diff options
Diffstat (limited to 'lib/asio/read_until.hpp')
| -rw-r--r-- | lib/asio/read_until.hpp | 1824 |
1 files changed, 1824 insertions, 0 deletions
diff --git a/lib/asio/read_until.hpp b/lib/asio/read_until.hpp new file mode 100644 index 0000000..f413d98 --- /dev/null +++ b/lib/asio/read_until.hpp @@ -0,0 +1,1824 @@ +// +// read_until.hpp +// ~~~~~~~~~~~~~~ +// +// Copyright (c) 2003-2018 Christopher M. Kohlhoff (chris at kohlhoff dot com) +// +// Distributed under the Boost Software License, Version 1.0. (See accompanying +// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt) +// + +#ifndef ASIO_READ_UNTIL_HPP +#define ASIO_READ_UNTIL_HPP + +#if defined(_MSC_VER) && (_MSC_VER >= 1200) +# pragma once +#endif // defined(_MSC_VER) && (_MSC_VER >= 1200) + +#include "asio/detail/config.hpp" +#include <cstddef> +#include <string> +#include "asio/async_result.hpp" +#include "asio/detail/regex_fwd.hpp" +#include "asio/detail/string_view.hpp" +#include "asio/detail/type_traits.hpp" +#include "asio/error.hpp" + +#if !defined(ASIO_NO_EXTENSIONS) +# include "asio/basic_streambuf_fwd.hpp" +#endif // !defined(ASIO_NO_EXTENSIONS) + +#include "asio/detail/push_options.hpp" + +namespace asio { + +namespace detail +{ + char (&has_result_type_helper(...))[2]; + + template <typename T> + char has_result_type_helper(T*, typename T::result_type* = 0); + + template <typename T> + struct has_result_type + { + enum { value = (sizeof((has_result_type_helper)((T*)(0))) == 1) }; + }; +} // namespace detail + +/// Type trait used to determine whether a type can be used as a match condition +/// function with read_until and async_read_until. +template <typename T> +struct is_match_condition +{ +#if defined(GENERATING_DOCUMENTATION) + /// The value member is true if the type may be used as a match condition. + static const bool value; +#else + enum + { + value = asio::is_function< + typename asio::remove_pointer<T>::type>::value + || detail::has_result_type<T>::value + }; +#endif +}; + +/** + * @defgroup read_until asio::read_until + * + * @brief Read data into a dynamic buffer sequence, or into a streambuf, until + * it contains a delimiter, matches a regular expression, or a function object + * indicates a match. + */ +/*@{*/ + +/// Read data into a dynamic buffer sequence until it contains a specified +/// delimiter. +/** + * This function is used to read data into the specified dynamic buffer + * sequence until the dynamic buffer sequence's get area contains the specified + * delimiter. The call will block until one of the following conditions is + * true: + * + * @li The get area of the dynamic buffer sequence contains the specified + * delimiter. + * + * @li An error occurred. + * + * This operation is implemented in terms of zero or more calls to the stream's + * read_some function. If the dynamic buffer sequence's get area already + * contains the delimiter, the function returns immediately. + * + * @param s The stream from which the data is to be read. The type must support + * the SyncReadStream concept. + * + * @param buffers The dynamic buffer sequence into which the data will be read. + * + * @param delim The delimiter character. + * + * @returns The number of bytes in the dynamic buffer sequence's get area up to + * and including the delimiter. + * + * @throws asio::system_error Thrown on failure. + * + * @note After a successful read_until operation, the dynamic buffer sequence + * may contain additional data beyond the delimiter. An application will + * typically leave that data in the dynamic buffer sequence for a subsequent + * read_until operation to examine. + * + * @par Example + * To read data into a @c std::string until a newline is encountered: + * @code std::string data; + * std::string n = asio::read_until(s, + * asio::dynamic_buffer(data), '\n'); + * std::string line = data.substr(0, n); + * data.erase(0, n); @endcode + * After the @c read_until operation completes successfully, the string @c data + * contains the delimiter: + * @code { 'a', 'b', ..., 'c', '\n', 'd', 'e', ... } @endcode + * The call to @c substr then extracts the data up to and including the + * delimiter, so that the string @c line contains: + * @code { 'a', 'b', ..., 'c', '\n' } @endcode + * After the call to @c erase, the remaining data is left in the buffer @c b as + * follows: + * @code { 'd', 'e', ... } @endcode + * This data may be the start of a new line, to be extracted by a subsequent + * @c read_until operation. + */ +template <typename SyncReadStream, typename DynamicBuffer> +std::size_t read_until(SyncReadStream& s, + ASIO_MOVE_ARG(DynamicBuffer) buffers, char delim); + +/// Read data into a dynamic buffer sequence until it contains a specified +/// delimiter. +/** + * This function is used to read data into the specified dynamic buffer + * sequence until the dynamic buffer sequence's get area contains the specified + * delimiter. The call will block until one of the following conditions is + * true: + * + * @li The get area of the dynamic buffer sequence contains the specified + * delimiter. + * + * @li An error occurred. + * + * This operation is implemented in terms of zero or more calls to the stream's + * read_some function. If the dynamic buffer sequence's get area already + * contains the delimiter, the function returns immediately. + * + * @param s The stream from which the data is to be read. The type must support + * the SyncReadStream concept. + * + * @param buffers The dynamic buffer sequence into which the data will be read. + * + * @param delim The delimiter character. + * + * @param ec Set to indicate what error occurred, if any. + * + * @returns The number of bytes in the dynamic buffer sequence's get area up to + * and including the delimiter. Returns 0 if an error occurred. + * + * @note After a successful read_until operation, the dynamic buffer sequence + * may contain additional data beyond the delimiter. An application will + * typically leave that data in the dynamic buffer sequence for a subsequent + * read_until operation to examine. + */ +template <typename SyncReadStream, typename DynamicBuffer> +std::size_t read_until(SyncReadStream& s, + ASIO_MOVE_ARG(DynamicBuffer) buffers, + char delim, asio::error_code& ec); + +/// Read data into a dynamic buffer sequence until it contains a specified +/// delimiter. +/** + * This function is used to read data into the specified dynamic buffer + * sequence until the dynamic buffer sequence's get area contains the specified + * delimiter. The call will block until one of the following conditions is + * true: + * + * @li The get area of the dynamic buffer sequence contains the specified + * delimiter. + * + * @li An error occurred. + * + * This operation is implemented in terms of zero or more calls to the stream's + * read_some function. If the dynamic buffer sequence's get area already + * contains the delimiter, the function returns immediately. + * + * @param s The stream from which the data is to be read. The type must support + * the SyncReadStream concept. + * + * @param buffers The dynamic buffer sequence into which the data will be read. + * + * @param delim The delimiter string. + * + * @returns The number of bytes in the dynamic buffer sequence's get area up to + * and including the delimiter. + * + * @note After a successful read_until operation, the dynamic buffer sequence + * may contain additional data beyond the delimiter. An application will + * typically leave that data in the dynamic buffer sequence for a subsequent + * read_until operation to examine. + * + * @par Example + * To read data into a @c std::string until a CR-LF sequence is encountered: + * @code std::string data; + * std::string n = asio::read_until(s, + * asio::dynamic_buffer(data), "\r\n"); + * std::string line = data.substr(0, n); + * data.erase(0, n); @endcode + * After the @c read_until operation completes successfully, the string @c data + * contains the delimiter: + * @code { 'a', 'b', ..., 'c', '\r', '\n', 'd', 'e', ... } @endcode + * The call to @c substr then extracts the data up to and including the + * delimiter, so that the string @c line contains: + * @code { 'a', 'b', ..., 'c', '\r', '\n' } @endcode + * After the call to @c erase, the remaining data is left in the buffer @c b as + * follows: + * @code { 'd', 'e', ... } @endcode + * This data may be the start of a new line, to be extracted by a subsequent + * @c read_until operation. + */ +template <typename SyncReadStream, typename DynamicBuffer> +std::size_t read_until(SyncReadStream& s, + ASIO_MOVE_ARG(DynamicBuffer) buffers, + ASIO_STRING_VIEW_PARAM delim); + +/// Read data into a dynamic buffer sequence until it contains a specified +/// delimiter. +/** + * This function is used to read data into the specified dynamic buffer + * sequence until the dynamic buffer sequence's get area contains the specified + * delimiter. The call will block until one of the following conditions is + * true: + * + * @li The get area of the dynamic buffer sequence contains the specified + * delimiter. + * + * @li An error occurred. + * + * This operation is implemented in terms of zero or more calls to the stream's + * read_some function. If the dynamic buffer sequence's get area already + * contains the delimiter, the function returns immediately. + * + * @param s The stream from which the data is to be read. The type must support + * the