file_stream.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_FILE_STREAM_H__
#define __TPIE_PIPELINING_FILE_STREAM_H__
 
#include <tpie/file_stream.h>
 
#include <tpie/pipelining/node.h>
#include <tpie/pipelining/factory_helpers.h>
#include <tpie/pipelining/pipe_base.h>
#include <tpie/maybe.h>
#include <tpie/flags.h>
 
namespace tpie::pipelining {
 
enum stream_option {
    STREAM_RESET=1,
    STREAM_CLOSE=2
};
 
TPIE_DECLARE_OPERATORS_FOR_FLAGS(stream_option)
typedef tpie::flags<stream_option> stream_options;
 
namespace bits {
 
template <typename dest_t>
class input_t : public node {
public:
    typedef typename push_type<dest_t>::type item_type;
 
    input_t(dest_t dest, file_stream<item_type> & fs, stream_options options) : options(options), fs(fs), dest(std::move(dest)) {
        add_push_destination(this->dest);
        set_name("Read", PRIORITY_INSIGNIFICANT);
        set_minimum_memory(fs.memory_usage());
    }
 
    void propagate() override {
        if (options & STREAM_RESET) fs.seek(0);
        
        if (fs.is_open()) {
            forward("items", fs.size() - fs.offset());
            set_steps(fs.size() - fs.offset());
        } else {
            forward("items", 0);
        }
    }
 
    void go() override {
        if (fs.is_open()) {
            while (fs.can_read()) {
                dest.push(fs.read());
                step();
            }
        }
    }
 
    void end() override {
        if (options & STREAM_CLOSE) fs.close();
    }
 
private:
    stream_options options;
    file_stream<item_type> & fs;
    dest_t dest;
};
 
template <typename dest_t>
class named_input_t : public node {
public:
    typedef typename push_type<dest_t>::type item_type;
 
    named_input_t(dest_t dest, std::string path) : dest(std::move(dest)), path(path) {
        add_push_destination(this->dest);
        set_name("Read", PRIORITY_INSIGNIFICANT);
        set_minimum_memory(file_stream<item_type>::memory_usage());
    }
 
    void propagate() override {
        fs.construct();
        fs->open(path, access_read);
        forward("items", fs->size());
        set_steps(fs->size());
    }
 
    void go() override {
        while (fs->can_read()) {
            dest.push(fs->read());
            step();
        }
        fs.destruct();
    }
private:
    dest_t dest;
    maybe<file_stream<item_type> > fs;
    std::string path;
};
 
 
template <typename T>
class pull_input_t : public node {
public:
    typedef T item_type;
 
    pull_input_t(file_stream<T> & fs, stream_options options) : options(options), fs(fs) {
        set_name("Read", PRIORITY_INSIGNIFICANT);
        set_minimum_memory(fs.memory_usage());
    }
 
    void propagate() override {
        if (options & STREAM_RESET) fs.seek(0);
        forward("items", fs.size()-fs.offset());
        set_steps(fs.size()-fs.offset());
    }
 
    T pull() {
        step();
        return fs.read();
    }
 
    bool can_pull() {
        return fs.can_read();
    }
 
    void end() override {
        if (options & STREAM_CLOSE) fs.close();
    }
 
private:
    stream_options options;
    file_stream<T> & fs;
};
 
template <typename T>
class pull_reverse_input_t : public node {
public:
    typedef T item_type;
 
    pull_reverse_input_t(file_stream<T> & fs, stream_options options) : options(options), fs(fs) {
        set_name("Read", PRIORITY_INSIGNIFICANT);
        set_minimum_memory(fs.memory_usage());
    }
 
    void propagate() override {
        if (options & STREAM_RESET) fs.seek(0, file_stream<T>::end);
        forward("items", fs.offset());
        set_steps(fs.offset());
    }
 
    T pull() {
        step();
        return fs.read_back();
    }
 
    bool can_pull() {
        return fs.can_read_back();
    }
 
    void end() override {
        if (options & STREAM_CLOSE) fs.close();
    }
 
private:
    stream_options options;
    file_stream<T> & fs;
};
 
template <typename T>
class named_pull_input_t : public node {
public:
    typedef T item_type;
 
    named_pull_input_t(std::string path): path(std::move(path)) {
        set_name("Read", PRIORITY_INSIGNIFICANT);
        set_minimum_memory(file_stream<T>::memory_usage());
    }
 
    void propagate() override {
        fs.construct();
        fs->open(path, access_read);
        forward("items", fs->size());
        set_steps(fs->size());
    }
 
