snprintf(buf, sizeof(buf), "ut_metadata data piece=%lu",
              static_cast<unsigned long>(getIndex()));
-  return buf;
 }
 
 void UTMetadataDataExtensionMessage::doReceivedAction()

src/UTMetadataRejectExtensionMessage.cc

@@ -54,10 +54,8 @@ std::string UTMetadataRejectExtensionMessage::getPayload()
 
 std::string UTMetadataRejectExtensionMessage::toString() const
 {
-  char buf[256];
+  return fmt("ut_metadata reject piece=%lu",
-  snprintf(buf, sizeof(buf), "ut_metadata reject piece=%lu",
              static_cast<unsigned long>(getIndex()));
-  return buf;
 }
 
 void UTMetadataRejectExtensionMessage::doReceivedAction()

src/UTMetadataRequestExtensionMessage.cc

@@ -69,10 +69,8 @@ std::string UTMetadataRequestExtensionMessage::getPayload()
 
 std::string UTMetadataRequestExtensionMessage::toString() const
 {
-  char buf[256];
+  return fmt("ut_metadata request piece=%lu",
-  snprintf(buf, sizeof(buf), "ut_metadata request piece=%lu",
              static_cast<unsigned long>(getIndex()));
-  return buf;
 }
 
 void UTMetadataRequestExtensionMessage::doReceivedAction()

src/UTPexExtensionMessage.cc

@@ -121,11 +121,9 @@ UTPexExtensionMessage::createCompactPeerListAndFlag
 
 std::string UTPexExtensionMessage::toString() const
 {
-  char buf[256];
+  return fmt("ut_pex added=%lu, dropped=%lu",
-  snprintf(buf, sizeof(buf), "ut_pex added=%lu, dropped=%lu",
              static_cast<unsigned long>(freshPeers_.size()),
              static_cast<unsigned long>(droppedPeers_.size()));
-  return buf;
 }
 
 void UTPexExtensionMessage::doReceivedAction()