SyncReadStream concept. + * + * @param buffers The dynamic buffer sequence into which the data will be read. + * + * @param delim The delimiter string. + * + * @param ec Set to indicate what error occurred, if any. + * + * @returns The number of bytes in the dynamic buffer sequence's get area up to + * and including the delimiter. Returns 0 if an error occurred. + * + * @note After a successful read_until operation, the dynamic buffer sequence + * may contain additional data beyond the delimiter. An application will + * typically leave that data in the dynamic buffer sequence for a subsequent + * read_until operation to examine. + */ +template <typename SyncReadStream, typename DynamicBuffer> +std::size_t read_until(SyncReadStream& s, + ASIO_MOVE_ARG(DynamicBuffer) buffers, + ASIO_STRING_VIEW_PARAM delim, + asio::error_code& ec); + +#if !defined(ASIO_NO_EXTENSIONS) +#if defined(ASIO_HAS_BOOST_REGEX) \ + || defined(GENERATING_DOCUMENTATION) + +/// Read data into a dynamic buffer sequence until some part of the data it +/// contains matches a regular expression. +/** + * This function is used to read data into the specified dynamic buffer + * sequence until the dynamic buffer sequence's get area contains some data + * that matches a regular expression. The call will block until one of the + * following conditions is true: + * + * @li A substring of the dynamic buffer sequence's get area matches the + * regular expression. + * + * @li An error occurred. + * + * This operation is implemented in terms of zero or more calls to the stream's + * read_some function. If the dynamic buffer sequence's get area already + * contains data that matches the regular expression, the function returns + * immediately. + * + * @param s The stream from which the data is to be read. The type must support + * the SyncReadStream concept. + * + * @param buffers A dynamic buffer sequence into which the data will be read. + * + * @param expr The regular expression. + * + * @returns The number of bytes in the dynamic buffer sequence's get area up to + * and including the substring that matches the regular expression. + * + * @throws asio::system_error Thrown on failure. + * + * @note After a successful read_until operation, the dynamic buffer sequence + * may contain additional data beyond that which matched the regular + * expression. An application will typically leave that data in the dynamic + * buffer sequence for a subsequent read_until operation to examine. + * + * @par Example + * To read data into a @c std::string until a CR-LF sequence is encountered: + * @code std::string data; + * std::string n = asio::read_until(s, + * asio::dynamic_buffer(data), boost::regex("\r\n")); + * std::string line = data.substr(0, n); + * data.erase(0, n); @endcode + * After the @c read_until operation completes successfully, the string @c data + * contains the delimiter: + * @code { 'a', 'b', ..., 'c', '\r', '\n', 'd', 'e', ... } @endcode + * The call to @c substr then extracts the data up to and including the + * delimiter, so that the string @c line contains: + * @code { 'a', 'b', ..., 'c', '\r', '\n' } @endcode + * After the call to @c erase, the remaining data is left in the buffer @c b as + * follows: + * @code { 'd', 'e', ... } @endcode + * This data may be the start of a new line, to be extracted by a subsequent + * @c read_until operation. + */ +template <typename SyncReadStream, typename DynamicBuffer> +std::size_t read_until(SyncReadStream& s, + ASIO_MOVE_ARG(DynamicBuffer) buffers, + const boost::regex& expr); + +/// Read data into a dynamic buffer sequence until some part of the data it +/// contains matches a regular expression. +/** + * This function is used to read data into the specified dynamic buffer + * sequence until the dynamic buffer sequence's get area contains some data + * that matches a regular expression. The call will block until one of the + * following conditions is true: + * + * @li A substring of the dynamic buffer sequence's get area matches the + * regular expression. + * + * @li An error occurred. + * + * This operation is implemented in terms of zero or more calls to the stream's + * read_some function. If the dynamic buffer sequence's get area already + * contains data that matches the regular expression, the function returns + * immediately. + * + * @param s The stream from which the data is to be read. The type must support + * the SyncReadStream concept. + * + * @param buffers A dynamic buffer sequence into which the data will be read. + * + * @param expr The regular expression. + * + * @param ec Set to indicate what error occurred, if any. + * + * @returns The number of bytes in the dynamic buffer sequence's get area up to + * and including the substring that matches the regular expression. Returns 0 + * if an error occurred. + * + * @note After a successful read_until operation, the dynamic buffer sequence + * may contain additional data beyond that which matched the regular + * expression. An application will typically leave that data in the dynamic + * buffer sequence for a subsequent read_until operation to examine. + */ +template <typename SyncReadStream, typename DynamicBuffer> +std::size_t read_until(SyncReadStream& s, + ASIO_MOVE_ARG(DynamicBuffer) buffers, + const boost::regex& expr, asio::error_code& ec); + +#endif // defined(ASIO_HAS_BOOST_REGEX) + // || defined(GENERATING_DOCUMENTATION) + +/// Read data into a dynamic buffer sequence until a function object indicates a +/// match. + +/** + * This function is used to read data into the specified dynamic buffer + * sequence until a user-defined match condition function object, when applied + * to the data contained in the dynamic buffer sequence, indicates a successful + * match. The call will block until one of the following conditions is true: + * + * @li The match condition function object returns a std::pair where the second + * element evaluates to true. + * + * @li An error occurred. + * + * This operation is implemented in terms of zero or more calls to the stream's + * read_some function. If the match condition function object already indicates + * a match, the function returns immediately. + * + * @param s The stream from which the data is to be read. The type must support + * the SyncReadStream concept. + * + * @param buffers A dynamic buffer sequence into which the data will be read. + * + * @param match_condition The function object to be called to determine whether + * a match exists. The signature of the function object must be: + * @code pair<iterator, bool> match_condition(iterator begin, iterator end); + * @endcode + * where @c iterator represents the type: + * @code buffers_iterator<typename DynamicBuffer::const_buffers_type> + * @endcode + * The iterator parameters @c begin and @c end define the range of bytes to be + * scanned to determine whether there is a match. The @c first member of the + * return value is an iterator marking one-past-the-end of the bytes that have + * been consumed by the match function. This iterator is used to calculate the + * @c begin parameter for any subsequent invocation of the match condition. The + * @c second member of the return value is true if a match has been found, false + * otherwise. + * + * @returns The number of bytes in the dynamic_buffer's get area that + * have been fully consumed by the match function. + * + * @throws asio::system_error Thrown on failure. + * + * @note After a successful read_until operation, the dynamic buffer sequence + * may contain additional data beyond that which matched the function object. + * An application will typically leave that data in the dynamic buffer sequence + * for a subsequent read_until operation to examine. + + * @note The default implementation of the @c is_match_condition type trait + * evaluates to true for function pointers and function objects with a + * @c result_type typedef. It must be specialised for other user-defined + * function objects. + * + * @par Examples + * To read data into a dynamic buffer sequence until whitespace is encountered: + * @code typedef asio::buffers_iterator< + * asio::const_buffers_1> iterator; + * + * std::pair<iterator, bool> + * match_whitespace(iterator begin, iterator end) + * { + * iterator i = begin; + * while (i != end) + * if (std::isspace(*i++)) + * return std::make_pair(i, true); + * return std::make_pair(i, false); + * } + * ... + * std::string data; + * asio::read_until(s, data, match_whitespace); + * @endcode + * + * To read data into a @c std::string until a matching character is found: + * @code class match_char + * { + * public: + * explicit match_char(char c) : c_(c) {} + * + * template <typename Iterator> + * std::pair<Iterator, bool> operator()( + * Iterator begin, Iterator end) const + * { + * Iterator i = begin; + * while (i != end) + * if (c_ == *i++) + * return std::make_pair(i, true); + * return std::make_pair(i, false); + * } + * + * private: + * char c_; + * }; + * + * namespace asio { + * template <> struct is_match_condition<match_char> + * : public boost::true_type {}; + * } // namespace asio + * ... + * std::string data; + * asio::read_until(s, data, match_char('a')); + * @endcode + */ +template <typename SyncReadStream, + typename DynamicBuffer, typename MatchCondition> +std::size_t read_until(SyncReadStream& s, + ASIO_MOVE_ARG(DynamicBuffer) buffers, + MatchCondition match_condition, + typename