boost/asio/buffer.hpp
// // buffer.hpp // ~~~~~~~~~~ // // Copyright (c) 2003-2019 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 BOOST_ASIO_BUFFER_HPP #define BOOST_ASIO_BUFFER_HPP #if defined(_MSC_VER) && (_MSC_VER >= 1200) # pragma once #endif // defined(_MSC_VER) && (_MSC_VER >= 1200) #include <boost/asio/detail/config.hpp> #include <cstddef> #include <cstring> #include <limits> #include <stdexcept> #include <string> #include <vector> #include <boost/asio/detail/array_fwd.hpp> #include <boost/asio/detail/memory.hpp> #include <boost/asio/detail/string_view.hpp> #include <boost/asio/detail/throw_exception.hpp> #include <boost/asio/detail/type_traits.hpp> #if defined(BOOST_ASIO_MSVC) && (BOOST_ASIO_MSVC >= 1700) # if defined(_HAS_ITERATOR_DEBUGGING) && (_HAS_ITERATOR_DEBUGGING != 0) # if !defined(BOOST_ASIO_DISABLE_BUFFER_DEBUGGING) # define BOOST_ASIO_ENABLE_BUFFER_DEBUGGING # endif // !defined(BOOST_ASIO_DISABLE_BUFFER_DEBUGGING) # endif // defined(_HAS_ITERATOR_DEBUGGING) #endif // defined(BOOST_ASIO_MSVC) && (BOOST_ASIO_MSVC >= 1700) #if defined(__GNUC__) # if defined(_GLIBCXX_DEBUG) # if !defined(BOOST_ASIO_DISABLE_BUFFER_DEBUGGING) # define BOOST_ASIO_ENABLE_BUFFER_DEBUGGING # endif // !defined(BOOST_ASIO_DISABLE_BUFFER_DEBUGGING) # endif // defined(_GLIBCXX_DEBUG) #endif // defined(__GNUC__) #if defined(BOOST_ASIO_ENABLE_BUFFER_DEBUGGING) # include <boost/asio/detail/functional.hpp> #endif // BOOST_ASIO_ENABLE_BUFFER_DEBUGGING #if defined(BOOST_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 BOOST_ASIO_ENABLE_ARRAY_BUFFER_WORKAROUND # endif // BOOST_WORKAROUND(__BORLANDC__, BOOST_TESTED_AT(0x582)) // || BOOST_WORKAROUND(__SUNPRO_CC, BOOST_TESTED_AT(0x590)) #endif // defined(BOOST_ASIO_HAS_BOOST_WORKAROUND) #if defined(BOOST_ASIO_ENABLE_ARRAY_BUFFER_WORKAROUND) # include <boost/asio/detail/type_traits.hpp> #endif // defined(BOOST_ASIO_ENABLE_ARRAY_BUFFER_WORKAROUND) #include <boost/asio/detail/push_options.hpp> namespace boost { 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 boost::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() BOOST_ASIO_NOEXCEPT : data_(0), size_(0) { } /// Construct a buffer to represent a given memory range. mutable_buffer(void* data, std::size_t size) BOOST_ASIO_NOEXCEPT : data_(data), size_(size) { } #if defined(BOOST_ASIO_ENABLE_BUFFER_DEBUGGING) mutable_buffer(void* data, std::size_t size, boost::asio::detail::function<void()> debug_check) : data_(data), size_(size), debug_check_(debug_check) { } const boost::asio::detail::function<void()>& get_debug_check() const { return debug_check_; } #endif // BOOST_ASIO_ENABLE_BUFFER_DEBUGGING /// Get a pointer to the beginning of the memory range. void* data() const BOOST_ASIO_NOEXCEPT { #if defined(BOOST_ASIO_ENABLE_BUFFER_DEBUGGING) if (size_ && debug_check_) debug_check_(); #endif // BOOST_ASIO_ENABLE_BUFFER_DEBUGGING return data_; } /// Get the size of the memory range. std::size_t size() const BOOST_ASIO_NOEXCEPT { return size_; } /// Move the start of the buffer by the specified number of bytes. mutable_buffer& operator+=(std::size_t n) BOOST_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(BOOST_ASIO_ENABLE_BUFFER_DEBUGGING) boost::asio::detail::function<void()> debug_check_; #endif // BOOST_ASIO_ENABLE_BUFFER_DEBUGGING }; #if !defined(BOOST_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) BOOST_ASIO_NOEXCEPT : mutable_buffer(data, size) { } #if defined(BOOST_ASIO_ENABLE_BUFFER_DEBUGGING) mutable_buffers_1(void* data, std::size_t size, boost::asio::detail::function<void()> debug_check) : mutable_buffer(data, size, debug_check) { } #endif // BOOST_ASIO_ENABLE_BUFFER_DEBUGGING /// Construct to represent a single modifiable buffer. explicit mutable_buffers_1(const mutable_buffer& b) BOOST_ASIO_NOEXCEPT : mutable_buffer(b) { } /// Get a random-access iterator to the first element. const_iterator begin() const BOOST_ASIO_NOEXCEPT { return this; } /// Get a random-access iterator for one past the last element. const_iterator end() const BOOST_ASIO_NOEXCEPT { return begin() + 1; } }; #endif // !defined(BOOST_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 