| // (C) Copyright 2008 CodeRage, LLC (turkanis at coderage dot com) |
| // (C) Copyright 2003-2007 Jonathan Turkanis |
| // Distributed under the Boost Software License, Version 1.0. (See accompanying |
| // file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt.) |
| |
| // See http://www.boost.org/libs/iostreams for documentation. |
| |
| #ifndef NDNBOOST_IOSTREAMS_AGGREGATE_FILTER_HPP_INCLUDED |
| #define NDNBOOST_IOSTREAMS_AGGREGATE_FILTER_HPP_INCLUDED |
| |
| #if defined(_MSC_VER) && (_MSC_VER >= 1020) |
| # pragma once |
| #endif |
| |
| #include <algorithm> // copy, min. |
| #include <ndnboost/assert.hpp> |
| #include <iterator> // back_inserter |
| #include <vector> |
| #include <ndnboost/iostreams/constants.hpp> // default_device_buffer_size |
| #include <ndnboost/iostreams/categories.hpp> |
| #include <ndnboost/iostreams/detail/char_traits.hpp> |
| #include <ndnboost/iostreams/detail/ios.hpp> // openmode, streamsize. |
| #include <ndnboost/iostreams/pipeline.hpp> |
| #include <ndnboost/iostreams/read.hpp> // check_eof |
| #include <ndnboost/iostreams/write.hpp> |
| #include <ndnboost/mpl/bool.hpp> |
| #include <ndnboost/type_traits/is_convertible.hpp> |
| |
| // Must come last. |
| #include <ndnboost/iostreams/detail/config/disable_warnings.hpp> // MSVC. |
| |
| namespace ndnboost { namespace iostreams { |
| |
| // |
| // Template name: aggregate_filter. |
| // Template parameters: |
| // Ch - The character type. |
| // Alloc - The allocator type. |
| // Description: Utility for defining DualUseFilters which filter an |
| // entire stream at once. To use, override the protected virtual |
| // member do_filter. |
| // Note: This filter should not be copied while it is in use. |
| // |
| template<typename Ch, typename Alloc = std::allocator<Ch> > |
| class aggregate_filter { |
| public: |
| typedef Ch char_type; |
| struct category |
| : dual_use, |
| filter_tag, |
| multichar_tag, |
| closable_tag |
| { }; |
| aggregate_filter() : ptr_(0), state_(0) { } |
| virtual ~aggregate_filter() { } |
| |
| template<typename Source> |
| std::streamsize read(Source& src, char_type* s, std::streamsize n) |
| { |
| using namespace std; |
| NDNBOOST_ASSERT(!(state_ & f_write)); |
| state_ |= f_read; |
| if (!(state_ & f_eof)) |
| do_read(src); |
| std::streamsize amt = |
| (std::min)(n, static_cast<std::streamsize>(data_.size() - ptr_)); |
| if (amt) { |
| NDNBOOST_IOSTREAMS_CHAR_TRAITS(char_type)::copy(s, &data_[ptr_], amt); |
| ptr_ += amt; |
| } |
| return detail::check_eof(amt); |
| } |
| |
| template<typename Sink> |
| std::streamsize write(Sink&, const char_type* s, std::streamsize n) |
| { |
| NDNBOOST_ASSERT(!(state_ & f_read)); |
| state_ |= f_write; |
| data_.insert(data_.end(), s, s + n); |
| return n; |
| } |
| |
| template<typename Sink> |
| void close(Sink& sink, NDNBOOST_IOS::openmode which) |
| { |
| if ((state_ & f_read) != 0 && which == NDNBOOST_IOS::in) |
| close_impl(); |
| if ((state_ & f_write) != 0 && which == NDNBOOST_IOS::out) { |
| try { |
| vector_type filtered; |
| do_filter(data_, filtered); |
| do_write( |
| sink, &filtered[0], |
| static_cast<std::streamsize>(filtered.size()) |
| ); |
| } catch (...) { |
| close_impl(); |
| throw; |
| } |
| close_impl(); |
| } |
| } |
| |
| protected: |
| typedef std::vector<Ch, Alloc> vector_type; |
| typedef typename vector_type::size_type size_type; |
| private: |
| virtual void do_filter(const vector_type& src, vector_type& dest) = 0; |
| virtual void do_close() { } |
| |
| template<typename Source> |
| void do_read(Source& src) |
| { |
| using std::streamsize; |
| vector_type data; |
| while (true) { |
| const std::streamsize size = default_device_buffer_size; |
| Ch buf[size]; |
| std::streamsize amt; |
| if ((amt = ndnboost::iostreams::read(src, buf, size)) == -1) |
| break; |
| data.insert(data.end(), buf, buf + amt); |
| } |
| do_filter(data, data_); |
| state_ |= f_eof; |
| } |
| |
| template<typename Sink> |
| void do_write(Sink& sink, const char_type* s, std::streamsize n) |
| { |
| typedef typename iostreams::category_of<Sink>::type category; |
| typedef is_convertible<category, output> can_write; |
| do_write(sink, s, n, can_write()); |
| } |
| |
| template<typename Sink> |
| void do_write(Sink& sink, const char_type* s, std::streamsize n, mpl::true_) |
| { iostreams::write(sink, s, n); } |
| |
| template<typename Sink> |
| void do_write(Sink&, const char_type*, std::streamsize, mpl::false_) { } |
| |
| void close_impl() |
| { |
| data_.clear(); |
| ptr_ = 0; |
| state_ = 0; |
| do_close(); |
| } |
| |
| enum flag_type { |
| f_read = 1, |
| f_write = f_read << 1, |
| f_eof = f_write << 1 |
| }; |
| |
| // Note: typically will not be copied while vector contains data. |
| vector_type data_; |
| size_type ptr_; |
| int state_; |
| }; |
| NDNBOOST_IOSTREAMS_PIPABLE(aggregate_filter, 1) |
| |
| } } // End namespaces iostreams, boost. |
| |
| #include <ndnboost/iostreams/detail/config/enable_warnings.hpp> // MSVC. |
| |
| #endif // #ifndef NDNBOOST_IOSTREAMS_AGGREGATE_FILTER_HPP_INCLUDED |