PSync: initial commit

refs: #4641

Change-Id: Iabed3ad7632544d97559e6798547b7972b416784
diff --git a/src/detail/iblt.hpp b/src/detail/iblt.hpp
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+/* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
+/*
+ * Copyright (c) 2014-2018,  The University of Memphis
+ *
+ * This file is part of PSync.
+ * See AUTHORS.md for complete list of PSync authors and contributors.
+ *
+ * PSync 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.
+ *
+ * PSync 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
+ * PSync, e.g., in COPYING.md file.  If not, see <http://www.gnu.org/licenses/>.
+ *
+
+ * This file incorporates work covered by the following copyright and
+ * permission notice:
+
+ * The MIT License (MIT)
+
+ * Copyright (c) 2014 Gavin Andresen
+
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+*/
+
+#ifndef PSYNC_IBLT_HPP
+#define PSYNC_IBLT_HPP
+
+#include <ndn-cxx/name.hpp>
+
+#include <inttypes.h>
+#include <set>
+#include <vector>
+#include <string>
+
+namespace psync {
+
+class HashTableEntry
+{
+public:
+  int32_t count;
+  uint32_t keySum;
+  uint32_t keyCheck;
+
+  bool
+  isPure() const;
+
+  bool
+  isEmpty() const;
+};
+
+extern const size_t N_HASH;
+extern const size_t N_HASHCHECK;
+
+/**
+ * @brief Invertible Bloom Lookup Table (Invertible Bloom Filter)
+ *
+ * Used by Partial Sync (PartialProducer) and Full Sync (Full Producer)
+ */
+class IBLT
+{
+public:
+  class Error : public std::runtime_error
+  {
+  public:
+    using std::runtime_error::runtime_error;
+  };
+
+  /**
+   * @brief constructor
+   *
+   * @param expectedNumEntries the expected number of entries in the IBLT
+   */
+  explicit IBLT(size_t expectedNumEntries);
+
+  /**
+   * @brief Populate the hash table using the vector representation of IBLT
+   *
+   * @param ibltName the Component representation of IBLT
+   * @throws Error if size of values is not compatible with this IBF
+   */
+  void
+  initialize(const ndn::name::Component& ibltName);
+
+  void
+  insert(uint32_t key);
+
+  void
+  erase(uint32_t key);
+
+  /**
+   * @brief List all the entries in the IBLT
+   *
+   * This is called on a difference of two IBLTs: ownIBLT - rcvdIBLT
+   * Entries listed in positive are in ownIBLT but not in rcvdIBLT
+   * Entries listed in negative are in rcvdIBLT but not in ownIBLT
+   *
+   * @param positive
+   * @param negative
+   * @return true if decoding is complete successfully
+   */
+  bool
+  listEntries(std::set<uint32_t>& positive, std::set<uint32_t>& negative) const;
+
+  IBLT
+  operator-(const IBLT& other) const;
+
+  std::vector<HashTableEntry>
+  getHashTable() const
+  {
+    return m_hashTable;
+  }
+
+  /**
+   * @brief Appends self to name
+   *
+   * Encodes our hash table from uint32_t vector to uint8_t vector
+   * We create a uin8_t vector 12 times the size of uint32_t vector
+   * We put the first count in first 4 cells, keySum in next 4, and keyCheck in next 4.
+   * Repeat for all the other cells of the hash table.
+   * Then we append this uint8_t vector to the name.
+   *
+   * @param name
+   */
+  void
+  appendToName(ndn::Name& name) const;
+
+  /**
+   * @brief Extracts IBLT from name component
+   *
+   * Converts the name into a uint8_t vector which is then decoded to a
+   * a uint32_t vector.
+   *
+   * @param ibltName IBLT represented as a Name Component
+   * @return a uint32_t vector representing the hash table of the IBLT
+   */
+  std::vector<uint32_t>
+  extractValueFromName(const ndn::name::Component& ibltName) const;
+
+private:
+  void
+  update(int plusOrMinus, uint32_t key);
+
+private:
+  std::vector<HashTableEntry> m_hashTable;
+  static const int INSERT = 1;
+  static const int ERASE = -1;
+};
+
+bool
+operator==(const IBLT& iblt1, const IBLT& iblt2);
+
+bool
+operator!=(const IBLT& iblt1, const IBLT& iblt2);
+
+std::ostream&
+operator<<(std::ostream& out, const IBLT& iblt);
+
+} // namespace psync
+
+#endif // PSYNC_IBLT_HPP
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