/* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
/*
* Copyright (c) 2005,2006 INRIA
* All rights reserved.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation;
*
* This program 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 this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*
* Author: Mathieu Lacage <mathieu.lacage@sophia.inria.fr>
*/
#ifndef BUFFER_H
#define BUFFER_H
#include <stdint.h>
#include <vector>
namespace ns3 {
/**
* \brief automatically resized byte buffer
*
* This represents a buffer of bytes. Its size is
* automatically adjusted to hold any data prepended
* or appended by the user. Its implementation is optimized
* to ensure that the number of buffer resizes is minimized,
* by creating new Buffers of the maximum size ever used.
* The correct maximum size is learned at runtime during use by
* recording the maximum size of each packet.
*/
class Buffer {
public:
/**
* \brief iterator in a Buffer instance
*/
class Iterator {
public:
inline Iterator ();
/**
* go forward by one byte
*/
inline void Next (void);
/**
* go backward by one byte
*/
inline void Prev (void);
/**
* \param delta number of bytes to go forward
*/
inline void Next (uint32_t delta);
/**
* \param delta number of bytes to go backward
*/
inline void Prev (uint32_t delta);
/**
* \param o the second iterator
* \return number of bytes included between the two iterators
*
* This method works only if the two iterators point
* to the same underlying buffer. Debug builds ensure
* this with an assert.
*/
inline int32_t GetDistanceFrom (Iterator const &o) const;
/**
* \return true if this iterator points to the end of the byte array.
* false otherwise.
*/
inline bool IsEnd (void) const;
/**
* \return true if this iterator points to the start of the byte array.
* false otherwise.
*/
inline bool IsStart (void) const;
/**
* \param data data to write in buffer
*
* Write the data in buffer and avance the iterator position
* by one byte.
*/
inline void WriteU8 (uint8_t data);
/**
* \param data data to write in buffer
* \param len number of times data must be written in buffer
*
* Write the data in buffer len times and avance the iterator position
* by len byte.
*/
inline void WriteU8 (uint8_t data, uint32_t len);
/**
* \param data data to write in buffer
*
* Write the data in buffer and avance the iterator position
* by two bytes. The format of the data written in the byte
* buffer is non-portable. We only ensure that readU16 will
* return exactly what we wrote with writeU16 if the program
* is run on the same machine.
*/
inline void WriteU16 (uint16_t data);
/**
* \param data data to write in buffer
*
* Write the data in buffer and avance the iterator position
* by four bytes. The format of the data written in the byte
* buffer is non-portable. We only ensure that readU32 will
* return exactly what we wrote with writeU32 if the program
* is run on the same machine.
*/
inline void WriteU32 (uint32_t data);
/**
* \param data data to write in buffer
*
* Write the data in buffer and avance the iterator position
* by eight bytes. The format of the data written in the byte
* buffer is non-portable. We only ensure that readU64 will
* return exactly what we wrote with writeU64 if the program
* is run on the same machine.
*/
inline void WriteU64 (uint64_t data);
/**
* \param data data to write in buffer
*
* Write the data in buffer and avance the iterator position
* by two bytes. The data is written in network order and the
* input data is expected to be in host order.
*/
inline void WriteHtonU16 (uint16_t data);
/**
* \param data data to write in buffer
*
* Write the data in buffer and avance the iterator position
* by four bytes. The data is written in network order and the
* input data is expected to be in host order.
*/
inline void WriteHtonU32 (uint32_t data);
/**
* \param data data to write in buffer
*
* Write the data in buffer and avance the iterator position
* by eight bytes. The data is written in network order and the
* input data is expected to be in host order.
*/
inline void WriteHtonU64 (uint64_t data);
/**
* \param buffer a byte buffer to copy in the internal buffer.
* \param size number of bytes to copy.
*
* Write the data in buffer and avance the iterator position
* by size bytes.
*/
inline void Write (uint8_t const*buffer, uint16_t size);
/**
* \param start the start of the data to copy
* \param end the end of the data to copy
*
* Write the data delimited by start and end in internal buffer
* and avance the iterator position by the number of bytes
* copied.
* The input interators _must_ not point to the same Buffer as
* we do to avoid overlapping copies. This is enforced
* in debug builds by asserts.
*/
inline void Write (Iterator start, Iterator end);
/**
* \return the byte read in the buffer.
*
* Read data and advance the Iterator by the number of bytes
* read.
*/
inline uint8_t ReadU8 (void);
/**
* \return the two bytes read in the buffer.
*
* Read data and advance the Iterator by the number of bytes
* read.
