// // buffer.hpp // ~~~~~~~~~~ // // Copyright (c) 2003-2007 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/push_options.hpp" #include "asio/detail/push_options.hpp" #include #include #include #include #include #include #include "asio/detail/pop_options.hpp" #if defined(BOOST_MSVC) # if defined(_HAS_ITERATOR_DEBUGGING) # if !defined(ASIO_DISABLE_BUFFER_DEBUGGING) # define ASIO_ENABLE_BUFFER_DEBUGGING # endif // !defined(ASIO_DISABLE_BUFFER_DEBUGGING) # endif // defined(_HAS_ITERATOR_DEBUGGING) #endif // defined(BOOST_MSVC) #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/push_options.hpp" # include # include "asio/detail/pop_options.hpp" #endif // ASIO_ENABLE_BUFFER_DEBUGGING namespace asio { class mutable_buffer; class const_buffer; namespace detail { void* buffer_cast_helper(const mutable_buffer&); const void* buffer_cast_helper(const const_buffer&); std::size_t buffer_size_helper(const mutable_buffer&); std::size_t buffer_size_helper(const const_buffer&); } // namespace detail /// 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. */ class mutable_buffer { public: /// Construct an empty buffer. mutable_buffer() : data_(0), size_(0) { } /// Construct a buffer to represent a given memory range. mutable_buffer(void* data, std::size_t size) : data_(data), size_(size) { } #if defined(ASIO_ENABLE_BUFFER_DEBUGGING) mutable_buffer(void* data, std::size_t size, boost::function debug_check) : data_(data), size_(size), debug_check_(debug_check) { } const boost::function& get_debug_check() const { return debug_check_; } #endif // ASIO_ENABLE_BUFFER_DEBUGGING private: friend void* asio::detail::buffer_cast_helper( const mutable_buffer& b); friend std::size_t asio::detail::buffer_size_helper( const mutable_buffer& b); void* data_; std::size_t size_; #if defined(ASIO_ENABLE_BUFFER_DEBUGGING) boost::function debug_check_; #endif // ASIO_ENABLE_BUFFER_DEBUGGING }; namespace detail { inline void* buffer_cast_helper(const mutable_buffer& b) { #if defined(ASIO_ENABLE_BUFFER_DEBUGGING) if (b.size_ && b.debug_check_) b.debug_check_(); #endif // ASIO_ENABLE_BUFFER_DEBUGGING return b.data_; } inline std::size_t buffer_size_helper(const mutable_buffer& b) { return b.size_; } } // namespace detail /// Cast a non-modifiable buffer to a specified pointer to POD type. /** * @relates mutable_buffer */ template inline PointerToPodType buffer_cast(const mutable_buffer& b) { return static_cast(detail::buffer_cast_helper(b)); } /// Get the number of bytes in a non-modifiable buffer. /** * @relates mutable_buffer */ inline std::size_t buffer_size(const mutable_buffer& b) { return detail::buffer_size_helper(b); } /// 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 start) { if (start > buffer_size(b)) return mutable_buffer(); char* new_data = buffer_cast(b) + start; std::size_t new_size = buffer_size(b) - start; 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 start, const mutable_buffer& b) { if (start > buffer_size(b)) return mutable_buffer(); char* new_data = buffer_cast(b) + start; std::size_t new_size = buffer_size(b) - start; return mutable_buffer(new_data, new_size #if defined(ASIO_ENABLE_BUFFER_DEBUGGING) , b.get_debug_check() #endif // ASIO_ENABLE_BUFFER_DEBUGGING ); } /// 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 single modifiable buffer. explicit mutable_buffers_1(const mutable_buffer& b) : mutable_buffer(b) { } /// Get a random-access iterator to the first element. const_iterator begin() const { return this; } /// Get a random-access iterator for one past the last element. const_iterator end() const { return begin() + 1; } }; /// 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. */ class const_buffer { public: /// Construct an empty buffer. const_buffer() : data_(0), size_(0) { } /// Construct a buffer to represent a given memory range. const_buffer(const void* data, std::size_t