enable_if<is_match_condition<MatchCondition>::value>::type* = 0); + +/// Read data into a dynamic buffer sequence until a function object indicates a +/// match. +/** + * This function is used to read data into the specified dynamic buffer + * sequence until a user-defined match condition function object, when applied + * to the data contained in the dynamic buffer sequence, indicates a successful + * match. The call will block until one of the following conditions is true: + * + * @li The match condition function object returns a std::pair where the second + * element evaluates to true. + * + * @li An error occurred. + * + * This operation is implemented in terms of zero or more calls to the stream's + * read_some function. If the match condition function object already indicates + * a match, the function returns immediately. + * + * @param s The stream from which the data is to be read. The type must support + * the SyncReadStream concept. + * + * @param buffers A dynamic buffer sequence into which the data will be read. + * + * @param match_condition The function object to be called to determine whether + * a match exists. The signature of the function object must be: + * @code pair<iterator, bool> match_condition(iterator begin, iterator end); + * @endcode + * where @c iterator represents the type: + * @code buffers_iterator<DynamicBuffer::const_buffers_type> + * @endcode + * The iterator parameters @c begin and @c end define the range of bytes to be + * scanned to determine whether there is a match. The @c first member of the + * return value is an iterator marking one-past-the-end of the bytes that have + * been consumed by the match function. This iterator is used to calculate the + * @c begin parameter for any subsequent invocation of the match condition. The + * @c second member of the return value is true if a match has been found, false + * otherwise. + * + * @param ec Set to indicate what error occurred, if any. + * + * @returns The number of bytes in the dynamic buffer sequence's get area that + * have been fully consumed by the match function. Returns 0 if an error + * occurred. + * + * @note After a successful read_until operation, the dynamic buffer sequence + * may contain additional data beyond that which matched the function object. + * An application will typically leave that data in the dynamic buffer sequence + * for a subsequent read_until operation to examine. + * + * @note The default implementation of the @c is_match_condition type trait + * evaluates to true for function pointers and function objects with a + * @c result_type typedef. It must be specialised for other user-defined + * function objects. + */ +template <typename SyncReadStream, + typename DynamicBuffer, typename MatchCondition> +std::size_t read_until(SyncReadStream& s, + ASIO_MOVE_ARG(DynamicBuffer) buffers, + MatchCondition match_condition, asio::error_code& ec, + typename enable_if<is_match_condition<MatchCondition>::value>::type* = 0); + +#if !defined(ASIO_NO_IOSTREAM) + +/// Read data into a streambuf until it contains a specified delimiter. +/** + * This function is used to read data into the specified streambuf until the + * streambuf's get area contains the specified delimiter. The call will block + * until one of the following conditions is true: + * + * @li The get area of the streambuf contains the specified delimiter. + * + * @li An error occurred. + * + * This operation is implemented in terms of zero or more calls to the stream's + * read_some function. If the streambuf's get area already contains the + * delimiter, the function returns immediately. + * + * @param s The stream from which the data is to be read. The type must support + * the SyncReadStream concept. + * + * @param b A streambuf object into which the data will be read. + * + * @param delim The delimiter character. + * + * @returns The number of bytes in the streambuf's get area up to and including + * the delimiter. + * + * @throws asio::system_error Thrown on failure. + * + * @note After a successful read_until operation, the streambuf may contain + * additional data beyond the delimiter. An application will typically leave + * that data in the streambuf for a subsequent read_until operation to examine. + * + * @par Example + * To read data into a streambuf until a newline is encountered: + * @code asio::streambuf b; + * asio::read_until(s, b, '\n'); + * std::istream is(&b); + * std::string line; + * std::getline(is, line); @endcode + * After the @c read_until operation completes successfully, the buffer @c b + * contains the delimiter: + * @code { 'a', 'b', ..., 'c', '\n', 'd', 'e', ... } @endcode + * The call to @c std::getline then extracts the data up to and including the + * newline (which is discarded), so that the string @c line contains: + * @code { 'a', 'b', ..., 'c' } @endcode + * The remaining data is left in the buffer @c b as follows: + * @code { 'd', 'e', ... } @endcode + * This data may be the start of a new line, to be extracted by a subsequent + * @c read_until operation. + */ +template <typename SyncReadStream, typename Allocator> +std::size_t read_until(SyncReadStream& s, + asio::basic_streambuf<Allocator>& b, char delim); + +/// Read data into a streambuf until it contains a specified delimiter. +/** + * This function is used to read data into the specified streambuf until the + * streambuf's get area contains the specified delimiter. The call will block + * until one of the following conditions is true: + * + * @li The get area of the streambuf contains the specified delimiter. + * + * @li An error occurred. + * + * This operation is implemented in terms of zero or more calls to the stream's + * read_some function. If the streambuf's get area already contains the + * delimiter, the function returns immediately. + * + * @param s The stream from which the data is to be read. The type must support + * the SyncReadStream concept. + * + * @param b A streambuf object into which the data will be read. + * + * @param delim The delimiter character. + * + * @param ec Set to indicate what error occurred, if any. + * + * @returns The number of bytes in the streambuf's get area up to and including + * the delimiter. Returns 0 if an error occurred. + * + * @note After a successful read_until operation, the streambuf may contain + * additional data beyond the delimiter. An application will typically leave + * that data in the streambuf for a subsequent read_until operation to examine. + */ +template <typename SyncReadStream, typename Allocator> +std::size_t read_until(SyncReadStream& s, + asio::basic_streambuf<Allocator>& b, char delim, + asio::error_code& ec); + +/// Read data into a streambuf until it contains a specified delimiter. +/** + * This function is used to read data into the specified streambuf until the + * streambuf's get area contains the specified delimiter. The call will block + * until one of the following conditions is true: + * + * @li The get area of the streambuf contains the specified delimiter. + * + * @li An error occurred. + * + * This operation is implemented in terms of zero or more calls to the stream's + * read_some function. If the streambuf's get area already contains the + * delimiter, the function returns immediately. + * + * @param s The stream from which the data is to be read. The type must support + * the SyncReadStream concept. + * + * @param b A streambuf object into which the data will be read. + * + * @param delim The delimiter string. + * + * @returns The number of bytes in the streambuf's get area up to and including + * the delimiter. + * + * @throws asio::system_error Thrown on failure. + * + * @note After a successful read_until operation, the streambuf may contain + * additional data beyond the delimiter. An application will typically leave + * that data in the streambuf for a subsequent read_until operation to examine. + * + * @par Example + * To read data into a streambuf until a newline is encountered: + * @code asio::streambuf b; + * asio::read_until(s, b, "\r\n"); + * std::istream is(&b); + * std::string line; + * std::getline(is, line); @endcode + * After the @c read_until operation completes successfully, the buffer @c b + * contains the delimiter: + * @code { 'a', 'b', ..., 'c', '\r', '\n', 'd', 'e', ... } @endcode + * The call to @c std::getline then extracts the data up to and including the + * newline (which is discarded), so that the string @c line contains: + * @code { 'a', 'b', ..., 'c', '\r' } @endcode + * The remaining data is left in the buffer @c b as follows: + * @code { 'd', 'e', ... } @endcode + * This data may be the start of a new line, to be extracted by a subsequent + * @c read_until operation. + */ +template <typename SyncReadStream, typename Allocator> +std::size_t read_until(SyncReadStream& s, + asio::basic_streambuf<Allocator>& b, + ASIO_STRING_VIEW_PARAM delim); + +/// Read data into a streambuf until it contains a specified delimiter. +/** + * This function is used to read data into the specified streambuf until the + * streambuf's get area contains the specified delimiter. The call will block + * until one of the following conditions is true: + * + * @li The get area of the streambuf contains the specified delimiter. + * + * @li An error occurred. + * + * This operation is implemented in terms of zero or more calls to the stream's + * read_some function. If the