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1 | // (C) Copyright 2008 CodeRage, LLC (turkanis at coderage dot com) |
2 | // (C) Copyright 2003-2007 Jonathan Turkanis | |
3 | // Distributed under the Boost Software License, Version 1.0. (See accompanying | |
4 | // file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt.) | |
5 | ||
6 | // See http://www.boost.org/libs/iostreams for documentation. | |
7 | ||
8 | // Contains: The function template copy, which reads data from a Source | |
9 | // and writes it to a Sink until the end of the sequence is reached, returning | |
10 | // the number of characters transfered. | |
11 | ||
12 | // The implementation is complicated by the need to handle smart adapters | |
13 | // and direct devices. | |
14 | ||
15 | #ifndef BOOST_IOSTREAMS_COPY_HPP_INCLUDED | |
16 | #define BOOST_IOSTREAMS_COPY_HPP_INCLUDED | |
17 | ||
18 | #if defined(_MSC_VER) | |
19 | # pragma once | |
20 | #endif | |
21 | ||
22 | #include <boost/config.hpp> // Make sure ptrdiff_t is in std. | |
23 | #include <algorithm> // copy, min. | |
24 | #include <cstddef> // ptrdiff_t. | |
25 | #include <utility> // pair. | |
26 | #include <boost/bind.hpp> | |
27 | #include <boost/detail/workaround.hpp> | |
28 | #include <boost/iostreams/chain.hpp> | |
29 | #include <boost/iostreams/constants.hpp> | |
30 | #include <boost/iostreams/detail/adapter/non_blocking_adapter.hpp> | |
31 | #include <boost/iostreams/detail/buffer.hpp> | |
32 | #include <boost/iostreams/detail/enable_if_stream.hpp> | |
33 | #include <boost/iostreams/detail/execute.hpp> | |
34 | #include <boost/iostreams/detail/functional.hpp> | |
35 | #include <boost/iostreams/detail/ios.hpp> // failure, streamsize. | |
36 | #include <boost/iostreams/detail/resolve.hpp> | |
37 | #include <boost/iostreams/detail/wrap_unwrap.hpp> | |
38 | #include <boost/iostreams/operations.hpp> // read, write, close. | |
39 | #include <boost/iostreams/pipeline.hpp> | |
40 | #include <boost/static_assert.hpp> | |
41 | #include <boost/type_traits/is_same.hpp> | |
42 | ||
43 | namespace boost { namespace iostreams { | |
44 | ||
45 | namespace detail { | |
46 | ||
47 | // The following four overloads of copy_impl() optimize | |
48 | // copying in the case that one or both of the two devices | |
49 | // models Direct (see | |
50 | // http://www.boost.org/libs/iostreams/doc/index.html?path=4.1.1.4) | |
51 | ||
52 | // Copy from a direct source to a direct sink | |
53 | template<typename Source, typename Sink> | |
54 | std::streamsize copy_impl( Source& src, Sink& snk, | |
55 | std::streamsize /* buffer_size */, | |
56 | mpl::true_, mpl::true_ ) | |
57 | { | |
58 | using namespace std; | |
59 | typedef typename char_type_of<Source>::type char_type; | |
60 | typedef std::pair<char_type*, char_type*> pair_type; | |
61 | pair_type p1 = iostreams::input_sequence(src); | |
62 | pair_type p2 = iostreams::output_sequence(snk); | |
63 | std::streamsize total = | |
64 | static_cast<std::streamsize>( | |
65 | (std::min)(p1.second - p1.first, p2.second - p2.first) | |
66 | ); | |
67 | std::copy(p1.first, p1.first + total, p2.first); | |
68 | return total; | |
69 | } | |
70 | ||
71 | // Copy from a direct source to an indirect sink | |
72 | template<typename Source, typename Sink> | |
73 | std::streamsize copy_impl( Source& src, Sink& snk, | |
74 | std::streamsize /* buffer_size */, | |
75 | mpl::true_, mpl::false_ ) | |
76 | { | |
77 | using namespace std; | |
