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.)
6 // See http://www.boost.org/libs/iostreams for documentation.
8 #ifndef BOOST_IOSTREAMS_DETAIL_CHAIN_HPP_INCLUDED
9 #define BOOST_IOSTREAMS_DETAIL_CHAIN_HPP_INCLUDED
11 #if defined(_MSC_VER) && (_MSC_VER >= 1020)
15 #include <boost/assert.hpp>
17 #include <functional> // unary_function.
18 #include <iterator> // advance.
20 #include <memory> // allocator, auto_ptr.
22 #include <stdexcept> // logic_error, out_of_range.
23 #include <boost/checked_delete.hpp>
24 #include <boost/config.hpp> // BOOST_MSVC, template friends,
25 #include <boost/detail/workaround.hpp> // BOOST_NESTED_TEMPLATE
26 #include <boost/iostreams/constants.hpp>
27 #include <boost/iostreams/detail/access_control.hpp>
28 #include <boost/iostreams/detail/char_traits.hpp>
29 #include <boost/iostreams/detail/push.hpp>
30 #include <boost/iostreams/detail/streambuf.hpp> // pubsync.
31 #include <boost/iostreams/detail/wrap_unwrap.hpp>
32 #include <boost/iostreams/device/null.hpp>
33 #include <boost/iostreams/positioning.hpp>
34 #include <boost/iostreams/traits.hpp> // is_filter.
35 #include <boost/iostreams/stream_buffer.hpp>
36 #include <boost/next_prior.hpp>
37 #include <boost/shared_ptr.hpp>
38 #include <boost/static_assert.hpp>
39 #include <boost/throw_exception.hpp>
40 #include <boost/type_traits/is_convertible.hpp>
41 #include <boost/type.hpp>
42 #include <boost/iostreams/detail/execute.hpp> // VC6.5 requires this
43 #if BOOST_WORKAROUND(BOOST_MSVC, < 1310) // #include order
44 # include <boost/mpl/int.hpp>
47 // Sometimes type_info objects must be compared by name. Borrowed from
48 // Boost.Python and Boost.Function.
49 #if (defined(__GNUC__) && __GNUC__ >= 3) || \
51 (defined(__sgi) && defined(__host_mips)) || \
52 (defined(linux) && defined(__INTEL_COMPILER) && defined(__ICC)) \
55 # define BOOST_IOSTREAMS_COMPARE_TYPE_ID(X,Y) \
56 (std::strcmp((X).name(),(Y).name()) == 0)
58 # define BOOST_IOSTREAMS_COMPARE_TYPE_ID(X,Y) ((X)==(Y))
62 #define BOOST_IOSTREAMS_COMPONENT_TYPE(chain, index) \
63 chain.component_type( index ) \
66 #if !BOOST_WORKAROUND(BOOST_MSVC, < 1310)
67 # define BOOST_IOSTREAMS_COMPONENT(chain, index, target) \
68 chain.component< target >( index ) \
71 # define BOOST_IOSTREAMS_COMPONENT(chain, index, target) \
72 chain.component( index, ::boost::type< target >() ) \
76 namespace boost { namespace iostreams {
78 //--------------Definition of chain and wchain--------------------------------//
82 template<typename Chain> class chain_client;
85 // Concept name: Chain.
86 // Description: Represents a chain of stream buffers which provides access
87 // to the first buffer in the chain and sends notifications when the
88 // streambufs are added to or removed from chain.
89 // Refines: Closable device with mode equal to typename Chain::mode.
90 // Models: chain, converting_chain.
95 // typedef xxx chain_type;
96 // typedef xxx client_type;
98 // bool is_complete() const; // Ready for i/o.
99 // template<typename T>
100 // void push( const T& t, // Adds a stream buffer to
101 // streamsize, // chain, based on t, with
102 // streamsize ); // given buffer and putback
103 // // buffer sizes. Pass -1 to
104 // // request default size.
106 // void register_client(client_type* client); // Associate client.
107 // void notify(); // Notify client.
112 // Description: Represents a chain of filters with an optional device at the
114 // Template parameters:
115 // Self - A class deriving from the current instantiation of this template.
116 // This is an example of the Curiously Recurring Template Pattern.
117 // Ch - The character type.
118 // Tr - The character traits type.
119 // Alloc - The allocator type.
120 // Mode - A mode tag.
122 template<typename Self, typename Ch, typename Tr, typename Alloc, typename Mode>
125 typedef Ch char_type;
126 BOOST_IOSTREAMS_STREAMBUF_TYPEDEFS(Tr)
127 typedef Alloc allocator_type;
133 typedef chain_client<Self> client_type;
134 friend class chain_client<Self>;
136 typedef linked_streambuf<Ch> streambuf_type;
137 typedef std::list<streambuf_type*> list_type;
138 typedef chain_base<Self, Ch, Tr, Alloc, Mode> my_type;
140 chain_base() : pimpl_(new chain_impl) { }
141 chain_base(const chain_base& rhs): pimpl_(rhs.pimpl_) { }
144 // dual_use is a pseudo-mode to facilitate filter writing,
145 // not a genuine mode.