* The data is read in the format written by writeU16.
*/
inline uint16_t ReadU16 (void);
/**
* \return the four bytes read in the buffer.
*
* Read data and advance the Iterator by the number of bytes
* read.
* The data is read in the format written by writeU32.
*/
inline uint32_t ReadU32 (void);
/**
* \return the eight bytes read in the buffer.
*
* Read data and advance the Iterator by the number of bytes
* read.
* The data is read in the format written by writeU64.
*/
inline uint64_t ReadU64 (void);
/**
* \return the two bytes read in the buffer.
*
* Read data and advance the Iterator by the number of bytes
* read.
* The data is read in network format and return in host format.
*/
inline uint16_t ReadNtohU16 (void);
/**
* \return the four bytes read in the buffer.
*
* Read data and advance the Iterator by the number of bytes
* read.
* The data is read in network format and return in host format.
*/
inline uint32_t ReadNtohU32 (void);
/**
* \return the eight bytes read in the buffer.
*
* Read data and advance the Iterator by the number of bytes
* read.
* The data is read in network format and return in host format.
*/
inline uint64_t ReadNtohU64 (void);
/**
* \param buffer 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 and avance the Iterator by the number of
* bytes read.
*/
inline void Read (uint8_t *buffer, uint16_t size);
private:
friend class Buffer;
inline Iterator (Buffer const*buffer, uint32_t m_current);
inline uint32_t GetIndex (uint32_t n);
uint32_t m_zeroStart;
uint32_t m_zeroEnd;
uint32_t m_dataEnd;
uint32_t m_current;
uint8_t *m_data;
};
/**
* \return the number of bytes stored in this buffer.
*/
inline uint32_t GetSize (void) const;
/**
* \return a pointer to the start of the internal
* byte buffer.
*
* The returned pointer points to an area of
* memory which is ns3::Buffer::GetSize () bytes big.
* Please, try to never ever use this method. It is really
* evil and is present only for a few specific uses.
*/
uint8_t const*PeekData (void) const;
/**
* \param start size to reserve
*
* Add bytes at the start of the Buffer. The
* content of these bytes is undefined but debugging
* builds initialize them to 0x33.
* Any call to this method invalidates any Iterator
* pointing to this Buffer.
*/
void AddAtStart (uint32_t start);
/**
* \param end size to reserve
*
* Add bytes at the end of the Buffer. The
* content of these bytes is undefined but debugging
* builds initialize them to 0x33.
* Any call to this method invalidates any Iterator
* pointing to this Buffer.
*/
void AddAtEnd (uint32_t end);
/**
* \param start size to remove
*
* Remove bytes at the start of the Buffer.
* Any call to this method invalidates any Iterator
* pointing to this Buffer.
*/
void RemoveAtStart (uint32_t start);
/**
* \param end size to remove
*
* Remove bytes at the end of the Buffer.
* Any call to this method invalidates any Iterator
* pointing to this Buffer.
*/
void RemoveAtEnd (uint32_t end);
/**
* \param start offset from start of packet
* \param length
*
* \return a fragment of size length starting at offset
* start.
*/
Buffer CreateFragment (uint32_t start, uint32_t length) const;
/**
* \return an Iterator which points to the
* start of this Buffer.
*/
inline Buffer::Iterator Begin (void) const;
/**
* \return an Iterator which points to the
* end of this Buffer.
*/
inline Buffer::Iterator End (void) const;
inline Buffer (Buffer const &o);
inline Buffer &operator = (Buffer const &o);
inline Buffer ();
inline Buffer (uint32_t dataSize);
inline ~Buffer ();
private:
struct BufferData {
uint32_t m_count;
uint32_t m_size;
uint32_t m_initialStart;
uint32_t m_dirtyStart;
uint32_t m_dirtySize;
uint8_t m_data[1];
};
typedef std::vector<struct Buffer::BufferData*> BufferDataList;
inline uint8_t *GetStart (void) const;
void TransformIntoRealBuffer (void) const;
static void Recycle (struct Buffer::BufferData *data);
static struct Buffer::BufferData *Create (void);
static struct Buffer::BufferData *Allocate (uint32_t size, uint32_t start);
static void Deallocate (struct Buffer::BufferData *data);
static BufferDataList m_freeList;
static uint32_t m_maxTotalAddStart;
static uint32_t m_maxTotalAddEnd;
struct BufferData *m_data;
uint32_t m_zeroAreaSize;
uint32_t m_start;
uint32_t m_size;
};
}; // namespace ns3
/**************************************************
Start of implementation of methods which
need to be inline for performance reasons.
