face: NDNLP partial message store
refs #1208
Change-Id: Ie10d590ebd2e3631c884a7b6b2d5ffce2758ab4d
diff --git a/daemon/face/ndnlp-parse.cpp b/daemon/face/ndnlp-parse.cpp
new file mode 100644
index 0000000..1162f0e
--- /dev/null
+++ b/daemon/face/ndnlp-parse.cpp
@@ -0,0 +1,68 @@
+/* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
+/**
+ * Copyright (C) 2014 Named Data Networking Project
+ * See COPYING for copyright and distribution information.
+ */
+
+#include "ndnlp-parse.hpp"
+
+namespace nfd {
+namespace ndnlp {
+
+void
+NdnlpData::wireDecode(const Block& wire)
+{
+ if (wire.type() != tlv::NdnlpData) {
+ throw ParseError("top element is not NdnlpData");
+ }
+ wire.parse();
+ const Block::element_container& elements = wire.elements();
+ if (elements.size() < 2) {
+ throw ParseError("NdnlpData element has incorrect number of children");
+ }
+
+ const Block& sequenceElement = elements.front();
+ if (sequenceElement.type() != tlv::NdnlpSequence) {
+ throw ParseError("NdnlpSequence element is missing");
+ }
+ if (sequenceElement.value_size() != sizeof(uint64_t)) {
+ throw ParseError("NdnlpSequence element has incorrect length");
+ }
+ m_seq = be64toh(*reinterpret_cast<const uint64_t*>(&*sequenceElement.value_begin()));
+
+ const Block& payloadElement = elements.back();
+ if (payloadElement.type() != tlv::NdnlpPayload) {
+ throw ParseError("NdnlpPayload element is missing");
+ }
+ m_payload = payloadElement;
+
+ if (elements.size() == 2) { // single wire packet
+ m_fragIndex = 0;
+ m_fragCount = 1;
+ return;
+ }
+ if (elements.size() != 4) {
+ throw ParseError("NdnlpData element has incorrect number of children");
+ }
+
+ const Block& fragIndexElement = elements.at(1);
+ if (fragIndexElement.type() != tlv::NdnlpFragIndex) {
+ throw ParseError("NdnlpFragIndex element is missing");
+ }
+ if (fragIndexElement.value_size() != sizeof(uint16_t)) {
+ throw ParseError("NdnlpFragIndex element has incorrect length");
+ }
+ m_fragIndex = be16toh(*reinterpret_cast<const uint16_t*>(&*fragIndexElement.value_begin()));
+
+ const Block& fragCountElement = elements.at(2);
+ if (fragCountElement.type() != tlv::NdnlpFragCount) {
+ throw ParseError("NdnlpFragCount element is missing");
+ }
+ if (fragCountElement.value_size() != sizeof(uint16_t)) {
+ throw ParseError("NdnlpFragCount element has incorrect length");
+ }
+ m_fragCount = be16toh(*reinterpret_cast<const uint16_t*>(&*fragCountElement.value_begin()));
+}
+
+} // namespace ndnlp
+} // namespace nfd
diff --git a/daemon/face/ndnlp-parse.hpp b/daemon/face/ndnlp-parse.hpp
new file mode 100644
index 0000000..2790569
--- /dev/null
+++ b/daemon/face/ndnlp-parse.hpp
@@ -0,0 +1,52 @@
+/* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
+/**
+ * Copyright (C) 2014 Named Data Networking Project
+ * See COPYING for copyright and distribution information.
+ */
+
+#ifndef NFD_FACE_NDNLP_PARSE_HPP
+#define NFD_FACE_NDNLP_PARSE_HPP
+
+#include "common.hpp"
+#include "ndnlp-tlv.hpp"
+
+namespace nfd {
+namespace ndnlp {
+
+struct ParseError : public std::runtime_error
+{
+ ParseError(const std::string& what)
+ : std::runtime_error(what)
+ {
+ }
+};
+
+/** \brief represents a NdnlpData packet
+ *
+ * NdnlpData ::= NDNLP-DATA-TYPE TLV-LENGTH
+ * NdnlpSequence
+ * NdnlpFragIndex?
+ * NdnlpFragCount?
+ * NdnlpPayload
+ */
+class NdnlpData
+{
+public:
+ /** \brief parse a NdnlpData packet
+ *
+ * \exception ParseError packet is malformated
+ */
+ void
+ wireDecode(const Block& wire);
+
+public:
+ uint64_t m_seq;
+ uint16_t m_fragIndex;
+ uint16_t m_fragCount;
+ Block m_payload;
+};
+
+} // namespace ndnlp
+} // namespace nfd
+
+#endif // NFD_FACE_NDNLP_PARSE_HPP
diff --git a/daemon/face/ndnlp-partial-message-store.cpp b/daemon/face/ndnlp-partial-message-store.cpp
new file mode 100644
index 0000000..22b493b
--- /dev/null
+++ b/daemon/face/ndnlp-partial-message-store.cpp
@@ -0,0 +1,119 @@
+/* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
+/**
+ * Copyright (C) 2014 Named Data Networking Project
+ * See COPYING for copyright and distribution information.
