//---------------------------------------------------------------------------// // Copyright (c) 2014 Roshan // // 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://boostorg.github.com/compute for more information. //---------------------------------------------------------------------------// #ifndef BOOST_COMPUTE_ALGORITHM_SEARCH_HPP #define BOOST_COMPUTE_ALGORITHM_SEARCH_HPP #include #include #include #include #include #include #include #include namespace boost { namespace compute { /// /// \brief Substring matching algorithm /// /// Searches for the first match of the pattern [p_first, p_last) /// in text [t_first, t_last). /// \return Iterator pointing to beginning of first occurrence /// /// \param t_first Iterator pointing to start of text /// \param t_last Iterator pointing to end of text /// \param p_first Iterator pointing to start of pattern /// \param p_last Iterator pointing to end of pattern /// \param queue Queue on which to execute /// /// Space complexity: \Omega(distance(\p t_first, \p t_last)) template inline TextIterator search(TextIterator t_first, TextIterator t_last, PatternIterator p_first, PatternIterator p_last, command_queue &queue = system::default_queue()) { BOOST_STATIC_ASSERT(is_device_iterator::value); BOOST_STATIC_ASSERT(is_device_iterator::value); // there is no need to check if pattern starts at last n - 1 indices vector matching_indices( detail::iterator_range_size(t_first, t_last) - detail::iterator_range_size(p_first, p_last) + 1, queue.get_context() ); // search_kernel puts value 1 at every index in vector where pattern starts at detail::search_kernel::iterator> kernel; kernel.set_range(p_first, p_last, t_first, t_last, matching_indices.begin()); kernel.exec(queue); vector::iterator index = ::boost::compute::find( matching_indices.begin(), matching_indices.end(), uint_(1), queue ); // pattern was not found if(index == matching_indices.end()) return t_last; return t_first + detail::iterator_range_size(matching_indices.begin(), index); } } //end compute namespace } //end boost namespace #endif // BOOST_COMPUTE_ALGORITHM_SEARCH_HPP