*************************************************/
#include <cassert>
namespace ns3 {
Buffer::Buffer ()
: m_data (Buffer::Create ()),
m_zeroAreaSize (0),
m_start (m_maxTotalAddStart),
m_size (0)
{
if (m_start > m_data->m_size)
{
m_start = 0;
}
assert (m_start <= m_data->m_size);
}
Buffer::Buffer (uint32_t dataSize)
: m_data (Buffer::Create ()),
m_zeroAreaSize (dataSize),
m_start (m_maxTotalAddStart),
m_size (0)
{
if (m_start > m_data->m_size)
{
m_start = 0;
}
assert (m_start <= m_data->m_size);
}
Buffer::Buffer (Buffer const&o)
: m_data (o.m_data),
m_zeroAreaSize (o.m_zeroAreaSize),
m_start (o.m_start),
m_size (o.m_size)
{
m_data->m_count++;
assert (m_start <= m_data->m_size);
}
Buffer &
Buffer::operator = (Buffer const&o)
{
if (m_data != o.m_data)
{
// not assignment to self.
m_data->m_count--;
if (m_data->m_count == 0)
{
Recycle (m_data);
}
m_data = o.m_data;
m_data->m_count++;
}
m_zeroAreaSize = o.m_zeroAreaSize;
m_start = o.m_start;
m_size = o.m_size;
assert (m_start <= m_data->m_size);
return *this;
}
Buffer::~Buffer ()
{
m_data->m_count--;
if (m_data->m_count == 0)
{
Recycle (m_data);
}
}
uint8_t *
Buffer::GetStart (void) const
{
return m_data->m_data + m_start;
}
uint32_t
Buffer::GetSize (void) const
{
return m_size + m_zeroAreaSize;
}
Buffer::Iterator
Buffer::Begin (void) const
{
return Buffer::Iterator (this, 0);
}
Buffer::Iterator
Buffer::End (void) const
{
return Buffer::Iterator (this, GetSize ());
}
Buffer::Iterator::Iterator ()
: m_zeroStart (0),
m_zeroEnd (0),
m_dataEnd (0),
m_current (0),
m_data (0)
{}
Buffer::Iterator::Iterator (Buffer const*buffer, uint32_t current)
: m_zeroStart (buffer->m_data->m_initialStart-buffer->m_start),
m_zeroEnd (m_zeroStart+buffer->m_zeroAreaSize),
m_dataEnd (buffer->GetSize ()),
m_current (current),
m_data (buffer->m_data->m_data+buffer->m_start)
{}
void
Buffer::Iterator::Next (void)
{
assert (m_current + 1 <= m_dataEnd);
m_current++;
}
void
Buffer::Iterator::Prev (void)
{
assert (m_current >= 1);
m_current--;
}
void
Buffer::Iterator::Next (uint32_t delta)
{
assert (m_current + delta <= m_dataEnd);
m_current += delta;
}
void
Buffer::Iterator::Prev (uint32_t delta)
{
assert (m_current >= delta);
m_current -= delta;
}
int32_t
Buffer::Iterator::GetDistanceFrom (Iterator const &o) const
{
assert (m_data == o.m_data);
int32_t start = m_current;
int32_t end = o.m_current;
return end - start;
}
bool
Buffer::Iterator::IsEnd (void) const
{
return m_current == m_dataEnd;
}
bool
Buffer::Iterator::IsStart (void) const
{
return m_current == 0;
}
uint32_t
Buffer::Iterator::GetIndex (uint32_t n)
{
assert (
(m_current + n <= m_dataEnd) &&
((m_current + n <= m_zeroStart) ||
(m_current >= m_zeroEnd))
);
uint32_t index;
if (m_current < m_zeroStart)
{
index = m_current;
}
else
{
index = m_current - (m_zeroEnd-m_zeroStart);
}
return index;
}
void
Buffer::Iterator::Write (Iterator start, Iterator end)
{
assert (start.m_data == end.m_data);
assert (start.m_current <= end.m_current);
assert (m_data != start.m_data);
uint32_t size = end.m_current - start.m_current;
uint8_t *src = start.m_data + start.GetIndex (size);
uint8_t *dest = m_data + GetIndex (size);
memcpy (dest, src, size);
m_current += size;
}
void
Buffer::Iterator::WriteU8 (uint8_t data, uint32_t len)
{
uint8_t *current = m_data + GetIndex (len);
memset (current, data, len);
m_current += len;
}
void
Buffer::Iterator::WriteU8 (uint8_t data)
