counting_source.hpp

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/*
 * Copyright 2015, alex at staticlibs.net
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

/* 
 * File:   counting_source.hpp
 * Author: alex
 *
 * Created on October 9, 2015, 12:23 PM
 */

#ifndef STATICLIB_IO_COUNTING_SOURCE_HPP
#define STATICLIB_IO_COUNTING_SOURCE_HPP

#include <ios>

#include "staticlib/config.hpp"

#include "staticlib/io/reference_source.hpp"
#include "staticlib/io/span.hpp"

namespace staticlib {
namespace io {

template<typename Source>
class counting_source {
    Source src;
    size_t count = 0;

public:
    explicit counting_source(Source&& src) :
    src(std::move(src)) { }

    counting_source(const counting_source&) = delete;

    counting_source& operator=(const counting_source&) = delete;

    counting_source(counting_source&& other) STATICLIB_NOEXCEPT :
    src(std::move(other.src)),
    count(other.count) {
        other.count = 0;
    }

    counting_source& operator=(counting_source&& other) STATICLIB_NOEXCEPT {
        src = std::move(other.src);
        count = other.count;
        other.count = 0;
        return *this;
    }

    std::streamsize read(span<char> span) {
        std::streamsize res = src.read(span);
        if (sl::support::is_sizet(res)) {
            count += static_cast<size_t>(res);
        }
        return res;
    }

    size_t get_count() {
        return count;
    }

    Source& get_source() {
        return src;
    }
    
};

template <typename Source,
        class = typename std::enable_if<!std::is_lvalue_reference<Source>::value>::type>
counting_source<Source> make_counting_source(Source&& source) {
    return counting_source<Source>(std::move(source));
}

template <typename Source>
counting_source<reference_source<Source>> make_counting_source(Source& source) {
    return counting_source<reference_source<Source>>(make_reference_source(source));
}

} // namespace
}

#endif /* STATICLIB_IO_COUNTING_SOURCE_HPP */