streambuf's get area already contains the + * delimiter, the function returns immediately. + * + * @param s The stream from which the data is to be read. The type must support + * the SyncReadStream concept. + * + * @param b A streambuf object into which the data will be read. + * + * @param delim The delimiter string. + * + * @param ec Set to indicate what error occurred, if any. + * + * @returns The number of bytes in the streambuf's get area up to and including + * the delimiter. Returns 0 if an error occurred. + * + * @note After a successful read_until operation, the streambuf may contain + * additional data beyond the delimiter. An application will typically leave + * that data in the streambuf for a subsequent read_until operation to examine. + */ +template <typename SyncReadStream, typename Allocator> +std::size_t read_until(SyncReadStream& s, + asio::basic_streambuf<Allocator>& b, + ASIO_STRING_VIEW_PARAM delim, asio::error_code& ec); + +#if defined(ASIO_HAS_BOOST_REGEX) \ + || defined(GENERATING_DOCUMENTATION) + +/// Read data into a streambuf until some part of the data it contains matches +/// a regular expression. +/** + * This function is used to read data into the specified streambuf until the + * streambuf's get area contains some data that matches a regular expression. + * The call will block until one of the following conditions is true: + * + * @li A substring of the streambuf's get area matches the regular expression. + * + * @li An error occurred. + * + * This operation is implemented in terms of zero or more calls to the stream's + * read_some function. If the streambuf's get area already contains data that + * matches the regular expression, the function returns immediately. + * + * @param s The stream from which the data is to be read. The type must support + * the SyncReadStream concept. + * + * @param b A streambuf object into which the data will be read. + * + * @param expr The regular expression. + * + * @returns The number of bytes in the streambuf's get area up to and including + * the substring that matches the regular expression. + * + * @throws asio::system_error Thrown on failure. + * + * @note After a successful read_until operation, the streambuf may contain + * additional data beyond that which matched the regular expression. An + * application will typically leave that data in the streambuf for a subsequent + * read_until operation to examine. + * + * @par Example + * To read data into a streambuf until a CR-LF sequence is encountered: + * @code asio::streambuf b; + * asio::read_until(s, b, boost::regex("\r\n")); + * std::istream is(&b); + * std::string line; + * std::getline(is, line); @endcode + * After the @c read_until operation completes successfully, the buffer @c b + * contains the data which matched the regular expression: + * @code { 'a', 'b', ..., 'c', '\r', '\n', 'd', 'e', ... } @endcode + * The call to @c std::getline then extracts the data up to and including the + * newline (which is discarded), so that the string @c line contains: + * @code { 'a', 'b', ..., 'c', '\r' } @endcode + * The remaining data is left in the buffer @c b as follows: + * @code { 'd', 'e', ... } @endcode + * This data may be the start of a new line, to be extracted by a subsequent + * @c read_until operation. + */ +template <typename SyncReadStream, typename Allocator> +std::size_t read_until(SyncReadStream& s, + asio::basic_streambuf<Allocator>& b, const boost::regex& expr); + +/// Read data into a streambuf until some part of the data it contains matches +/// a regular expression. +/** + * This function is used to read data into the specified streambuf until the + * streambuf's get area contains some data that matches a regular expression. + * The call will block until one of the following conditions is true: + * + * @li A substring of the streambuf's get area matches the regular expression. + * + * @li An error occurred. + * + * This operation is implemented in terms of zero or more calls to the stream's + * read_some function. If the streambuf's get area already contains data that + * matches the regular expression, the function returns immediately. + * + * @param s The stream from which the data is to be read. The type must support + * the SyncReadStream concept. + * + * @param b A streambuf object into which the data will be read. + * + * @param expr The regular expression. + * + * @param ec Set to indicate what error occurred, if any. + * + * @returns The number of bytes in the streambuf's get area up to and including + * the substring that matches the regular expression. Returns 0 if an error + * occurred. + * + * @note After a successful read_until operation, the streambuf may contain + * additional data beyond that which matched the regular expression. An + * application will typically leave that data in the streambuf for a subsequent + * read_until operation to examine. + */ +template <typename SyncReadStream, typename Allocator> +std::size_t read_until(SyncReadStream& s, + asio::basic_streambuf<Allocator>& b, const boost::regex& expr, + asio::error_code& ec); + +#endif // defined(ASIO_HAS_BOOST_REGEX) + // || defined(GENERATING_DOCUMENTATION) + +/// Read data into a streambuf until a function object indicates a match. +/** + * This function is used to read data into the specified streambuf until a + * user-defined match condition function object, when applied to the data + * contained in the streambuf, indicates a successful match. The call will + * block until one of the following conditions is true: + * + * @li The match condition function object returns a std::pair where the second + * element evaluates to true. + * + * @li An error occurred. + * + * This operation is implemented in terms of zero or more calls to the stream's + * read_some function. If the match condition function object already indicates + * a match, the function returns immediately. + * + * @param s The stream from which the data is to be read. The type must support + * the SyncReadStream concept. + * + * @param b A streambuf object into which the data will be read. + * + * @param match_condition The function object to be called to determine whether + * a match exists. The signature of the function object must be: + * @code pair<iterator, bool> match_condition(iterator begin, iterator end); + * @endcode + * where @c iterator represents the type: + * @code buffers_iterator<basic_streambuf<Allocator>::const_buffers_type> + * @endcode + * The iterator parameters @c begin and @c end define the range of bytes to be + * scanned to determine whether there is a match. The @c first member of the + * return value is an iterator marking one-past-the-end of the bytes that have + * been consumed by the match function. This iterator is used to calculate the + * @c begin parameter for any subsequent invocation of the match condition. The + * @c second member of the return value is true if a match has been found, false + * otherwise. + * + * @returns The number of bytes in the streambuf's get area that have been fully + * consumed by the match function. + * + * @throws asio::system_error Thrown on failure. + * + * @note After a successful read_until operation, the streambuf may contain + * additional data beyond that which matched the function object. An application + * will typically leave that data in the streambuf for a subsequent read_until + * operation to examine. + * + * @note The default implementation of the @c is_match_condition type trait + * evaluates to true for function pointers and function objects with a + * @c result_type typedef. It must be specialised for other user-defined + * function objects. + * + * @par Examples + * To read data into a streambuf until whitespace is encountered: + * @code typedef asio::buffers_iterator< + * asio::streambuf::const_buffers_type> iterator; + * + * std::pair<iterator, bool> + * match_whitespace(iterator begin, iterator end) + * { + * iterator i = begin; + * while (i != end) + * if (std::isspace(*i++)) + * return std::make_pair(i, true); + * return std::make_pair(i, false); + * } + * ... + * asio::streambuf b; + * asio::read_until(s, b, match_whitespace); + * @endcode + * + * To read data into a streambuf until a matching character is found: + * @code class match_char + * { + * public: + * explicit match_char(char c) : c_(c) {} + * + * template <typename Iterator> + * std::pair<Iterator, bool> operator()( + * Iterator begin, Iterator end) const + * { + * Iterator i = begin; + * while (i != end) + * if (c_ == *i++) + * return std::make_pair(i, true); + * return std::make_pair(i, false); + * } + * + * private: + * char c_; + * }; + * + * namespace asio { + * template <> struct is_match_condition<match_char> + * : public boost::true_type {}; + * } // namespace asio + * ... + * asio::streambuf b; + * asio::read_until(s, b, match_char('a')); + * @endcode + */ +template <typename SyncReadStream, typename Allocator, typename MatchCondition> +std::size_t read_until(SyncReadStream& s, + asio::basic_streambuf<Allocator>& b, MatchCondition match_condition, + typename enable_if<is_match_condition<MatchCondition>::value>::type* = 0); + +/// Read data into a streambuf until a function object indicates a match. +/** + * This function is used to read data into the specified streambuf until a + * user-defined match condition function object, when applied to the data + * contained in the streambuf, indicates