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//
// buffer.hpp
// ~~~~~~~~~~
//
// Copyright (c) 2003-2021 Christopher M. Kohlhoff (chris at kohlhoff dot com)
//
// Distributed under the Boost Software License, Version 1.0. (See accompanying
// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
//
#ifndef ASIO_BUFFER_HPP
#define ASIO_BUFFER_HPP
#if defined(_MSC_VER) && (_MSC_VER >= 1200)
# pragma once
#endif // defined(_MSC_VER) && (_MSC_VER >= 1200)
#include "asio/detail/config.hpp"
#include <cstddef>
#include <cstring>
#include <limits>
#include <stdexcept>
#include <string>
#include <vector>
#include "asio/detail/array_fwd.hpp"
#include "asio/detail/memory.hpp"
#include "asio/detail/string_view.hpp"
#include "asio/detail/throw_exception.hpp"
#include "asio/detail/type_traits.hpp"
#if defined(ASIO_MSVC) && (ASIO_MSVC >= 1700)
# if defined(_HAS_ITERATOR_DEBUGGING) && (_HAS_ITERATOR_DEBUGGING != 0)
# if !defined(ASIO_DISABLE_BUFFER_DEBUGGING)
# define ASIO_ENABLE_BUFFER_DEBUGGING
# endif // !defined(ASIO_DISABLE_BUFFER_DEBUGGING)
# endif // defined(_HAS_ITERATOR_DEBUGGING)
#endif // defined(ASIO_MSVC) && (ASIO_MSVC >= 1700)
#if defined(__GNUC__)
# if defined(_GLIBCXX_DEBUG)
# if !defined(ASIO_DISABLE_BUFFER_DEBUGGING)
# define ASIO_ENABLE_BUFFER_DEBUGGING
# endif // !defined(ASIO_DISABLE_BUFFER_DEBUGGING)
# endif // defined(_GLIBCXX_DEBUG)
#endif // defined(__GNUC__)
#if defined(ASIO_ENABLE_BUFFER_DEBUGGING)
# include "asio/detail/functional.hpp"
#endif // ASIO_ENABLE_BUFFER_DEBUGGING
#if defined(ASIO_HAS_BOOST_WORKAROUND)
# include <boost/detail/workaround.hpp>
# if !defined(__clang__)
# if BOOST_WORKAROUND(__BORLANDC__, BOOST_TESTED_AT(0x582))
# define ASIO_ENABLE_ARRAY_BUFFER_WORKAROUND
# endif // BOOST_WORKAROUND(__BORLANDC__, BOOST_TESTED_AT(0x582))
# elif BOOST_WORKAROUND(__SUNPRO_CC, BOOST_TESTED_AT(0x590))
# define ASIO_ENABLE_ARRAY_BUFFER_WORKAROUND
# endif // BOOST_WORKAROUND(__SUNPRO_CC, BOOST_TESTED_AT(0x590))
#endif // defined(ASIO_HAS_BOOST_WORKAROUND)
#if defined(ASIO_ENABLE_ARRAY_BUFFER_WORKAROUND)
# include "asio/detail/type_traits.hpp"
#endif // defined(ASIO_ENABLE_ARRAY_BUFFER_WORKAROUND)
#include "asio/detail/push_options.hpp"
namespace asio {
class mutable_buffer;
class const_buffer;
/// Holds a buffer that can be modified.
/**
* The mutable_buffer class provides a safe representation of a buffer that can
* be modified. It does not own the underlying data, and so is cheap to copy or
* assign.
*
* @par Accessing Buffer Contents
*
* The contents of a buffer may be accessed using the @c data() and @c size()
* member functions:
*
* @code asio::mutable_buffer b1 = ...;
* std::size_t s1 = b1.size();
* unsigned char* p1 = static_cast<unsigned char*>(b1.data());
* @endcode
*
* The @c data() member function permits violations of type safety, so uses of
* it in application code should be carefully considered.
*/
class mutable_buffer
{
public:
/// Construct an empty buffer.
mutable_buffer() ASIO_NOEXCEPT
: data_(0),
size_(0)
{
}
/// Construct a buffer to represent a given memory range.
mutable_buffer(void* data, std::size_t size) ASIO_NOEXCEPT
: data_(data),
size_(size)
{
}
#if defined(ASIO_ENABLE_BUFFER_DEBUGGING)
mutable_buffer(void* data, std::size_t size,
asio::detail::function<void()> debug_check)
: data_(data),
size_(size),
debug_check_(debug_check)
{
}
const asio::detail::function<void()>& get_debug_check() const
{
return debug_check_;
}
#endif // ASIO_ENABLE_BUFFER_DEBUGGING
/// Get a pointer to the beginning of the memory range.
void* data() const ASIO_NOEXCEPT
{
#if defined(ASIO_ENABLE_BUFFER_DEBUGGING)
if (size_ && debug_check_)
debug_check_();
#endif // ASIO_ENABLE_BUFFER_DEBUGGING
return data_;
}
/// Get the size of the memory range.
std::size_t size() const ASIO_NOEXCEPT
{
return size_;
}
/// Move the start of the buffer by the specified number of bytes.
mutable_buffer& operator+=(std::size_t n) ASIO_NOEXCEPT
{
std::size_t offset = n < size_ ? n : size_;
data_ = static_cast<char*>(data_) + offset;
size_ -= offset;
return *this;
}
private:
void* data_;
std::size_t size_;
#if defined(ASIO_ENABLE_BUFFER_DEBUGGING)
asio::detail::function<void()> debug_check_;
#endif // ASIO_ENABLE_BUFFER_DEBUGGING
};
#if !defined(ASIO_NO_DEPRECATED)
/// (Deprecated: Use mutable_buffer.) Adapts a single modifiable buffer so that
/// it meets the requirements of the MutableBufferSequence concept.
class mutable_buffers_1
: public mutable_buffer
{
public:
/// The type for each element in the list of buffers.
typedef mutable_buffer value_type;
/// A random-access iterator type that may be used to read elements.
typedef const mutable_buffer* const_iterator;
/// Construct to represent a given memory range.
mutable_buffers_1(void* data, std::size_t size) ASIO_NOEXCEPT
: mutable_buffer(data, size)
{
}
#if defined(ASIO_ENABLE_BUFFER_DEBUGGING)
mutable_buffers_1(void* data, std::size_t size,
asio::detail::function<void()> debug_check)
: mutable_buffer(data, size, debug_check)
{
}
#endif // ASIO_ENABLE_BUFFER_DEBUGGING
/// Construct to represent a single modifiable buffer.
explicit mutable_buffers_1(const mutable_buffer& b) ASIO_NOEXCEPT
: mutable_buffer(b)
{
}
/// Get a random-access iterator to the first element.
const_iterator begin() const ASIO_NOEXCEPT
{
return this;
}
/// Get a random-access iterator for one past the last element.
const_iterator end() const ASIO_NOEXCEPT
{
return begin() + 1;
}
};
#endif // !defined(ASIO_NO_DEPRECATED)
/// Holds a buffer that cannot be modified.
/**
* The const_buffer class provides a safe representation of a buffer that cannot
* be modified. It does not own the underlying data, and so is cheap to copy or
* assign.
*
* @par Accessing Buffer Contents
*
* The contents of a buffer may be accessed using the @c data() and @c size()
* member functions:
*
* @code asio::const_buffer b1 = ...;
* std::size_t s1 = b1.size();
* const unsigned char* p1 = static_cast<const unsigned char*>(b1.data());
* @endcode
*
* The @c data() member function permits violations of type safety, so uses of
* it in application code should be carefully considered.
*/
class const_buffer
{
public:
/// Construct an empty buffer.
const_buffer() ASIO_NOEXCEPT
: data_(0),
size_(0)
{
}
/// Construct a buffer to represent a given memory range.
const_buffer(const void* data, std::size_t size) ASIO_NOEXCEPT
: data_(data),
size_(size)
{
}
/// Construct a non-modifiable buffer from a modifiable one.
const_buffer(const mutable_buffer& b) ASIO_NOEXCEPT
: data_(b.data()),
size_(b.size())
#if defined(ASIO_ENABLE_BUFFER_DEBUGGING)
, debug_check_(b.get_debug_check())
#endif // ASIO_ENABLE_BUFFER_DEBUGGING
{
}
#if defined(ASIO_ENABLE_BUFFER_DEBUGGING)
const_buffer(const void* data, std::size_t size,
asio::detail::function<void()> debug_check)
: data_(data),
size_(size),
debug_check_(debug_check)
{
}
const asio::detail::function<void()>& get_debug_check() const
{
return debug_check_;
}
#endif // ASIO_ENABLE_BUFFER_DEBUGGING
/// Get a pointer to the beginning of the memory range.
const void* data() const ASIO_NOEXCEPT
{
#if defined(ASIO_ENABLE_BUFFER_DEBUGGING)
if (size_ && debug_check_)
debug_check_();
#endif // ASIO_ENABLE_BUFFER_DEBUGGING
return data_;
}
/// Get the size of the memory range.
std::size_t size() const ASIO_NOEXCEPT
{
return size_;
}
/// Move the start of the buffer by the specified number of bytes.
const_buffer& operator+=(std::size_t n) ASIO_NOEXCEPT
{
std::size_t offset = n < size_ ? n : size_;
data_ = static_cast<const char*>(data_) + offset;
size_ -= offset;
return *this;
}
private:
const void* data_;
std::size_t size_;
#if defined(ASIO_ENABLE_BUFFER_DEBUGGING)
asio::detail::function<void()> debug_check_;
#endif // ASIO_ENABLE_BUFFER_DEBUGGING
};
#if !defined(ASIO_NO_DEPRECATED)
/// (Deprecated: Use const_buffer.) Adapts a single non-modifiable buffer so
/// that it meets the requirements of the ConstBufferSequence concept.
class const_buffers_1
: public const_buffer
{
public:
/// The type for each element in the list of buffers.
typedef const_buffer value_type;
/// A random-access iterator type that may be used to read elements.
typedef const const_buffer* const_iterator;
/// Construct to represent a given memory range.
const_buffers_1(const void* data, std::size_t size) ASIO_NOEXCEPT
: const_buffer(data, size)
{
}
#if defined(ASIO_ENABLE_BUFFER_DEBUGGING)
const_buffers_1(const void* data, std::size_t size,
asio::detail::function<void()> debug_check)
: const_buffer(data, size, debug_check)
{
}
#endif // ASIO_ENABLE_BUFFER_DEBUGGING
/// Construct to represent a single non-modifiable buffer.
explicit const_buffers_1(const const_buffer& b) ASIO_NOEXCEPT
: const_buffer(b)
{
}
/// Get a random-access iterator to the first element.
const_iterator begin() const ASIO_NOEXCEPT
{
return this;
}
/// Get a random-access iterator for one past the last element.
const_iterator end() const ASIO_NOEXCEPT
{
return begin() + 1;
}
};
#endif // !defined(ASIO_NO_DEPRECATED)
/// (Deprecated: Use the socket/descriptor wait() and async_wait() member
/// functions.) An implementation of both the ConstBufferSequence and
/// MutableBufferSequence concepts to represent a null buffer sequence.
class null_buffers
{
public:
/// The type for each element in the list of buffers.
typedef mutable_buffer value_type;
/// A random-access iterator type that may be used to read elements.
typedef const mutable_buffer* const_iterator;
/// Get a random-access iterator to the first element.
const_iterator begin() const ASIO_NOEXCEPT
{
return &buf_;
}
/// Get a random-access iterator for one past the last element.
const_iterator end() const ASIO_NOEXCEPT
{
return &buf_;
}
private:
mutable_buffer buf_;
};
/** @defgroup buffer_sequence_begin asio::buffer_sequence_begin
*
* @brief The asio::buffer_sequence_begin function returns an iterator
* pointing to the first element in a buffer sequence.
