/* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
/*
* Copyright (c) 2005,2006,2007 INRIA
*
* 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:
Iterator ();
/**
* go forward by one byte
*/
void Next (void);
/**
* go backward by one byte
*/
void Prev (void);
/**
* \param delta number of bytes to go forward
*/
void Next (uint32_t delta);
/**
* \param delta number of bytes to go backward
*/
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.
*/
uint32_t GetDistanceFrom (Iterator const &o) const;
/**
* \return true if this iterator points to the end of the byte array.
* false otherwise.
*/
bool IsEnd (void) const;
/**
* \return true if this iterator points to the start of the byte array.
* false otherwise.
*/
bool IsStart (void) const;
/**
* \param data data to write in buffer
*
* Write the data in buffer and avance the iterator position
* by one byte.
*/
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.
*/
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.
*/
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.
*/
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.
*/
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.
*/
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.
*/
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.
*/
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.
*/
void Write (uint8_t const*buffer, uint32_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.
*/
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.
*/
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.
*/
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.
*/
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.
*/
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.
*/
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.
*/
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.
*/
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.
*/
void Read (uint8_t *buffer, uint32_t size);
private:
friend class Buffer;
Iterator (Buffer const*buffer);
Iterator (Buffer const*buffer, bool);
void Construct (const Buffer *buffer);
uint32_t m_zeroStart;
uint32_t m_zeroEnd;
uint32_t m_dataStart;
uint32_t m_dataEnd;
uint32_t m_current;
uint8_t *m_data;
};
/**
* \return the number of bytes stored in this buffer.
*/
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.
*/
Buffer::Iterator Begin (void) const;
/**
* \return an Iterator which points to the
* end of this Buffer.
*/
Buffer::Iterator End (void) const;
Buffer CreateFullCopy (void) const;
Buffer (Buffer const &o);
Buffer &operator = (Buffer const &o);
Buffer ();
Buffer (uint32_t dataSize);
~Buffer ();
private:
void TransformIntoRealBuffer (void) const;
bool CheckInternalState (void) const;
void Initialize (uint32_t zeroSize);
uint32_t GetInternalSize (void) const;
uint32_t GetInternalEnd (void) const;
static void Recycle (struct BufferData *data);
static struct BufferData *Create (uint32_t size);
struct BufferData *m_data;
uint32_t m_maxZeroAreaStart;
uint32_t m_zeroAreaStart;
uint32_t m_zeroAreaEnd;
uint32_t m_start;
uint32_t m_end;
};
} // namespace ns3
#endif /* BUFFER_H */