146 BOOST_STATIC_ASSERT((!is_convertible<mode, dual_use>::value));
148 //----------Buffer sizing-------------------------------------------------//
150 // Sets the size of the buffer created for the devices to be added to this
151 // chain. Does not affect the size of the buffer for devices already
153 void set_device_buffer_size(std::streamsize n)
154 { pimpl_->device_buffer_size_ = n; }
156 // Sets the size of the buffer created for the filters to be added
157 // to this chain. Does not affect the size of the buffer for filters already
159 void set_filter_buffer_size(std::streamsize n)
160 { pimpl_->filter_buffer_size_ = n; }
162 // Sets the size of the putback buffer for filters and devices to be added
163 // to this chain. Does not affect the size of the buffer for filters or
164 // devices already added.
165 void set_pback_size(std::streamsize n)
166 { pimpl_->pback_size_ = n; }
168 //----------Device interface----------------------------------------------//
170 std::streamsize read(char_type* s, std::streamsize n);
171 std::streamsize write(const char_type* s, std::streamsize n);
172 std::streampos seek(stream_offset off, BOOST_IOS::seekdir way);
174 //----------Direct component access---------------------------------------//
176 const std::type_info& component_type(int n) const
178 if (static_cast<size_type>(n) >= size())
179 boost::throw_exception(std::out_of_range("bad chain offset"));
180 return (*boost::next(list().begin(), n))->component_type();
183 #if !BOOST_WORKAROUND(BOOST_MSVC, < 1310)
186 const std::type_info& component_type() const { return component_type(N); }
189 T* component(int n) const { return component(n, boost::type<T>()); }
192 template<int N, typename T>
193 T* component() const { return component<T>(N); }
196 #if !BOOST_WORKAROUND(BOOST_MSVC, < 1310)
200 T* component(int n, boost::type<T>) const
202 if (static_cast<size_type>(n) >= size())
203 boost::throw_exception(std::out_of_range("bad chain offset"));
204 streambuf_type* link = *boost::next(list().begin(), n);
205 if (BOOST_IOSTREAMS_COMPARE_TYPE_ID(link->component_type(), typeid(T)))
206 return static_cast<T*>(link->component_impl());
212 //----------Container-like interface--------------------------------------//
214 typedef typename list_type::size_type size_type;
215 streambuf_type& front() { return *list().front(); }
216 BOOST_IOSTREAMS_DEFINE_PUSH(push, mode, char_type, push_impl)
218 bool empty() const { return list().empty(); }
219 size_type size() const { return list().size(); }
222 //----------Additional i/o functions--------------------------------------//
224 // Returns true if this chain is non-empty and its final link
225 // is a source or sink, i.e., if it is ready to perform i/o.
226 bool is_complete() const;
227 bool auto_close() const;
228 void set_auto_close(bool close);
229 bool sync() { return front().BOOST_IOSTREAMS_PUBSYNC() != -1; }
233 void push_impl(const T& t, std::streamsize buffer_size = -1,
234 std::streamsize pback_size = -1)
236 typedef typename iostreams::category_of<T>::type category;
237 typedef typename unwrap_ios<T>::type component_type;
238 typedef stream_buffer<
240 BOOST_IOSTREAMS_CHAR_TRAITS(char_type),
243 typedef typename list_type::iterator iterator;
244 BOOST_STATIC_ASSERT((is_convertible<category, Mode>::value));
246 boost::throw_exception(std::logic_error("chain complete"));
247 streambuf_type* prev = !empty() ? list().back() : 0;
251 iostreams::optimal_buffer_size(t);
256 std::auto_ptr<streambuf_t>
257 buf(new streambuf_t(t, buffer_size, pback_size));
258 list().push_back(buf.get());
260 if (is_device<component_type>::value) {
261 pimpl_->flags_ |= f_complete | f_open;
262 for ( iterator first = list().begin(),
267 (*first)->set_needs_close();
270 if (prev) prev->set_next(list().back());
274 list_type& list() { return pimpl_->links_; }
275 const list_type& list() const { return pimpl_->links_; }
