| Line | Branch | Exec | Source |
|---|---|---|---|
| 1 | // | ||
| 2 | // Copyright (c) 2019 Vinnie Falco (vinnie.falco@gmail.com) | ||
| 3 | // | ||
| 4 | // Distributed under the Boost Software License, Version 1.0. (See accompanying | ||
| 5 | // file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt) | ||
| 6 | // | ||
| 7 | // Official repository: https://github.com/cppalliance/http_proto | ||
| 8 | // | ||
| 9 | |||
| 10 | #ifndef BOOST_HTTP_PROTO_SOURCE_HPP | ||
| 11 | #define BOOST_HTTP_PROTO_SOURCE_HPP | ||
| 12 | |||
| 13 | #include <boost/http_proto/detail/config.hpp> | ||
| 14 | #include <boost/buffers/mutable_buffer_span.hpp> | ||
| 15 | #include <boost/buffers/type_traits.hpp> | ||
| 16 | #include <boost/system/error_code.hpp> | ||
| 17 | #include <cstddef> | ||
| 18 | #include <type_traits> | ||
| 19 | |||
| 20 | namespace boost { | ||
| 21 | namespace http_proto { | ||
| 22 | |||
| 23 | /** An algorithm for producing buffers of data. | ||
| 24 | |||
| 25 | This interface abstracts the production of | ||
| 26 | a finite stream of data, returned by writing | ||
| 27 | into caller-provided buffers until there | ||
| 28 | is no more output data. | ||
| 29 | |||
| 30 | @par Thread Safety | ||
| 31 | Non-const member functions may not be | ||
| 32 | called concurrently on the same instance. | ||
| 33 | */ | ||
| 34 | struct BOOST_SYMBOL_VISIBLE | ||
| 35 | source | ||
| 36 | { | ||
| 37 | /** The results of producing data. | ||
| 38 | */ | ||
| 39 | struct results | ||
| 40 | { | ||
| 41 | /** The error, if any occurred. | ||
| 42 | */ | ||
| 43 | system::error_code ec; | ||
| 44 | |||
| 45 | /** The number of bytes produced in the output. | ||
| 46 | */ | ||
| 47 | std::size_t bytes = 0; | ||
| 48 | |||
| 49 | /** True if there will be no more output. | ||
| 50 | */ | ||
| 51 | bool finished = false; | ||
| 52 | |||
| 53 | /** Accumulate results. | ||
| 54 | */ | ||
| 55 | results& | ||
| 56 | operator+=( | ||
| 57 | results const& rv) noexcept; | ||
| 58 | }; | ||
| 59 | |||
| 60 | /** Produce data. | ||
| 61 | |||
| 62 | This function attempts to read from the | ||
| 63 | source, placing the data into the given | ||
| 64 | mutable buffer sequence. | ||
| 65 | The return value indicates the number of | ||
| 66 | bytes placed into the buffers, the error | ||
| 67 | if any occurred, and a `bool` indicating | ||
| 68 | whether or not there is more data | ||
| 69 | remaining in the source. | ||
| 70 | |||
| 71 | @par Preconditions | ||
| 72 | @li @ref init was called, and | ||
| 73 | @li There is more data remaining. | ||
| 74 | |||
| 75 | @return The result of the operation. | ||
| 76 | |||
| 77 | @param bs The buffers to use. | ||
| 78 | Each buffer in the sequence will | ||
| 79 | be filled completely before data | ||
| 80 | is placed in the next buffer. | ||
| 81 | */ | ||
| 82 | template<class MutableBufferSequence> | ||
| 83 | results | ||
| 84 | 5512 | read(MutableBufferSequence const& bs) | |
| 85 | { | ||
| 86 | static_assert( | ||
| 87 | buffers::is_mutable_buffer_sequence< | ||
| 88 | MutableBufferSequence>::value, | ||
| 89 | "Type requirements not met"); | ||
| 90 | |||
| 91 | 5512 | return read_impl(bs); | |
| 92 | } | ||
| 93 | |||
| 94 | #ifdef BOOST_HTTP_PROTO_DOCS | ||
| 95 | protected: | ||
| 96 | #else | ||
| 97 | private: | ||
| 98 | #endif | ||
| 99 | /** Derived class override. | ||
| 100 | |||
| 101 | This pure virtual function is called by | ||
