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diff --git a/lib/asio/buffer.hpp b/lib/asio/buffer.hpp new file mode 100644 index 0000000..a9aa8aa --- /dev/null +++ b/lib/asio/buffer.hpp @@ -0,0 +1,2162 @@ +// +// buffer.hpp +// ~~~~~~~~~~ +// +// Copyright (c) 2003-2018 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/is_buffer_sequence.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 BOOST_WORKAROUND(__BORLANDC__, BOOST_TESTED_AT(0x582)) \ + || BOOST_WORKAROUND(__SUNPRO_CC, BOOST_TESTED_AT(0x590)) +# define ASIO_ENABLE_ARRAY_BUFFER_WORKAROUND +# endif // BOOST_WORKAROUND(__BORLANDC__, BOOST_TESTED_AT(0x582)) + // || 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) + +/// 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) +{ +}; + +/// Trait to determine whether a type satisfies the DynamicBuffer requirements. +template <typename T> +struct is_dynamic_buffer +#if defined(GENERATING_DOCUMENTATION) + : integral_constant<bool, automatically_determined> +#else // defined(GENERATING_DOCUMENTATION) + : asio::detail::is_dynamic_buffer<T> +#endif // defined(GENERATING_DOCUMENTATION) +{ +}; + +/// (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. +inline const mutable_buffer* buffer_sequence_begin(const mutable_buffer& b) +{ + return &b; +} + +/// Get an iterator to the first element in a buffer sequence. +inline const const_buffer* buffer_sequence_begin(const const_buffer& b) +{ + return &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) -> 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) -> 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) +{ + return c.begin(); +} + +template <typename C> +inline typename C::const_iterator buffer_sequence_begin(const C& c) +{ + 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. +inline const mutable_buffer* buffer_sequence_end(const mutable_buffer& b) +{ + return &b + 1; +} + +/// Get an iterator to one past the end element in a buffer sequence. +inline const const_buffer* buffer_sequence_end(const const_buffer& b) +{ + return &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) -> 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) -> 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) +{ + return c.end(); +} + +template <typename C> +inline typename C::const_iterator buffer_sequence_end(const C& c) +{ + 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 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 + * + * @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 the input sequence as a list of buffers. + typedef ASIO_CONST_BUFFER const_buffers_type; + + /// The type used to represent the output sequence as a list of buffers. + 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. + * Any existing data in the string is treated as the dynamic buffer's input + * sequence. The object stores a reference to the string and the user is + * responsible for ensuring that the string object remains valid until the + * dynamic_string_buffer object is destroyed. + * + * @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), + size_(string_.size()), + max_size_(maximum_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_), + size_(other.size_), + max_size_(other.max_size_) + { + } +#endif // defined(ASIO_HAS_MOVE) || defined(GENERATING_DOCUMENTATION) + + /// Get the size of the input sequence. + std::size_t size() const ASIO_NOEXCEPT + { + return size_; + } + + /// Get the maximum size of the dynamic buffer. + /** + * @returns The allowed maximum of the sum of the sizes of the input sequence + * and output sequence. + */ + std::size_t max_size() const ASIO_NOEXCEPT + { + return max_size_; + } + + /// Get the current capacity of the dynamic buffer. + /** + * @returns The current total capacity of the buffer, i.e. for both the input + * sequence and output sequence. + */ + std::size_t capacity() const ASIO_NOEXCEPT + { + return string_.capacity(); + } + + /// 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 + * input sequence. + * + * @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. + */ + const_buffers_type data() const ASIO_NOEXCEPT + { + return const_buffers_type(asio::buffer(string_, size_)); + } + + /// 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); + } + + string_.resize(size_ + n); + + return asio::buffer(asio::buffer(string_) + size_, n); + } + + /// 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_); + } + + /// Remove characters from the input sequence. + /** + * 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. + */ + void consume(std::size_t n) + { + std::size_t consume_length = (std::min)(n, size_); + string_.erase(0, consume_length); + size_ -= consume_length; + } + +private: + std::basic_string<Elem, Traits, Allocator>& string_; + std::size_t size_; + 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 the input sequence as a list of buffers. + typedef ASIO_CONST_BUFFER const_buffers_type; + + /// The type used to represent the output sequence as a list of buffers. + typedef ASIO_MUTABLE_BUFFER mutable_buffers_type; + + /// Construct a dynamic buffer from a string. + /** + * @param v The vector to be used as backing storage for the dynamic buffer. + * Any existing data in the vector is treated as the dynamic buffer's input + * sequence. The object stores a reference to the vector and the user is + * responsible for ensuring that the vector object remains valid until the + * dynamic_vector_buffer object is destroyed. + * + * @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), + size_(vector_.size()), + max_size_(maximum_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_), + size_(other.size_), + max_size_(other.max_size_) + { + } +#endif // defined(ASIO_HAS_MOVE) || defined(GENERATING_DOCUMENTATION) + + /// Get the size of the input sequence. + std::size_t size() const ASIO_NOEXCEPT + { + return size_; + } + + /// Get the maximum size of the dynamic buffer. + /** + * @returns The allowed maximum of the sum of the sizes of the input sequence + * and output sequence. + */ + std::size_t max_size() const ASIO_NOEXCEPT + { + return max_size_; + } + + /// Get the current capacity of the dynamic buffer. + /** + * @returns The current total capacity of the buffer, i.e. for both the input + * sequence and output sequence. + */ + std::size_t capacity() const ASIO_NOEXCEPT + { + return vector_.capacity(); + } + + /// 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 + * input sequence. + * + * @note The returned object is invalidated by any @c dynamic_vector_buffer + * or @c basic_string 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_)); + } + + /// 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_vector_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_vector_buffer too long"); + asio::detail::throw_exception(ex); + } + + vector_.resize(size_ + n); + + return asio::buffer(asio::buffer(vector_) + size_, n); + } + + /// 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_); + } + + /// Remove characters from the input sequence. + /** + * 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. + */ + void consume(std::size_t n) + { + std::size_t consume_length = (std::min)(n, size_); + vector_.erase(vector_.begin(), vector_.begin() + consume_length); + size_ -= consume_length; + } + +private: + std::vector<Elem, Allocator>& vector_; + std::size_t size_; + 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" + +#endif // ASIO_BUFFER_HPP |