core: Add Mtree

Change-Id: I80205fb0d1f4ee5bcbc6c73651bb697fe854bf53
diff --git a/core/sub-tree.cpp b/core/sub-tree.cpp
new file mode 100644
index 0000000..46f3f5c
--- /dev/null
+++ b/core/sub-tree.cpp
@@ -0,0 +1,213 @@
+/* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
+/**
+ * Copyright (c) 2014,  Regents of the University of California
+ *
+ * This file is part of NSL (NDN Signature Logger).
+ * See AUTHORS.md for complete list of NSL authors and contributors.
+ *
+ * NSL 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.
+ *
+ * NSL 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
+ * NSL, e.g., in COPYING.md file.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ * @author Peizhen Guo <patrick.guopz@gmail.com>
+ */
+
+#include "sub-tree.hpp"
+#include "Auditor.hpp"
+#include <math.h>
+
+
+namespace nsl {
+
+void
+SubTree::addNode(ndn::ConstBufferPtr hash_ptr)
+{
+  if(m_remainPosition > 0)
+    {
+      uint8_t seqNo = 127 - m_remainPosition;
+      m_nodeHashes[seqNo] = ndn::make_shared<ndn::Buffer>(*hash_ptr);
+      m_remainPosition -= 1;
+      updateHash();
+    }
+}
+
+void
+SubTree::updateHash()
+{
+  uint8_t i_ = 6;
+  uint8_t lastNo = 126 - m_remainPosition;
+  for (; i_ > 0; i_--)
+    {
+      for (int i = int(pow(2, i_)) - 1; i <= lastNo; i+= 2)
+        {
+          if ((i + 1) <= lastNo)
+            {
+              uint8_t up_idx = (i-1) / 2;
+              Auditor hasher;
+              ndn::ConstBufferPtr buf = hasher.computeHash(m_nodeHashes[i],
+                                                           m_nodeHashes[i + 1]);
+              m_nodeHashes[up_idx] = ndn::make_shared<ndn::Buffer>(*buf);
+            }
+          else
+            {
+              uint8_t up_idx = (i-1) / 2;
+              Auditor hasher;
+              ndn::ConstBufferPtr buf = hasher.computeHashOneSide(m_nodeHashes[i]);
+              m_nodeHashes[up_idx] = ndn::make_shared<ndn::Buffer>(*buf);
+            }
+        }
+      lastNo = (lastNo - 1) / 2;
+    }
+  m_callBackUpdate(m_remainPosition, m_nodeHashes[0]);
+}
+
+
+
+
+void
+SubTree::updateLeafHash(Index subRootIndex, ndn::ConstBufferPtr hash)
+{
+  uint8_t lastNo = 126 - m_remainPosition;
+  uint64_t sequenceNo = subRootIndex.number;
+  uint64_t level = subRootIndex.level;
+  uint8_t indexBase = int(pow(2, m_root.level - level) - 1);
+  uint8_t indexOffset = (sequenceNo - m_root.number) / int(pow(2, level));
+  m_nodeHashes[indexBase + indexOffset] = ndn::make_shared<ndn::Buffer>(*hash);
+  if (lastNo < indexBase + indexOffset) // update value ? add new value
+    {
+      m_remainPosition -= 1;
+    }
+  updateHash();
+}
+
+ndn::ConstBufferPtr
+SubTree::getHash(Index nodeIndex)
+{
+  uint64_t sequenceNo = nodeIndex.number;
+  uint64_t level = nodeIndex.level;
+  uint8_t indexBase = int(pow(2, m_root.level - level) - 1);
+  uint8_t indexOffset = (sequenceNo - m_root.number) / int(pow(2, level));
+  return m_nodeHashes[indexBase + indexOffset];
+}
+
+
+
+
+Index
+SubTree::getRootIndex()
+{
+  return m_root;
+}
+
+uint8_t
+SubTree::getRemainPosition()
+{
+  return m_remainPosition;
+}
+
+Index
+SubTree::getParentRootIndex()
+{
+  Index parentIndex;
+  parentIndex.number = m_root.number;
+  parentIndex.level = m_root.level;
+  for (int i = 0; i < 6; i++)
+    {
+      parentIndex.number -= parentIndex.number%int(pow(2, parentIndex.level + 1));
+      parentIndex.level += 1;
+    }
+  return parentIndex;
+}
+
+
+
+std::string
+SubTree::encoding()
+{
+  std::string subTreeInfo = "";
+  uint64_t seq = m_root.number;
+  uint64_t lev = m_root.level;
+  unsigned char div_seq[8];
+  unsigned char div_lev[8];
+  for (int i = 0; i < 8; i++)
+    {
+      div_seq[i] = (seq >> (8*i)) & 0xFF;
+      div_lev[i] = (lev >> (8*i)) & 0xFF;
+    }
+  for (int i = 0; i < 8; i++)
+    {
+      subTreeInfo += div_seq[i];
+    }
+  for (int i = 0; i < 8; i++)
+    {
+      subTreeInfo += div_lev[i];
+    }
+  subTreeInfo += m_remainPosition;
+  for (int i = 0; i < 127; i++)
+    {
+      for (int j = 0; j < m_nodeHashes[i]->size(); j++)
+        {
+          subTreeInfo += (*m_nodeHashes[i])[j];
+        }
+      uint8_t flag = 0;
+      for (int j = m_nodeHashes[i]->size(); j < 32; j++)
+        {
+          subTreeInfo += flag;
+        }
+    }
+  return subTreeInfo;
+}
+
+void
+SubTree::resumeFromString(uint8_t remain, std::vector<ndn::BufferPtr> hashes)
+{
+  m_remainPosition = remain;
+  if (remain == 0)
+    {
+      for (int i = 0; i < hashes.size(); i++)
+        {
+          m_nodeHashes[i] = hashes[i];
+        }
+    }
+  else
+    {
+      for (int i = 0; i < hashes.size(); i++)
+        {
+          m_nodeHashes[63 + i] = hashes[i];
+        }
+      uint8_t i_ = 6;
+      uint8_t lastNo = 126 - m_remainPosition;
+      for (; i_ > 0; i_--)
+        {
+          for (int i = int(pow(2, i_)) - 1; i <= lastNo; i+= 2)
+            {
+              if ((i + 1) <= lastNo)
+                {
+                  uint8_t up_idx = (i-1) / 2;
+                  Auditor hasher;
+                  ndn::ConstBufferPtr buf = hasher.computeHash(m_nodeHashes[i],
+                                                               m_nodeHashes[i + 1]);
+                  m_nodeHashes[up_idx] = ndn::make_shared<ndn::Buffer>(*buf);
+                }
+              else
+                {
+                  uint8_t up_idx = (i-1) / 2;
+                  Auditor hasher;
+                  ndn::ConstBufferPtr buf = hasher.computeHashOneSide(m_nodeHashes[i]);
+                  m_nodeHashes[up_idx] = ndn::make_shared<ndn::Buffer>(*buf);
+                }
+            }
+          lastNo = (lastNo - 1) / 2;
+        }
+    }
+}
+
+
+} // namespace nsl