78 | typedef typename char_type_of<Source>::type char_type; | |
79 | typedef std::pair<char_type*, char_type*> pair_type; | |
80 | pair_type p = iostreams::input_sequence(src); | |
81 | std::streamsize size, total; | |
82 | for ( total = 0, size = static_cast<std::streamsize>(p.second - p.first); | |
83 | total < size; ) | |
84 | { | |
85 | std::streamsize amt = | |
86 | iostreams::write(snk, p.first + total, size - total); | |
87 | total += amt; | |
88 | } | |
89 | return total; | |
90 | } | |
91 | ||
92 | // Copy from an indirect source to a direct sink | |
93 | template<typename Source, typename Sink> | |
94 | std::streamsize copy_impl( Source& src, Sink& snk, | |
95 | std::streamsize buffer_size, | |
96 | mpl::false_, mpl::true_ ) | |
97 | { | |
98 | typedef typename char_type_of<Source>::type char_type; | |
99 | typedef std::pair<char_type*, char_type*> pair_type; | |
100 | detail::basic_buffer<char_type> buf(buffer_size); | |
101 | pair_type p = snk.output_sequence(); | |
102 | std::streamsize total = 0; | |
103 | std::ptrdiff_t capacity = p.second - p.first; | |
104 | while (true) { | |
105 | std::streamsize amt = | |
106 | iostreams::read( | |
107 | src, | |
108 | buf.data(), | |
109 | buffer_size < capacity - total ? | |
110 | buffer_size : | |
111 | static_cast<std::streamsize>(capacity - total) | |
112 | ); | |
113 | if (amt == -1) | |
114 | break; | |
115 | std::copy(buf.data(), buf.data() + amt, p.first + total); | |
116 | total += amt; | |
117 | } | |
118 | return total; | |
119 | } | |
120 | ||
121 | // Copy from an indirect source to an indirect sink | |
122 | template<typename Source, typename Sink> | |
123 | std::streamsize copy_impl( Source& src, Sink& snk, | |
124 | std::streamsize buffer_size, | |
125 | mpl::false_, mpl::false_ ) | |
126 | { | |
127 | typedef typename char_type_of<Source>::type char_type; | |
128 | detail::basic_buffer<char_type> buf(buffer_size); | |
129 | non_blocking_adapter<Sink> nb(snk); | |
130 | std::streamsize total = 0; | |
131 | bool done = false; | |
132 | while (!done) { | |
133 | std::streamsize amt; | |
134 | done = (amt = iostreams::read(src, buf.data(), buffer_size)) == -1; | |
135 | if (amt != -1) { | |
136 | iostreams::write(nb, buf.data(), amt); | |
137 | total += amt; | |
138 | } | |
139 | } | |
140 | return total; | |
141 | } | |
142 | ||
143 | // The following function object is used with | |
144 | // boost::iostreams::detail::execute() in the primary | |
145 | // overload of copy_impl(), below | |
146 | ||
147 | // Function object that delegates to one of the above four | |
148 | // overloads of compl_impl() | |
149 | template<typename Source, typename Sink> | |
150 | class copy_operation { | |
151 | public: | |
152 | typedef std::streamsize result_type; | |
153 | copy_operation(Source& src, Sink& snk, std::streamsize buffer_size) | |
154 | : src_(src), snk_(snk), buffer_size_(buffer_size) | |
155 | { } | |
156 | std::streamsize operator()() | |
157 | { | |
158 | return copy_impl( src_, snk_, buffer_size_, | |
159 | is_direct<Source>(), is_direct<Sink>() ); | |
160 | } | |
161 | private: | |
162 | copy_operation& operator=(const copy_operation&); | |
163 | Source& src_; | |
164 | Sink& snk_; | |
165 | std::streamsize buffer_size_; | |
166 | }; | |
167 | ||
168 | // Primary overload of copy_impl. Delegates to one of the above four | |
169 | // overloads of compl_impl(), depending on which of the two given | |
170 | // devices, if any, models Direct (see | |