a successful match. The call will + * block until one of the following conditions is true: + * + * @li The match condition function object returns a std::pair where the second + * element evaluates to true. + * + * @li An error occurred. + * + * This operation is implemented in terms of zero or more calls to the stream's + * read_some function. If the match condition function object already indicates + * a match, the function returns immediately. + * + * @param s The stream from which the data is to be read. The type must support + * the SyncReadStream concept. + * + * @param b A streambuf object into which the data will be read. + * + * @param match_condition The function object to be called to determine whether + * a match exists. The signature of the function object must be: + * @code pair<iterator, bool> match_condition(iterator begin, iterator end); + * @endcode + * where @c iterator represents the type: + * @code buffers_iterator<basic_streambuf<Allocator>::const_buffers_type> + * @endcode + * The iterator parameters @c begin and @c end define the range of bytes to be + * scanned to determine whether there is a match. The @c first member of the + * return value is an iterator marking one-past-the-end of the bytes that have + * been consumed by the match function. This iterator is used to calculate the + * @c begin parameter for any subsequent invocation of the match condition. The + * @c second member of the return value is true if a match has been found, false + * otherwise. + * + * @param ec Set to indicate what error occurred, if any. + * + * @returns The number of bytes in the streambuf's get area that have been fully + * consumed by the match function. Returns 0 if an error occurred. + * + * @note After a successful read_until operation, the streambuf may contain + * additional data beyond that which matched the function object. An application + * will typically leave that data in the streambuf for a subsequent read_until + * operation to examine. + * + * @note The default implementation of the @c is_match_condition type trait + * evaluates to true for function pointers and function objects with a + * @c result_type typedef. It must be specialised for other user-defined + * function objects. + */ +template <typename SyncReadStream, typename Allocator, typename MatchCondition> +std::size_t read_until(SyncReadStream& s, + asio::basic_streambuf<Allocator>& b, + MatchCondition match_condition, asio::error_code& ec, + typename enable_if<is_match_condition<MatchCondition>::value>::type* = 0); + +#endif // !defined(ASIO_NO_IOSTREAM) +#endif // !defined(ASIO_NO_EXTENSIONS) + +/*@}*/ +/** + * @defgroup async_read_until asio::async_read_until + * + * @brief Start an asynchronous operation to read data into a dynamic buffer + * sequence, or into a streambuf, until it contains a delimiter, matches a + * regular expression, or a function object indicates a match. + */ +/*@{*/ + +/// Start an asynchronous operation to read data into a dynamic buffer sequence +/// until it contains a specified delimiter. +/** + * This function is used to asynchronously read data into the specified dynamic + * buffer sequence until the dynamic buffer sequence's get area contains the + * specified delimiter. The function call always returns immediately. The + * asynchronous operation will continue until one of the following conditions + * is true: + * + * @li The get area of the dynamic buffer sequence contains the specified + * delimiter. + * + * @li An error occurred. + * + * This operation is implemented in terms of zero or more calls to the stream's + * async_read_some function, and is known as a <em>composed operation</em>. If + * the dynamic buffer sequence's get area already contains the delimiter, this + * asynchronous operation completes immediately. The program must ensure that + * the stream performs no other read operations (such as async_read, + * async_read_until, the stream's async_read_some function, or any other + * composed operations that perform reads) until this operation completes. + * + * @param s The stream from which the data is to be read. The type must support + * the AsyncReadStream concept. + * + * @param buffers The dynamic buffer sequence into which the data will be read. + * Although the buffers object may be copied as necessary, ownership of the + * underlying memory blocks is retained by the caller, which must guarantee + * that they remain valid until the handler is called. + * + * @param delim The delimiter character. + * + * @param handler The handler to be called when the read operation completes. + * Copies will be made of the handler as required. The function signature of the + * handler must be: + * @code void handler( + * // Result of operation. + * const asio::error_code& error, + * + * // The number of bytes in the dynamic buffer sequence's + * // get area up to and including the delimiter. + * // 0 if an error occurred. + * std::size_t bytes_transferred + * ); @endcode + * Regardless of whether the asynchronous operation completes immediately or + * not, the handler will not be invoked from within this function. Invocation of + * the handler will be performed in a manner equivalent to using + * asio::io_context::post(). + * + * @note After a successful async_read_until operation, the dynamic buffer + * sequence may contain additional data beyond the delimiter. An application + * will typically leave that data in the dynamic buffer sequence for a + * subsequent async_read_until operation to examine. + * + * @par Example + * To asynchronously read data into a @c std::string until a newline is + * encountered: + * @code std::string data; + * ... + * void handler(const asio::error_code& e, std::size_t size) + * { + * if (!e) + * { + * std::string line = data.substr(0, n); + * data.erase(0, n); + * ... + * } + * } + * ... + * asio::async_read_until(s, data, '\n', handler); @endcode + * After the @c async_read_until operation completes successfully, the buffer + * @c data contains the delimiter: + * @code { 'a', 'b', ..., 'c', '\n', 'd', 'e', ... } @endcode + * The call to @c substr then extracts the data up to and including the + * delimiter, so that the string @c line contains: + * @code { 'a', 'b', ..., 'c', '\n' } @endcode + * After the call to @c erase, the remaining data is left in the buffer @c data + * as follows: + * @code { 'd', 'e', ... } @endcode + * This data may be the start of a new line, to be extracted by a subsequent + * @c async_read_until operation. + */ +template <typename AsyncReadStream, + typename DynamicBuffer, typename ReadHandler> +ASIO_INITFN_RESULT_TYPE(ReadHandler, + void (asio::error_code, std::size_t)) +async_read_until(AsyncReadStream& s, + ASIO_MOVE_ARG(DynamicBuffer) buffers, + char delim, ASIO_MOVE_ARG(ReadHandler) handler); + +/// Start an asynchronous operation to read data into a dynamic buffer sequence +/// until it contains a specified delimiter. +/** + * This function is used to asynchronously read data into the specified dynamic + * buffer sequence until the dynamic buffer sequence's get area contains the + * specified delimiter. The function call always returns immediately. The + * asynchronous operation will continue until one of the following conditions + * is true: + * + * @li The get area of the dynamic buffer sequence contains the specified + * delimiter. + * + * @li An error occurred. + * + * This operation is implemented in terms of zero or more calls to the stream's + * async_read_some function, and is known as a <em>composed operation</em>. If + * the dynamic buffer sequence's get area already contains the delimiter, this + * asynchronous operation completes immediately. The program must ensure that + * the stream performs no other read operations (such as async_read, + * async_read_until, the stream's async_read_some function, or any other + * composed operations that perform reads) until this operation completes. + * + * @param s The stream from which the data is to be read. The type must support + * the AsyncReadStream concept. + * + * @param buffers The dynamic buffer sequence into which the data will be read. + * Although the buffers object may be copied as necessary, ownership of the + * underlying memory blocks is retained by the caller, which must guarantee + * that they remain valid until the handler is called. + * + * @param delim The delimiter string. + * + * @param handler The handler to be called when the read operation completes. + * Copies will be made of the handler as required. The function signature of the + * handler must be: + * @code void handler( + * // Result of operation. + * const asio::error_code& error, + * + * // The number of bytes in the dynamic buffer sequence's + * // get area up to and including the delimiter. + * // 0 if an error occurred. + * std::size_t bytes_transferred + * ); @endcode + * Regardless of whether the asynchronous operation completes immediately or + * not, the handler will not be invoked from within this function. Invocation of + * the handler will be performed in a manner equivalent to using + * asio::io_context::post(). + * + * @note After a successful async_read_until operation, the dynamic buffer + * sequence may contain additional data beyond the delimiter. An application + * will typically leave that data in the dynamic buffer sequence for a + * subsequent async_read_until operation to