{
m_data[GetIndex (1)] = data;
m_current++;
}
void
Buffer::Iterator::WriteU16 (uint16_t data)
{
uint16_t *buffer = (uint16_t *)(m_data + GetIndex (2));
*buffer = data;
m_current += 2;
}
void
Buffer::Iterator::WriteU32 (uint32_t data)
{
uint32_t *buffer = (uint32_t *)(m_data + GetIndex (4));
*buffer = data;
m_current += 4;
}
void
Buffer::Iterator::WriteU64 (uint64_t data)
{
uint64_t *buffer = (uint64_t *)(m_data + GetIndex (8));
*buffer = data;
m_current += 8;
}
void
Buffer::Iterator::WriteHtonU16 (uint16_t data)
{
uint8_t *current = m_data + GetIndex (2);
*(current+0) = (data >> 8) & 0xff;
*(current+1) = (data >> 0) & 0xff;
m_current += 2;
}
void
Buffer::Iterator::WriteHtonU32 (uint32_t data)
{
uint8_t *current = m_data + GetIndex (4);
*(current+0) = (data >> 24) & 0xff;
*(current+1) = (data >> 16) & 0xff;
*(current+2) = (data >> 8) & 0xff;
*(current+3) = (data >> 0) & 0xff;
m_current += 4;
}
void
Buffer::Iterator::WriteHtonU64 (uint64_t data)
{
uint8_t *current = m_data + GetIndex (8);
*(current+0) = (data >> 56) & 0xff;
*(current+1) = (data >> 48) & 0xff;
*(current+2) = (data >> 40) & 0xff;
*(current+3) = (data >> 32) & 0xff;
*(current+4) = (data >> 24) & 0xff;
*(current+5) = (data >> 16) & 0xff;
*(current+6) = (data >> 8) & 0xff;
*(current+7) = (data >> 0) & 0xff;
m_current += 8;
}
void
Buffer::Iterator::Write (uint8_t const*buffer, uint16_t size)
{
uint8_t *current = m_data + GetIndex (size);
memcpy (current, buffer, size);
m_current += size;
}
uint8_t
Buffer::Iterator::ReadU8 (void)
{
uint8_t data = m_data[GetIndex(1)];
m_current++;
return data;
}
uint16_t
Buffer::Iterator::ReadU16 (void)
{
uint16_t *buffer = reinterpret_cast<uint16_t *>(m_data + GetIndex (2));
m_current += 2;
return *buffer;
}
uint32_t
Buffer::Iterator::ReadU32 (void)
{
uint32_t *buffer = reinterpret_cast<uint32_t *>(m_data + GetIndex (4));
m_current += 4;
return *buffer;
}
uint64_t
Buffer::Iterator::ReadU64 (void)
{
uint64_t *buffer = reinterpret_cast<uint64_t *>(m_data + GetIndex (8));
m_current += 8;
return *buffer;
}
uint16_t
Buffer::Iterator::ReadNtohU16 (void)
{
uint8_t *current = m_data + GetIndex (2);
uint16_t retval = 0;
retval |= static_cast<uint16_t> (current[0]) << 8;
retval |= static_cast<uint16_t> (current[1]) << 0;
m_current += 2;
return retval;
}
uint32_t
Buffer::Iterator::ReadNtohU32 (void)
{
uint8_t *current = m_data + GetIndex (4);
uint32_t retval = 0;
retval |= static_cast<uint32_t> (current[0]) << 24;
retval |= static_cast<uint32_t> (current[1]) << 16;
retval |= static_cast<uint32_t> (current[2]) << 8;
retval |= static_cast<uint32_t> (current[3]) << 0;
m_current += 4;
return retval;
}
uint64_t
Buffer::Iterator::ReadNtohU64 (void)
{
uint8_t *current = m_data + GetIndex (8);
uint64_t retval = 0;
retval |= static_cast<uint64_t> (current[0]) << 56;
retval |= static_cast<uint64_t> (current[1]) << 48;
retval |= static_cast<uint64_t> (current[2]) << 40;
retval |= static_cast<uint64_t> (current[3]) << 32;
retval |= static_cast<uint64_t> (current[4]) << 24;
retval |= static_cast<uint64_t> (current[5]) << 16;
retval |= static_cast<uint64_t> (current[6]) << 8;
retval |= static_cast<uint64_t> (current[7]) << 0;
m_current += 8;
return retval;
}
void
Buffer::Iterator::Read (uint8_t *buffer, uint16_t size)
{
uint8_t *current = m_data + GetIndex (size);
memcpy (buffer, current, size);
m_current += size;
}
}; // namespace ns3
#endif /* BUFFER_H */