size) : data_(data), size_(size) { } /// Construct a non-modifiable buffer from a modifiable one. const_buffer(const mutable_buffer& b) : data_(asio::detail::buffer_cast_helper(b)), size_(asio::detail::buffer_size_helper(b)) #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, boost::function debug_check) : data_(data), size_(size), debug_check_(debug_check) { } const boost::function& get_debug_check() const { return debug_check_; } #endif // ASIO_ENABLE_BUFFER_DEBUGGING private: friend const void* asio::detail::buffer_cast_helper( const const_buffer& b); friend std::size_t asio::detail::buffer_size_helper( const const_buffer& b); const void* data_; std::size_t size_; #if defined(ASIO_ENABLE_BUFFER_DEBUGGING) boost::function debug_check_; #endif // ASIO_ENABLE_BUFFER_DEBUGGING }; namespace detail { inline const void* buffer_cast_helper(const const_buffer& b) { #if defined(ASIO_ENABLE_BUFFER_DEBUGGING) if (b.size_ && b.debug_check_) b.debug_check_(); #endif // ASIO_ENABLE_BUFFER_DEBUGGING return b.data_; } inline std::size_t buffer_size_helper(const const_buffer& b) { return b.size_; } } // namespace detail /// Cast a non-modifiable buffer to a specified pointer to POD type. /** * @relates const_buffer */ template inline PointerToPodType buffer_cast(const const_buffer& b) { return static_cast(detail::buffer_cast_helper(b)); } /// Get the number of bytes in a non-modifiable buffer. /** * @relates const_buffer */ inline std::size_t buffer_size(const const_buffer& b) { return detail::buffer_size_helper(b); } /// 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 start) { if (start > buffer_size(b)) return const_buffer(); const char* new_data = buffer_cast(b) + start; std::size_t new_size = buffer_size(b) - start; 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 start, const const_buffer& b) { if (start > buffer_size(b)) return const_buffer(); const char* new_data = buffer_cast(b) + start; std::size_t new_size = buffer_size(b) - start; return const_buffer(new_data, new_size #if defined(ASIO_ENABLE_BUFFER_DEBUGGING) , b.get_debug_check() #endif // ASIO_ENABLE_BUFFER_DEBUGGING ); } /// 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 single non-modifiable buffer. explicit const_buffers_1(const const_buffer& b) : const_buffer(b) { } /// Get a random-access iterator to the first element. const_iterator begin() const { return this; } /// Get a random-access iterator for one past the last element. const_iterator end() const { return begin() + 1; } }; #if defined(ASIO_ENABLE_BUFFER_DEBUGGING) namespace detail { template class buffer_debug_check { public: buffer_debug_check(Iterator iter) : iter_(iter) { } void operator()() { *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, or a vector of POD elements. * * The simplest use case involves reading or writing a single buffer of a * specified size: * * @code sock.write(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 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.read(asio::buffer(d1)); * * std::vector d2(128); * bytes_transferred = sock.read(asio::buffer(d2)); * * boost::array d3; * bytes_transferred = sock.read(asio::buffer(d3)); @endcode * * 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 d2(128); * boost::array d3; * * boost::array bufs1 = { * asio::buffer(d1), * asio::buffer(d2), * asio::buffer(d3) }; * bytes_transferred = sock.read(bufs1); * * std::vector bufs2; * bufs2.push_back(asio::buffer(d1)); * bufs2.push_back(asio::buffer(d2)); * bufs2.push_back(asio::buffer(d3)); * bytes_transferred = sock.write(bufs2); @endcode */ /*@{*/ /// Create a new modifiable buffer from an existing buffer. inline mutable_buffers_1 buffer(const mutable_buffer& b) { return mutable_buffers_1(b); } /// Create a new modifiable buffer from an existing buffer. inline mutable_buffers_1 buffer(const mutable_buffer& b, std::size_t max_size_in_bytes) { return