ns-3
ns3::Buffer Class Reference

automatically resized byte buffer More...

#include <buffer.h>

List of all members.

Classes

struct  Data
class  Iterator
 iterator in a Buffer instance More...

Public Member Functions

uint32_t GetSize (void) const
uint8_t const * PeekData (void) const
bool AddAtStart (uint32_t start)
bool AddAtEnd (uint32_t end)
void AddAtEnd (const Buffer &o)
void RemoveAtStart (uint32_t start)
void RemoveAtEnd (uint32_t end)
Buffer CreateFragment (uint32_t start, uint32_t length) const
Buffer::Iterator Begin (void) const
Buffer::Iterator End (void) const
Buffer CreateFullCopy (void) const
uint32_t GetSerializedSize (void) const
uint32_t Serialize (uint8_t *buffer, uint32_t maxSize) const
uint32_t Deserialize (const uint8_t *buffer, uint32_t size)
int32_t GetCurrentStartOffset (void) const
int32_t GetCurrentEndOffset (void) const
void CopyData (std::ostream *os, uint32_t size) const
uint32_t CopyData (uint8_t *buffer, uint32_t size) const
 Buffer (Buffer const &o)
Bufferoperator= (Buffer const &o)
 Buffer (uint32_t dataSize)
 Buffer (uint32_t dataSize, bool initialize)

Detailed Description

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.


Member Function Documentation

bool ns3::Buffer::AddAtEnd ( uint32_t  end)
void ns3::Buffer::AddAtEnd ( const Buffer o)
Parameters:
othe buffer to append to the end of this buffer.

Add bytes at the end of the Buffer. Any call to this method invalidates any Iterator pointing to this Buffer.

This is an optimization which kicks in when we attempt to aggregate two buffers which contain adjacent zero areas.

References AddAtEnd(), Begin(), End(), GetSize(), NS_ASSERT, NS_LOG_FUNCTION, ns3::Buffer::Iterator::Prev(), and ns3::Buffer::Iterator::Write().

bool ns3::Buffer::AddAtStart ( uint32_t  start)
Parameters:
startsize to reserve
Returns:
true if the buffer needed resizing, false otherwise.

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.

References NS_ASSERT, and NS_LOG_FUNCTION.

Referenced by ns3::Packet::AddHeader(), ns3::Icmpv6Header::CalculatePseudoHeaderChecksum(), Deserialize(), ns3::PbbTlv::Deserialize(), ns3::Packet::Packet(), ns3::Ipv6ExtensionLooseRouting::Process(), ns3::PbbTlv::SetValue(), and ns3::PcapFile::Write().

void ns3::Buffer::CopyData ( std::ostream *  os,
uint32_t  size 
) const

Copy the specified amount of data from the buffer to the given output stream.

Parameters:
osthe output stream
sizethe maximum amount of bytes to copy. If zero, nothing is copied.

Referenced by ns3::Packet::CopyData(), and ns3::PcapFile::Write().

Buffer ns3::Buffer::CreateFragment ( uint32_t  start,
uint32_t  length 
) const
Parameters:
startoffset from start of packet
length
Returns:
a fragment of size length starting at offset start.

References GetSize(), NS_ASSERT, NS_LOG_FUNCTION, RemoveAtEnd(), and RemoveAtStart().

Referenced by ns3::Packet::CreateFragment().

uint32_t ns3::Buffer::Deserialize ( const uint8_t *  buffer,
uint32_t  size 
)
Returns:
zero if a complete buffer is not deserialized
Parameters:
bufferpoints to buffer for deserialization
sizenumber of bytes to deserialize

The raw character buffer is deserialized and all the data is placed into this buffer.

References AddAtEnd(), AddAtStart(), Begin(), End(), NS_ASSERT, ns3::Buffer::Iterator::Prev(), and ns3::Buffer::Iterator::Write().

uint32_t ns3::Buffer::GetSerializedSize ( void  ) const
Returns:
the number of bytes required for serialization

Referenced by ns3::Packet::GetSerializedSize().

uint8_t const * ns3::Buffer::PeekData ( void  ) const
Returns:
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.

References NS_ASSERT.

Referenced by ns3::WifiInformationElement::operator==(), ns3::Packet::PeekData(), ns3::Ipv6ExtensionHeader::Serialize(), and ns3::dsr::DsrFsHeader::Serialize().

void ns3::Buffer::RemoveAtEnd ( uint32_t  end)
Parameters:
endsize to remove

Remove bytes at the end of the Buffer. Any call to this method invalidates any Iterator pointing to this Buffer.

References NS_ASSERT, and NS_LOG_FUNCTION.

Referenced by CreateFragment(), ns3::Ipv6ExtensionHeader::Deserialize(), ns3::dsr::DsrFsHeader::Deserialize(), ns3::Packet::RemoveAtEnd(), and ns3::Packet::RemoveTrailer().

void ns3::Buffer::RemoveAtStart ( uint32_t  start)
Parameters:
startsize to remove

Remove bytes at the start of the Buffer. Any call to this method invalidates any Iterator pointing to this Buffer.

References NS_ASSERT, and NS_LOG_FUNCTION.

Referenced by CreateFragment(), ns3::Packet::RemoveAtStart(), and ns3::Packet::RemoveHeader().

uint32_t ns3::Buffer::Serialize ( uint8_t *  buffer,
uint32_t  maxSize 
) const
Returns:
zero if buffer not large enough
Parameters:
bufferpoints to serialization buffer
maxSizemax number of bytes to write

This buffer's contents are serialized into the raw character buffer parameter. Note: The zero length data is not copied entirely. Only the length of zero byte data is serialized.

References NS_LOG_FUNCTION.


The documentation for this class was generated from the following files: