chunks: segmented file transfer
refs #3071
Change-Id: I88e4fc1a8e33a0d61a95e2291cccc7b998647489
diff --git a/tools/chunks/catchunks/data-fetcher.hpp b/tools/chunks/catchunks/data-fetcher.hpp
new file mode 100644
index 0000000..4335ab2
--- /dev/null
+++ b/tools/chunks/catchunks/data-fetcher.hpp
@@ -0,0 +1,132 @@
+/* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
+/**
+ * Copyright (c) 2016, Regents of the University of California,
+ * Colorado State University,
+ * University Pierre & Marie Curie, Sorbonne University.
+ *
+ * This file is part of ndn-tools (Named Data Networking Essential Tools).
+ * See AUTHORS.md for complete list of ndn-tools authors and contributors.
+ *
+ * ndn-tools 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 3 of the License, or (at your option) any later version.
+ *
+ * ndn-tools 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
+ * ndn-tools, e.g., in COPYING.md file. If not, see <http://www.gnu.org/licenses/>.
+ *
+ * See AUTHORS.md for complete list of ndn-cxx authors and contributors.
+ *
+ * @author Andrea Tosatto
+ * @author Davide Pesavento
+ */
+
+#ifndef NDN_TOOLS_CHUNKS_CATCHUNKS_DATA_FETCHER_HPP
+#define NDN_TOOLS_CHUNKS_CATCHUNKS_DATA_FETCHER_HPP
+
+#include "core/common.hpp"
+
+namespace ndn {
+namespace chunks {
+
+/**
+ * @brief fetch data for a given interest and handle timeout or nack error with retries
+ *
+ * To instantiate a DataFetcher you need to use the static method fetch, this will also express the
+ * interest. After a timeout or nack is received, the same interest with a different nonce will be
+ * requested for a maximum number of time specified by the class user. There are separate retry
+ * counters for timeouts and nacks.
+ *
+ * A specified callback is called after the data matching the expressed interest is received. A
+ * different callback is called in case one of the retries counter reach the maximum. This callback
+ * can be different for timeout and nack. The data callback must be defined but the others callback
+ * are optional.
+ *
+ */
+class DataFetcher
+{
+public:
+ /**
+ * @brief means that there is no maximum number of retries,
+ * i.e. fetching must be retried indefinitely
+ */
+ static const int MAX_RETRIES_INFINITE;
+
+ /**
+ * @brief ceiling value for backoff time used in congestion handling
+ */
+ static const time::milliseconds MAX_CONGESTION_BACKOFF_TIME;
+
+ typedef function<void(const Interest& interest, const std::string& reason)> FailureCallback;
+
+ /**
+ * @brief instantiate a DataFetcher object and start fetching data
+ *
+ * @param onData callback for segment correctly received, must not be empty
+ */
+ static shared_ptr<DataFetcher>
+ fetch(Face& face, const Interest& interest, int maxNackRetries, int maxTimeoutRetries,
+ DataCallback onData, FailureCallback onTimeout, FailureCallback onNack,
+ bool isVerbose);
+
+ /**
+ * @brief stop data fetching without error and calling any callback
+ */
+ void
+ cancel();
+
+ bool
+ isRunning() const
+ {
+ return !m_isStopped && !m_hasError;
+ }
+
+ bool
+ hasError() const
+ {
+ return m_hasError;
+ }
+
+private:
+ DataFetcher(Face& face, int maxNackRetries, int maxTimeoutRetries,
+ DataCallback onData, FailureCallback onNack, FailureCallback onTimeout,
+ bool isVerbose);
+
+ void
+ expressInterest(const Interest& interest, const shared_ptr<DataFetcher>& self);
+
+ void
+ handleData(const Interest& interest, const Data& data, const shared_ptr<DataFetcher>& self);
+
+ void
+ handleNack(const Interest& interest, const lp::Nack& nack, const shared_ptr<DataFetcher>& self);
+
+ void
+ handleTimeout(const Interest& interest, const shared_ptr<DataFetcher>& self);
+
+private:
+ Face& m_face;
+ Scheduler m_scheduler;
+ const PendingInterestId* m_interestId;
+ DataCallback m_onData;
+ FailureCallback m_onNack;
+ FailureCallback m_onTimeout;
+
+ int m_maxNackRetries;
+ int m_maxTimeoutRetries;
+ int m_nNacks;
+ int m_nTimeouts;
+ uint32_t m_nCongestionRetries;
+
+ bool m_isVerbose;
+ bool m_isStopped;
+ bool m_hasError;
+};
+
+} // namespace chunks
+} // namespace ndn
+
+#endif // NDN_TOOLS_CHUNKS_CATCHUNKS_DATA_FETCHER_HPP