*/
/*@{*/
/// Get an iterator to the first element in a buffer sequence.
template <typename MutableBuffer>
inline const mutable_buffer* buffer_sequence_begin(const MutableBuffer& b,
typename constraint<
is_convertible<const MutableBuffer*, const mutable_buffer*>::value
>::type = 0) ASIO_NOEXCEPT
{
return static_cast<const mutable_buffer*>(detail::addressof(b));
}
/// Get an iterator to the first element in a buffer sequence.
template <typename ConstBuffer>
inline const const_buffer* buffer_sequence_begin(const ConstBuffer& b,
typename constraint<
is_convertible<const ConstBuffer*, const const_buffer*>::value
>::type = 0) ASIO_NOEXCEPT
{
return static_cast<const const_buffer*>(detail::addressof(b));
}
#if defined(ASIO_HAS_DECLTYPE) || defined(GENERATING_DOCUMENTATION)
/// Get an iterator to the first element in a buffer sequence.
template <typename C>
inline auto buffer_sequence_begin(C& c,
typename constraint<
!is_convertible<const C*, const mutable_buffer*>::value
&& !is_convertible<const C*, const const_buffer*>::value
>::type = 0) ASIO_NOEXCEPT -> decltype(c.begin())
{
return c.begin();
}
/// Get an iterator to the first element in a buffer sequence.
template <typename C>
inline auto buffer_sequence_begin(const C& c,
typename constraint<
!is_convertible<const C*, const mutable_buffer*>::value
&& !is_convertible<const C*, const const_buffer*>::value
>::type = 0) ASIO_NOEXCEPT -> decltype(c.begin())
{
return c.begin();
}
#else // defined(ASIO_HAS_DECLTYPE) || defined(GENERATING_DOCUMENTATION)
template <typename C>
inline typename C::iterator buffer_sequence_begin(C& c,
typename constraint<
!is_convertible<const C*, const mutable_buffer*>::value
&& !is_convertible<const C*, const const_buffer*>::value
>::type = 0) ASIO_NOEXCEPT
{
return c.begin();
}
template <typename C>
inline typename C::const_iterator buffer_sequence_begin(const C& c,
typename constraint<
!is_convertible<const C*, const mutable_buffer*>::value
&& !is_convertible<const C*, const const_buffer*>::value
>::type = 0) ASIO_NOEXCEPT
{
return c.begin();
}
#endif // defined(ASIO_HAS_DECLTYPE) || defined(GENERATING_DOCUMENTATION)
/*@}*/
/** @defgroup buffer_sequence_end asio::buffer_sequence_end
*
* @brief The asio::buffer_sequence_end function returns an iterator
* pointing to one past the end element in a buffer sequence.
*/
/*@{*/
/// Get an iterator to one past the end element in a buffer sequence.
template <typename MutableBuffer>
inline const mutable_buffer* buffer_sequence_end(const MutableBuffer& b,
typename constraint<
is_convertible<const MutableBuffer*, const mutable_buffer*>::value
>::type = 0) ASIO_NOEXCEPT
{
return static_cast<const mutable_buffer*>(detail::addressof(b)) + 1;
}
/// Get an iterator to one past the end element in a buffer sequence.
template <typename ConstBuffer>
inline const const_buffer* buffer_sequence_end(const ConstBuffer& b,
typename constraint<
is_convertible<const ConstBuffer*, const const_buffer*>::value
>::type = 0) ASIO_NOEXCEPT
{
return static_cast<const const_buffer*>(detail::addressof(b)) + 1;
}
#if defined(ASIO_HAS_DECLTYPE) || defined(GENERATING_DOCUMENTATION)
/// Get an iterator to one past the end element in a buffer sequence.
template <typename C>
inline auto buffer_sequence_end(C& c,
typename constraint<
!is_convertible<const C*, const mutable_buffer*>::value
&& !is_convertible<const C*, const const_buffer*>::value
>::type = 0) ASIO_NOEXCEPT -> decltype(c.end())
{
return c.end();
}
/// Get an iterator to one past the end element in a buffer sequence.
template <typename C>
inline auto buffer_sequence_end(const C& c,
typename constraint<
!is_convertible<const C*, const mutable_buffer*>::value
&& !is_convertible<const C*, const const_buffer*>::value
>::type = 0) ASIO_NOEXCEPT -> decltype(c.end())
{
return c.end();
}
#else // defined(ASIO_HAS_DECLTYPE) || defined(GENERATING_DOCUMENTATION)
template <typename C>
inline typename C::iterator buffer_sequence_end(C& c,
typename constraint<
!is_convertible<const C*, const mutable_buffer*>::value
&& !is_convertible<const C*, const const_buffer*>::value
>::type = 0) ASIO_NOEXCEPT
{
return c.end();
}
template <typename C>
inline typename C::const_iterator buffer_sequence_end(const C& c,
typename constraint<
!is_convertible<const C*, const mutable_buffer*>::value
&& !is_convertible<const C*, const const_buffer*>::value
>::type = 0) ASIO_NOEXCEPT
{
return c.end();
}
#endif // defined(ASIO_HAS_DECLTYPE) || defined(GENERATING_DOCUMENTATION)
/*@}*/
namespace detail {
// Tag types used to select appropriately optimised overloads.
struct one_buffer {};
struct multiple_buffers {};
// Helper trait to detect single buffers.
template <typename BufferSequence>
struct buffer_sequence_cardinality :
conditional<
is_same<BufferSequence, mutable_buffer>::value
#if !defined(ASIO_NO_DEPRECATED)
|| is_same<BufferSequence, mutable_buffers_1>::value
|| is_same<BufferSequence, const_buffers_1>::value
#endif // !defined(ASIO_NO_DEPRECATED)
|| is_same<BufferSequence, const_buffer>::value,
one_buffer, multiple_buffers>::type {};
template <typename Iterator>
inline std::size_t buffer_size(one_buffer,
Iterator begin, Iterator) ASIO_NOEXCEPT
{
return const_buffer(*begin).size();
}
template <typename Iterator>
inline std::size_t buffer_size(multiple_buffers,
Iterator begin, Iterator end) ASIO_NOEXCEPT
{
std::size_t total_buffer_size = 0;
Iterator iter = begin;
for (; iter != end; ++iter)
{
const_buffer b(*iter);
total_buffer_size += b.size();
}
return total_buffer_size;
}
} // namespace detail
/// Get the total number of bytes in a buffer sequence.
/**
* The @c buffer_size function determines the total size of all buffers in the
* buffer sequence, as if computed as follows:
*
* @code size_t total_size = 0;
* auto i = asio::buffer_sequence_begin(buffers);
* auto end = asio::buffer_sequence_end(buffers);
* for (; i != end; ++i)
* {
* const_buffer b(*i);
* total_size += b.size();
* }
* return total_size; @endcode
*
* The @c BufferSequence template parameter may meet either of the @c
* ConstBufferSequence or @c MutableBufferSequence type requirements.
*/
template <typename BufferSequence>
inline std::size_t buffer_size(const BufferSequence& b) ASIO_NOEXCEPT
{
return detail::buffer_size(
detail::buffer_sequence_cardinality<BufferSequence>(),
asio::buffer_sequence_begin(b),
asio::buffer_sequence_end(b));
}
#if !defined(ASIO_NO_DEPRECATED)
/** @defgroup buffer_cast asio::buffer_cast
*
* @brief (Deprecated: Use the @c data() member function.) The
* asio::buffer_cast function is used to obtain a pointer to the
* underlying memory region associated with a buffer.
*
* @par Examples:
*
* To access the memory of a non-modifiable buffer, use:
* @code asio::const_buffer b1 = ...;
* const unsigned char* p1 = asio::buffer_cast<const unsigned char*>(b1);
* @endcode
*
* To access the memory of a modifiable buffer, use:
* @code asio::mutable_buffer b2 = ...;
* unsigned char* p2 = asio::buffer_cast<unsigned char*>(b2);
* @endcode
*
* The asio::buffer_cast function permits violations of type safety, so
* uses of it in application code should be carefully considered.
*/
/*@{*/
/// Cast a non-modifiable buffer to a specified pointer to POD type.
template <typename PointerToPodType>
inline PointerToPodType buffer_cast(const mutable_buffer& b) ASIO_NOEXCEPT
{
return static_cast<PointerToPodType>(b.data());
}
/// Cast a non-modifiable buffer to a specified pointer to POD type.
template <typename PointerToPodType>
inline PointerToPodType buffer_cast(const const_buffer& b) ASIO_NOEXCEPT
{
return static_cast<PointerToPodType>(b.data());
}
/*@}*/
#endif // !defined(ASIO_NO_DEPRECATED)
/// Create a new modifiable buffer that is offset from the start of another.
/**
* @relates mutable_buffer
*/
inline mutable_buffer operator+(const mutable_buffer& b,
std::size_t n) ASIO_NOEXCEPT
{
std::size_t offset = n < b.size() ? n : b.size();
char* new_data = static_cast<char*>(b.data()) + offset;
std::size_t new_size = b.size() - offset;
return mutable_buffer(new_data, new_size
#if defined(ASIO_ENABLE_BUFFER_DEBUGGING)
, b.get_debug_check()
#endif // ASIO_ENABLE_BUFFER_DEBUGGING
);
}
/// Create a new modifiable buffer that is offset from the start of another.
/**
* @relates mutable_buffer
*/
inline mutable_buffer operator+(std::size_t n,
const mutable_buffer& b) ASIO_NOEXCEPT
{
return b + n;
}
/// Create a new non-modifiable buffer that is offset from the start of another.
/**
* @relates const_buffer
*/
inline const_buffer operator+(const const_buffer& b,
std::size_t n) ASIO_NOEXCEPT
{
std::size_t offset = n < b.size() ? n : b.size();
const char* new_data = static_cast<const char*>(b.data()) + offset;
std::size_t new_size = b.size() - offset;
return const_buffer(new_data, new_size
#if defined(ASIO_ENABLE_BUFFER_DEBUGGING)
, b.get_debug_check()
#endif // ASIO_ENABLE_BUFFER_DEBUGGING
);
}
/// Create a new non-modifiable buffer that is offset from the start of another.