| 102 | the implementation and must be overriden. | ||
| 103 | The callee should attempt to place data | ||
| 104 | into the given mutable buffer. | ||
| 105 | The return value must be set to indicate | ||
| 106 | the number of bytes placed into the | ||
| 107 | buffers, the error if any occurred, | ||
| 108 | and a `bool` indicating whether or | ||
| 109 | not there is more data remaining | ||
| 110 | in the source. | ||
| 111 | |||
| 112 | @par Preconditions | ||
| 113 | @li @ref init was called, and | ||
| 114 | @li There is more data remaining. | ||
| 115 | |||
| 116 | @return The result of the operation. | ||
| 117 | |||
| 118 | @param b The buffer to use. | ||
| 119 | If this is not filled completely, | ||
| 120 | then the result must indicate failure | ||
| 121 | or that no more data remains (or both). | ||
| 122 | */ | ||
| 123 | virtual | ||
| 124 | results | ||
| 125 | on_read( | ||
| 126 | buffers::mutable_buffer b) = 0; | ||
| 127 | |||
| 128 | /** Derived class override. | ||
| 129 | |||
| 130 | This pure virtual function is called by | ||
| 131 | the implementation and must be overriden. | ||
| 132 | The callee should attempt to place data | ||
| 133 | into the given mutable buffer sequence. | ||
| 134 | The return value must be set to indicate | ||
| 135 | the number of bytes placed into the | ||
| 136 | buffers, the error if any occurred, | ||
| 137 | and a `bool` indicating whether or | ||
| 138 | not there is more data remaining | ||
| 139 | in the source. | ||
| 140 | |||
| 141 | @par Preconditions | ||
| 142 | @li @ref init was called, and | ||
| 143 | @li There is more data remaining. | ||
| 144 | |||
| 145 | @return The result of the operation. | ||
| 146 | |||
| 147 | @param bs The buffer sequence to use. | ||
| 148 | Each buffer in the sequence must | ||
| 149 | be filled completely before data | ||
| 150 | is placed in the next buffer. | ||
| 151 | If the buffers are not filled | ||
| 152 | completely, then the result must | ||
| 153 | indicate failure or that no more | ||
| 154 | data remains (or both). | ||
| 155 | */ | ||
| 156 | BOOST_HTTP_PROTO_DECL | ||
| 157 | virtual | ||
| 158 | results | ||
| 159 | on_read( | ||
| 160 | buffers::mutable_buffer_span bs); | ||
| 161 | |||
| 162 | private: | ||
| 163 | results | ||
| 164 | 2 | read_impl( | |
| 165 | buffers::mutable_buffer const& b) | ||
| 166 | { | ||
| 167 | 2 | return on_read(b); | |
| 168 | } | ||
| 169 | |||
| 170 | results | ||
| 171 | 5 | read_impl( | |
| 172 | buffers::mutable_buffer_span const& bs) | ||
| 173 | { | ||
| 174 | 5 | return on_read(bs); | |
| 175 | } | ||
| 176 | |||
| 177 | template<class T> | ||
| 178 | results | ||
| 179 | read_impl(T const&); | ||
| 180 | }; | ||
| 181 | |||
| 182 | //------------------------------------------------ | ||
| 183 | |||
| 184 | /** Metafunction which determines if T is a source | ||
| 185 | |||
| 186 | @see | ||
| 187 | @ref source. | ||
| 188 | */ | ||
| 189 | #ifdef BOOST_HTTP_PROTO_DOCS | ||
| 190 | template<class T> | ||
| 191 | using is_source = __see_below__; | ||
| 192 | #else | ||
| 193 | template<class T> | ||
| 194 | using is_source = | ||
| 195 | std::is_convertible< | ||
| 196 | typename std::decay<T>::type*, | ||
| 197 | source*>; | ||
| 198 | #endif | ||
| 199 | |||
| 200 | } // http_proto | ||
| 201 | } // boost | ||
| 202 | |||
| 203 | #include <boost/http_proto/impl/source.hpp> | ||
| 204 | |||
| 205 | #endif | ||
| 206 |