boost::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() BOOST_ASIO_NOEXCEPT : data_(0), size_(0) { } /// Construct a buffer to represent a given memory range. const_buffer(const void* data, std::size_t size) BOOST_ASIO_NOEXCEPT : data_(data), size_(size) { } /// Construct a non-modifiable buffer from a modifiable one. const_buffer(const mutable_buffer& b) BOOST_ASIO_NOEXCEPT : data_(b.data()), size_(b.size()) #if defined(BOOST_ASIO_ENABLE_BUFFER_DEBUGGING) , debug_check_(b.get_debug_check()) #endif // BOOST_ASIO_ENABLE_BUFFER_DEBUGGING { } #if defined(BOOST_ASIO_ENABLE_BUFFER_DEBUGGING) const_buffer(const void* data, std::size_t size, boost::asio::detail::function<void()> debug_check) : data_(data), size_(size), debug_check_(debug_check) { } const boost::asio::detail::function<void()>& get_debug_check() const { return debug_check_; } #endif // BOOST_ASIO_ENABLE_BUFFER_DEBUGGING /// Get a pointer to the beginning of the memory range. const void* data() const BOOST_ASIO_NOEXCEPT { #if defined(BOOST_ASIO_ENABLE_BUFFER_DEBUGGING) if (size_ && debug_check_) debug_check_(); #endif // BOOST_ASIO_ENABLE_BUFFER_DEBUGGING return data_; } /// Get the size of the memory range. std::size_t size() const BOOST_ASIO_NOEXCEPT { return size_; } /// Move the start of the buffer by the specified number of bytes. const_buffer& operator+=(std::size_t n) BOOST_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(BOOST_ASIO_ENABLE_BUFFER_DEBUGGING) boost::asio::detail::function<void()> debug_check_; #endif // BOOST_ASIO_ENABLE_BUFFER_DEBUGGING }; #if !defined(BOOST_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) BOOST_ASIO_NOEXCEPT : const_buffer(data, size) { } #if defined(BOOST_ASIO_ENABLE_BUFFER_DEBUGGING) const_buffers_1(const void* data, std::size_t size, boost::asio::detail::function<void()> debug_check) : const_buffer(data, size, debug_check) { } #endif // BOOST_ASIO_ENABLE_BUFFER_DEBUGGING /// Construct to represent a single non-modifiable buffer. explicit const_buffers_1(const const_buffer& b) BOOST_ASIO_NOEXCEPT : const_buffer(b) { } /// Get a random-access iterator to the first element. const_iterator begin() const BOOST_ASIO_NOEXCEPT { return this; } /// Get a random-access iterator for one past the last element. const_iterator end() const BOOST_ASIO_NOEXCEPT { return begin() + 1; } }; #endif // !defined(BOOST_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 BOOST_ASIO_NOEXCEPT { return &buf_; } /// Get a random-access iterator for one past the last element. const_iterator end() const BOOST_ASIO_NOEXCEPT { return &buf_; } private: mutable_buffer buf_; }; /** @defgroup buffer_sequence_begin boost::asio::buffer_sequence_begin * * @brief The boost::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 enable_if< is_convertible<const MutableBuffer*, const mutable_buffer*>::value >::type* = 0) BOOST_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 enable_if< is_convertible<const ConstBuffer*, const const_buffer*>::value >::type* = 0) BOOST_ASIO_NOEXCEPT { return static_cast<const const_buffer*>(detail::addressof(b)); } #if defined(BOOST_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 enable_if< !is_convertible<const C*, const mutable_buffer*>::value && !is_convertible<const C*, const const_buffer*>::value >::type* = 0) BOOST_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 enable_if< !is_convertible<const C*, const mutable_buffer*>::value && !is_convertible<const C*, const const_buffer*>::value >::type* = 0) BOOST_ASIO_NOEXCEPT -> decltype(c.begin()) { return c.begin(); } #else // defined(BOOST_ASIO_HAS_DECLTYPE) || defined(GENERATING_DOCUMENTATION) template <typename C> inline typename C::iterator buffer_sequence_begin(C& c, typename enable_if< !is_convertible<const C*, const mutable_buffer*>::value && !is_convertible<const C*, const const_buffer*>::value >::type* = 0) BOOST_ASIO_NOEXCEPT { return c.begin(); } template <typename C> inline typename C::const_iterator buffer_sequence_begin(const C& c, typename enable_if< !is_convertible<const C*, const mutable_buffer*>::value && !is_convertible<const C*, const