/**
* @relates const_buffer
*/
inline const_buffer operator+(std::size_t n,
const const_buffer& b) ASIO_NOEXCEPT
{
return b + n;
}
#if defined(ASIO_ENABLE_BUFFER_DEBUGGING)
namespace detail {
template <typename Iterator>
class buffer_debug_check
{
public:
buffer_debug_check(Iterator iter)
: iter_(iter)
{
}
~buffer_debug_check()
{
#if defined(ASIO_MSVC) && (ASIO_MSVC == 1400)
// MSVC 8's string iterator checking may crash in a std::string::iterator
// object's destructor when the iterator points to an already-destroyed
// std::string object, unless the iterator is cleared first.
iter_ = Iterator();
#endif // defined(ASIO_MSVC) && (ASIO_MSVC == 1400)
}
void operator()()
{
(void)*iter_;
}
private:
Iterator iter_;
};
} // namespace detail
#endif // ASIO_ENABLE_BUFFER_DEBUGGING
/** @defgroup buffer asio::buffer
*
* @brief The asio::buffer function is used to create a buffer object to
* represent raw memory, an array of POD elements, a vector of POD elements,
* or a std::string.
*
* A buffer object represents a contiguous region of memory as a 2-tuple
* consisting of a pointer and size in bytes. A tuple of the form <tt>{void*,
* size_t}</tt> specifies a mutable (modifiable) region of memory. Similarly, a
* tuple of the form <tt>{const void*, size_t}</tt> specifies a const
* (non-modifiable) region of memory. These two forms correspond to the classes
* mutable_buffer and const_buffer, respectively. To mirror C++'s conversion
* rules, a mutable_buffer is implicitly convertible to a const_buffer, and the
* opposite conversion is not permitted.
*
* The simplest use case involves reading or writing a single buffer of a
* specified size:
*
* @code sock.send(asio::buffer(data, size)); @endcode
*
* In the above example, the return value of asio::buffer meets the
* requirements of the ConstBufferSequence concept so that it may be directly
* passed to the socket's write function. A buffer created for modifiable
* memory also meets the requirements of the MutableBufferSequence concept.
*
* An individual buffer may be created from a builtin array, std::vector,
* std::array or boost::array of POD elements. This helps prevent buffer
* overruns by automatically determining the size of the buffer:
*
* @code char d1[128];
* size_t bytes_transferred = sock.receive(asio::buffer(d1));
*
* std::vector<char> d2(128);
* bytes_transferred = sock.receive(asio::buffer(d2));
*
* std::array<char, 128> d3;
* bytes_transferred = sock.receive(asio::buffer(d3));
*
* boost::array<char, 128> d4;
* bytes_transferred = sock.receive(asio::buffer(d4)); @endcode
*
* In all three cases above, the buffers created are exactly 128 bytes long.
* Note that a vector is @e never automatically resized when creating or using
* a buffer. The buffer size is determined using the vector's <tt>size()</tt>
* member function, and not its capacity.
*
* @par Accessing Buffer Contents
*
* The contents of a buffer may be accessed using the @c data() and @c size()
* member functions:
*
* @code asio::mutable_buffer b1 = ...;
* std::size_t s1 = b1.size();
* unsigned char* p1 = static_cast<unsigned char*>(b1.data());
*
* asio::const_buffer b2 = ...;
* std::size_t s2 = b2.size();
* const void* p2 = b2.data(); @endcode
*
* The @c data() member function permits violations of type safety, so
* uses of it in application code should be carefully considered.
*
* For convenience, a @ref buffer_size function is provided that works with
* both buffers and buffer sequences (that is, types meeting the
* ConstBufferSequence or MutableBufferSequence type requirements). In this
* case, the function returns the total size of all buffers in the sequence.
*
* @par Buffer Copying
*
* The @ref buffer_copy function may be used to copy raw bytes between
* individual buffers and buffer sequences.
*
* In particular, when used with the @ref buffer_size function, the @ref
* buffer_copy function can be used to linearise a sequence of buffers. For
* example:
*
* @code vector<const_buffer> buffers = ...;
*
* vector<unsigned char> data(asio::buffer_size(buffers));
* asio::buffer_copy(asio::buffer(data), buffers); @endcode
*
* Note that @ref buffer_copy is implemented in terms of @c memcpy, and
* consequently it cannot be used to copy between overlapping memory regions.
*
* @par Buffer Invalidation
*
* A buffer object does not have any ownership of the memory it refers to. It
* is the responsibility of the application to ensure the memory region remains
* valid until it is no longer required for an I/O operation. When the memory
* is no longer available, the buffer is said to have been invalidated.
*
* For the asio::buffer overloads that accept an argument of type
* std::vector, the buffer objects returned are invalidated by any vector
* operation that also invalidates all references, pointers and iterators
* referring to the elements in the sequence (C++ Std, 23.2.4)
*
* For the asio::buffer overloads that accept an argument of type
* std::basic_string, the buffer objects returned are invalidated according to
* the rules defined for invalidation of references, pointers and iterators
* referring to elements of the sequence (C++ Std, 21.3).
*
* @par Buffer Arithmetic
*
* Buffer objects may be manipulated using simple arithmetic in a safe way
* which helps prevent buffer overruns. Consider an array initialised as
* follows:
*
* @code boost::array<char, 6> a = { 'a', 'b', 'c', 'd', 'e' }; @endcode
*
* A buffer object @c b1 created using:
*
* @code b1 = asio::buffer(a); @endcode
*
* represents the entire array, <tt>{ 'a', 'b', 'c', 'd', 'e' }</tt>. An
* optional second argument to the asio::buffer function may be used to
* limit the size, in bytes, of the buffer:
*
* @code b2 = asio::buffer(a, 3); @endcode
*
* such that @c b2 represents the data <tt>{ 'a', 'b', 'c' }</tt>. Even if the
* size argument exceeds the actual size of the array, the size of the buffer
* object created will be limited to the array size.
*
* An offset may be applied to an existing buffer to create a new one:
*
* @code b3 = b1 + 2; @endcode
*
* where @c b3 will set to represent <tt>{ 'c', 'd', 'e' }</tt>. If the offset
* exceeds the size of the existing buffer, the newly created buffer will be
* empty.
*
* Both an offset and size may be specified to create a buffer that corresponds
* to a specific range of bytes within an existing buffer:
*
* @code b4 = asio::buffer(b1 + 1, 3); @endcode
*
* so that @c b4 will refer to the bytes <tt>{ 'b', 'c', 'd' }</tt>.
*
* @par Buffers and Scatter-Gather I/O
*
* To read or write using multiple buffers (i.e. scatter-gather I/O), multiple
* buffer objects may be assigned into a container that supports the
* MutableBufferSequence (for read) or ConstBufferSequence (for write) concepts:
*
* @code
* char d1[128];
* std::vector<char> d2(128);
* boost::array<char, 128> d3;
*
* boost::array<mutable_buffer, 3> bufs1 = {
* asio::buffer(d1),
* asio::buffer(d2),
* asio::buffer(d3) };
* bytes_transferred = sock.receive(bufs1);
*
* std::vector<const_buffer> bufs2;
* bufs2.push_back(asio::buffer(d1));
* bufs2.push_back(asio::buffer(d2));
* bufs2.push_back(asio::buffer(d3));
* bytes_transferred = sock.send(bufs2); @endcode
*/
/*@{*/
#if defined(ASIO_NO_DEPRECATED) || defined(GENERATING_DOCUMENTATION)
# define ASIO_MUTABLE_BUFFER mutable_buffer
# define ASIO_CONST_BUFFER const_buffer
#else // defined(ASIO_NO_DEPRECATED) || defined(GENERATING_DOCUMENTATION)
# define ASIO_MUTABLE_BUFFER mutable_buffers_1
# define ASIO_CONST_BUFFER const_buffers_1
#endif // defined(ASIO_NO_DEPRECATED) || defined(GENERATING_DOCUMENTATION)
/// Create a new modifiable buffer from an existing buffer.
/**
* @returns <tt>mutable_buffer(b)</tt>.
*/
inline ASIO_MUTABLE_BUFFER buffer(
const mutable_buffer& b) ASIO_NOEXCEPT
{
return ASIO_MUTABLE_BUFFER(b);
}
/// Create a new modifiable buffer from an existing buffer.
/**
* @returns A mutable_buffer value equivalent to:
* @code mutable_buffer(
* b.data(),
* min(b.size(), max_size_in_bytes)); @endcode
*/
inline ASIO_MUTABLE_BUFFER buffer(const mutable_buffer& b,
std::size_t max_size_in_bytes) ASIO_NOEXCEPT
{
return ASIO_MUTABLE_BUFFER(
mutable_buffer(b.data(),
b.size() < max_size_in_bytes
? b.size() : max_size_in_bytes
#if defined(ASIO_ENABLE_BUFFER_DEBUGGING)
, b.get_debug_check()
#endif // ASIO_ENABLE_BUFFER_DEBUGGING
));
}
/// Create a new non-modifiable buffer from an existing buffer.
/**
* @returns <tt>const_buffer(b)</tt>.
*/
inline ASIO_CONST_BUFFER buffer(
const const_buffer& b) ASIO_NOEXCEPT
{
return ASIO_CONST_BUFFER(b);
}
/// Create a new non-modifiable buffer from an existing buffer.
/**
* @returns A const_buffer value equivalent to:
* @code const_buffer(
* b.data(),
* min(b.size(), max_size_in_bytes)); @endcode
*/
inline ASIO_CONST_BUFFER buffer(const const_buffer& b,
std::size_t max_size_in_bytes) ASIO_NOEXCEPT
{
return ASIO_CONST_BUFFER(b.data(),
b.size() < max_size_in_bytes
? b.size() : max_size_in_bytes
#if defined(ASIO_ENABLE_BUFFER_DEBUGGING)
, b.get_debug_check()
#endif // ASIO_ENABLE_BUFFER_DEBUGGING
);
}
/// Create a new modifiable buffer that represents the given memory range.
/**
* @returns <tt>mutable_buffer(data, size_in_bytes)</tt>.
*/
inline ASIO_MUTABLE_BUFFER buffer(void* data,
std::size_t size_in_bytes) ASIO_NOEXCEPT
{
return ASIO_MUTABLE_BUFFER(data, size_in_bytes);
}
/// Create a new non-modifiable buffer that represents the given memory range.
/**
* @returns <tt>const_buffer(data, size_in_bytes)</tt>.
*/
inline ASIO_CONST_BUFFER buffer(const void* data,
std::size_t size_in_bytes) ASIO_NOEXCEPT
{
return ASIO_CONST_BUFFER(data, size_in_bytes);
}
/// Create a new modifiable buffer that represents the given POD array.