mutable_buffers_1( mutable_buffer(buffer_cast(b), buffer_size(b) < max_size_in_bytes ? buffer_size(b) : 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. inline const_buffers_1 buffer(const const_buffer& b) { return const_buffers_1(b); } /// Create a new non-modifiable buffer from an existing buffer. inline const_buffers_1 buffer(const const_buffer& b, std::size_t max_size_in_bytes) { return const_buffers_1( const_buffer(buffer_cast(b), buffer_size(b) < max_size_in_bytes ? buffer_size(b) : 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. inline mutable_buffers_1 buffer(void* data, std::size_t size_in_bytes) { return mutable_buffers_1(mutable_buffer(data, size_in_bytes)); } /// Create a new non-modifiable buffer that represents the given memory range. inline const_buffers_1 buffer(const void* data, std::size_t size_in_bytes) { return const_buffers_1(const_buffer(data, size_in_bytes)); } /// Create a new modifiable buffer that represents the given POD array. template inline mutable_buffers_1 buffer(PodType (&data)[N]) { return mutable_buffers_1(mutable_buffer(data, N * sizeof(PodType))); } /// Create a new modifiable buffer that represents the given POD array. template inline mutable_buffers_1 buffer(PodType (&data)[N], std::size_t max_size_in_bytes) { return mutable_buffers_1( 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. template inline const_buffers_1 buffer(const PodType (&data)[N]) { return const_buffers_1(const_buffer(data, N * sizeof(PodType))); } /// Create a new non-modifiable buffer that represents the given POD array. template inline const_buffers_1 buffer(const PodType (&data)[N], std::size_t max_size_in_bytes) { return const_buffers_1( const_buffer(data, N * sizeof(PodType) < max_size_in_bytes ? N * sizeof(PodType) : max_size_in_bytes)); } #if BOOST_WORKAROUND(__BORLANDC__, BOOST_TESTED_AT(0x582)) \ || BOOST_WORKAROUND(__SUNPRO_CC, BOOST_TESTED_AT(0x590)) // Borland C++ and Sun Studio think the overloads: // // unspecified buffer(boost::array& array ...); // // and // // unspecified buffer(boost::array& 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 struct buffer_types_base; template <> struct buffer_types_base { typedef mutable_buffer buffer_type; typedef mutable_buffers_1 container_type; }; template <> struct buffer_types_base { typedef const_buffer buffer_type; typedef const_buffers_1 container_type; }; template struct buffer_types : public buffer_types_base::value> { }; } // namespace detail template inline typename detail::buffer_types::container_type buffer(boost::array& data) { typedef typename asio::detail::buffer_types::buffer_type buffer_type; typedef typename asio::detail::buffer_types::container_type container_type; return container_type( buffer_type(data.c_array(), data.size() * sizeof(PodType))); } template inline typename detail::buffer_types::container_type buffer(boost::array& data, std::size_t max_size_in_bytes) { typedef typename asio::detail::buffer_types::buffer_type buffer_type; typedef typename asio::detail::buffer_types::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 // BOOST_WORKAROUND(__BORLANDC__, BOOST_TESTED_AT(0x582)) // || BOOST_WORKAROUND(__SUNPRO_CC, BOOST_TESTED_AT(0x590)) /// Create a new modifiable buffer that represents the given POD array. template inline mutable_buffers_1 buffer(boost::array& data) { return mutable_buffers_1( mutable_buffer(data.c_array(), data.size() * sizeof(PodType))); } /// Create a new modifiable buffer that represents the given POD array. template inline mutable_buffers_1 buffer(boost::array& data, std::size_t max_size_in_bytes) { return mutable_buffers_1( 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. template inline const_buffers_1 buffer(boost::array& data) { return const_buffers_1( const_buffer(data.data(), data.size() * sizeof(PodType))); } /// Create a new non-modifiable buffer