1 // (C) Copyright 2008 CodeRage, LLC (turkanis at coderage dot com) 2 // (C) Copyright 2005-2007 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_EXAMPLE_CONTAINTER_DEVICE_HPP_INCLUDED 9 #define BOOST_IOSTREAMS_EXAMPLE_CONTAINTER_DEVICE_HPP_INCLUDED 10 11 #include <algorithm> // copy, min. 12 #include <cassert> 13 #include <boost/config.hpp> // BOOST_NO_STDC_NAMESPACE. 14 #include <boost/iostreams/categories.hpp> 15 #include <boost/iostreams/detail/ios.hpp> // failure. 16 17 // Must come last. 18 #include <boost/iostreams/detail/config/disable_warnings.hpp> 19 20 namespace boost { namespace iostreams { namespace example { 21 22 // 23 // Model of Source which reads from an STL-compatible sequence 24 // whose iterators are random-access iterators. 25 // 26 template<typename Container> 27 class container_source { 28 public: 29 typedef typename Container::value_type char_type; 30 typedef source_tag category; container_source(Container & container)31 container_source(Container& container) 32 : container_(container), pos_(0) 33 { } read(char_type * s,std::streamsize n)34 std::streamsize read(char_type* s, std::streamsize n) 35 { 36 using namespace std; 37 std::streamsize amt = 38 static_cast<std::streamsize>(container_.size() - pos_); 39 std::streamsize result = (min)(n, amt); 40 if (result != 0) { 41 std::copy( container_.begin() + pos_, 42 container_.begin() + pos_ + result, 43 s ); 44 pos_ += result; 45 return result; 46 } else { 47 return -1; // EOF 48 } 49 } container()50 Container& container() { return container_; } 51 private: 52 container_source operator=(const container_source&); 53 typedef typename Container::size_type size_type; 54 Container& container_; 55 size_type pos_; 56 }; 57 58 // 59 // Model of Sink which appends to an STL-compatible sequence. 60 // 61 template<typename Container> 62 class container_sink { 63 public: 64 typedef typename Container::value_type char_type; 65 typedef sink_tag category; container_sink(Container & container)66 container_sink(Container& container) : container_(container) { } write(const char_type * s,std::streamsize n)67 std::streamsize write(const char_type* s, std::streamsize n) 68 { 69 container_.insert(container_.end(), s, s + n); 70 return n; 71 } container()72 Container& container() { return container_; } 73 private: 74 container_sink operator=(const container_sink&); 75 Container& container_; 76 }; 77 78 // 79 // Model of SeekableDevice which accessS an TL-compatible sequence 80 // whose iterators are random-access iterators. 81 // 82 template<typename Container> 83 class container_device { 84 public: 85 typedef typename Container::value_type char_type; 86 typedef seekable_device_tag category; container_device(Container & container)87 container_device(Container& container) 88 : container_(container), pos_(0) 89 { } 90 read(char_type * s,std::streamsize n)91 std::streamsize read(char_type* s, std::streamsize n) 92 { 93 using namespace std; 94 std::streamsize amt = 95 static_cast<std::streamsize>(container_.size() - pos_); 96 std::streamsize result = (min)(n, amt); 97 if (result != 0) { 98 std::copy( container_.begin() + pos_, 99 container_.begin() + pos_ + result, 100 s ); 101 pos_ += result; 102 return result; 103 } else { 104 return -1; // EOF 105 } 106 } write(const char_type * s,std::streamsize n)107 std::streamsize write(const char_type* s, std::streamsize n) 108 { 109 using namespace std; 110 std::streamsize result = 0; 111 if (pos_ != container_.size()) { 112 std::streamsize amt = 113 static_cast<std::streamsize>(container_.size() - pos_); 114 result = (min)(n, amt); 115 std::copy(s, s + result, container_.begin() + pos_); 116 pos_ += result; 117 } 118 if (result < n) { 119 container_.insert(container_.end(), s, s + n); 120 pos_ = container_.size(); 121 } 122 return n; 123 } seek(stream_offset off,BOOST_IOS::seekdir way)124 stream_offset seek(stream_offset off, BOOST_IOS::seekdir way) 125 { 126 using namespace std; 127 128 // Determine new value of pos_ 129 stream_offset next; 130 if (way == BOOST_IOS::beg) { 131 next = off; 132 } else if (way == BOOST_IOS::cur) { 133 next = pos_ + off; 134 } else if (way == BOOST_IOS::end) { 135 next = container_.size() + off - 1; 136 } else { 137 throw BOOST_IOSTREAMS_FAILURE("bad seek direction"); 138 } 139 140 // Check for errors 141 if (next < 0 || next > static_cast<stream_offset>(container_.size())) 142 throw BOOST_IOSTREAMS_FAILURE("bad seek offset"); 143 144 pos_ = next; 145 return pos_; 146 } 147 container()148 Container& container() { return container_; } 149 private: 150 container_device operator=(const container_device&); 151 typedef typename Container::size_type size_type; 152 Container& container_; 153 size_type pos_; 154 }; 155 156 } } } // End namespaces example, iostreams, boost. 157 158 #include <boost/iostreams/detail/config/enable_warnings.hpp> 159 160 #endif // #ifndef BOOST_IOSTREAMS_EXAMPLE_CONTAINTER_DEVICE_HPP_INCLUDED 161