/**
* @returns A mutable_buffer value equivalent to:
* @code mutable_buffer(
* static_cast<void*>(data),
* N * sizeof(PodType)); @endcode
*/
template <typename PodType, std::size_t N>
inline ASIO_MUTABLE_BUFFER buffer(PodType (&data)[N]) ASIO_NOEXCEPT
{
return ASIO_MUTABLE_BUFFER(data, N * sizeof(PodType));
}
/// Create a new modifiable buffer that represents the given POD array.
/**
* @returns A mutable_buffer value equivalent to:
* @code mutable_buffer(
* static_cast<void*>(data),
* min(N * sizeof(PodType), max_size_in_bytes)); @endcode
*/
template <typename PodType, std::size_t N>
inline ASIO_MUTABLE_BUFFER buffer(PodType (&data)[N],
std::size_t max_size_in_bytes) ASIO_NOEXCEPT
{
return ASIO_MUTABLE_BUFFER(data,
N * sizeof(PodType) < max_size_in_bytes
? N * sizeof(PodType) : max_size_in_bytes);
}
/// Create a new non-modifiable buffer that represents the given POD array.
/**
* @returns A const_buffer value equivalent to:
* @code const_buffer(
* static_cast<const void*>(data),
* N * sizeof(PodType)); @endcode
*/
template <typename PodType, std::size_t N>
inline ASIO_CONST_BUFFER buffer(
const PodType (&data)[N]) ASIO_NOEXCEPT
{
return ASIO_CONST_BUFFER(data, N * sizeof(PodType));
}
/// Create a new non-modifiable buffer that represents the given POD array.
/**
* @returns A const_buffer value equivalent to:
* @code const_buffer(
* static_cast<const void*>(data),
* min(N * sizeof(PodType), max_size_in_bytes)); @endcode
*/
template <typename PodType, std::size_t N>
inline ASIO_CONST_BUFFER buffer(const PodType (&data)[N],
std::size_t max_size_in_bytes) ASIO_NOEXCEPT
{
return ASIO_CONST_BUFFER(data,
N * sizeof(PodType) < max_size_in_bytes
? N * sizeof(PodType) : max_size_in_bytes);
}
#if defined(ASIO_ENABLE_ARRAY_BUFFER_WORKAROUND)
// Borland C++ and Sun Studio think the overloads:
//
// unspecified buffer(boost::array<PodType, N>& array ...);
//
// and
//
// unspecified buffer(boost::array<const PodType, N>& array ...);
//
// are ambiguous. This will be worked around by using a buffer_types traits
// class that contains typedefs for the appropriate buffer and container
// classes, based on whether PodType is const or non-const.
namespace detail {
template <bool IsConst>
struct buffer_types_base;
template <>
struct buffer_types_base<false>
{
typedef mutable_buffer buffer_type;
typedef ASIO_MUTABLE_BUFFER container_type;
};
template <>
struct buffer_types_base<true>
{
typedef const_buffer buffer_type;
typedef ASIO_CONST_BUFFER container_type;
};
template <typename PodType>
struct buffer_types
: public buffer_types_base<is_const<PodType>::value>
{
};
} // namespace detail
template <typename PodType, std::size_t N>
inline typename detail::buffer_types<PodType>::container_type
buffer(boost::array<PodType, N>& data) ASIO_NOEXCEPT
{
typedef typename asio::detail::buffer_types<PodType>::buffer_type
buffer_type;
typedef typename asio::detail::buffer_types<PodType>::container_type
container_type;
return container_type(
buffer_type(data.c_array(), data.size() * sizeof(PodType)));
}
template <typename PodType, std::size_t N>
inline typename detail::buffer_types<PodType>::container_type
buffer(boost::array<PodType, N>& data,
std::size_t max_size_in_bytes) ASIO_NOEXCEPT
{
typedef typename asio::detail::buffer_types<PodType>::buffer_type
buffer_type;
typedef typename asio::detail::buffer_types<PodType>::container_type
container_type;
return container_type(
buffer_type(data.c_array(),
data.size() * sizeof(PodType) < max_size_in_bytes
? data.size() * sizeof(PodType) : max_size_in_bytes));
}
#else // defined(ASIO_ENABLE_ARRAY_BUFFER_WORKAROUND)
/// Create a new modifiable buffer that represents the given POD array.
/**
* @returns A mutable_buffer value equivalent to:
* @code mutable_buffer(
* data.data(),
* data.size() * sizeof(PodType)); @endcode
*/
template <typename PodType, std::size_t N>
inline ASIO_MUTABLE_BUFFER buffer(
boost::array<PodType, N>& data) ASIO_NOEXCEPT
{
return ASIO_MUTABLE_BUFFER(
data.c_array(), data.size() * sizeof(PodType));
}
/// Create a new modifiable buffer that represents the given POD array.
/**
* @returns A mutable_buffer value equivalent to:
* @code mutable_buffer(
* data.data(),
* min(data.size() * sizeof(PodType), max_size_in_bytes)); @endcode
*/
template <typename PodType, std::size_t N>
inline ASIO_MUTABLE_BUFFER buffer(boost::array<PodType, N>& data,
std::size_t max_size_in_bytes) ASIO_NOEXCEPT
{
return ASIO_MUTABLE_BUFFER(data.c_array(),
data.size() * sizeof(PodType) < max_size_in_bytes
? data.size() * sizeof(PodType) : max_size_in_bytes);
}
/// Create a new non-modifiable buffer that represents the given POD array.
/**
* @returns A const_buffer value equivalent to:
* @code const_buffer(
* data.data(),
* data.size() * sizeof(PodType)); @endcode
*/
template <typename PodType, std::size_t N>
inline ASIO_CONST_BUFFER buffer(
boost::array<const PodType, N>& data) ASIO_NOEXCEPT
{
return ASIO_CONST_BUFFER(data.data(), data.size() * sizeof(PodType));
}
/// Create a new non-modifiable buffer that represents the given POD array.
/**
* @returns A const_buffer value equivalent to:
* @code const_buffer(
* data.data(),
* min(data.size() * sizeof(PodType), max_size_in_bytes)); @endcode
*/
template <typename PodType, std::size_t N>
inline ASIO_CONST_BUFFER buffer(boost::array<const PodType, N>& data,
std::size_t max_size_in_bytes) ASIO_NOEXCEPT
{
return ASIO_CONST_BUFFER(data.data(),
data.size() * sizeof(PodType) < max_size_in_bytes
? data.size() * sizeof(PodType) : max_size_in_bytes);
}
#endif // defined(ASIO_ENABLE_ARRAY_BUFFER_WORKAROUND)
/// Create a new non-modifiable buffer that represents the given POD array.
/**
* @returns A const_buffer value equivalent to:
* @code const_buffer(
* data.data(),
* data.size() * sizeof(PodType)); @endcode
*/
template <typename PodType, std::size_t N>
inline ASIO_CONST_BUFFER buffer(
const boost::array<PodType, N>& data) ASIO_NOEXCEPT
{
return ASIO_CONST_BUFFER(data.data(), data.size() * sizeof(PodType));
}
/// Create a new non-modifiable buffer that represents the given POD array.
/**
* @returns A const_buffer value equivalent to:
* @code const_buffer(
* data.data(),
* min(data.size() * sizeof(PodType), max_size_in_bytes)); @endcode
*/
template <typename PodType, std::size_t N>
inline ASIO_CONST_BUFFER buffer(const boost::array<PodType, N>& data,
std::size_t max_size_in_bytes) ASIO_NOEXCEPT
{
return ASIO_CONST_BUFFER(data.data(),
data.size() * sizeof(PodType) < max_size_in_bytes
? data.size() * sizeof(PodType) : max_size_in_bytes);
}
#if defined(ASIO_HAS_STD_ARRAY) || defined(GENERATING_DOCUMENTATION)
/// Create a new modifiable buffer that represents the given POD array.
/**
* @returns A mutable_buffer value equivalent to:
* @code mutable_buffer(
* data.data(),
* data.size() * sizeof(PodType)); @endcode
*/
template <typename PodType, std::size_t N>
inline ASIO_MUTABLE_BUFFER buffer(
std::array<PodType, N>& data) ASIO_NOEXCEPT
{
return ASIO_MUTABLE_BUFFER(data.data(), data.size() * sizeof(PodType));
}
/// Create a new modifiable buffer that represents the given POD array.
/**
* @returns A mutable_buffer value equivalent to:
* @code mutable_buffer(
* data.data(),
* min(data.size() * sizeof(PodType), max_size_in_bytes)); @endcode
*/
template <typename PodType, std::size_t N>
inline ASIO_MUTABLE_BUFFER buffer(std::array<PodType, N>& data,
std::size_t max_size_in_bytes) ASIO_NOEXCEPT
{
return ASIO_MUTABLE_BUFFER(data.data(),
data.size() * sizeof(PodType) < max_size_in_bytes
? data.size() * sizeof(PodType) : max_size_in_bytes);
}
/// Create a new non-modifiable buffer that represents the given POD array.
/**
* @returns A const_buffer value equivalent to:
* @code const_buffer(
* data.data(),
* data.size() * sizeof(PodType)); @endcode
*/
template <typename PodType, std::size_t N>
inline ASIO_CONST_BUFFER buffer(
std::array<const PodType, N>& data) ASIO_NOEXCEPT
{
return ASIO_CONST_BUFFER(data.data(), data.size() * sizeof(PodType));
}
/// Create a new non-modifiable buffer that represents the given POD array.
/**
* @returns A const_buffer value equivalent to:
* @code const_buffer(
* data.data(),
* min(data.size() * sizeof(PodType), max_size_in_bytes)); @endcode
*/
template <typename PodType, std::size_t N>
inline ASIO_CONST_BUFFER buffer(std::array<const PodType, N>& data,
std::size_t max_size_in_bytes) ASIO_NOEXCEPT
{
return ASIO_CONST_BUFFER(data.data(),
data.size() * sizeof(PodType) < max_size_in_bytes
? data.size() * sizeof(PodType) : max_size_in_bytes);
}
/// Create a new non-modifiable buffer that represents the given POD array.
/**
* @returns A const_buffer value equivalent to:
* @code const_buffer(
* data.data(),
* data.size() * sizeof(PodType)); @endcode
*/
template <typename PodType, std::size_t N>
inline ASIO_CONST_BUFFER buffer(
const std::array<PodType, N>& data) ASIO_NOEXCEPT
{
return ASIO_CONST_BUFFER(data.data(), data.size() * sizeof(PodType));
}
/// Create a new non-modifiable buffer that represents the given POD array.
/**
* @returns A const_buffer value equivalent to:
* @code const_buffer(
* data.data(),
* min(data.size() * sizeof(PodType), max_size_in_bytes)); @endcode
*/
template <typename PodType, std::size_t N>
inline ASIO_CONST_BUFFER buffer(const std::array<PodType, N>& data,
std::size_t max_size_in_bytes) ASIO_NOEXCEPT
{
return ASIO_CONST_BUFFER(data.data(),
data.size() * sizeof(PodType) < max_size_in_bytes
? data.size() * sizeof(PodType) : max_size_in_bytes);
}
#endif // defined(ASIO_HAS_STD_ARRAY) || defined(GENERATING_DOCUMENTATION)
/// Create a new modifiable buffer that represents the given POD vector.
