qi::Buffer, qi::BufferReader

Summary

Global Classes

• class qi::BufferReader

  Functions (class qi::BufferReader)

  qi::BufferReader::peek

  qi::BufferReader::seek

  qi::BufferReader::position

  qi::BufferReader::BufferReader

  qi::BufferReader::hasSubBuffer

  qi::BufferReader::~BufferReader

  qi::BufferReader::subBuffer

  qi::BufferReader::read

• class qi::Buffer

  Functions (class qi::Buffer)

  qi::Buffer::addSubBuffer

  qi::Buffer::clear

  qi::Buffer::Buffer

  qi::Buffer::write

  qi::Buffer::reserve

  qi::Buffer::subBuffers

  qi::Buffer::read

  qi::Buffer::hasSubBuffer

  qi::Buffer::totalSize

  qi::Buffer::size

  qi::Buffer::data

  qi::Buffer::operator=

  qi::Buffer::subBuffer

Reference

qi::Buffer Class Reference

Introduction

Class to store buffer. . More...

#include <qi/buffer.hpp>

Public Functions

Buffer()

Buffer(const Buffer& buffer)

Buffer& operator=(const Buffer& buffer)

Buffer(Buffer&& buffer)

Buffer& operator=(Buffer&& buffer)

bool write(const void* data, size_t size)

size_t addSubBuffer(const Buffer& buffer)

bool hasSubBuffer(size_t offset) const

const Buffer& subBuffer(size_t offset) const

size_t size() const

size_t totalSize() const

const std::vector<std::pair<size_t, Buffer>>& subBuffers() const

void* reserve(size_t size)

void clear()

void* data()

const void* data() const

const void* read(size_t offset, size_t length) const

size_t read(void* buffer, size_t offset, size_t length) const

Detailed Description

This class can store buffer and sub-buffers. Here is a representation of internal management of sub-buffers.

Function Documentation

qi::Buffer::Buffer()

Default constructor.

qi::Buffer::Buffer(const Buffer& buffer)

Brief: Copy constructor.

Parameters:

• buffer – The buffer to copy.

As data are store as a shared pointer, the different copy of the same buffer all handle the same data.

Buffer& qi::Buffer::operator=(const Buffer& buffer)

Brief: Assignment operator. As data are store as a shared pointer, the different copy of the same buffer all handle the same data.

Parameters:

• buffer – The buffer to copy.

qi::Buffer::Buffer(Buffer&& buffer)

Brief: Move constructor. The moved-from buffer’s state is like a default constructed Buffer.

Parameters:

• buffer – The buffer to move from.

Buffer& qi::Buffer::operator=(Buffer&& buffer)

Brief: Move assignment operator. The moved-from buffer’s state is like a default constructed Buffer.

Parameters:

• buffer – The buffer to move from.

bool qi::Buffer::write(const void* data, size_t size)

Brief: Write data in the buffer.

Parameters:

• data – The data to write
• size – The size of the data to write

Returns:

true if operation succeeded, false otherwise.

size_t qi::Buffer::addSubBuffer(const Buffer& buffer)

Brief: Add a sub-buffer to the main buffer. This function add a uint32_t for the size of sub-buffers in main buffer and add the buffer to the list of sub-buffers.

Parameters:

• buffer – The buffer to have as sub-buffer.

Returns:

return te offset at which sub-buffer have been added.

bool qi::Buffer::hasSubBuffer(size_t offset) const

Brief: Check if there is a sub-buffer at given offset.

Parameters:

• offset – The offset to look at the presence of sub-buffer.

Returns:

true if there is a sub-buffer, false otherwise.

const Buffer& qi::Buffer::subBuffer(size_t offset) const

Brief: Return the sub-buffer at given offset. If there is no sub-buffer throw a std::runtime_error.

Parameters:

• offset – The offset to look for sub-buffer.

Returns:

the sub-buffer.

size_t qi::Buffer::size() const

Brief: Return the content size of this buffer not counting sub-buffers.

