osmium::memory::CallbackBuffer Class Reference

#include <callback_buffer.hpp>

Public Types
using	callback_func_type = std::function< void(osmium::memory::Buffer &&)>
	The type for the callback function. More...

Public Member Functions
	CallbackBuffer (std::size_t initial_buffer_size=default_initial_buffer_size, std::size_t max_buffer_size=default_max_buffer_size)
	CallbackBuffer (callback_func_type callback, std::size_t initial_buffer_size=default_initial_buffer_size, std::size_t max_buffer_size=default_max_buffer_size)
osmium::memory::Buffer &	buffer () noexcept
void	set_callback (const callback_func_type &callback=nullptr) noexcept
void	flush ()
void	possibly_flush ()
osmium::memory::Buffer	read ()

Private Types
enum	{ default_initial_buffer_size = 1024UL * 1024UL }
enum	{ default_max_buffer_size = 800UL * 1024UL }

Private Attributes
osmium::memory::Buffer	m_buffer
std::size_t	m_initial_buffer_size
std::size_t	m_max_buffer_size
callback_func_type	m_callback

Detailed Description

This is basically a wrapper around osmium::memory::Buffer with an additional callback function that is called whenever the buffer is full.

The internal buffer is created with the initial_buffer_size set in the constructor. When it grows beyond the max_buffer_size set in the constructor, the callback function is called with the buffer and a new, empty buffer is created internally.

Note that the buffer can grow beyond the initial buffer size if needed. This can happen if a new object doesn't fit into the rest of the buffer available or if no callback function is set (yet).

Example:

CallbackBuffer cb;
cb.set_callback([&](osmium::memory::Buffer&& buffer) {
    ...handle buffer...
}
osmium::builder::add_node(cb.buffer(), _id(9), ...);
osmium::builder::add_way(cb.buffer(), _id(27), ...);

Member Typedef Documentation

callback_func_type

using osmium::memory::CallbackBuffer::callback_func_type = std::function<void(osmium::memory::Buffer&&)>

The type for the callback function.

Member Enumeration Documentation

anonymous enum

anonymous enum

private

Enumerator
default_initial_buffer_size

anonymous enum

anonymous enum

private

Enumerator
default_max_buffer_size

Constructor & Destructor Documentation

CallbackBuffer() [1/2]

osmium::memory::CallbackBuffer::CallbackBuffer ( std::size_t  initial_buffer_size = default_initial_buffer_size, std::size_t  max_buffer_size = default_max_buffer_size  )

inlineexplicit

Construct a CallbackBuffer without a callback function. You can later call set the callback with set_callback().

Parameters

initial_buffer_size	The initial size of newly created internal buffers.
max_buffer_size	If the buffer grows beyond this size the callback will be called.

CallbackBuffer() [2/2]

osmium::memory::CallbackBuffer::CallbackBuffer ( callback_func_type  callback, std::size_t  initial_buffer_size = default_initial_buffer_size, std::size_t  max_buffer_size = default_max_buffer_size  )

inlineexplicit

Construct a CallbackBuffer with a callback function.

Parameters

callback	The callback function. Must be of type void(osmium::memory::Buffer&&)
initial_buffer_size	The initial size of newly created internal buffers.
max_buffer_size	If the buffer grows beyond this size the callback will be called.

Member Function Documentation

buffer()

osmium::memory::Buffer & osmium::memory::CallbackBuffer::buffer ( )

inlinenoexcept

Access the internal buffer. This is used to fill the buffer, the CallbackBuffer still owns the buffer.

Use read() or the callback if you need to own the buffer.

flush()

void osmium::memory::CallbackBuffer::flush ( )

inline

Flush the internal buffer regardless of how full it is. Calls the callback with the buffer and creates an new empty internal one.

This will do nothing if no callback is set or if the buffer is empty.

possibly_flush()

void osmium::memory::CallbackBuffer::possibly_flush ( )

inline

Flush the internal buffer if and only if it contains more than the max_buffer_size set in the constructor. Calls the callback with the buffer and creates an new empty internal one.

This will do nothing if no callback is set or if the buffer is empty.

read()

osmium::memory::Buffer osmium::memory::CallbackBuffer::read ( )

inline

Return the internal buffer and create a new empty internal one. You can use this as an alternative access instead of using the callback.

set_callback()

void osmium::memory::CallbackBuffer::set_callback ( const callback_func_type &  callback = nullptr )

inlinenoexcept

Set the callback. The function must take a rvalue reference to a buffer and return void.

Parameters

callback

The callback function. Must be of type void(osmium::memory::Buffer&&)

Member Data Documentation

m_buffer

osmium::memory::Buffer osmium::memory::CallbackBuffer::m_buffer

private

m_callback

callback_func_type osmium::memory::CallbackBuffer::m_callback

private

m_initial_buffer_size

std::size_t osmium::memory::CallbackBuffer::m_initial_buffer_size

private

m_max_buffer_size

std::size_t osmium::memory::CallbackBuffer::m_max_buffer_size

private

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

• include/osmium/memory/callback_buffer.hpp