/**
* @returns A mutable_buffer value equivalent to:
* @code mutable_buffer(
* data.size() ? &data[0] : 0,
* data.size() * sizeof(PodType)); @endcode
*
* @note The buffer is invalidated by any vector operation that would also
* invalidate iterators.
*/
template <typename PodType, typename Allocator>
inline ASIO_MUTABLE_BUFFER buffer(
std::vector<PodType, Allocator>& data) ASIO_NOEXCEPT
{
return ASIO_MUTABLE_BUFFER(
data.size() ? &data[0] : 0, data.size() * sizeof(PodType)
#if defined(ASIO_ENABLE_BUFFER_DEBUGGING)
, detail::buffer_debug_check<
typename std::vector<PodType, Allocator>::iterator
>(data.begin())
#endif // ASIO_ENABLE_BUFFER_DEBUGGING
);
}
/// Create a new modifiable buffer that represents the given POD vector.
/**
* @returns A mutable_buffer value equivalent to:
* @code mutable_buffer(
* data.size() ? &data[0] : 0,
* min(data.size() * sizeof(PodType), max_size_in_bytes)); @endcode
*
* @note The buffer is invalidated by any vector operation that would also
* invalidate iterators.
*/
template <typename PodType, typename Allocator>
inline ASIO_MUTABLE_BUFFER buffer(std::vector<PodType, Allocator>& data,
std::size_t max_size_in_bytes) ASIO_NOEXCEPT
{
return ASIO_MUTABLE_BUFFER(data.size() ? &data[0] : 0,
data.size() * sizeof(PodType) < max_size_in_bytes
? data.size() * sizeof(PodType) : max_size_in_bytes
#if defined(ASIO_ENABLE_BUFFER_DEBUGGING)
, detail::buffer_debug_check<
typename std::vector<PodType, Allocator>::iterator
>(data.begin())
#endif // ASIO_ENABLE_BUFFER_DEBUGGING
);
}
/// Create a new non-modifiable buffer that represents the given POD vector.
/**
* @returns A const_buffer value equivalent to:
* @code const_buffer(
* data.size() ? &data[0] : 0,
* data.size() * sizeof(PodType)); @endcode
*
* @note The buffer is invalidated by any vector operation that would also
* invalidate iterators.
*/
template <typename PodType, typename Allocator>
inline ASIO_CONST_BUFFER buffer(
const std::vector<PodType, Allocator>& data) ASIO_NOEXCEPT
{
return ASIO_CONST_BUFFER(
data.size() ? &data[0] : 0, data.size() * sizeof(PodType)
#if defined(ASIO_ENABLE_BUFFER_DEBUGGING)
, detail::buffer_debug_check<
typename std::vector<PodType, Allocator>::const_iterator
>(data.begin())
#endif // ASIO_ENABLE_BUFFER_DEBUGGING
);
}
/// Create a new non-modifiable buffer that represents the given POD vector.
/**
* @returns A const_buffer value equivalent to:
* @code const_buffer(
* data.size() ? &data[0] : 0,
* min(data.size() * sizeof(PodType), max_size_in_bytes)); @endcode
*
* @note The buffer is invalidated by any vector operation that would also
* invalidate iterators.
*/
template <typename PodType, typename Allocator>
inline ASIO_CONST_BUFFER buffer(
const std::vector<PodType, Allocator>& data,
std::size_t max_size_in_bytes) ASIO_NOEXCEPT
{
return ASIO_CONST_BUFFER(data.size() ? &data[0] : 0,
data.size() * sizeof(PodType) < max_size_in_bytes
? data.size() * sizeof(PodType) : max_size_in_bytes
#if defined(ASIO_ENABLE_BUFFER_DEBUGGING)
, detail::buffer_debug_check<
typename std::vector<PodType, Allocator>::const_iterator
>(data.begin())
#endif // ASIO_ENABLE_BUFFER_DEBUGGING
);
}
/// Create a new modifiable buffer that represents the given string.
/**
* @returns <tt>mutable_buffer(data.size() ? &data[0] : 0,
* data.size() * sizeof(Elem))</tt>.
*
* @note The buffer is invalidated by any non-const operation called on the
* given string object.
*/
template <typename Elem, typename Traits, typename Allocator>
inline ASIO_MUTABLE_BUFFER buffer(
std::basic_string<Elem, Traits, Allocator>& data) ASIO_NOEXCEPT
{
return ASIO_MUTABLE_BUFFER(data.size() ? &data[0] : 0,
data.size() * sizeof(Elem)
#if defined(ASIO_ENABLE_BUFFER_DEBUGGING)
, detail::buffer_debug_check<
typename std::basic_string<Elem, Traits, Allocator>::iterator
>(data.begin())
#endif // ASIO_ENABLE_BUFFER_DEBUGGING
);
}
/// Create a new modifiable buffer that represents the given string.
/**
* @returns A mutable_buffer value equivalent to:
* @code mutable_buffer(
* data.size() ? &data[0] : 0,
* min(data.size() * sizeof(Elem), max_size_in_bytes)); @endcode
*
* @note The buffer is invalidated by any non-const operation called on the
* given string object.
*/
template <typename Elem, typename Traits, typename Allocator>
inline ASIO_MUTABLE_BUFFER buffer(
std::basic_string<Elem, Traits, Allocator>& data,
std::size_t max_size_in_bytes) ASIO_NOEXCEPT
{
return ASIO_MUTABLE_BUFFER(data.size() ? &data[0] : 0,
data.size() * sizeof(Elem) < max_size_in_bytes
? data.size() * sizeof(Elem) : max_size_in_bytes
#if defined(ASIO_ENABLE_BUFFER_DEBUGGING)
, detail::buffer_debug_check<
typename std::basic_string<Elem, Traits, Allocator>::iterator
>(data.begin())
#endif // ASIO_ENABLE_BUFFER_DEBUGGING
);
}
/// Create a new non-modifiable buffer that represents the given string.
/**
* @returns <tt>const_buffer(data.data(), data.size() * sizeof(Elem))</tt>.
*
* @note The buffer is invalidated by any non-const operation called on the
* given string object.
*/
template <typename Elem, typename Traits, typename Allocator>
inline ASIO_CONST_BUFFER buffer(
const std::basic_string<Elem, Traits, Allocator>& data) ASIO_NOEXCEPT
{
return ASIO_CONST_BUFFER(data.data(), data.size() * sizeof(Elem)
#if defined(ASIO_ENABLE_BUFFER_DEBUGGING)
, detail::buffer_debug_check<
typename std::basic_string<Elem, Traits, Allocator>::const_iterator
>(data.begin())
#endif // ASIO_ENABLE_BUFFER_DEBUGGING
);
}
/// Create a new non-modifiable buffer that represents the given string.
/**
* @returns A const_buffer value equivalent to:
* @code const_buffer(
* data.data(),
* min(data.size() * sizeof(Elem), max_size_in_bytes)); @endcode
*
* @note The buffer is invalidated by any non-const operation called on the
* given string object.
*/
template <typename Elem, typename Traits, typename Allocator>
inline ASIO_CONST_BUFFER buffer(
const std::basic_string<Elem, Traits, Allocator>& data,
std::size_t max_size_in_bytes) ASIO_NOEXCEPT
{
return ASIO_CONST_BUFFER(data.data(),
data.size() * sizeof(Elem) < max_size_in_bytes
? data.size() * sizeof(Elem) : max_size_in_bytes
#if defined(ASIO_ENABLE_BUFFER_DEBUGGING)
, detail::buffer_debug_check<
typename std::basic_string<Elem, Traits, Allocator>::const_iterator
>(data.begin())
#endif // ASIO_ENABLE_BUFFER_DEBUGGING
);
}
#if defined(ASIO_HAS_STRING_VIEW) \
|| defined(GENERATING_DOCUMENTATION)
/// Create a new modifiable buffer that represents the given string_view.
/**
* @returns <tt>mutable_buffer(data.size() ? &data[0] : 0,
* data.size() * sizeof(Elem))</tt>.
*/
template <typename Elem, typename Traits>
inline ASIO_CONST_BUFFER buffer(
basic_string_view<Elem, Traits> data) ASIO_NOEXCEPT
{
return ASIO_CONST_BUFFER(data.size() ? &data[0] : 0,
data.size() * sizeof(Elem)
#if defined(ASIO_ENABLE_BUFFER_DEBUGGING)
, detail::buffer_debug_check<
typename basic_string_view<Elem, Traits>::iterator
>(data.begin())
#endif // ASIO_ENABLE_BUFFER_DEBUGGING
);
}
/// Create a new non-modifiable buffer that represents the given string.
/**
* @returns A mutable_buffer value equivalent to:
* @code mutable_buffer(
* data.size() ? &data[0] : 0,
* min(data.size() * sizeof(Elem), max_size_in_bytes)); @endcode
*/
template <typename Elem, typename Traits>
inline ASIO_CONST_BUFFER buffer(
basic_string_view<Elem, Traits> data,
std::size_t max_size_in_bytes) ASIO_NOEXCEPT
{
return ASIO_CONST_BUFFER(data.size() ? &data[0] : 0,
data.size() * sizeof(Elem) < max_size_in_bytes
? data.size() * sizeof(Elem) : max_size_in_bytes
#if defined(ASIO_ENABLE_BUFFER_DEBUGGING)
, detail::buffer_debug_check<
typename basic_string_view<Elem, Traits>::iterator
>(data.begin())
#endif // ASIO_ENABLE_BUFFER_DEBUGGING
);
}
#endif // defined(ASIO_HAS_STRING_VIEW)
// || defined(GENERATING_DOCUMENTATION)
/*@}*/
/// Adapt a basic_string to the DynamicBuffer requirements.
/**
* Requires that <tt>sizeof(Elem) == 1</tt>.
*/
template <typename Elem, typename Traits, typename Allocator>
class dynamic_string_buffer
{
public:
/// The type used to represent a sequence of constant buffers that refers to
/// the underlying memory.
typedef ASIO_CONST_BUFFER const_buffers_type;
/// The type used to represent a sequence of mutable buffers that refers to
/// the underlying memory.
typedef ASIO_MUTABLE_BUFFER mutable_buffers_type;
/// Construct a dynamic buffer from a string.
/**
* @param s The string to be used as backing storage for the dynamic buffer.
* The object stores a reference to the string and the user is responsible
* for ensuring that the string object remains valid while the
* dynamic_string_buffer object, and copies of the object, are in use.
*
* @b DynamicBuffer_v1: Any existing data in the string is treated as the
* dynamic buffer's input sequence.