const_buffer*>::value >::type* = 0) BOOST_ASIO_NOEXCEPT { return c.begin(); } #endif // defined(BOOST_ASIO_HAS_DECLTYPE) || defined(GENERATING_DOCUMENTATION) /*@}*/ /** @defgroup buffer_sequence_end boost::asio::buffer_sequence_end * * @brief The boost::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 enable_if< is_convertible<const MutableBuffer*, const mutable_buffer*>::value >::type* = 0) BOOST_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 enable_if< is_convertible<const ConstBuffer*, const const_buffer*>::value >::type* = 0) BOOST_ASIO_NOEXCEPT { return static_cast<const const_buffer*>(detail::addressof(b)) + 1; } #if defined(BOOST_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 enable_if< !is_convertible<const C*, const mutable_buffer*>::value && !is_convertible<const C*, const const_buffer*>::value >::type* = 0) BOOST_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 enable_if< !is_convertible<const C*, const mutable_buffer*>::value && !is_convertible<const C*, const const_buffer*>::value >::type* = 0) BOOST_ASIO_NOEXCEPT -> decltype(c.end()) { return c.end(); } #else // defined(BOOST_ASIO_HAS_DECLTYPE) || defined(GENERATING_DOCUMENTATION) template <typename C> inline typename C::iterator buffer_sequence_end(C& c, typename enable_if< !is_convertible<const C*, const mutable_buffer*>::value && !is_convertible<const C*, const const_buffer*>::value >::type* = 0) BOOST_ASIO_NOEXCEPT { return c.end(); } template <typename C> inline typename C::const_iterator buffer_sequence_end(const C& c, typename enable_if< !is_convertible<const C*, const mutable_buffer*>::value && !is_convertible<const C*, const const_buffer*>::value >::type* = 0) BOOST_ASIO_NOEXCEPT { return c.end(); } #endif // defined(BOOST_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(BOOST_ASIO_NO_DEPRECATED) || is_same<BufferSequence, mutable_buffers_1>::value || is_same<BufferSequence, const_buffers_1>::value #endif // !defined(BOOST_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) BOOST_ASIO_NOEXCEPT { return const_buffer(*begin).size(); } template <typename Iterator> inline std::size_t buffer_size(multiple_buffers, Iterator begin, Iterator end) BOOST_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 = boost::asio::buffer_sequence_begin(buffers); * auto end = boost::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) BOOST_ASIO_NOEXCEPT { return detail::buffer_size( detail::buffer_sequence_cardinality<BufferSequence>(), boost::asio::buffer_sequence_begin(b), boost::asio::buffer_sequence_end(b)); } #if !defined(BOOST_ASIO_NO_DEPRECATED) /** @defgroup buffer_cast boost::asio::buffer_cast * * @brief (Deprecated: Use the @c data() member function.) The * boost::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 boost::asio::const_buffer b1 = ...; * const unsigned char* p1 = boost::asio::buffer_cast<const unsigned char*>(b1); * @endcode * * To access the memory of a modifiable buffer, use: * @code boost::asio::mutable_buffer b2 = ...; * unsigned char* p2 = boost::asio::buffer_cast<unsigned char*>(b2); * @endcode * * The boost::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) BOOST_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) BOOST_ASIO_NOEXCEPT { return static_cast<PointerToPodType>(b.data()); } /*@}*/ #endif // !defined(BOOST_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) BOOST_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(BOOST_ASIO_ENABLE_BUFFER_DEBUGGING) , b.get_debug_check() #endif // BOOST_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) BOOST_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) BOOST_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(BOOST_ASIO_ENABLE_BUFFER_DEBUGGING) , b.get_debug_check() #endif // BOOST_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) BOOST_ASIO_NOEXCEPT { return b + n; } #if defined(BOOST_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(BOOST_ASIO_MSVC) && (BOOST_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(BOOST_ASIO_MSVC) && (BOOST_ASIO_MSVC == 1400) } void operator()() { (void)*iter_; } private: Iterator iter_; }; } // namespace detail #endif // BOOST_ASIO_ENABLE_BUFFER_DEBUGGING /** @defgroup buffer boost::asio::buffer * * @brief The boost::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(boost::asio::buffer(data, size)); @endcode * * In the above example, the return value of boost::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(boost::asio::buffer(d1)); * * std::vector<char> d2(128); * bytes_transferred = sock.receive(boost::asio::buffer(d2)); * * std::array<char, 128> d3; * bytes_transferred = sock.receive(boost::asio::buffer(d3)); * * boost::array<char, 128> d4; * bytes_transferred = sock.receive(boost::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 boost::asio::mutable_buffer b1 = ...; * std::size_t s1 = b1.size(); * unsigned char* p1 = static_cast<unsigned char*>(b1.data()); * * boost::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(boost::asio::buffer_size(buffers)); * boost::asio::buffer_copy(boost::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 boost::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 boost::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 = boost::asio::buffer(a); @endcode * * represents the entire array, <tt>{ 'a', 'b', 'c', 'd', 'e' }</tt>. An * optional second argument to the boost::asio::buffer function may be used to * limit the size, in bytes, of the buffer: * * @code b2 = boost::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 = boost::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 = { * boost::asio::buffer(d1), * boost::asio::buffer(d2), * boost::asio::buffer(d3) }; * bytes_transferred = sock.receive(bufs1); * * std::vector<const_buffer> bufs2; * bufs2.push_back(boost::asio::buffer(d1)); * bufs2.push_back(boost::asio::buffer(d2)); * bufs2.push_back(boost::asio::buffer(d3)); * bytes_transferred = sock.send(bufs2); @endcode */ /*@{*/ #if defined(BOOST_ASIO_NO_DEPRECATED) || defined(GENERATING_DOCUMENTATION) # define BOOST_ASIO_MUTABLE_BUFFER mutable_buffer # define BOOST_ASIO_CONST_BUFFER const_buffer #else // defined(BOOST_ASIO_NO_DEPRECATED) || defined(GENERATING_DOCUMENTATION) # define BOOST_ASIO_MUTABLE_BUFFER mutable_buffers_1 # define BOOST_ASIO_CONST_BUFFER const_buffers_1 #endif // defined(BOOST_ASIO_NO_DEPRECATED) || defined(GENERATING_DOCUMENTATION) /// Create a new modifiable buffer from an existing buffer. /** * @returns <tt>mutable_buffer(b)</tt>. */ inline BOOST_ASIO_MUTABLE_BUFFER buffer( const mutable_buffer& b) BOOST_ASIO_NOEXCEPT { return BOOST_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 BOOST_ASIO_MUTABLE_BUFFER buffer(const mutable_buffer& b, std::size_t max_size_in_bytes) BOOST_ASIO_NOEXCEPT { return BOOST_ASIO_MUTABLE_BUFFER( mutable_buffer(b.data(), b.size() < max_size_in_bytes ? b.size() : max_size_in_bytes #if defined(BOOST_ASIO_ENABLE_BUFFER_DEBUGGING) , b.get_debug_check() #endif // BOOST_ASIO_ENABLE_BUFFER_DEBUGGING )); } /// Create a new non-modifiable buffer from an existing buffer. /** * @returns <tt>const_buffer(b)</tt>. */ inline BOOST_ASIO_CONST_BUFFER buffer( const const_buffer& b) BOOST_ASIO_NOEXCEPT { return BOOST_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 BOOST_ASIO_CONST_BUFFER buffer(const const_buffer& b, std::size_t max_size_in_bytes) BOOST_ASIO_NOEXCEPT { return BOOST_ASIO_CONST_BUFFER(b.data(), b.size() < max_size_in_bytes ? b.size() : max_size_in_bytes #if defined(BOOST_ASIO_ENABLE_BUFFER_DEBUGGING) , b.get_debug_check() #endif // BOOST_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 BOOST_ASIO_MUTABLE_BUFFER buffer(void* data, std::size_t size_in_bytes) BOOST_ASIO_NOEXCEPT { return BOOST_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 BOOST_ASIO_CONST_BUFFER buffer(const void* data, std::size_t size_in_bytes) BOOST_ASIO_NOEXCEPT { return BOOST_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 BOOST_ASIO_MUTABLE_BUFFER buffer(PodType (&data)[N]) BOOST_ASIO_NOEXCEPT { return BOOST_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 BOOST_ASIO_MUTABLE_BUFFER buffer(PodType (&data)[N], std::size_t max_size_in_bytes) BOOST_ASIO_NOEXCEPT { return BOOST_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 BOOST_ASIO_CONST_BUFFER