examine. + * + * @par Example + * To asynchronously read data into a @c std::string until a CR-LF sequence is + * encountered: + * @code std::string data; + * ... + * void handler(const asio::error_code& e, std::size_t size) + * { + * if (!e) + * { + * std::string line = data.substr(0, n); + * data.erase(0, n); + * ... + * } + * } + * ... + * asio::async_read_until(s, data, "\r\n", handler); @endcode + * After the @c async_read_until operation completes successfully, the string + * @c data contains the delimiter: + * @code { 'a', 'b', ..., 'c', '\r', '\n', 'd', 'e', ... } @endcode + * The call to @c substr then extracts the data up to and including the + * delimiter, so that the string @c line contains: + * @code { 'a', 'b', ..., 'c', '\r', '\n' } @endcode + * After the call to @c erase, the remaining data is left in the string @c data + * as follows: + * @code { 'd', 'e', ... } @endcode + * This data may be the start of a new line, to be extracted by a subsequent + * @c async_read_until operation. + */ +template <typename AsyncReadStream, + typename DynamicBuffer, typename ReadHandler> +ASIO_INITFN_RESULT_TYPE(ReadHandler, + void (asio::error_code, std::size_t)) +async_read_until(AsyncReadStream& s, + ASIO_MOVE_ARG(DynamicBuffer) buffers, + ASIO_STRING_VIEW_PARAM delim, + ASIO_MOVE_ARG(ReadHandler) handler); + +#if !defined(ASIO_NO_EXTENSIONS) +#if defined(ASIO_HAS_BOOST_REGEX) \ + || defined(GENERATING_DOCUMENTATION) + +/// Start an asynchronous operation to read data into a dynamic buffer sequence +/// until some part of its data matches a regular expression. +/** + * This function is used to asynchronously read data into the specified dynamic + * buffer sequence until the dynamic buffer sequence's get area contains some + * data that matches a regular expression. The function call always returns + * immediately. The asynchronous operation will continue until one of the + * following conditions is true: + * + * @li A substring of the dynamic buffer sequence's get area matches the regular + * expression. + * + * @li An error occurred. + * + * This operation is implemented in terms of zero or more calls to the stream's + * async_read_some function, and is known as a <em>composed operation</em>. If + * the dynamic buffer sequence's get area already contains data that matches + * the regular expression, this asynchronous operation completes immediately. + * The program must ensure that the stream performs no other read operations + * (such as async_read, async_read_until, the stream's async_read_some + * function, or any other composed operations that perform reads) until this + * operation completes. + * + * @param s The stream from which the data is to be read. The type must support + * the AsyncReadStream concept. + * + * @param buffers The dynamic buffer sequence into which the data will be read. + * Although the buffers object may be copied as necessary, ownership of the + * underlying memory blocks is retained by the caller, which must guarantee + * that they remain valid until the handler is called. + * + * @param expr The regular expression. + * + * @param handler The handler to be called when the read operation completes. + * Copies will be made of the handler as required. The function signature of the + * handler must be: + * @code void handler( + * // Result of operation. + * const asio::error_code& error, + * + * // The number of bytes in the dynamic buffer + * // sequence's get area up to and including the + * // substring that matches the regular expression. + * // 0 if an error occurred. + * std::size_t bytes_transferred + * ); @endcode + * Regardless of whether the asynchronous operation completes immediately or + * not, the handler will not be invoked from within this function. Invocation of + * the handler will be performed in a manner equivalent to using + * asio::io_context::post(). + * + * @note After a successful async_read_until operation, the dynamic buffer + * sequence may contain additional data beyond that which matched the regular + * expression. An application will typically leave that data in the dynamic + * buffer sequence for a subsequent async_read_until operation to examine. + * + * @par Example + * To asynchronously read data into a @c std::string until a CR-LF sequence is + * encountered: + * @code std::string data; + * ... + * void handler(const asio::error_code& e, std::size_t size) + * { + * if (!e) + * { + * std::string line = data.substr(0, n); + * data.erase(0, n); + * ... + * } + * } + * ... + * asio::async_read_until(s, data, + * boost::regex("\r\n"), handler); @endcode + * After the @c async_read_until operation completes successfully, the string + * @c data contains the data which matched the regular expression: + * @code { 'a', 'b', ..., 'c', '\r', '\n', 'd', 'e', ... } @endcode + * The call to @c substr then extracts the data up to and including the match, + * so that the string @c line contains: + * @code { 'a', 'b', ..., 'c', '\r', '\n' } @endcode + * After the call to @c erase, the remaining data is left in the string @c data + * as follows: + * @code { 'd', 'e', ... } @endcode + * This data may be the start of a new line, to be extracted by a subsequent + * @c async_read_until operation. + */ +template <typename AsyncReadStream, + typename DynamicBuffer, typename ReadHandler> +ASIO_INITFN_RESULT_TYPE(ReadHandler, + void (asio::error_code, std::size_t)) +async_read_until(AsyncReadStream& s, + ASIO_MOVE_ARG(DynamicBuffer) buffers, + const boost::regex& expr, + ASIO_MOVE_ARG(ReadHandler) handler); + +#endif // defined(ASIO_HAS_BOOST_REGEX) + // || defined(GENERATING_DOCUMENTATION) + +/// Start an asynchronous operation to read data into a dynamic buffer sequence +/// until a function object indicates a match. +/** + * This function is used to asynchronously read data into the specified dynamic + * buffer sequence until a user-defined match condition function object, when + * applied to the data contained in the dynamic buffer sequence, indicates a + * successful match. The function call always returns immediately. The + * asynchronous operation will continue until one of the following conditions + * is true: + * + * @li The match condition function object returns a std::pair where the second + * element evaluates to true. + * + * @li An error occurred. + * + * This operation is implemented in terms of zero or more calls to the stream's + * async_read_some function, and is known as a <em>composed operation</em>. If + * the match condition function object already indicates a match, this + * asynchronous operation completes immediately. The program must ensure that + * the stream performs no other read operations (such as async_read, + * async_read_until, the stream's async_read_some function, or any other + * composed operations that perform reads) until this operation completes. + * + * @param s The stream from which the data is to be read. The type must support + * the AsyncReadStream concept. + * + * @param buffers The dynamic buffer sequence into which the data will be read. + * Although the buffers object may be copied as necessary, ownership of the + * underlying memory blocks is retained by the caller, which must guarantee + * that they remain valid until the handler is called. + * + * @param match_condition The function object to be called to determine whether + * a match exists. The signature of the function object must be: + * @code pair<iterator, bool> match_condition(iterator begin, iterator end); + * @endcode + * where @c iterator represents the type: + * @code buffers_iterator<typename DynamicBuffer::const_buffers_type> + * @endcode + * The iterator parameters @c begin and @c end define the range of bytes to be + * scanned to determine whether there is a match. The @c first member of the + * return value is an iterator marking one-past-the-end of the bytes that have + * been consumed by the match function. This iterator is used to calculate the + * @c begin parameter for any subsequent invocation of the match condition. The + * @c second member of the return value is true if a match has been found, false + * otherwise. + * + * @param handler The handler to be called when the read operation completes. + * Copies will be made of the handler as required. The function signature of the + * handler must be: + * @code void handler( + * // Result of operation. + * const asio::error_code& error, + * + * // The number of bytes in the dynamic buffer sequence's + * // get area that have been fully consumed by the match + * // function. O if an error occurred. + * std::size_t bytes_transferred + * ); @endcode + * Regardless of whether the asynchronous operation completes immediately or + * not, the handler will not be invoked from within this function. Invocation of + * the handler will be performed in a manner equivalent to using + * asio::io_context::post(). + * + * @note After a successful async_read_until operation, the dynamic buffer + * sequence may contain additional data beyond that which matched the function + * object. An application will typically leave that data in the dynamic buffer + * sequence for a subsequent async_read_until operation to examine. + * + * @note The default implementation of the @c is_match_condition type trait + * evaluates to true for function pointers and function objects with a + * @c result_type typedef. It must be specialised for other