#include "mtag-buffer.h"

#include "ns3/assert.h"

namespace ns3 {

void 

MtagBuffer::WriteU8 (uint8_t v)

{

  NS_ASSERT (m_current + 1 <= m_end);

  *m_current = v;

  m_current++;

}

void 

MtagBuffer::WriteU16 (uint16_t data)

{

  WriteU8 ((data >> 0) & 0xff);

  WriteU8 ((data >> 8) & 0xff);

}

void 

MtagBuffer::WriteU32 (uint32_t data)

{

  WriteU8 ((data >> 0) & 0xff);

  WriteU8 ((data >> 8) & 0xff);

  WriteU8 ((data >> 16) & 0xff);

  WriteU8 ((data >> 24) & 0xff);

}

void 

MtagBuffer::WriteU64 (uint64_t data)

{

  WriteU8 ((data >> 0) & 0xff);

  WriteU8 ((data >> 8) & 0xff);

  WriteU8 ((data >> 16) & 0xff);

  WriteU8 ((data >> 24) & 0xff);

  WriteU8 ((data >> 32) & 0xff);

  WriteU8 ((data >> 40) & 0xff);

  WriteU8 ((data >> 48) & 0xff);

  WriteU8 ((data >> 54) & 0xff);

}

uint8_t  

MtagBuffer::ReadU8 (void)

{

  NS_ASSERT (m_current + 1 <= m_end);

  uint8_t v;

  v = *m_current;

  m_current++;

  return v;

}

uint16_t 

MtagBuffer::ReadU16 (void)

{

  uint8_t byte0 = ReadU8 ();

  uint8_t byte1 = ReadU8 ();

  uint16_t data = byte1;

  data <<= 8;

  data |= byte0;

  return data;

}

uint32_t 

MtagBuffer::ReadU32 (void)

{

  uint8_t byte0 = ReadU8 ();

  uint8_t byte1 = ReadU8 ();

  uint8_t byte2 = ReadU8 ();

  uint8_t byte3 = ReadU8 ();

  uint32_t data = byte3;

  data <<= 8;

  data |= byte2;

  data <<= 8;

  data |= byte1;

  data <<= 8;

  data |= byte0;

  return data;

}

uint64_t 

MtagBuffer::ReadU64 (void)

{

  uint8_t byte0 = ReadU8 ();

  uint8_t byte1 = ReadU8 ();

  uint8_t byte2 = ReadU8 ();

  uint8_t byte3 = ReadU8 ();

  uint8_t byte4 = ReadU8 ();

  uint8_t byte5 = ReadU8 ();

  uint8_t byte6 = ReadU8 ();

  uint8_t byte7 = ReadU8 ();

  uint32_t data = byte7;

  data <<= 8;

  data |= byte6;

  data <<= 8;

  data |= byte5;

  data <<= 8;

  data |= byte4;

  data <<= 8;

  data |= byte3;

  data <<= 8;

  data |= byte2;

  data <<= 8;

  data |= byte1;

  data <<= 8;

  data |= byte0;

  return data;

}

MtagBuffer::MtagBuffer (uint8_t *start, uint8_t *end)

  : m_current (start),

    m_end (end)

{}

void 

MtagBuffer::TrimAtEnd (uint32_t trim)

{

  NS_ASSERT (m_current <= (m_end - trim));

  m_end -= trim;

}

void 

MtagBuffer::CopyFrom (MtagBuffer o)

{

  uint32_t size = o.m_end - o.m_current;

  NS_ASSERT (size <= m_end - m_current);

  memcpy (m_current, o.m_current, size);

  m_current += size;

}

} // namespace ns3