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 #ifndef BOOST_IOSTREAMS_DETAIL_BUFFERS_HPP_INCLUDED
9 #define BOOST_IOSTREAMS_DETAIL_BUFFERS_HPP_INCLUDED
10
11 #if defined(_MSC_VER)
12 # pragma once
13 #endif
14
15 #include <algorithm> // swap.
16 #include <memory> // allocator.
17 #include <boost/config.hpp> // member templates.
18 #include <boost/iostreams/char_traits.hpp>
19 #include <boost/iostreams/detail/ios.hpp> // streamsize.
20 #include <boost/iostreams/read.hpp>
21 #include <boost/iostreams/traits.hpp> // int_type_of.
22 #include <boost/iostreams/checked_operations.hpp>
23 #include <boost/mpl/if.hpp>
24 #include <boost/type_traits/is_same.hpp>
25
26 namespace boost { namespace iostreams { namespace detail {
27
28 //----------------Buffers-----------------------------------------------------//
29
30 //
31 // Template name: buffer
32 // Description: Character buffer.
33 // Template parameters:
34 // Ch - The character type.
35 // Alloc - The Allocator type.
36 //
37 template< typename Ch,
38 typename Alloc = std::allocator<Ch> >
39 class basic_buffer {
40 private:
41 #ifndef BOOST_NO_STD_ALLOCATOR
42 #if defined(BOOST_NO_CXX11_ALLOCATOR)
43 typedef typename Alloc::template rebind<Ch>::other allocator_type;
44 #else
45 typedef typename std::allocator_traits<Alloc>::template rebind_alloc<Ch> allocator_type;
46 typedef std::allocator_traits<allocator_type> allocator_traits;
47 #endif
48 #else
49 typedef std::allocator<Ch> allocator_type;
50 #endif
51 static Ch* allocate(std::streamsize buffer_size);
52 public:
53 basic_buffer();
54 basic_buffer(std::streamsize buffer_size);
55 ~basic_buffer();
56 void resize(std::streamsize buffer_size);
begin() const57 Ch* begin() const { return buf_; }
end() const58 Ch* end() const { return buf_ + size_; }
data() const59 Ch* data() const { return buf_; }
size() const60 std::streamsize size() const { return size_; }
61 void swap(basic_buffer& rhs);
62 private:
63 // Disallow copying and assignment.
64 basic_buffer(const basic_buffer&);
65 basic_buffer& operator=(const basic_buffer&);
66 Ch* buf_;
67 std::streamsize size_;
68 };
69
70 template<typename Ch, typename Alloc>
swap(basic_buffer<Ch,Alloc> & lhs,basic_buffer<Ch,Alloc> & rhs)71 void swap(basic_buffer<Ch, Alloc>& lhs, basic_buffer<Ch, Alloc>& rhs)
72 { lhs.swap(rhs); }
73
74 //
75 // Template name: buffer
76 // Description: Character buffer with two pointers accessible via ptr() and
77 // eptr().
78 // Template parameters:
79 // Ch - A character type.
80 //
81 template< typename Ch,
82 typename Alloc = std::allocator<Ch> >
83 class buffer : public basic_buffer<Ch, Alloc> {
84 private:
85 typedef basic_buffer<Ch, Alloc> base;
86 public:
87 typedef iostreams::char_traits<Ch> traits_type;
88 using base::resize;
89 using base::data;
90 using base::size;
91 typedef Ch* const const_pointer;
92 buffer(std::streamsize buffer_size);
ptr()93 Ch* & ptr() { return ptr_; }
ptr() const94 const_pointer& ptr() const { return ptr_; }
eptr()95 Ch* & eptr() { return eptr_; }
eptr() const96 const_pointer& eptr() const { return eptr_; }
97 void set(std::streamsize ptr, std::streamsize end);
98 void swap(buffer& rhs);
99
100 // Returns an int_type as a status code.
101 template<typename Source>
fill(Source & src)102 typename int_type_of<Source>::type fill(Source& src)
103 {
104 using namespace std;
105 std::streamsize keep;
106 if ((keep = static_cast<std::streamsize>(eptr_ - ptr_)) > 0)
107 traits_type::move(
108 this->data(),
109 ptr_,
110 static_cast<size_t>(keep)
111 );
112 set(0, keep);
113 std::streamsize result =
114 iostreams::read(src, this->data() + keep, this->size() - keep);
115 if (result != -1)
116 this->set(0, keep + result);
117 return result == -1 ?
118 traits_type::eof() :
119 result == 0 ?
120 traits_type::would_block() :
121 traits_type::good();
122
123 }
124
125 // Returns true if one or more characters were written.