user-defined + * function objects. + * + * @par Examples + * To asynchronously read data into a @c std::string until whitespace is + * encountered: + * @code typedef asio::buffers_iterator< + * asio::const_buffers_1> iterator; + * + * std::pair<iterator, bool> + * match_whitespace(iterator begin, iterator end) + * { + * iterator i = begin; + * while (i != end) + * if (std::isspace(*i++)) + * return std::make_pair(i, true); + * return std::make_pair(i, false); + * } + * ... + * void handler(const asio::error_code& e, std::size_t size); + * ... + * std::string data; + * asio::async_read_until(s, data, match_whitespace, handler); + * @endcode + * + * To asynchronously read data into a @c std::string until a matching character + * is found: + * @code class match_char + * { + * public: + * explicit match_char(char c) : c_(c) {} + * + * template <typename Iterator> + * std::pair<Iterator, bool> operator()( + * Iterator begin, Iterator end) const + * { + * Iterator i = begin; + * while (i != end) + * if (c_ == *i++) + * return std::make_pair(i, true); + * return std::make_pair(i, false); + * } + * + * private: + * char c_; + * }; + * + * namespace asio { + * template <> struct is_match_condition<match_char> + * : public boost::true_type {}; + * } // namespace asio + * ... + * void handler(const asio::error_code& e, std::size_t size); + * ... + * std::string data; + * asio::async_read_until(s, data, match_char('a'), handler); + * @endcode + */ +template <typename AsyncReadStream, typename DynamicBuffer, + typename MatchCondition, typename ReadHandler> +ASIO_INITFN_RESULT_TYPE(ReadHandler, + void (asio::error_code, std::size_t)) +async_read_until(AsyncReadStream& s, + ASIO_MOVE_ARG(DynamicBuffer) buffers, + MatchCondition match_condition, ASIO_MOVE_ARG(ReadHandler) handler, + typename enable_if<is_match_condition<MatchCondition>::value>::type* = 0); + +#if !defined(ASIO_NO_IOSTREAM) + +/// Start an asynchronous operation to read data into a streambuf until it +/// contains a specified delimiter. +/** + * This function is used to asynchronously read data into the specified + * streambuf until the streambuf's get area contains the specified delimiter. + * The function call always returns immediately. The asynchronous operation + * will continue until one of the following conditions is true: + * + * @li The get area of the streambuf contains the specified delimiter. + * + * @li An error occurred. + * + * This operation is implemented in terms of zero or more calls to the stream's + * async_read_some function, and is known as a <em>composed operation</em>. If + * the streambuf's get area already contains the delimiter, this asynchronous + * operation completes immediately. The program must ensure that the stream + * performs no other read operations (such as async_read, async_read_until, the + * stream's async_read_some function, or any other composed operations that + * perform reads) until this operation completes. + * + * @param s The stream from which the data is to be read. The type must support + * the AsyncReadStream concept. + * + * @param b A streambuf object into which the data will be read. Ownership of + * the streambuf is retained by the caller, which must guarantee that it remains + * valid until the handler is called. + * + * @param delim The delimiter character. + * + * @param handler The handler to be called when the read operation completes. + * Copies will be made of the handler as required. The function signature of the + * handler must be: + * @code void handler( + * // Result of operation. + * const asio::error_code& error, + * + * // The number of bytes in the streambuf's get + * // area up to and including the delimiter. + * // 0 if an error occurred. + * std::size_t bytes_transferred + * ); @endcode + * Regardless of whether the asynchronous operation completes immediately or + * not, the handler will not be invoked from within this function. Invocation of + * the handler will be performed in a manner equivalent to using + * asio::io_context::post(). + * + * @note After a successful async_read_until operation, the streambuf may + * contain additional data beyond the delimiter. An application will typically + * leave that data in the streambuf for a subsequent async_read_until operation + * to examine. + * + * @par Example + * To asynchronously read data into a streambuf until a newline is encountered: + * @code asio::streambuf b; + * ... + * void handler(const asio::error_code& e, std::size_t size) + * { + * if (!e) + * { + * std::istream is(&b); + * std::string line; + * std::getline(is, line); + * ... + * } + * } + * ... + * asio::async_read_until(s, b, '\n', handler); @endcode + * After the @c async_read_until operation completes successfully, the buffer + * @c b contains the delimiter: + * @code { 'a', 'b', ..., 'c', '\n', 'd', 'e', ... } @endcode + * The call to @c std::getline then extracts the data up to and including the + * newline (which is discarded), so that the string @c line contains: + * @code { 'a', 'b', ..., 'c' } @endcode + * The remaining data is left in the buffer @c b as follows: + * @code { 'd', 'e', ... } @endcode + * This data may be the start of a new line, to be extracted by a subsequent + * @c async_read_until operation. + */ +template <typename AsyncReadStream, typename Allocator, typename ReadHandler> +ASIO_INITFN_RESULT_TYPE(ReadHandler, + void (asio::error_code, std::size_t)) +async_read_until(AsyncReadStream& s, + asio::basic_streambuf<Allocator>& b, + char delim, ASIO_MOVE_ARG(ReadHandler) handler); + +/// Start an asynchronous operation to read data into a streambuf until it +/// contains a specified delimiter. +/** + * This function is used to asynchronously read data into the specified + * streambuf until the streambuf's get area contains the specified delimiter. + * The function call always returns immediately. The asynchronous operation + * will continue until one of the following conditions is true: + * + * @li The get area of the streambuf contains the specified delimiter. + * + * @li An error occurred. + * + * This operation is implemented in terms of zero or more calls to the stream's + * async_read_some function, and is known as a <em>composed operation</em>. If + * the streambuf's get area already contains the delimiter, this asynchronous + * operation completes immediately. The program must ensure that the stream + * performs no other read operations (such as async_read, async_read_until, the + * stream's async_read_some function, or any other composed operations that + * perform reads) until this operation completes. + * + * @param s The stream from which the data is to be read. The type must support + * the AsyncReadStream concept. + * + * @param b A streambuf object into which the data will be read. Ownership of + * the streambuf is retained by the caller, which must guarantee that it remains + * valid until the handler is called. + * + * @param delim The delimiter string. + * + * @param handler The handler to be called when the read operation completes. + * Copies will be made of the handler as required. The function signature of the + * handler must be: + * @code void handler( + * // Result of operation. + * const asio::error_code& error, + * + * // The number of bytes in the streambuf's get + * // area up to and including the delimiter. + * // 0 if an error occurred. + * std::size_t bytes_transferred + * ); @endcode + * Regardless of whether the asynchronous operation completes immediately or + * not, the handler will not be invoked from within this function. Invocation of + * the handler will be performed in a manner equivalent to using + * asio::io_context::post(). + * + * @note After a successful async_read_until operation, the streambuf may + * contain additional data beyond the delimiter. An application will typically + * leave that data in the streambuf for a subsequent async_read_until operation + * to examine. + * + * @par Example + * To asynchronously read data into a streambuf until a newline is encountered: + * @code asio::streambuf b; + * ... + * void handler(const asio::error_code& e, std::size_t size) + * { + * if (!e) + * { + * std::istream is(&b); + * std::string line; + * std::getline(is, line); + * ... + * } + * } + * ... + * asio::async_read_until(s, b, "\r\n", handler); @endcode + * After the @c async_read_until operation completes successfully, the buffer + * @c b contains the delimiter: + * @code { 'a', 'b', ..., 'c', '\r', '\n', 'd', 'e', ... } @endcode + * The call to @c std::getline then extracts the data up to and including the + * newline (which is discarded), so that the string @c line contains: + * @code { 'a', 'b', ..., 'c', '\r' } @endcode + * The remaining data is left in the buffer @c b as follows: + * @code { 'd', 'e', ... } @endcode + * This data may be the start of a new line, to be extracted by a subsequent + * @c async_read_until operation. + */ +template <typename AsyncReadStream, typename Allocator, typename ReadHandler> +ASIO_INITFN_RESULT_TYPE(ReadHandler, + void (asio::error_code, std::size_t)) +async_read_until(AsyncReadStream& s, + asio::basic_streambuf<Allocator>& b, + ASIO_STRING_VIEW_PARAM delim, + ASIO_MOVE_ARG(ReadHandler) handler); + +#if defined(ASIO_HAS_BOOST_REGEX) \ + || defined(GENERATING_DOCUMENTATION) + +/// Start an asynchronous operation to read data into a streambuf until some +/// part of its data matches