network: Adding Read (Buffer::Iterator start, uint32_t size) and PeakU8 methods to ns3::Buffer::Iterator class

src/network/model/buffer.h

@@ -248,6 +248,13 @@ public:
      */
     void Write (Iterator start, Iterator end);
 
+    /**
+     * \return the byte read in the buffer.
+     *
+     * Read data, but do not advance the Iterator read.
+     */
+    inline uint8_t  PeekU8 (void);
+
     /**
      * \return the byte read in the buffer.
      *
@@ -332,11 +339,21 @@ public:
      * \param size number of bytes to copy
      *
      * Copy size bytes of data from the internal buffer to the
-     * input buffer and avance the Iterator by the number of
+     * input buffer and advance the Iterator by the number of
      * bytes read.
      */
     void Read (uint8_t *buffer, uint32_t size);
 
+    /**
+     * \param start start iterator of the buffer to copy data into
+     * \param size  number of bytes to copy
+     *
+     * Copy size bytes of data from the internal buffer to the input buffer via
+     * the provided iterator and advance the Iterator by the number of bytes
+     * read.
+     */
+    inline void Read (Iterator start, uint32_t size);
+
     /**
      * \brief Calculate the checksum.
      * \param size size of the buffer.
@@ -813,6 +830,14 @@ Buffer::Iterator::ReadNtohU32 (void)
   return retval;
 }
 
+uint8_t
+Buffer::Iterator::PeekU8 (void)
+{
+  uint8_t ret = ReadU8 ();
+  Prev ();
+  return ret;
+}
+
 uint8_t
 Buffer::Iterator::ReadU8 (void)
 {
@@ -851,6 +876,16 @@ Buffer::Iterator::ReadU16 (void)
   return data;
 }
 
+void
+Buffer::Iterator::Read (Buffer::Iterator start, uint32_t size)
+{
+  Buffer::Iterator end = *this;
+  end.Next (size);
+  
+  start.Write (*this, end);
+}
+
+
 Buffer::Buffer (Buffer const&o)
   : m_data (o.m_data),
     m_maxZeroAreaStart (o.m_zeroAreaStart),