*
* @param maximum_size Specifies a maximum size for the buffer, in bytes.
*/
explicit dynamic_string_buffer(std::basic_string<Elem, Traits, Allocator>& s,
std::size_t maximum_size =
(std::numeric_limits<std::size_t>::max)()) ASIO_NOEXCEPT
: string_(s),
#if !defined(ASIO_NO_DYNAMIC_BUFFER_V1)
size_((std::numeric_limits<std::size_t>::max)()),
#endif // !defined(ASIO_NO_DYNAMIC_BUFFER_V1)
max_size_(maximum_size)
{
}
/// @b DynamicBuffer_v2: Copy construct a dynamic buffer.
dynamic_string_buffer(const dynamic_string_buffer& other) ASIO_NOEXCEPT
: string_(other.string_),
#if !defined(ASIO_NO_DYNAMIC_BUFFER_V1)
size_(other.size_),
#endif // !defined(ASIO_NO_DYNAMIC_BUFFER_V1)
max_size_(other.max_size_)
{
}
#if defined(ASIO_HAS_MOVE) || defined(GENERATING_DOCUMENTATION)
/// Move construct a dynamic buffer.
dynamic_string_buffer(dynamic_string_buffer&& other) ASIO_NOEXCEPT
: string_(other.string_),
#if !defined(ASIO_NO_DYNAMIC_BUFFER_V1)
size_(other.size_),
#endif // !defined(ASIO_NO_DYNAMIC_BUFFER_V1)
max_size_(other.max_size_)
{
}
#endif // defined(ASIO_HAS_MOVE) || defined(GENERATING_DOCUMENTATION)
/// @b DynamicBuffer_v1: Get the size of the input sequence.
/// @b DynamicBuffer_v2: Get the current size of the underlying memory.
/**
* @returns @b DynamicBuffer_v1 The current size of the input sequence.
* @b DynamicBuffer_v2: The current size of the underlying string if less than
* max_size(). Otherwise returns max_size().
*/
std::size_t size() const ASIO_NOEXCEPT
{
#if !defined(ASIO_NO_DYNAMIC_BUFFER_V1)
if (size_ != (std::numeric_limits<std::size_t>::max)())
return size_;
#endif // !defined(ASIO_NO_DYNAMIC_BUFFER_V1)
return (std::min)(string_.size(), max_size());
}
/// Get the maximum size of the dynamic buffer.
/**
* @returns The allowed maximum size of the underlying memory.
*/
std::size_t max_size() const ASIO_NOEXCEPT
{
return max_size_;
}
/// Get the maximum size that the buffer may grow to without triggering
/// reallocation.
/**
* @returns The current capacity of the underlying string if less than
* max_size(). Otherwise returns max_size().
*/
std::size_t capacity() const ASIO_NOEXCEPT
{
return (std::min)(string_.capacity(), max_size());
}
#if !defined(ASIO_NO_DYNAMIC_BUFFER_V1)
/// @b DynamicBuffer_v1: Get a list of buffers that represents the input
/// sequence.
/**
* @returns An object of type @c const_buffers_type that satisfies
* ConstBufferSequence requirements, representing the basic_string memory in
* the input sequence.
*
* @note The returned object is invalidated by any @c dynamic_string_buffer
* or @c basic_string member function that resizes or erases the string.
*/
const_buffers_type data() const ASIO_NOEXCEPT
{
return const_buffers_type(asio::buffer(string_, size_));
}
#endif // !defined(ASIO_NO_DYNAMIC_BUFFER_V1)
/// @b DynamicBuffer_v2: Get a sequence of buffers that represents the
/// underlying memory.
/**
* @param pos Position of the first byte to represent in the buffer sequence
*
* @param n The number of bytes to return in the buffer sequence. If the
* underlying memory is shorter, the buffer sequence represents as many bytes
* as are available.
*
* @returns An object of type @c mutable_buffers_type that satisfies
* MutableBufferSequence requirements, representing the basic_string memory.
*
* @note The returned object is invalidated by any @c dynamic_string_buffer
* or @c basic_string member function that resizes or erases the string.
*/
mutable_buffers_type data(std::size_t pos, std::size_t n) ASIO_NOEXCEPT
{
return mutable_buffers_type(asio::buffer(
asio::buffer(string_, max_size_) + pos, n));
}
/// @b DynamicBuffer_v2: Get a sequence of buffers that represents the
/// underlying memory.
/**
* @param pos Position of the first byte to represent in the buffer sequence
*
* @param n The number of bytes to return in the buffer sequence. If the
* underlying memory is shorter, the buffer sequence represents as many bytes
* as are available.
*
* @note The returned object is invalidated by any @c dynamic_string_buffer
* or @c basic_string member function that resizes or erases the string.
*/
const_buffers_type data(std::size_t pos,
std::size_t n) const ASIO_NOEXCEPT
{
return const_buffers_type(asio::buffer(
asio::buffer(string_, max_size_) + pos, n));
}
#if !defined(ASIO_NO_DYNAMIC_BUFFER_V1)
/// @b DynamicBuffer_v1: Get a list of buffers that represents the output
/// sequence, with the given size.
/**
* Ensures that the output sequence can accommodate @c n bytes, resizing the
* basic_string object as necessary.
*
* @returns An object of type @c mutable_buffers_type that satisfies
* MutableBufferSequence requirements, representing basic_string memory
* at the start of the output sequence of size @c n.
*
* @throws std::length_error If <tt>size() + n > max_size()</tt>.
*
* @note The returned object is invalidated by any @c dynamic_string_buffer
* or @c basic_string member function that modifies the input sequence or
* output sequence.
*/
mutable_buffers_type prepare(std::size_t n)
{
if (size() > max_size() || max_size() - size() < n)
{
std::length_error ex("dynamic_string_buffer too long");
asio::detail::throw_exception(ex);
}
if (size_ == (std::numeric_limits<std::size_t>::max)())
size_ = string_.size(); // Enable v1 behaviour.
string_.resize(size_ + n);
return asio::buffer(asio::buffer(string_) + size_, n);
}
/// @b DynamicBuffer_v1: Move bytes from the output sequence to the input
/// sequence.
/**
* @param n The number of bytes to append from the start of the output
* sequence to the end of the input sequence. The remainder of the output
* sequence is discarded.
*
* Requires a preceding call <tt>prepare(x)</tt> where <tt>x >= n</tt>, and
* no intervening operations that modify the input or output sequence.
*
* @note If @c n is greater than the size of the output sequence, the entire
* output sequence is moved to the input sequence and no error is issued.
*/
void commit(std::size_t n)
{
size_ += (std::min)(n, string_.size() - size_);
string_.resize(size_);
}
#endif // !defined(ASIO_NO_DYNAMIC_BUFFER_V1)
/// @b DynamicBuffer_v2: Grow the underlying memory by the specified number of
/// bytes.
/**
* Resizes the string to accommodate an additional @c n bytes at the end.
*
* @throws std::length_error If <tt>size() + n > max_size()</tt>.
*/
void grow(std::size_t n)
{
if (size() > max_size() || max_size() - size() < n)
{
std::length_error ex("dynamic_string_buffer too long");
asio::detail::throw_exception(ex);
}
string_.resize(size() + n);
}
/// @b DynamicBuffer_v2: Shrink the underlying memory by the specified number
/// of bytes.
/**
* Erases @c n bytes from the end of the string by resizing the basic_string
* object. If @c n is greater than the current size of the string, the string
* is emptied.
*/
void shrink(std::size_t n)
{
string_.resize(n > size() ? 0 : size() - n);
}
/// @b DynamicBuffer_v1: Remove characters from the input sequence.
/// @b DynamicBuffer_v2: Consume the specified number of bytes from the
/// beginning of the underlying memory.
/**
* @b DynamicBuffer_v1: Removes @c n characters from the beginning of the
* input sequence. @note If @c n is greater than the size of the input
* sequence, the entire input sequence is consumed and no error is issued.
*
* @b DynamicBuffer_v2: Erases @c n bytes from the beginning of the string.
* If @c n is greater than the current size of the string, the string is
* emptied.
*/
void consume(std::size_t n)
{
#if !defined(ASIO_NO_DYNAMIC_BUFFER_V1)
if (size_ != (std::numeric_limits<std::size_t>::max)())
{
std::size_t consume_length = (std::min)(n, size_);
string_.erase(0, consume_length);
size_ -= consume_length;
return;
}
#endif // !defined(ASIO_NO_DYNAMIC_BUFFER_V1)
string_.erase(0, n);
}
private:
std::basic_string<Elem, Traits, Allocator>& string_;
#if !defined(ASIO_NO_DYNAMIC_BUFFER_V1)
std::size_t size_;
#endif // !defined(ASIO_NO_DYNAMIC_BUFFER_V1)
const std::size_t max_size_;
};
/// Adapt a vector to the DynamicBuffer requirements.
/**
* Requires that <tt>sizeof(Elem) == 1</tt>.
*/
template <typename Elem, typename Allocator>
class dynamic_vector_buffer
{
public:
/// The type used to represent a sequence of constant buffers that refers to
/// the underlying memory.
typedef ASIO_CONST_BUFFER const_buffers_type;
/// The type used to represent a sequence of mutable buffers that refers to
/// the underlying memory.
typedef ASIO_MUTABLE_BUFFER mutable_buffers_type;
/// Construct a dynamic buffer from a vector.
/**
* @param v The vector to be used as backing storage for the dynamic buffer.
* The object stores a reference to the vector and the user is responsible
* for ensuring that the vector object remains valid while the
* dynamic_vector_buffer object, and copies of the object, are in use.
*
* @param maximum_size Specifies a maximum size for the buffer, in bytes.
*/
explicit dynamic_vector_buffer(std::vector<Elem, Allocator>& v,
std::size_t maximum_size =
(std::numeric_limits<std::size_t>::max)()) ASIO_NOEXCEPT
: vector_(v),
#if !defined(ASIO_NO_DYNAMIC_BUFFER_V1)
size_((std::numeric_limits<std::size_t>::max)()),
#endif // !defined(ASIO_NO_DYNAMIC_BUFFER_V1)
max_size_(maximum_size)
{
}
/// @b DynamicBuffer_v2: Copy construct a dynamic buffer.
dynamic_vector_buffer(const dynamic_vector_buffer& other) ASIO_NOEXCEPT
: vector_(other.vector_),
#if !defined(ASIO_NO_DYNAMIC_BUFFER_V1)
size_(other.size_),
#endif // !defined(ASIO_NO_DYNAMIC_BUFFER_V1)
max_size_(other.max_size_)
{
}
#if defined(ASIO_HAS_MOVE) || defined(GENERATING_DOCUMENTATION)
/// Move construct a dynamic buffer.
dynamic_vector_buffer(dynamic_vector_buffer&& other) ASIO_NOEXCEPT
: vector_(other.vector_),
#if !defined(ASIO_NO_DYNAMIC_BUFFER_V1)
size_(other.size_),
#endif // !defined(ASIO_NO_DYNAMIC_BUFFER_V1)
max_size_(other.max_size_)
{
}
#endif // defined(ASIO_HAS_MOVE) || defined(GENERATING_DOCUMENTATION)
/// @b DynamicBuffer_v1: Get the size of the input sequence.