a regular expression. +/** + * This function is used to asynchronously read data into the specified + * streambuf until the streambuf's get area contains some data that matches a + * regular expression. The function call always returns immediately. The + * asynchronous operation will continue until one of the following conditions + * is true: + * + * @li A substring of the streambuf's get area matches the regular expression. + * + * @li An error occurred. + * + * This operation is implemented in terms of zero or more calls to the stream's + * async_read_some function, and is known as a <em>composed operation</em>. If + * the streambuf's get area already contains data that matches the regular + * expression, this asynchronous operation completes immediately. The program + * must ensure that the stream performs no other read operations (such as + * async_read, async_read_until, the stream's async_read_some function, or any + * other composed operations that perform reads) until this operation + * completes. + * + * @param s The stream from which the data is to be read. The type must support + * the AsyncReadStream concept. + * + * @param b A streambuf object into which the data will be read. Ownership of + * the streambuf is retained by the caller, which must guarantee that it remains + * valid until the handler is called. + * + * @param expr The regular expression. + * + * @param handler The handler to be called when the read operation completes. + * Copies will be made of the handler as required. The function signature of the + * handler must be: + * @code void handler( + * // Result of operation. + * const asio::error_code& error, + * + * // The number of bytes in the streambuf's get + * // area up to and including the substring + * // that matches the regular. expression. + * // 0 if an error occurred. + * std::size_t bytes_transferred + * ); @endcode + * Regardless of whether the asynchronous operation completes immediately or + * not, the handler will not be invoked from within this function. Invocation of + * the handler will be performed in a manner equivalent to using + * asio::io_context::post(). + * + * @note After a successful async_read_until operation, the streambuf may + * contain additional data beyond that which matched the regular expression. An + * application will typically leave that data in the streambuf for a subsequent + * async_read_until operation to examine. + * + * @par Example + * To asynchronously read data into a streambuf until a CR-LF sequence is + * encountered: + * @code asio::streambuf b; + * ... + * void handler(const asio::error_code& e, std::size_t size) + * { + * if (!e) + * { + * std::istream is(&b); + * std::string line; + * std::getline(is, line); + * ... + * } + * } + * ... + * asio::async_read_until(s, b, boost::regex("\r\n"), handler); @endcode + * After the @c async_read_until operation completes successfully, the buffer + * @c b contains the data which matched the regular expression: + * @code { 'a', 'b', ..., 'c', '\r', '\n', 'd', 'e', ... } @endcode + * The call to @c std::getline then extracts the data up to and including the + * newline (which is discarded), so that the string @c line contains: + * @code { 'a', 'b', ..., 'c', '\r' } @endcode + * The remaining data is left in the buffer @c b as follows: + * @code { 'd', 'e', ... } @endcode + * This data may be the start of a new line, to be extracted by a subsequent + * @c async_read_until operation. + */ +template <typename AsyncReadStream, typename Allocator, typename ReadHandler> +ASIO_INITFN_RESULT_TYPE(ReadHandler, + void (asio::error_code, std::size_t)) +async_read_until(AsyncReadStream& s, + asio::basic_streambuf<Allocator>& b, const boost::regex& expr, + ASIO_MOVE_ARG(ReadHandler) handler); + +#endif // defined(ASIO_HAS_BOOST_REGEX) + // || defined(GENERATING_DOCUMENTATION) + +/// Start an asynchronous operation to read data into a streambuf until a +/// function object indicates a match. +/** + * This function is used to asynchronously read data into the specified + * streambuf until a user-defined match condition function object, when applied + * to the data contained in the streambuf, indicates a successful match. The + * function call always returns immediately. The asynchronous operation will + * continue until one of the following conditions is true: + * + * @li The match condition function object returns a std::pair where the second + * element evaluates to true. + * + * @li An error occurred. + * + * This operation is implemented in terms of zero or more calls to the stream's + * async_read_some function, and is known as a <em>composed operation</em>. If + * the match condition function object already indicates a match, this + * asynchronous operation completes immediately. The program must ensure that + * the stream performs no other read operations (such as async_read, + * async_read_until, the stream's async_read_some function, or any other + * composed operations that perform reads) until this operation completes. + * + * @param s The stream from which the data is to be read. The type must support + * the AsyncReadStream concept. + * + * @param b A streambuf object into which the data will be read. + * + * @param match_condition The function object to be called to determine whether + * a match exists. The signature of the function object must be: + * @code pair<iterator, bool> match_condition(iterator begin, iterator end); + * @endcode + * where @c iterator represents the type: + * @code buffers_iterator<basic_streambuf<Allocator>::const_buffers_type> + * @endcode + * The iterator parameters @c begin and @c end define the range of bytes to be + * scanned to determine whether there is a match. The @c first member of the + * return value is an iterator marking one-past-the-end of the bytes that have + * been consumed by the match function. This iterator is used to calculate the + * @c begin parameter for any subsequent invocation of the match condition. The + * @c second member of the return value is true if a match has been found, false + * otherwise. + * + * @param handler The handler to be called when the read operation completes. + * Copies will be made of the handler as required. The function signature of the + * handler must be: + * @code void handler( + * // Result of operation. + * const asio::error_code& error, + * + * // The number of bytes in the streambuf's get + * // area that have been fully consumed by the + * // match function. O if an error occurred. + * std::size_t bytes_transferred + * ); @endcode + * Regardless of whether the asynchronous operation completes immediately or + * not, the handler will not be invoked from within this function. Invocation of + * the handler will be performed in a manner equivalent to using + * asio::io_context::post(). + * + * @note After a successful async_read_until operation, the streambuf may + * contain additional data beyond that which matched the function object. An + * application will typically leave that data in the streambuf for a subsequent + * async_read_until operation to examine. + * + * @note The default implementation of the @c is_match_condition type trait + * evaluates to true for function pointers and function objects with a + * @c result_type typedef. It must be specialised for other user-defined + * function objects. + * + * @par Examples + * To asynchronously read data into a streambuf until whitespace is encountered: + * @code typedef asio::buffers_iterator< + * asio::streambuf::const_buffers_type> iterator; + * + * std::pair<iterator, bool> + * match_whitespace(iterator begin, iterator end) + * { + * iterator i = begin; + * while (i != end) + * if (std::isspace(*i++)) + * return std::make_pair(i, true); + * return std::make_pair(i, false); + * } + * ... + * void handler(const asio::error_code& e, std::size_t size); + * ... + * asio::streambuf b; + * asio::async_read_until(s, b, match_whitespace, handler); + * @endcode + * + * To asynchronously read data into a streambuf until a matching character is + * found: + * @code class match_char + * { + * public: + * explicit match_char(char c) : c_(c) {} + * + * template <typename Iterator> + * std::pair<Iterator, bool> operator()( + * Iterator begin, Iterator end) const + * { + * Iterator i = begin; + * while (i != end) + * if (c_ == *i++) + * return std::make_pair(i, true); + * return std::make_pair(i, false); + * } + * + * private: + * char c_; + * }; + * + * namespace asio { + * template <> struct is_match_condition<match_char> + * : public boost::true_type {}; + * } // namespace asio + * ... + * void handler(const asio::error_code& e, std::size_t size); + * ... + * asio::streambuf b; + * asio::async_read_until(s, b, match_char('a'), handler); + * @endcode + */ +template <typename AsyncReadStream, typename Allocator, + typename MatchCondition, typename ReadHandler> +ASIO_INITFN_RESULT_TYPE(ReadHandler, + void (asio::error_code, std::size_t)) +async_read_until(AsyncReadStream& s, + asio::basic_streambuf<Allocator>& b, + MatchCondition match_condition, ASIO_MOVE_ARG(ReadHandler) handler, + typename enable_if<is_match_condition<MatchCondition>::value>::type* = 0); + +#endif // !defined(ASIO_NO_IOSTREAM) +#endif // !defined(ASIO_NO_EXTENSIONS) + +/*@}*/ + +} // namespace asio + +#include "asio/detail/pop_options.hpp" + +#include "asio/impl/read_until.hpp" + +#endif // ASIO_READ_UNTIL_HPP |