+ */
+
+#include "ndnlp-partial-message-store.hpp"
+
+namespace nfd {
+namespace ndnlp {
+
+PartialMessage::PartialMessage()
+ : m_fragCount(0)
+ , m_received(0)
+ , m_totalLength(0)
+{
+}
+
+bool
+PartialMessage::add(uint16_t fragIndex, uint16_t fragCount, const Block& payload)
+{
+ if (m_received == 0) { // first packet
+ m_fragCount = fragCount;
+ m_payloads.resize(fragCount);
+ }
+
+ if (m_fragCount != fragCount || fragIndex >= m_fragCount) {
+ return false;
+ }
+
+ if (!m_payloads[fragIndex].empty()) { // duplicate
+ return false;
+ }
+
+ m_payloads[fragIndex] = payload;
+ ++m_received;
+ m_totalLength += payload.value_size();
+}
+
+bool
+PartialMessage::isComplete() const
+{
+ return m_received == m_fragCount;
+}
+
+Block
+PartialMessage::reassemble()
+{
+ BOOST_ASSERT(this->isComplete());
+
+ ndn::BufferPtr buffer = make_shared<ndn::Buffer>(m_totalLength);
+ uint8_t* buf = buffer->get();
+ for (std::vector<Block>::const_iterator it = m_payloads.begin();
+ it != m_payloads.end(); ++it) {
+ const Block& payload = *it;
+ memcpy(buf, payload.value(), payload.value_size());
+ buf += payload.value_size();
+ }
+
+ return Block(buffer);
+}
+
+PartialMessageStore::PartialMessageStore(Scheduler& scheduler, time::Duration idleDuration)
+ : m_scheduler(scheduler)
+ , m_idleDuration(idleDuration)
+{
+}
+
+PartialMessageStore::~PartialMessageStore()
+{
+}
+
+void
+PartialMessageStore::receiveNdnlpData(const Block& pkt)
+{
+ NdnlpData parsed;
+ parsed.wireDecode(pkt);
+ if (parsed.m_fragCount == 1) { // single fragment
+ this->onReceive(parsed.m_payload.blockFromValue());
+ return;
+ }
+
+ uint64_t messageIdentifier = parsed.m_seq - parsed.m_fragIndex;
+ shared_ptr<PartialMessage> pm = m_partialMessages[messageIdentifier];
+ if (!static_cast<bool>(pm)) {
+ m_partialMessages[messageIdentifier] = pm = make_shared<PartialMessage>();
+ }
+ this->scheduleCleanup(messageIdentifier, pm);
+
+ pm->add(parsed.m_fragIndex, parsed.m_fragCount, parsed.m_payload);
+ if (pm->isComplete()) {
+ this->onReceive(pm->reassemble());
+ this->cleanup(messageIdentifier);
+ }
+}
+
+void
+PartialMessageStore::scheduleCleanup(uint64_t messageIdentifier,
+ shared_ptr<PartialMessage> partialMessage)
+{
+ partialMessage->m_expiry = m_scheduler.scheduleEvent(m_idleDuration,
+ bind(&PartialMessageStore::cleanup, this, messageIdentifier));
+}
+
+void
+PartialMessageStore::cleanup(uint64_t messageIdentifier)
+{
+ std::map<uint64_t, shared_ptr<PartialMessage> >::iterator it =
+ m_partialMessages.find(messageIdentifier);
+ if (it == m_partialMessages.end()) {
+ return;
+ }
+
+ m_scheduler.cancelEvent(it->second->m_expiry);
+ m_partialMessages.erase(it);
+}
+
+} // namespace ndnlp
+} // namespace nfd
diff --git a/daemon/face/ndnlp-partial-message-store.hpp b/daemon/face/ndnlp-partial-message-store.hpp
new file mode 100644
index 0000000..954b79a
--- /dev/null
+++ b/daemon/face/ndnlp-partial-message-store.hpp
@@ -0,0 +1,89 @@
+/* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
+/**
+ * Copyright (C) 2014 Named Data Networking Project
+ * See COPYING for copyright and distribution information.
+ */
+
+#ifndef NFD_FACE_NDNLP_PARTIAL_MESSAGE_STORE_HPP
+#define NFD_FACE_NDNLP_PARTIAL_MESSAGE_STORE_HPP
+
+#include "ndnlp-parse.hpp"
+#include "core/event-emitter.hpp"
+#include "core/scheduler.hpp"
+
+namespace nfd {
+namespace ndnlp {
+
+/** \brief represents a partially received message
+ */
+class PartialMessage : noncopyable
+{
+public:
+ PartialMessage();
+
+ bool
+ add(uint16_t fragIndex, uint16_t fragCount, const Block& payload);
+
+ bool
+ isComplete() const;
+
+ /** \brief reassemble network layer packet
+ *
+ * isComplete() must be true before calling this method
+ *
+ * \exception ndn::Block::Error packet is malformated
+ * \return network layer packet
+ */
+ Block
+ reassemble();
+
+public:
+ EventId m_expiry;
+
+private:
+ size_t m_fragCount;
+ size_t m_received;
+ std::vector<Block> m_payloads;
+ size_t m_totalLength;
+};
+
+/** \brief provides reassembly feature at receiver
+ */
+class PartialMessageStore : noncopyable
+{
+public:
+ PartialMessageStore(Scheduler& scheduler,
+ time::Duration idleDuration = time::milliseconds(100));
+
+ virtual
+ ~PartialMessageStore();
+
+ /** \brief receive a NdnlpData packet
+ *
+ * \exception ParseError NDNLP packet is malformated
+ * \exception ndn::Block::Error network layer packet is malformated
+ */
+ void
+ receiveNdnlpData(const Block& pkt);
+
+ /// fires when network layer packet is received
+ EventEmitter<Block> onReceive;
+
+private:
+ void
+ scheduleCleanup(uint64_t messageIdentifier, shared_ptr<PartialMessage> partialMessage);
+
+ void
+ cleanup(uint64_t messageIdentifier);
+
+private:
+ std::map<uint64_t, shared_ptr<PartialMessage> > m_partialMessages;
+
+ Scheduler& m_scheduler;
+ time::Duration m_idleDuration;
+};
+
+} // namespace ndnlp
+} // namespace nfd
+
+#endif // NFD_FACE_NDNLP_PARTIAL_MESSAGE_STORE_HPP