/// @b DynamicBuffer_v2: Get the current size of the underlying memory.
/**
* @returns @b DynamicBuffer_v1 The current size of the input sequence.
* @b DynamicBuffer_v2: The current size of the underlying vector if less than
* max_size(). Otherwise returns max_size().
*/
std::size_t size() const ASIO_NOEXCEPT
{
#if !defined(ASIO_NO_DYNAMIC_BUFFER_V1)
if (size_ != (std::numeric_limits<std::size_t>::max)())
return size_;
#endif // !defined(ASIO_NO_DYNAMIC_BUFFER_V1)
return (std::min)(vector_.size(), max_size());
}
/// Get the maximum size of the dynamic buffer.
/**
* @returns @b DynamicBuffer_v1: The allowed maximum of the sum of the sizes
* of the input sequence and output sequence. @b DynamicBuffer_v2: The allowed
* maximum size of the underlying memory.
*/
std::size_t max_size() const ASIO_NOEXCEPT
{
return max_size_;
}
/// Get the maximum size that the buffer may grow to without triggering
/// reallocation.
/**
* @returns @b DynamicBuffer_v1: The current total capacity of the buffer,
* i.e. for both the input sequence and output sequence. @b DynamicBuffer_v2:
* The current capacity of the underlying vector if less than max_size().
* Otherwise returns max_size().
*/
std::size_t capacity() const ASIO_NOEXCEPT
{
return (std::min)(vector_.capacity(), max_size());
}
#if !defined(ASIO_NO_DYNAMIC_BUFFER_V1)
/// @b DynamicBuffer_v1: Get a list of buffers that represents the input
/// sequence.
/**
* @returns An object of type @c const_buffers_type that satisfies
* ConstBufferSequence requirements, representing the vector memory in the
* input sequence.
*
* @note The returned object is invalidated by any @c dynamic_vector_buffer
* or @c vector member function that modifies the input sequence or output
* sequence.
*/
const_buffers_type data() const ASIO_NOEXCEPT
{
return const_buffers_type(asio::buffer(vector_, size_));
}
#endif // !defined(ASIO_NO_DYNAMIC_BUFFER_V1)
/// @b DynamicBuffer_v2: Get a sequence of buffers that represents the
/// underlying memory.
/**
* @param pos Position of the first byte to represent in the buffer sequence
*
* @param n The number of bytes to return in the buffer sequence. If the
* underlying memory is shorter, the buffer sequence represents as many bytes
* as are available.
*
* @returns An object of type @c mutable_buffers_type that satisfies
* MutableBufferSequence requirements, representing the vector memory.
*
* @note The returned object is invalidated by any @c dynamic_vector_buffer
* or @c vector member function that resizes or erases the vector.
*/
mutable_buffers_type data(std::size_t pos, std::size_t n) ASIO_NOEXCEPT
{
return mutable_buffers_type(asio::buffer(
asio::buffer(vector_, max_size_) + pos, n));
}
/// @b DynamicBuffer_v2: Get a sequence of buffers that represents the
/// underlying memory.
/**
* @param pos Position of the first byte to represent in the buffer sequence
*
* @param n The number of bytes to return in the buffer sequence. If the
* underlying memory is shorter, the buffer sequence represents as many bytes
* as are available.
*
* @note The returned object is invalidated by any @c dynamic_vector_buffer
* or @c vector member function that resizes or erases the vector.
*/
const_buffers_type data(std::size_t pos,
std::size_t n) const ASIO_NOEXCEPT
{
return const_buffers_type(asio::buffer(
asio::buffer(vector_, max_size_) + pos, n));
}
#if !defined(ASIO_NO_DYNAMIC_BUFFER_V1)
/// @b DynamicBuffer_v1: Get a list of buffers that represents the output
/// sequence, with the given size.
/**
* Ensures that the output sequence can accommodate @c n bytes, resizing the
* vector object as necessary.
*
* @returns An object of type @c mutable_buffers_type that satisfies
* MutableBufferSequence requirements, representing vector memory at the
* start of the output sequence of size @c n.
*
* @throws std::length_error If <tt>size() + n > max_size()</tt>.
*
* @note The returned object is invalidated by any @c dynamic_vector_buffer
* or @c vector member function that modifies the input sequence or output
* sequence.
*/
mutable_buffers_type prepare(std::size_t n)
{
if (size () > max_size() || max_size() - size() < n)
{
std::length_error ex("dynamic_vector_buffer too long");
asio::detail::throw_exception(ex);
}
if (size_ == (std::numeric_limits<std::size_t>::max)())
size_ = vector_.size(); // Enable v1 behaviour.
vector_.resize(size_ + n);
return asio::buffer(asio::buffer(vector_) + size_, n);
}
/// @b DynamicBuffer_v1: Move bytes from the output sequence to the input
/// sequence.
/**
* @param n The number of bytes to append from the start of the output
* sequence to the end of the input sequence. The remainder of the output
* sequence is discarded.
*
* Requires a preceding call <tt>prepare(x)</tt> where <tt>x >= n</tt>, and
* no intervening operations that modify the input or output sequence.
*
* @note If @c n is greater than the size of the output sequence, the entire
* output sequence is moved to the input sequence and no error is issued.
*/
void commit(std::size_t n)
{
size_ += (std::min)(n, vector_.size() - size_);
vector_.resize(size_);
}
#endif // !defined(ASIO_NO_DYNAMIC_BUFFER_V1)
/// @b DynamicBuffer_v2: Grow the underlying memory by the specified number of
/// bytes.
/**
* Resizes the vector to accommodate an additional @c n bytes at the end.
*
* @throws std::length_error If <tt>size() + n > max_size()</tt>.
*/
void grow(std::size_t n)
{
if (size() > max_size() || max_size() - size() < n)
{
std::length_error ex("dynamic_vector_buffer too long");
asio::detail::throw_exception(ex);
}
vector_.resize(size() + n);
}
/// @b DynamicBuffer_v2: Shrink the underlying memory by the specified number
/// of bytes.
/**
* Erases @c n bytes from the end of the vector by resizing the vector
* object. If @c n is greater than the current size of the vector, the vector
* is emptied.
*/
void shrink(std::size_t n)
{
vector_.resize(n > size() ? 0 : size() - n);
}
/// @b DynamicBuffer_v1: Remove characters from the input sequence.
/// @b DynamicBuffer_v2: Consume the specified number of bytes from the
/// beginning of the underlying memory.
/**
* @b DynamicBuffer_v1: Removes @c n characters from the beginning of the
* input sequence. @note If @c n is greater than the size of the input
* sequence, the entire input sequence is consumed and no error is issued.
*
* @b DynamicBuffer_v2: Erases @c n bytes from the beginning of the vector.
* If @c n is greater than the current size of the vector, the vector is
* emptied.
*/
void consume(std::size_t n)
{
#if !defined(ASIO_NO_DYNAMIC_BUFFER_V1)
if (size_ != (std::numeric_limits<std::size_t>::max)())
{
std::size_t consume_length = (std::min)(n, size_);
vector_.erase(vector_.begin(), vector_.begin() + consume_length);
size_ -= consume_length;
return;
}
#endif // !defined(ASIO_NO_DYNAMIC_BUFFER_V1)
vector_.erase(vector_.begin(), vector_.begin() + (std::min)(size(), n));
}
private:
std::vector<Elem, Allocator>& vector_;
#if !defined(ASIO_NO_DYNAMIC_BUFFER_V1)
std::size_t size_;
#endif // !defined(ASIO_NO_DYNAMIC_BUFFER_V1)
const std::size_t max_size_;
};
/** @defgroup dynamic_buffer asio::dynamic_buffer
*
* @brief The asio::dynamic_buffer function is used to create a
* dynamically resized buffer from a @c std::basic_string or @c std::vector.
*/
/*@{*/
/// Create a new dynamic buffer that represents the given string.
/**
* @returns <tt>dynamic_string_buffer<Elem, Traits, Allocator>(data)</tt>.
*/
template <typename Elem, typename Traits, typename Allocator>
inline dynamic_string_buffer<Elem, Traits, Allocator> dynamic_buffer(
std::basic_string<Elem, Traits, Allocator>& data) ASIO_NOEXCEPT
{
return dynamic_string_buffer<Elem, Traits, Allocator>(data);
}
/// Create a new dynamic buffer that represents the given string.
/**
* @returns <tt>dynamic_string_buffer<Elem, Traits, Allocator>(data,
* max_size)</tt>.
*/
template <typename Elem, typename Traits, typename Allocator>
inline dynamic_string_buffer<Elem, Traits, Allocator> dynamic_buffer(
std::basic_string<Elem, Traits, Allocator>& data,
std::size_t max_size) ASIO_NOEXCEPT
{
return dynamic_string_buffer<Elem, Traits, Allocator>(data, max_size);
}
/// Create a new dynamic buffer that represents the given vector.
/**
* @returns <tt>dynamic_vector_buffer<Elem, Allocator>(data)</tt>.
*/
template <typename Elem, typename Allocator>
inline dynamic_vector_buffer<Elem, Allocator> dynamic_buffer(
std::vector<Elem, Allocator>& data) ASIO_NOEXCEPT
{
return dynamic_vector_buffer<Elem, Allocator>(data);
}
/// Create a new dynamic buffer that represents the given vector.
/**
* @returns <tt>dynamic_vector_buffer<Elem, Allocator>(data, max_size)</tt>.
*/
template <typename Elem, typename Allocator>
inline dynamic_vector_buffer<Elem, Allocator> dynamic_buffer(
std::vector<Elem, Allocator>& data,
std::size_t max_size) ASIO_NOEXCEPT
{
return dynamic_vector_buffer<Elem, Allocator>(data, max_size);
}
/*@}*/
/** @defgroup buffer_copy asio::buffer_copy
*
* @brief The asio::buffer_copy function is used to copy bytes from a
* source buffer (or buffer sequence) to a target buffer (or buffer sequence).
*
* The @c buffer_copy function is available in two forms:
*
* @li A 2-argument form: @c buffer_copy(target, source)
*
* @li A 3-argument form: @c buffer_copy(target, source, max_bytes_to_copy)
*
* Both forms return the number of bytes actually copied. The number of bytes
* copied is the lesser of:
*
* @li @c buffer_size(target)
*
* @li @c buffer_size(source)
*
* @li @c If specified, @c max_bytes_to_copy.
*
* This prevents buffer overflow, regardless of the buffer sizes used in the
* copy operation.
*
* Note that @ref buffer_copy is implemented in terms of @c memcpy, and
* consequently it cannot be used to copy between overlapping memory regions.