Returns:the size.

size_t qi::Buffer::totalSize() const

Brief: Return the content size of this buffer and of all its sub-buffers.

Returns:the size.

const std::vector<std::pair<size_t, Buffer>>& qi::Buffer::subBuffers() const

Brief: Return a vector of sub-buffers of the current buffer.

Returns:a vector of pairs. The first value of the pair is the offset of the sub-buffer into the master buffer. The second value is the sub-buffer itself.

void* qi::Buffer::reserve(size_t size)

Brief: Reserve bytes at the end of current buffer.

Parameters:

• size – number of new bytes to reserve at the end of buffer.

Returns:

a pointer to the data.

void qi::Buffer::clear()

Erase content of buffer and remove sub-buffers whithout clearing them.

void* qi::Buffer::data()

Brief: Return a pointer to the raw data storage of this buffer.

Returns:the pointer to the data.

const void* qi::Buffer::data() const

Brief: Return a const pointer to the raw data in this buffer.

Returns:the pointer to the data.

const void* qi::Buffer::read(size_t offset = 0, size_t length = 0) const

Brief: Read some data from the buffer.

Parameters:

• offset – offset at which reading begin in the buffer.
• length – length of the data to read.

Returns:

0 if the buffer is empty or if we try to read data after the end of the buffer. Otherwise return a pointer to the data. Only length bytes can be read in the returned buffer.

size_t qi::Buffer::read(void* buffer, size_t offset = 0, size_t length = 0) const

Brief: Read some data in the buffer and store it in a new pre-allocated buffer.

Parameters:

• buffer – the pre-allocated buffer to store data.
• offset – Offset in the current buffer to start copy.
• length – Length of the data to be copied.

Returns:

-1 if there is no data in buffer or if offset is bigger than total data in buffer. Otherwise return the total length of copied data.

qi::BufferReader Class Reference

Introduction

Class to read const buffer. This class is intendeed to read buffer. It store an internal data cursor and an internal sub-buffer index. All offset are relative to the current position. More...

#include <qi/buffer.hpp>

Public Functions

BufferReader(const Buffer& buf)

~BufferReader()

size_t read(void* data, size_t length)

void* read(size_t offset)

bool seek(size_t offset)

void* peek(size_t offset) const

bool hasSubBuffer() const

const Buffer& subBuffer()

size_t position() const

Detailed Description

Class to read const buffer. This class is intendeed to read buffer. It store an internal data cursor and an internal sub-buffer index. All offset are relative to the current position.

Function Documentation

qi::BufferReader::BufferReader(const Buffer& buf)

Brief: Constructor.

Parameters:

• buf – The buffer to copy.

qi::BufferReader::~BufferReader()

Default destructor.

size_t qi::BufferReader::read(void* data, size_t length)

Brief: read and store data from the buffer.

Parameters:

• data – A pre-allocated pointer to store read data.
• length – Size of the object pointed by data or size to read.

Returns:

size of really read and stored data.

void* qi::BufferReader::read(size_t offset)

Brief: read data from buffer.

Parameters:

• offset – Number of bytes to read.

Returns:

a pointer to data at the given

bool qi::BufferReader::seek(size_t offset)

Brief: Move forward the buffer cursor by the given offset.

Parameters:

• offset – Value for move forward the cursor.

Returns:

Return true if succeed, false otherwise.

void* qi::BufferReader::peek(size_t offset) const

Brief: Check if we can read from the actual position toward offset bytes.

Parameters:

• offset – The relative offset.

Returns:

The pointer if it succeed. If actual position + offset exceed size of buffer return 0.

bool qi::BufferReader::hasSubBuffer() const

Brief: Check if there is sub-buffer at the actual position.

Returns:true if there is sub-buffer, false otherwise.

const Buffer& qi::BufferReader::subBuffer()

Brief: return the sub-buffer at the actual position. If there is no sub-buffer at actual position throw a std::runtime-error.

Returns:Return the sub-buffer if any.

size_t qi::BufferReader::position() const

Brief: Return the actual position in the buffer.

Returns:The current offset.