Use ndn::Buffer::data() instead of buf()

The latter is considered deprecated.

Change-Id: If92406ccedca391e3551b456491ebb47737f1bc1
diff --git a/src/diff-state-container.hpp b/src/diff-state-container.hpp
index f03caf1..dbd4a11 100644
--- a/src/diff-state-container.hpp
+++ b/src/diff-state-container.hpp
@@ -46,7 +46,7 @@
   {
     BOOST_ASSERT(digest->size() > sizeof(std::size_t));
 
-    return *reinterpret_cast<const std::size_t*>(digest->buf());
+    return *reinterpret_cast<const std::size_t*>(digest->data());
   }
 };
 
diff --git a/src/leaf-container.hpp b/src/leaf-container.hpp
index f08f8f9..95ddc75 100644
--- a/src/leaf-container.hpp
+++ b/src/leaf-container.hpp
@@ -49,7 +49,7 @@
 
     BOOST_ASSERT(buffer->size() > sizeof(std::size_t));
 
-    return *reinterpret_cast<const std::size_t*>(buffer->buf());
+    return *reinterpret_cast<const std::size_t*>(buffer->data());
   }
 };
 
diff --git a/src/logic.cpp b/src/logic.cpp
index 44115eb..ca1f6e2 100644
--- a/src/logic.cpp
+++ b/src/logic.cpp
@@ -252,7 +252,7 @@
       _LOG_DEBUG_ID("updateSeqNo: not in Reset ");
       ConstBufferPtr previousRoot = m_state.getRootDigest();
       {
-        std::string hash = ndn::toHex(previousRoot->buf(), previousRoot->size(), false);
+        std::string hash = ndn::toHex(previousRoot->data(), previousRoot->size(), false);
         _LOG_DEBUG_ID("Hash: " << hash);
       }
 
@@ -691,7 +691,7 @@
 void
 Logic::printDigest(ConstBufferPtr digest)
 {
-  std::string hash = ndn::toHex(digest->buf(), digest->size(), false);
+  std::string hash = ndn::toHex(digest->data(), digest->size(), false);
   _LOG_DEBUG_ID("Hash: " << hash);
 }
 
diff --git a/src/state.cpp b/src/state.cpp
index b89509b..c6b3ead 100644
--- a/src/state.cpp
+++ b/src/state.cpp
@@ -26,9 +26,7 @@
 
 namespace chronosync {
 
-State::~State()
-{
-}
+State::~State() = default;
 
 /**
  * @brief Add or update leaf to the sync tree
@@ -68,7 +66,7 @@
   BOOST_FOREACH (ConstLeafPtr leaf, m_leaves.get<ordered>())
     {
       BOOST_ASSERT(leaf != 0);
-      m_digest.update(leaf->getDigest()->buf(), leaf->getDigest()->size());
+      m_digest.update(leaf->getDigest()->data(), leaf->getDigest()->size());
     }
 
   return m_digest.computeDigest();
diff --git a/tests/unit-tests/test-leaf.cpp b/tests/unit-tests/test-leaf.cpp
index 1588514..94ee50c 100644
--- a/tests/unit-tests/test-leaf.cpp
+++ b/tests/unit-tests/test-leaf.cpp
@@ -56,7 +56,7 @@
   BOOST_CHECK_NO_THROW(leaf.getDigest());
 
   ndn::ConstBufferPtr digest = leaf.getDigest();
-  BOOST_CHECK_EQUAL(result, ndn::toHex(digest->buf(), digest->size(), false));
+  BOOST_CHECK_EQUAL(result, ndn::toHex(digest->data(), digest->size(), false));
 }
 
 BOOST_AUTO_TEST_CASE(Container)