*/
/*@{*/
namespace detail {
inline std::size_t buffer_copy_1(const mutable_buffer& target,
const const_buffer& source)
{
using namespace std; // For memcpy.
std::size_t target_size = target.size();
std::size_t source_size = source.size();
std::size_t n = target_size < source_size ? target_size : source_size;
if (n > 0)
memcpy(target.data(), source.data(), n);
return n;
}
template <typename TargetIterator, typename SourceIterator>
inline std::size_t buffer_copy(one_buffer, one_buffer,
TargetIterator target_begin, TargetIterator,
SourceIterator source_begin, SourceIterator) ASIO_NOEXCEPT
{
return (buffer_copy_1)(*target_begin, *source_begin);
}
template <typename TargetIterator, typename SourceIterator>
inline std::size_t buffer_copy(one_buffer, one_buffer,
TargetIterator target_begin, TargetIterator,
SourceIterator source_begin, SourceIterator,
std::size_t max_bytes_to_copy) ASIO_NOEXCEPT
{
return (buffer_copy_1)(*target_begin,
asio::buffer(*source_begin, max_bytes_to_copy));
}
template <typename TargetIterator, typename SourceIterator>
std::size_t buffer_copy(one_buffer, multiple_buffers,
TargetIterator target_begin, TargetIterator,
SourceIterator source_begin, SourceIterator source_end,
std::size_t max_bytes_to_copy
= (std::numeric_limits<std::size_t>::max)()) ASIO_NOEXCEPT
{
std::size_t total_bytes_copied = 0;
SourceIterator source_iter = source_begin;
for (mutable_buffer target_buffer(
asio::buffer(*target_begin, max_bytes_to_copy));
target_buffer.size() && source_iter != source_end; ++source_iter)
{
const_buffer source_buffer(*source_iter);
std::size_t bytes_copied = (buffer_copy_1)(target_buffer, source_buffer);
total_bytes_copied += bytes_copied;
target_buffer += bytes_copied;
}
return total_bytes_copied;
}
template <typename TargetIterator, typename SourceIterator>
std::size_t buffer_copy(multiple_buffers, one_buffer,
TargetIterator target_begin, TargetIterator target_end,
SourceIterator source_begin, SourceIterator,
std::size_t max_bytes_to_copy
= (std::numeric_limits<std::size_t>::max)()) ASIO_NOEXCEPT
{
std::size_t total_bytes_copied = 0;
TargetIterator target_iter = target_begin;
for (const_buffer source_buffer(
asio::buffer(*source_begin, max_bytes_to_copy));
source_buffer.size() && target_iter != target_end; ++target_iter)
{
mutable_buffer target_buffer(*target_iter);
std::size_t bytes_copied = (buffer_copy_1)(target_buffer, source_buffer);
total_bytes_copied += bytes_copied;
source_buffer += bytes_copied;
}
return total_bytes_copied;
}
template <typename TargetIterator, typename SourceIterator>
std::size_t buffer_copy(multiple_buffers, multiple_buffers,
TargetIterator target_begin, TargetIterator target_end,
SourceIterator source_begin, SourceIterator source_end) ASIO_NOEXCEPT
{
std::size_t total_bytes_copied = 0;
TargetIterator target_iter = target_begin;
std::size_t target_buffer_offset = 0;
SourceIterator source_iter = source_begin;
std::size_t source_buffer_offset = 0;
while (target_iter != target_end && source_iter != source_end)
{
mutable_buffer target_buffer =
mutable_buffer(*target_iter) + target_buffer_offset;
const_buffer source_buffer =
const_buffer(*source_iter) + source_buffer_offset;
std::size_t bytes_copied = (buffer_copy_1)(target_buffer, source_buffer);
total_bytes_copied += bytes_copied;
if (bytes_copied == target_buffer.size())
{
++target_iter;
target_buffer_offset = 0;
}
else
target_buffer_offset += bytes_copied;
if (bytes_copied == source_buffer.size())
{
++source_iter;
source_buffer_offset = 0;
}
else
source_buffer_offset += bytes_copied;
}
return total_bytes_copied;
}
template <typename TargetIterator, typename SourceIterator>
std::size_t buffer_copy(multiple_buffers, multiple_buffers,
TargetIterator target_begin, TargetIterator target_end,
SourceIterator source_begin, SourceIterator source_end,
std::size_t max_bytes_to_copy) ASIO_NOEXCEPT
{
std::size_t total_bytes_copied = 0;
TargetIterator target_iter = target_begin;
std::size_t target_buffer_offset = 0;
SourceIterator source_iter = source_begin;
std::size_t source_buffer_offset = 0;
while (total_bytes_copied != max_bytes_to_copy
&& target_iter != target_end && source_iter != source_end)
{
mutable_buffer target_buffer =
mutable_buffer(*target_iter) + target_buffer_offset;
const_buffer source_buffer =
const_buffer(*source_iter) + source_buffer_offset;
std::size_t bytes_copied = (buffer_copy_1)(
target_buffer, asio::buffer(source_buffer,
max_bytes_to_copy - total_bytes_copied));
total_bytes_copied += bytes_copied;
if (bytes_copied == target_buffer.size())
{
++target_iter;
target_buffer_offset = 0;
}
else
target_buffer_offset += bytes_copied;
if (bytes_copied == source_buffer.size())
{
++source_iter;
source_buffer_offset = 0;
}
else
source_buffer_offset += bytes_copied;
}
return total_bytes_copied;
}
} // namespace detail
/// Copies bytes from a source buffer sequence to a target buffer sequence.
/**
* @param target A modifiable buffer sequence representing the memory regions to
* which the bytes will be copied.
*
* @param source A non-modifiable buffer sequence representing the memory
* regions from which the bytes will be copied.
*
* @returns The number of bytes copied.
*
* @note The number of bytes copied is the lesser of:
*
* @li @c buffer_size(target)
*
* @li @c buffer_size(source)
*
* This function is implemented in terms of @c memcpy, and consequently it
* cannot be used to copy between overlapping memory regions.
*/
template <typename MutableBufferSequence, typename ConstBufferSequence>
inline std::size_t buffer_copy(const MutableBufferSequence& target,
const ConstBufferSequence& source) ASIO_NOEXCEPT
{
return detail::buffer_copy(
detail::buffer_sequence_cardinality<MutableBufferSequence>(),
detail::buffer_sequence_cardinality<ConstBufferSequence>(),
asio::buffer_sequence_begin(target),
asio::buffer_sequence_end(target),
asio::buffer_sequence_begin(source),
asio::buffer_sequence_end(source));
}
/// Copies a limited number of bytes from a source buffer sequence to a target
/// buffer sequence.
/**
* @param target A modifiable buffer sequence representing the memory regions to
* which the bytes will be copied.
*
* @param source A non-modifiable buffer sequence representing the memory
* regions from which the bytes will be copied.
*
* @param max_bytes_to_copy The maximum number of bytes to be copied.
*
* @returns The number of bytes copied.
*
* @note The number of bytes copied is the lesser of:
*
* @li @c buffer_size(target)
*
* @li @c buffer_size(source)
*
* @li @c max_bytes_to_copy
*
* This function is implemented in terms of @c memcpy, and consequently it
* cannot be used to copy between overlapping memory regions.
*/
template <typename MutableBufferSequence, typename ConstBufferSequence>
inline std::size_t buffer_copy(const MutableBufferSequence& target,
const ConstBufferSequence& source,
std::size_t max_bytes_to_copy) ASIO_NOEXCEPT
{
return detail::buffer_copy(
detail::buffer_sequence_cardinality<MutableBufferSequence>(),
detail::buffer_sequence_cardinality<ConstBufferSequence>(),
asio::buffer_sequence_begin(target),
asio::buffer_sequence_end(target),
asio::buffer_sequence_begin(source),
asio::buffer_sequence_end(source), max_bytes_to_copy);
}
/*@}*/
} // namespace asio
#include "asio/detail/pop_options.hpp"
#include "asio/detail/is_buffer_sequence.hpp"
#include "asio/detail/push_options.hpp"
namespace asio {
/// Trait to determine whether a type satisfies the MutableBufferSequence
/// requirements.
template <typename T>
struct is_mutable_buffer_sequence
#if defined(GENERATING_DOCUMENTATION)
: integral_constant<bool, automatically_determined>
#else // defined(GENERATING_DOCUMENTATION)
: asio::detail::is_buffer_sequence<T, mutable_buffer>
#endif // defined(GENERATING_DOCUMENTATION)
{
};
/// Trait to determine whether a type satisfies the ConstBufferSequence
/// requirements.
template <typename T>
struct is_const_buffer_sequence
#if defined(GENERATING_DOCUMENTATION)
: integral_constant<bool, automatically_determined>
#else // defined(GENERATING_DOCUMENTATION)
: asio::detail::is_buffer_sequence<T, const_buffer>
#endif // defined(GENERATING_DOCUMENTATION)
{
};
#if !defined(ASIO_NO_DYNAMIC_BUFFER_V1)
/// Trait to determine whether a type satisfies the DynamicBuffer_v1
/// requirements.
template <typename T>
struct is_dynamic_buffer_v1
#if defined(GENERATING_DOCUMENTATION)
: integral_constant<bool, automatically_determined>
#else // defined(GENERATING_DOCUMENTATION)
: asio::detail::is_dynamic_buffer_v1<T>
#endif // defined(GENERATING_DOCUMENTATION)
{
};
#endif // !defined(ASIO_NO_DYNAMIC_BUFFER_V1)
/// Trait to determine whether a type satisfies the DynamicBuffer_v2
/// requirements.
template <typename T>
struct is_dynamic_buffer_v2
#if defined(GENERATING_DOCUMENTATION)
: integral_constant<bool, automatically_determined>
#else // defined(GENERATING_DOCUMENTATION)
: asio::detail::is_dynamic_buffer_v2<T>
#endif // defined(GENERATING_DOCUMENTATION)
{
};
/// Trait to determine whether a type satisfies the DynamicBuffer requirements.
/**
* If @c ASIO_NO_DYNAMIC_BUFFER_V1 is not defined, determines whether the
* type satisfies the DynamicBuffer_v1 requirements. Otherwise, if @c
* ASIO_NO_DYNAMIC_BUFFER_V1 is defined, determines whether the type
* satisfies the DynamicBuffer_v2 requirements.
*/
template <typename T>
struct is_dynamic_buffer
#if defined(GENERATING_DOCUMENTATION)
: integral_constant<bool, automatically_determined>
#elif defined(ASIO_NO_DYNAMIC_BUFFER_V1)
: asio::is_dynamic_buffer_v2<T>
#else // defined(ASIO_NO_DYNAMIC_BUFFER_V1)
: asio::is_dynamic_buffer_v1<T>
#endif // defined(ASIO_NO_DYNAMIC_BUFFER_V1)
{
};
} // namespace asio
#include "asio/detail/pop_options.hpp"
#endif // ASIO_BUFFER_HPP
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