    T pull() {
        step();
        return fs->read();
    }
 
    bool can_pull() {
        return fs->can_read();
    }
 
    void end() override {
        fs->close();
        fs.destruct();
    }
private:
    maybe<file_stream<T> > fs;
    std::string path;
};
 
 
template <typename T>
class output_t : public node {
public:
    typedef T item_type;
 
    output_t(file_stream<T> & fs) : fs(fs) {
        set_name("Write", PRIORITY_INSIGNIFICANT);
        set_minimum_memory(fs.memory_usage());
    }
 
    void push(const T & item) {
        fs.write(item);
    }
private:
    file_stream<T> & fs;
};
 
template <typename T>
class named_output_t : public node {
public:
    typedef T item_type;
 
    named_output_t(const std::string & path): path(path) {
        set_name("Write", PRIORITY_INSIGNIFICANT);
        set_minimum_memory(file_stream<T>::memory_usage());
    }
 
    void begin() override {
        fs.construct();
        fs->open(path, access_write);
    }
    
    void push(const T & item) {
        fs->write(item);
    }
 
    void end() override {
        fs->close();
        fs.destruct();
    }
private:
    maybe<file_stream<T> > fs;
    std::string path;
};
 
 
template <typename source_t>
class pull_output_t : public node {
public:
    typedef typename pull_type<source_t>::type item_type;
 
    pull_output_t(source_t source, file_stream<item_type> & fs) : source(std::move(source)), fs(fs) {
        add_pull_source(this->source);
        set_name("Write", PRIORITY_INSIGNIFICANT);
        set_minimum_memory(fs.memory_usage());
    }
 
    void go() override {
        source.begin();
        while (source.can_pull()) {
            fs.write(source.pull());
        }
        source.end();
    }
    
private:
    source_t source;
    file_stream<item_type> & fs;
};
 
template <typename dest_t, typename T>
class tee_t: public node {
public:
    typedef T item_type;
    tee_t(dest_t dest, file_stream<item_type> & fs): fs(fs), dest(std::move(dest)) {
        set_minimum_memory(fs.memory_usage());
    }
    
    void push(const item_type & i) {
        fs.write(i);
        dest.push(i);
    }
private:
    file_stream<item_type> & fs;
    dest_t dest;
};
 
template <typename source_t, typename T>
class pull_tee_t {
public:
    typedef T item_type;
    pull_tee_t(source_t source, file_stream<item_type> & fs): fs(fs), source(std::move(source)) {
        set_minimum_memory(fs.memory_usage());
    }
        
    bool can_pull() {
        return source.can_pull();
    }
    
    item_type pull() {
        item_type i = source.pull();
        fs.write(i);
        return i;
    }
private:
    file_stream<item_type> & fs;
    source_t source;
};
 
} // namespace bits
 
template<typename T>
inline pipe_begin<factory<bits::input_t, file_stream<T> &, stream_options> > input(file_stream<T> & fs,
                                                                                   stream_options options=stream_options()) {
    return {fs, options};
}
 
typedef pipe_begin<factory<bits::named_input_t, std::string> > named_input; 
 
template<typename T>
inline pullpipe_begin<termfactory<bits::pull_input_t<T>, file_stream<T> &, stream_options> > pull_input(
    file_stream<T> & fs,
    stream_options options=stream_options()) {
    return {fs, options};
}
 
template<typename T>
inline pullpipe_begin<termfactory<bits::pull_reverse_input_t<T>, file_stream<T> &, stream_options> > pull_reverse_input(
    file_stream<T> & fs,
    stream_options options=stream_options()) {
    return {fs, options};
}
 
template<typename T>
inline pullpipe_begin<termfactory<bits::named_pull_input_t<T>, std::string> > named_pull_input(std::string path) {
    return {std::move(path)};
}
 
 
template <typename T>
inline pipe_end<termfactory<bits::output_t<T>, file_stream<T> &> > output(file_stream<T> & fs) {
    return {fs};
}
 
template <typename T>
inline pipe_end<termfactory<bits::named_output_t<T>, std::string> > named_output(std::string path) {
    return {std::move(path)}; 
}
 
 
template<typename T>
inline pullpipe_end<factory<bits::pull_output_t, file_stream<T> &> > pull_output(file_stream<T> & fs) {
    return {fs};
}
 
template <typename T>
inline pipe_middle<tfactory<bits::tee_t, Args<typename T::item_type>, T &> > tee(T & fs) {
    return {fs};
}
 
template <typename T>
inline pullpipe_middle<tfactory<bits::pull_tee_t, Args<typename T::item_type>, T &> > pull_tee(T & fs) {
    return {fs};
}
 
} // namespace tpie::pipelining
#endif