buffer( const PodType (&data)[N]) BOOST_ASIO_NOEXCEPT { return BOOST_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 BOOST_ASIO_CONST_BUFFER buffer(const PodType (&data)[N], std::size_t max_size_in_bytes) BOOST_ASIO_NOEXCEPT { return BOOST_ASIO_CONST_BUFFER(data, N * sizeof(PodType) < max_size_in_bytes ? N * sizeof(PodType) : max_size_in_bytes); } #if defined(BOOST_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 BOOST_ASIO_MUTABLE_BUFFER container_type; }; template <> struct buffer_types_base<true> { typedef const_buffer buffer_type; typedef BOOST_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) BOOST_ASIO_NOEXCEPT { typedef typename boost::asio::detail::buffer_types<PodType>::buffer_type buffer_type; typedef typename boost::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) BOOST_ASIO_NOEXCEPT { typedef typename boost::asio::detail::buffer_types<PodType>::buffer_type buffer_type; typedef typename boost::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(BOOST_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 BOOST_ASIO_MUTABLE_BUFFER buffer( boost::array<PodType, N>& data) BOOST_ASIO_NOEXCEPT { return BOOST_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 BOOST_ASIO_MUTABLE_BUFFER buffer(boost::array<PodType, N>& data, std::size_t max_size_in_bytes) BOOST_ASIO_NOEXCEPT { return BOOST_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 BOOST_ASIO_CONST_BUFFER buffer( boost::array<const PodType, N>& data) BOOST_ASIO_NOEXCEPT { return BOOST_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 BOOST_ASIO_CONST_BUFFER buffer(boost::array<const PodType, N>& data, std::size_t max_size_in_bytes) BOOST_ASIO_NOEXCEPT { return BOOST_ASIO_CONST_BUFFER(data.data(), data.size() * sizeof(PodType) < max_size_in_bytes ? data.size() * sizeof(PodType) : max_size_in_bytes); } #endif // defined(BOOST_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 BOOST_ASIO_CONST_BUFFER buffer( const boost::array<PodType, N>& data) BOOST_ASIO_NOEXCEPT { return BOOST_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 BOOST_ASIO_CONST_BUFFER buffer(const boost::array<PodType, N>& data, std::size_t max_size_in_bytes) BOOST_ASIO_NOEXCEPT { return BOOST_ASIO_CONST_BUFFER(data.data(), data.size() * sizeof(PodType) < max_size_in_bytes ? data.size() * sizeof(PodType) : max_size_in_bytes); } #if defined(BOOST_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 BOOST_ASIO_MUTABLE_BUFFER buffer( std::array<PodType, N>& data) BOOST_ASIO_NOEXCEPT { return BOOST_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 BOOST_ASIO_MUTABLE_BUFFER buffer(std::array<PodType, N>& data, std::size_t max_size_in_bytes) BOOST_ASIO_NOEXCEPT { return BOOST_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 BOOST_ASIO_CONST_BUFFER buffer( std::array<const PodType, N>& data) BOOST_ASIO_NOEXCEPT { return BOOST_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 BOOST_ASIO_CONST_BUFFER buffer(std::array<const PodType, N>& data, std::size_t max_size_in_bytes) BOOST_ASIO_NOEXCEPT { return BOOST_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 BOOST_ASIO_CONST_BUFFER buffer( const std::array<PodType, N>& data) BOOST_ASIO_NOEXCEPT { return BOOST_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 BOOST_ASIO_CONST_BUFFER buffer(const std::array<PodType, N>& data, std::size_t max_size_in_bytes) BOOST_ASIO_NOEXCEPT { return BOOST_ASIO_CONST_BUFFER(data.data(), data.size() * sizeof(PodType) < max_size_in_bytes ? data.size() * sizeof(PodType) : max_size_in_bytes); } #endif // defined(BOOST_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 BOOST_ASIO_MUTABLE_BUFFER buffer( std::vector<PodType, Allocator>& data) BOOST_ASIO_NOEXCEPT { return BOOST_ASIO_MUTABLE_BUFFER( data.size() ? &data[0] : 0, data.size() * sizeof(PodType) #if defined(BOOST_ASIO_ENABLE_BUFFER_DEBUGGING) , detail::buffer_debug_check< typename std::vector<PodType, Allocator>::iterator >(data.begin()) #endif // BOOST_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 BOOST_ASIO_MUTABLE_BUFFER buffer(std::vector<PodType, Allocator>& data, std::size_t max_size_in_bytes) BOOST_ASIO_NOEXCEPT { return BOOST_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(BOOST_ASIO_ENABLE_BUFFER_DEBUGGING) , detail::buffer_debug_check< typename std::vector<PodType, Allocator>::iterator >(data.begin()) #endif // BOOST_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 BOOST_ASIO_CONST_BUFFER buffer( const std::vector<PodType, Allocator>& data) BOOST_ASIO_NOEXCEPT { return BOOST_ASIO_CONST_BUFFER( data.size() ? &data[0] : 0, data.size() * sizeof(PodType) #if defined(BOOST_ASIO_ENABLE_BUFFER_DEBUGGING) , detail::buffer_debug_check< typename std::vector<PodType, Allocator>::const_iterator >(data.begin()) #endif // BOOST_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 BOOST_ASIO_CONST_BUFFER buffer( const std::vector<PodType, Allocator>& data, std::size_t max_size_in_bytes) BOOST_ASIO_NOEXCEPT { return BOOST_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(BOOST_ASIO_ENABLE_BUFFER_DEBUGGING) , detail::buffer_debug_check< typename std::vector<PodType, Allocator>::const_iterator >(data.begin()) #endif // BOOST_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 BOOST_ASIO_MUTABLE_BUFFER buffer( std::basic_string<Elem, Traits, Allocator>& data) BOOST_ASIO_NOEXCEPT { return BOOST_ASIO_MUTABLE_BUFFER(data.size() ? &data[0] : 0, data.size() * sizeof(Elem) #if defined(BOOST_ASIO_ENABLE_BUFFER_DEBUGGING) , detail::buffer_debug_check< typename std::basic_string<Elem, Traits, Allocator>::iterator >(data.begin()) #endif // BOOST_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 BOOST_ASIO_MUTABLE_BUFFER buffer( std::basic_string<Elem, Traits, Allocator>& data, std::size_t max_size_in_bytes) BOOST_ASIO_NOEXCEPT { return BOOST_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(BOOST_ASIO_ENABLE_BUFFER_DEBUGGING) , detail::buffer_debug_check< typename std::basic_string<Elem, Traits, Allocator>::iterator >(data.begin()) #endif // BOOST_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 BOOST_ASIO_CONST_BUFFER buffer( const std::basic_string<Elem, Traits, Allocator>& data) BOOST_ASIO_NOEXCEPT { return BOOST_ASIO_CONST_BUFFER(data.data(), data.size() * sizeof(Elem) #if defined(BOOST_ASIO_ENABLE_BUFFER_DEBUGGING) , detail::buffer_debug_check< typename std::basic_string<Elem, Traits, Allocator>::const_iterator >(data.begin()) #endif // BOOST_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 BOOST_ASIO_CONST_BUFFER buffer( const std::basic_string<Elem, Traits, Allocator>& data, std::size_t max_size_in_bytes) BOOST_ASIO_NOEXCEPT { return BOOST_ASIO_CONST_BUFFER(data.data(), data.size() * sizeof(Elem) < max_size_in_bytes ? data.size() * sizeof(Elem) : max_size_in_bytes #if defined(BOOST_ASIO_ENABLE_BUFFER_DEBUGGING) , detail::buffer_debug_check< typename std::basic_string<Elem, Traits, Allocator>::const_iterator >(data.begin()) #endif // BOOST_ASIO_ENABLE_BUFFER_DEBUGGING ); } #if defined(BOOST_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 BOOST_ASIO_CONST_BUFFER buffer( basic_string_view<Elem, Traits> data) BOOST_ASIO_NOEXCEPT { return BOOST_ASIO_CONST_BUFFER(data.size() ? &data[0] : 0, data.size() * sizeof(Elem) #if defined(BOOST_ASIO_ENABLE_BUFFER_DEBUGGING) , detail::buffer_debug_check< typename basic_string_view<Elem, Traits>::iterator >(data.begin()) #endif // BOOST_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 BOOST_ASIO_CONST_BUFFER buffer( basic_string_view<Elem, Traits> data, std::size_t max_size_in_bytes) BOOST_ASIO_NOEXCEPT { return BOOST_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(BOOST_ASIO_ENABLE_BUFFER_DEBUGGING) , detail::buffer_debug_check< typename basic_string_view<Elem, Traits>::iterator >(data.begin()) #endif // BOOST_ASIO_ENABLE_BUFFER_DEBUGGING ); } #endif // defined(BOOST_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 BOOST_ASIO_CONST_BUFFER const_buffers_type; /// The type used to represent a sequence of mutable buffers that refers to /// the underlying memory. typedef BOOST_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)()) BOOST_ASIO_NOEXCEPT : string_(s), #if !defined(BOOST_ASIO_NO_DYNAMIC_BUFFER_V1) size_((std::numeric_limits<std::size_t>::max)()), #endif // !defined(BOOST_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) BOOST_ASIO_NOEXCEPT : string_(other.string_), #if !defined(BOOST_ASIO_NO_DYNAMIC_BUFFER_V1) size_(other.size_), #endif // !defined(BOOST_ASIO_NO_DYNAMIC_BUFFER_V1) max_size_(other.max_size_) { } #if defined(BOOST_ASIO_HAS_MOVE) || defined(GENERATING_DOCUMENTATION) /// Move construct a dynamic buffer. dynamic_string_buffer(dynamic_string_buffer&& other) BOOST_ASIO_NOEXCEPT : string_(other.string_), #if !defined(BOOST_ASIO_NO_DYNAMIC_BUFFER_V1) size_(other.size_), #endif // !defined(BOOST_ASIO_NO_DYNAMIC_BUFFER_V1) max_size_(other.max_size_) { } #endif // defined(BOOST_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 BOOST_ASIO_NOEXCEPT { #if !defined(BOOST_ASIO_NO_DYNAMIC_BUFFER_V1) if (size_ != (std::numeric_limits<std::size_t>::max)()) return size_; #endif // !defined(BOOST_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 BOOST_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 BOOST_ASIO_NOEXCEPT { return (std::min)(string_.capacity(), max_size()); } #if !defined(BOOST_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 BOOST_ASIO_NOEXCEPT { return const_buffers_type(boost::asio::buffer(string_, size_)); } #endif // !defined(BOOST_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) BOOST_ASIO_NOEXCEPT { return mutable_buffers_type(boost::asio::buffer( boost::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 BOOST_ASIO_NOEXCEPT { return const_buffers_type(boost::asio::buffer( boost::asio::buffer(string_, max_size_) + pos, n)); } #if !defined(BOOST_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"); boost::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 boost::asio::buffer(boost::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(BOOST_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"); boost::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(BOOST_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(BOOST_ASIO_NO_DYNAMIC_BUFFER_V1) string_.erase(0, n); } private: std::basic_string<Elem, Traits, Allocator>& string_; #if !defined(BOOST_ASIO_NO_DYNAMIC_BUFFER_V1) std::size_t size_; #endif // !defined(BOOST_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 BOOST_ASIO_CONST_BUFFER const_buffers_type; /// The type used to represent a sequence of mutable buffers that refers to /// the underlying memory. typedef BOOST_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)()) BOOST_ASIO_NOEXCEPT : vector_(v), #if !defined(BOOST_ASIO_NO_DYNAMIC_BUFFER_V1) size_((std::numeric_limits<std::size_t>::max)()), #endif // !defined(BOOST_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) BOOST_ASIO_NOEXCEPT : vector_(other.vector_), #if !defined(BOOST_ASIO_NO_DYNAMIC_BUFFER_V1) size_(other.size_), #endif // !defined(BOOST_ASIO_NO_DYNAMIC_BUFFER_V1) max_size_(other.max_size_) { } #if defined(BOOST_ASIO_HAS_MOVE) || defined(GENERATING_DOCUMENTATION) /// Move construct a dynamic buffer. dynamic_vector_buffer(dynamic_vector_buffer&& other) BOOST_ASIO_NOEXCEPT : vector_(other.vector_), #if !defined(BOOST_ASIO_NO_DYNAMIC_BUFFER_V1) size_(other.size_), #endif // !defined(BOOST_ASIO_NO_DYNAMIC_BUFFER_V1) max_size_(other.max_size_) { } #endif // defined(BOOST_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 BOOST_ASIO_NOEXCEPT { #if !defined(BOOST_ASIO_NO_DYNAMIC_BUFFER_V1) if (size_ != (std::numeric_limits<std::size_t>::max)()) return size_; #endif // !defined(BOOST_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 BOOST_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 BOOST_ASIO_NOEXCEPT { return (std::min)(vector_.capacity(), max_size()); } #if !defined(BOOST_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 BOOST_ASIO_NOEXCEPT { return const_buffers_type(boost::asio::buffer(vector_, size_)); } #endif // !defined(BOOST_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) BOOST_ASIO_NOEXCEPT { return mutable_buffers_type(boost::asio::buffer( boost::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 BOOST_ASIO_NOEXCEPT { return const_buffers_type(boost::asio::buffer( boost::asio::buffer(vector_, max_size_) + pos, n)); } #if !defined(BOOST_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"); boost::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 boost::asio::buffer(boost::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(BOOST_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"); boost::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(BOOST_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(BOOST_ASIO_NO_DYNAMIC_BUFFER_V1) vector_.erase(vector_.begin(), vector_.begin() + (std::min)(size(), n)); } private: std::vector<Elem, Allocator>& vector_; #if !defined(BOOST_ASIO_NO_DYNAMIC_BUFFER_V1) std::size_t size_; #endif // !defined(BOOST_ASIO_NO_DYNAMIC_BUFFER_V1) const std::size_t max_size_; }; /** @defgroup dynamic_buffer boost::asio::dynamic_buffer * * @brief The boost::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) BOOST_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) BOOST_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) BOOST_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) BOOST_ASIO_NOEXCEPT { return dynamic_vector_buffer<Elem, Allocator>(data, max_size); } /*@}*/ /** @defgroup buffer_copy boost::asio::buffer_copy * * @brief The boost::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) BOOST_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) BOOST_ASIO_NOEXCEPT { return (buffer_copy_1)(*target_begin, boost::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)()) BOOST_ASIO_NOEXCEPT { std::size_t total_bytes_copied = 0; SourceIterator source_iter = source_begin; for (mutable_buffer target_buffer( boost::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)()) BOOST_ASIO_NOEXCEPT { std::size_t total_bytes_copied = 0; TargetIterator target_iter = target_begin; for (const_buffer source_buffer( boost::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) BOOST_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) BOOST_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, boost::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) BOOST_ASIO_NOEXCEPT { return detail::buffer_copy( detail::buffer_sequence_cardinality<MutableBufferSequence>(), detail::buffer_sequence_cardinality<ConstBufferSequence>(), boost::asio::buffer_sequence_begin(target), boost::asio::buffer_sequence_end(target), boost::asio::buffer_sequence_begin(source), boost::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) BOOST_ASIO_NOEXCEPT { return detail::buffer_copy( detail::buffer_sequence_cardinality<MutableBufferSequence>(), detail::buffer_sequence_cardinality<ConstBufferSequence>(), boost::asio::buffer_sequence_begin(target), boost::asio::buffer_sequence_end(target), boost::asio::buffer_sequence_begin(source), boost::asio::buffer_sequence_end(source), max_bytes_to_copy); } /*@}*/ } // namespace asio } // namespace boost #include <boost/asio/detail/pop_options.hpp> #include <boost/asio/detail/is_buffer_sequence.hpp> #include <boost/asio/detail/push_options.hpp> namespace boost { 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) : boost::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) : boost::asio::detail::is_buffer_sequence<T, const_buffer> #endif // defined(GENERATING_DOCUMENTATION) { }; #if !defined(BOOST_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) : boost::asio::detail::is_dynamic_buffer_v1<T> #endif // defined(GENERATING_DOCUMENTATION) { }; #endif // !defined(BOOST_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) : boost::asio::detail::is_dynamic_buffer_v2<T> #endif // defined(GENERATING_DOCUMENTATION) { }; /// Trait to determine whether a type satisfies the DynamicBuffer requirements. /** * If @c BOOST_ASIO_NO_DYNAMIC_BUFFER_V1 is not defined, determines whether the * type satisfies the DynamicBuffer_v1 requirements. Otherwise, if @c * BOOST_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(BOOST_ASIO_NO_DYNAMIC_BUFFER_V1) : boost::asio::is_dynamic_buffer_v2<T> #else // defined(BOOST_ASIO_NO_DYNAMIC_BUFFER_V1) : boost::asio::is_dynamic_buffer_v1<T> #endif // defined(BOOST_ASIO_NO_DYNAMIC_BUFFER_V1) { }; } // namespace asio } // namespace boost #include <boost/asio/detail/pop_options.hpp> #endif // BOOST_ASIO_BUFFER_HPP