276 void register_client(client_type* client) { pimpl_->client_ = client; }
277 void notify() { if (pimpl_->client_) pimpl_->client_->notify(); }
279 //----------Nested classes------------------------------------------------//
281 static void close(streambuf_type* b, BOOST_IOS::openmode m)
283 if (m == BOOST_IOS::out && is_convertible<Mode, output>::value)
284 b->BOOST_IOSTREAMS_PUBSYNC();
288 static void set_next(streambuf_type* b, streambuf_type* next)
289 { b->set_next(next); }
291 static void set_auto_close(streambuf_type* b, bool close)
292 { b->set_auto_close(close); }
294 struct closer : public std::unary_function<streambuf_type*, void> {
295 closer(BOOST_IOS::openmode m) : mode_(m) { }
296 void operator() (streambuf_type* b)
300 BOOST_IOS::openmode mode_;
302 friend struct closer;
312 : client_(0), device_buffer_size_(default_device_buffer_size),
313 filter_buffer_size_(default_filter_buffer_size),
314 pback_size_(default_pback_buffer_size),
319 try { close(); } catch (...) { }
320 try { reset(); } catch (...) { }
324 if ((flags_ & f_open) != 0) {
326 stream_buffer< basic_null_device<Ch, Mode> > null;
327 if ((flags_ & f_complete) == 0) {
328 null.open(basic_null_device<Ch, Mode>());
329 set_next(links_.back(), &null);
331 links_.front()->BOOST_IOSTREAMS_PUBSYNC();
333 boost::iostreams::detail::execute_foreach(
334 links_.rbegin(), links_.rend(),
335 closer(BOOST_IOS::in)
339 boost::iostreams::detail::execute_foreach(
340 links_.begin(), links_.end(),
341 closer(BOOST_IOS::out)
346 boost::iostreams::detail::execute_foreach(
347 links_.begin(), links_.end(),
348 closer(BOOST_IOS::out)
354 typedef typename list_type::iterator iterator;
355 for ( iterator first = links_.begin(),
360 if ( (flags_ & f_complete) == 0 ||
361 (flags_ & f_auto_close) == 0 )
363 set_auto_close(*first, false);
365 streambuf_type* buf = 0;
366 std::swap(buf, *first);
370 flags_ &= ~f_complete;
374 client_type* client_;
375 std::streamsize device_buffer_size_,
380 friend struct chain_impl;
382 //----------Member data---------------------------------------------------//
385 shared_ptr<chain_impl> pimpl_;
388 } // End namespace detail.
391 // Macro: BOOST_IOSTREAMS_DECL_CHAIN(name, category)
392 // Description: Defines a template derived from chain_base appropriate for a
393 // particular i/o category. The template has the following parameters:
394 // Ch - The character type.
395 // Tr - The character traits type.
396 // Alloc - The allocator type.
398 // name_ - The name of the template to be defined.
399 // category_ - The i/o category of the template to be defined.
401 #define BOOST_IOSTREAMS_DECL_CHAIN(name_, default_char_) \
402 template< typename Mode, typename Ch = default_char_, \
403 typename Tr = BOOST_IOSTREAMS_CHAR_TRAITS(Ch), \
404 typename Alloc = std::allocator<Ch> > \
405 class name_ : public boost::iostreams::detail::chain_base< \
406 name_<Mode, Ch, Tr, Alloc>, \
407 Ch, Tr, Alloc, Mode \
411 struct category : device_tag, Mode { }; \
414 typedef boost::iostreams::detail::chain_base< \
415 name_<Mode, Ch, Tr, Alloc>, \
416 Ch, Tr, Alloc, Mode \
419 typedef Ch char_type; \
420 typedef Tr traits_type; \
421 typedef typename traits_type::int_type int_type; \
422 typedef typename traits_type::off_type off_type; \
424 name_(const name_& rhs) : base_type(rhs) { } \
425 name_& operator=(const name_& rhs) \
426 { base_type::operator=(rhs); return *this; } \
429 BOOST_IOSTREAMS_DECL_CHAIN(chain, char)
430 BOOST_IOSTREAMS_DECL_CHAIN(wchain, wchar_t)
431 #undef BOOST_IOSTREAMS_DECL_CHAIN
433 //--------------Definition of chain_client------------------------------------//
438 // Template name: chain_client
439 // Description: Class whose instances provide access to an underlying chain
440 // using an interface similar to the chains.
441 // Subclasses: the various stream and stream buffer templates.