171 | // http://www.boost.org/libs/iostreams/doc/index.html?path=4.1.1.4) | |
172 | template<typename Source, typename Sink> | |
173 | std::streamsize copy_impl(Source src, Sink snk, std::streamsize buffer_size) | |
174 | { | |
175 | using namespace std; | |
176 | typedef typename char_type_of<Source>::type src_char; | |
177 | typedef typename char_type_of<Sink>::type snk_char; | |
178 | BOOST_STATIC_ASSERT((is_same<src_char, snk_char>::value)); | |
179 | return detail::execute_all( | |
180 | copy_operation<Source, Sink>(src, snk, buffer_size), | |
181 | detail::call_close_all(src), | |
182 | detail::call_close_all(snk) | |
183 | ); | |
184 | } | |
185 | ||
186 | } // End namespace detail. | |
187 | ||
188 | //------------------Definition of copy----------------------------------------// | |
189 | ||
190 | // Overload of copy() for the case where neither the source nor the sink is | |
191 | // a standard stream or stream buffer | |
192 | template<typename Source, typename Sink> | |
193 | std::streamsize | |
194 | copy( const Source& src, const Sink& snk, | |
195 | std::streamsize buffer_size = default_device_buffer_size | |
196 | BOOST_IOSTREAMS_DISABLE_IF_STREAM(Source) | |
197 | BOOST_IOSTREAMS_DISABLE_IF_STREAM(Sink) ) | |
198 | { | |
199 | typedef typename char_type_of<Source>::type char_type; | |
200 | return detail::copy_impl( detail::resolve<input, char_type>(src), | |
201 | detail::resolve<output, char_type>(snk), | |
202 | buffer_size ); | |
203 | } | |
204 | ||
205 | // Overload of copy() for the case where the source, but not the sink, is | |
206 | // a standard stream or stream buffer | |
207 | template<typename Source, typename Sink> | |
208 | std::streamsize | |
209 | copy( Source& src, const Sink& snk, | |
210 | std::streamsize buffer_size = default_device_buffer_size | |
211 | BOOST_IOSTREAMS_ENABLE_IF_STREAM(Source) | |
212 | BOOST_IOSTREAMS_DISABLE_IF_STREAM(Sink) ) | |
213 | { | |
214 | typedef typename char_type_of<Source>::type char_type; | |
215 | return detail::copy_impl( detail::wrap(src), | |
216 | detail::resolve<output, char_type>(snk), | |
217 | buffer_size ); | |
218 | } | |
219 | ||
220 | // Overload of copy() for the case where the sink, but not the source, is | |
221 | // a standard stream or stream buffer | |
222 | template<typename Source, typename Sink> | |
223 | std::streamsize | |
224 | copy( const Source& src, Sink& snk, | |
225 | std::streamsize buffer_size = default_device_buffer_size | |
226 | BOOST_IOSTREAMS_DISABLE_IF_STREAM(Source) | |
227 | BOOST_IOSTREAMS_ENABLE_IF_STREAM(Sink) ) | |
228 | { | |
229 | typedef typename char_type_of<Source>::type char_type; | |
230 | return detail::copy_impl( detail::resolve<input, char_type>(src), | |
231 | detail::wrap(snk), buffer_size ); | |
232 | } | |
233 | ||
234 | // Overload of copy() for the case where neither the source nor the sink is | |
235 | // a standard stream or stream buffer | |
236 | template<typename Source, typename Sink> | |
237 | std::streamsize | |
238 | copy( Source& src, Sink& snk, | |
239 | std::streamsize buffer_size = default_device_buffer_size | |
240 | BOOST_IOSTREAMS_ENABLE_IF_STREAM(Source) | |
241 | BOOST_IOSTREAMS_ENABLE_IF_STREAM(Sink) ) | |
242 | { | |
243 | return detail::copy_impl(detail::wrap(src), detail::wrap(snk), buffer_size); | |
244 | } | |
245 | ||
246 | } } // End namespaces iostreams, boost. | |
247 | ||
248 | #endif // #ifndef BOOST_IOSTREAMS_COPY_HPP_INCLUDED |