that represents the given POD array. template inline const_buffers_1 buffer(boost::array& data, std::size_t max_size_in_bytes) { return const_buffers_1( const_buffer(data.data(), data.size() * sizeof(PodType) < max_size_in_bytes ? data.size() * sizeof(PodType) : max_size_in_bytes)); } #endif // BOOST_WORKAROUND(__BORLANDC__, BOOST_TESTED_AT(0x582)) // || BOOST_WORKAROUND(__SUNPRO_CC, BOOST_TESTED_AT(0x590)) /// Create a new non-modifiable buffer that represents the given POD array. template inline const_buffers_1 buffer(const boost::array& data) { return const_buffers_1( const_buffer(data.data(), data.size() * sizeof(PodType))); } /// Create a new non-modifiable buffer that represents the given POD array. template inline const_buffers_1 buffer(const boost::array& data, std::size_t max_size_in_bytes) { return const_buffers_1( const_buffer(data.data(), data.size() * sizeof(PodType) < max_size_in_bytes ? data.size() * sizeof(PodType) : max_size_in_bytes)); } /// Create a new modifiable buffer that represents the given POD vector. /** * @note The buffer is invalidated by any vector operation that would also * invalidate iterators. */ template inline mutable_buffers_1 buffer(std::vector& data) { return mutable_buffers_1( mutable_buffer(&data[0], data.size() * sizeof(PodType) #if defined(ASIO_ENABLE_BUFFER_DEBUGGING) , detail::buffer_debug_check< typename std::vector::iterator >(data.begin()) #endif // ASIO_ENABLE_BUFFER_DEBUGGING )); } /// Create a new modifiable buffer that represents the given POD vector. /** * @note The buffer is invalidated by any vector operation that would also * invalidate iterators. */ template inline mutable_buffers_1 buffer(std::vector& data, std::size_t max_size_in_bytes) { return mutable_buffers_1( mutable_buffer(&data[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::iterator >(data.begin()) #endif // ASIO_ENABLE_BUFFER_DEBUGGING )); } /// Create a new non-modifiable buffer that represents the given POD vector. /** * @note The buffer is invalidated by any vector operation that would also * invalidate iterators. */ template inline const_buffers_1 buffer( const std::vector& data) { return const_buffers_1( const_buffer(&data[0], data.size() * sizeof(PodType) #if defined(ASIO_ENABLE_BUFFER_DEBUGGING) , detail::buffer_debug_check< typename std::vector::const_iterator >(data.begin()) #endif // ASIO_ENABLE_BUFFER_DEBUGGING )); } /// Create a new non-modifiable buffer that represents the given POD vector. /** * @note The buffer is invalidated by any vector operation that would also * invalidate iterators. */ template inline const_buffers_1 buffer( const std::vector& data, std::size_t max_size_in_bytes) { return const_buffers_1( const_buffer(&data[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::const_iterator >(data.begin()) #endif // ASIO_ENABLE_BUFFER_DEBUGGING )); } /// Create a new non-modifiable buffer that represents the given string. /** * @note The buffer is invalidated by any non-const operation called on the * given string object. */ inline const_buffers_1 buffer(const std::string& data) { return const_buffers_1(const_buffer(data.data(), data.size() #if defined(ASIO_ENABLE_BUFFER_DEBUGGING) , detail::buffer_debug_check(data.begin()) #endif // ASIO_ENABLE_BUFFER_DEBUGGING )); } /// Create a new non-modifiable buffer that represents the given string. /** * @note The buffer is invalidated by any non-const operation called on the * given string object. */ inline const_buffers_1 buffer(const std::string& data, std::size_t max_size_in_bytes) { return const_buffers_1( const_buffer(data.data(), data.size() < max_size_in_bytes ? data.size() : max_size_in_bytes #if defined(ASIO_ENABLE_BUFFER_DEBUGGING) , detail::buffer_debug_check(data.begin()) #endif // ASIO_ENABLE_BUFFER_DEBUGGING )); } /*@}*/ } // namespace asio #include "asio/detail/pop_options.hpp" #endif // ASIO_BUFFER_HPP