443 template<typename Chain>
446 typedef Chain chain_type;
447 typedef typename chain_type::char_type char_type;
448 typedef typename chain_type::traits_type traits_type;
449 typedef typename chain_type::size_type size_type;
450 typedef typename chain_type::mode mode;
452 chain_client(chain_type* chn = 0) : chain_(chn ) { }
453 chain_client(chain_client* client) : chain_(client->chain_) { }
454 virtual ~chain_client() { }
456 const std::type_info& component_type(int n) const
457 { return chain_->component_type(n); }
459 #if !BOOST_WORKAROUND(BOOST_MSVC, < 1310)
462 const std::type_info& component_type() const
463 { return chain_->BOOST_NESTED_TEMPLATE component_type<N>(); }
466 T* component(int n) const
467 { return chain_->BOOST_NESTED_TEMPLATE component<T>(n); }
470 template<int N, typename T>
472 { return chain_->BOOST_NESTED_TEMPLATE component<N, T>(); }
475 T* component(int n, boost::type<T> t) const
476 { return chain_->component(n, t); }
479 bool is_complete() const { return chain_->is_complete(); }
480 bool auto_close() const { return chain_->auto_close(); }
481 void set_auto_close(bool close) { chain_->set_auto_close(close); }
482 bool strict_sync() { return chain_->strict_sync(); }
483 void set_device_buffer_size(std::streamsize n)
484 { chain_->set_device_buffer_size(n); }
485 void set_filter_buffer_size(std::streamsize n)
486 { chain_->set_filter_buffer_size(n); }
487 void set_pback_size(std::streamsize n) { chain_->set_pback_size(n); }
488 BOOST_IOSTREAMS_DEFINE_PUSH(push, mode, char_type, push_impl)
489 void pop() { chain_->pop(); }
490 bool empty() const { return chain_->empty(); }
491 size_type size() { return chain_->size(); }
492 void reset() { chain_->reset(); }
494 // Returns a copy of the underlying chain.
495 chain_type filters() { return *chain_; }
496 chain_type filters() const { return *chain_; }
499 void push_impl(const T& t BOOST_IOSTREAMS_PUSH_PARAMS())
500 { chain_->push(t BOOST_IOSTREAMS_PUSH_ARGS()); }
501 chain_type& ref() { return *chain_; }
502 void set_chain(chain_type* c)
503 { chain_ = c; chain_->register_client(this); }
504 #if !defined(BOOST_NO_MEMBER_TEMPLATE_FRIENDS) && \
505 (!BOOST_WORKAROUND(__BORLANDC__, < 0x600))
506 template<typename S, typename C, typename T, typename A, typename M>
507 friend class chain_base;
511 virtual void notify() { }
516 //--------------Implementation of chain_base----------------------------------//
518 template<typename Self, typename Ch, typename Tr, typename Alloc, typename Mode>
519 inline std::streamsize chain_base<Self, Ch, Tr, Alloc, Mode>::read
520 (char_type* s, std::streamsize n)
521 { return iostreams::read(*list().front(), s, n); }
523 template<typename Self, typename Ch, typename Tr, typename Alloc, typename Mode>
524 inline std::streamsize chain_base<Self, Ch, Tr, Alloc, Mode>::write
525 (const char_type* s, std::streamsize n)
526 { return iostreams::write(*list().front(), s, n); }
528 template<typename Self, typename Ch, typename Tr, typename Alloc, typename Mode>
529 inline std::streampos chain_base<Self, Ch, Tr, Alloc, Mode>::seek
530 (stream_offset off, BOOST_IOS::seekdir way)
531 { return iostreams::seek(*list().front(), off, way); }
533 template<typename Self, typename Ch, typename Tr, typename Alloc, typename Mode>
534 void chain_base<Self, Ch, Tr, Alloc, Mode>::reset()
541 template<typename Self, typename Ch, typename Tr, typename Alloc, typename Mode>
542 bool chain_base<Self, Ch, Tr, Alloc, Mode>::is_complete() const
544 return (pimpl_->flags_ & f_complete) != 0;
547 template<typename Self, typename Ch, typename Tr, typename Alloc, typename Mode>
548 bool chain_base<Self, Ch, Tr, Alloc, Mode>::auto_close() const
550 return (pimpl_->flags_ & f_auto_close) != 0;
553 template<typename Self, typename Ch, typename Tr, typename Alloc, typename Mode>
554 void chain_base<Self, Ch, Tr, Alloc, Mode>::set_auto_close(bool close)
557 (pimpl_->flags_ & ~f_auto_close) |
558 (close ? f_auto_close : 0);
561 template<typename Self, typename Ch, typename Tr, typename Alloc, typename Mode>
562 bool chain_base<Self, Ch, Tr, Alloc, Mode>::strict_sync()
564 typedef typename list_type::iterator iterator;
566 for ( iterator first = list().begin(),
571 bool s = (*first)->strict_sync();
572 result = result && s;
577 template<typename Self, typename Ch, typename Tr, typename Alloc, typename Mode>
578 void chain_base<Self, Ch, Tr, Alloc, Mode>::pop()
580 BOOST_ASSERT(!empty());
583 streambuf_type* buf = 0;
584 std::swap(buf, list().back());
585 buf->set_auto_close(false);
589 pimpl_->flags_ &= ~f_complete;
590 if (auto_close() || list().empty())
591 pimpl_->flags_ &= ~f_open;
594 } // End namespace detail.
596 } } // End namespaces iostreams, boost.
598 #endif // #ifndef BOOST_IOSTREAMS_DETAIL_CHAIN_HPP_INCLUDED