126 template<typename Sink>
flush(Sink & dest)127 bool flush(Sink& dest)
128 {
129 using namespace std;
130 std::streamsize amt = static_cast<std::streamsize>(eptr_ - ptr_);
131 std::streamsize result = iostreams::write_if(dest, ptr_, amt);
132 if (result < amt) {
133 traits_type::move( this->data(),
134 ptr_ + static_cast<size_t>(result),
135 static_cast<size_t>(amt - result) );
136 }
137 this->set(0, amt - result);
138 return result != 0;
139 }
140 private:
141 Ch *ptr_, *eptr_;
142 };
143
144 template<typename Ch, typename Alloc>
swap(buffer<Ch,Alloc> & lhs,buffer<Ch,Alloc> & rhs)145 void swap(buffer<Ch, Alloc>& lhs, buffer<Ch, Alloc>& rhs)
146 { lhs.swap(rhs); }
147
148 //--------------Implementation of basic_buffer--------------------------------//
149
150 template<typename Ch, typename Alloc>
basic_buffer()151 basic_buffer<Ch, Alloc>::basic_buffer() : buf_(0), size_(0) { }
152
153 template<typename Ch, typename Alloc>
allocate(std::streamsize buffer_size)154 inline Ch* basic_buffer<Ch, Alloc>::allocate(std::streamsize buffer_size)
155 {
156 #if defined(BOOST_NO_CXX11_ALLOCATOR) || defined(BOOST_NO_STD_ALLOCATOR)
157 return static_cast<Ch*>(allocator_type().allocate(
158 static_cast<BOOST_DEDUCED_TYPENAME Alloc::size_type>(buffer_size), 0));
159 #else
160 allocator_type alloc;
161 return static_cast<Ch*>(allocator_traits::allocate(alloc,
162 static_cast<BOOST_DEDUCED_TYPENAME allocator_traits::size_type>(buffer_size)));
163 #endif
164 }
165
166 template<typename Ch, typename Alloc>
basic_buffer(std::streamsize buffer_size)167 basic_buffer<Ch, Alloc>::basic_buffer(std::streamsize buffer_size)
168 : buf_(allocate(buffer_size)),
169 size_(buffer_size) // Cast for SunPro 5.3.
170 { }
171
172 template<typename Ch, typename Alloc>
~basic_buffer()173 inline basic_buffer<Ch, Alloc>::~basic_buffer()
174 {
175 if (buf_) {
176 #if defined(BOOST_NO_CXX11_ALLOCATOR) || defined(BOOST_NO_STD_ALLOCATOR)
177 allocator_type().deallocate(buf_,
178 static_cast<BOOST_DEDUCED_TYPENAME Alloc::size_type>(size_));
179 #else
180 allocator_type alloc;
181 allocator_traits::deallocate(alloc, buf_,
182 static_cast<BOOST_DEDUCED_TYPENAME allocator_traits::size_type>(size_));
183 #endif
184 }
185 }
186
187 template<typename Ch, typename Alloc>
resize(std::streamsize buffer_size)188 inline void basic_buffer<Ch, Alloc>::resize(std::streamsize buffer_size)
189 {
190 if (size_ != buffer_size) {
191 basic_buffer<Ch, Alloc> temp(buffer_size);
192 std::swap(size_, temp.size_);
193 std::swap(buf_, temp.buf_);
194 }
195 }
196
197 template<typename Ch, typename Alloc>
swap(basic_buffer & rhs)198 void basic_buffer<Ch, Alloc>::swap(basic_buffer& rhs)
199 {
200 std::swap(buf_, rhs.buf_);
201 std::swap(size_, rhs.size_);
202 }
203
204 //--------------Implementation of buffer--------------------------------------//
205
206 template<typename Ch, typename Alloc>
buffer(std::streamsize buffer_size)207 buffer<Ch, Alloc>::buffer(std::streamsize buffer_size)
208 : basic_buffer<Ch, Alloc>(buffer_size), ptr_(data()), eptr_(data() + buffer_size) { }
209
210 template<typename Ch, typename Alloc>
set(std::streamsize ptr,std::streamsize end)211 inline void buffer<Ch, Alloc>::set(std::streamsize ptr, std::streamsize end)
212 {
213 ptr_ = data() + ptr;
214 eptr_ = data() + end;
215 }
216
217 template<typename Ch, typename Alloc>
swap(buffer & rhs)218 inline void buffer<Ch, Alloc>::swap(buffer& rhs)
219 {
220 base::swap(rhs);
221 std::swap(ptr_, rhs.ptr_);
222 std::swap(eptr_, rhs.eptr_);
223 }
224
225 //----------------------------------------------------------------------------//
226
227 } } } // End namespaces detail, iostreams, boost.
228
229 #endif // #ifndef BOOST_IOSTREAMS_DETAIL_BUFFERS_HPP_INCLUDED
230