uniq.h

// -*- mode: c++; tab-width: 4; indent-tabs-mode: t; eval: (progn (c-set-style "stroustrup") (c-set-offset 'innamespace 0)); -*-
// vi:set ts=4 sts=4 sw=4 noet :
// Copyright 2011, 2012, The TPIE development team
// 
// This file is part of TPIE.
// 
// TPIE is free software: you can redistribute it and/or modify it under
// the terms of the GNU Lesser General Public License as published by the
// Free Software Foundation, either version 3 of the License, or (at your
// option) any later version.
// 
// TPIE is distributed in the hope that it will be useful, but WITHOUT ANY
// WARRANTY; without even the implied warranty of MERCHANTABILITY or
// FITNESS FOR A PARTICULAR PURPOSE.  See the GNU Lesser General Public
// License for more details.
// 
// You should have received a copy of the GNU Lesser General Public License
// along with TPIE.  If not, see <http://www.gnu.org/licenses/>
 
#ifndef __TPIE_PIPELINING_UNIQ_H__
#define __TPIE_PIPELINING_UNIQ_H__
 
#include <tpie/pipelining/node.h>
#include <tpie/pipelining/pipe_base.h>
#include <tpie/pipelining/factory_helpers.h>
#include <tpie/file_stream.h>
 
namespace tpie::pipelining {
namespace bits {
 
template <typename dest_t>
class count_consecutive_t : public node {
public:
    typedef uint64_t count_t;
    typedef typename push_type<dest_t>::type::first_type item_type;
 
    count_consecutive_t(dest_t dest)
        : dest(std::move(dest))
        , current_count(0)
    {
        add_push_destination(this->dest);
    }
 
    void end() override {
        node::end();
        flush();
    }
 
    void push(const item_type & item) {
        if (current_count && item == item_buffer) {
            ++current_count;
        } else {
            flush();
            item_buffer = item;
            current_count = 1;
        }
    }
private:
    void flush() {
        if (!current_count) return;
        dest.push(std::make_pair(item_buffer, current_count));
        current_count = 0;
    }
    dest_t dest;
    item_type item_buffer;
    count_t current_count;
};
 
class any_type {
public:
    template <typename T>
    any_type(const T &) {}
    template <typename T>
    any_type & operator=(const T &) {return *this;}
};
 
template <typename dest_t>
class extract_first_t : public node {
public:
    typedef std::pair<typename push_type<dest_t>::type, any_type> item_type;
 
    extract_first_t(dest_t dest) : dest(std::move(dest)) {
        add_push_destination(this->dest);
    }
 
    void push(const item_type & item) {
        dest.push(item.first);
    }
private:
    dest_t dest;
};
 
} // namespace bits
 
inline pipe_middle<bits::pair_factory<factory<bits::count_consecutive_t>, factory<bits::extract_first_t> > >
pipeuniq() {
    return bits::pair_factory<factory<bits::count_consecutive_t>, factory<bits::extract_first_t> >
        (factory<bits::count_consecutive_t>(), factory<bits::extract_first_t>());
}
 
} //namespace tpie::pipelining
 
#endif //__TPIE_PIPELINING_UNIQ_H__