使用自制课程

我无法使用 boost::progress_display 因此,我实现了我自己的RAII类,它在Linux下工作得很有魅力:

进度条。h

#ifndef PROGRESS_BAR_H
#define PROGRESS_BAR_H

#include <string>

/**
 * RAII implementation of a progress bar.
 */
class ProgressBar
{
public:
    /**
     * Constructor.
     * It takes two values: the expected number of iterations whose progress we
     * want to monitor and an initial message to be displayed on top of the bar
     * (which can be updated with updateLastPrintedMessage()).
     */
    ProgressBar(
            uint32_t expectedIterations, const std::string& initialMessage="");

    /**
     * Destructor to guarantee RAII.
     */
    ~ProgressBar();

    // Make the object non-copyable
    ProgressBar(const ProgressBar& o) = delete;
    ProgressBar& operator=(const ProgressBar& o) = delete;

    /**
     * Must be invoked when the progress bar is no longer needed to restore the
     * position of the cursor to the end of the output.
     * It is automatically invoked when the object is destroyed.
     */
    void endProgressBar();

    /**
     * Prints a new message under the last printed message, without overwriting
     * it. This moves the progress bar down to be placed under the newly
     * written message.
     */
    void printNewMessage(const std::string& message);

    /**
     * Prints a message while the progress bar is on the screen on top on the
     * last printed message. Since the cursor is right at the beginning of the
     * progress bar, it moves the cursor up by one line before printing, and
     * then returns it to its original position.
     */
    void updateLastPrintedMessage(const std::string& message);

    /**
     * Overloaded prefix operator, used to indicate that the has been a new
     * iteration.
     */
    void operator++();

private:
    unsigned int mTotalIterations;
    unsigned int mNumberOfTicks;
    bool mEnded;
    size_t mLengthOfLastPrintedMessage;
};

#endif /* PROGRESS_BAR_H */

进度条。清洁石油产品

#include "ProgressBar.h"
#include <iostream>
#include <iomanip>
#include <sstream>

#define LENGTH_OF_PROGRESS_BAR 55
#define PERCENTAGE_BIN_SIZE (100.0/LENGTH_OF_PROGRESS_BAR)

namespace
{
    std::string generateProgressBar(unsigned int percentage)
    {
        const int progress = static_cast<int>(percentage/PERCENTAGE_BIN_SIZE);
        std::ostringstream ss;
        ss << " " << std::setw(3) << std::right << percentage << "% ";
        std::string bar("[" + std::string(LENGTH_OF_PROGRESS_BAR-2, ' ') + "]");

        unsigned int numberOfSymbols = std::min(
                std::max(0, progress - 1),
                LENGTH_OF_PROGRESS_BAR - 2);

        bar.replace(1, numberOfSymbols, std::string(numberOfSymbols, '|'));

        ss << bar;
        return ss.str();
    }
}

ProgressBar::ProgressBar(
            uint32_t expectedIterations, const std::string& initialMessage)
    : mTotalIterations(expectedIterations),
      mNumberOfTicks(0),
      mEnded(false)
{
    std::cout << initialMessage << "\n";
    mLengthOfLastPrintedMessage = initialMessage.size();
    std::cout << generateProgressBar(0) << "\r" << std::flush;
}

ProgressBar::~ProgressBar()
{
    endProgressBar();
}

void ProgressBar::operator++()
{
    if (mEnded)
    {
        throw std::runtime_error(
                "Attempted to use progress bar after having terminated it");
    }

    mNumberOfTicks = std::min(mTotalIterations, mNumberOfTicks+1);
    const unsigned int percentage = static_cast<unsigned int>(
            mNumberOfTicks*100.0/mTotalIterations);

    std::cout << generateProgressBar(percentage) << "\r" << std::flush;
}

void ProgressBar::printNewMessage(const std::string& message)
{
    if (mEnded)
    {
        throw std::runtime_error(
                "Attempted to use progress bar after having terminated it");
    }

    std::cout << "\r"
        << std::left
        << std::setw(LENGTH_OF_PROGRESS_BAR + 6)
        << message << "\n";
    mLengthOfLastPrintedMessage = message.size();
    const unsigned int percentage = static_cast<unsigned int>(
            mNumberOfTicks*100.0/mTotalIterations);

    std::cout << generateProgressBar(percentage) << "\r" << std::flush;

}

void ProgressBar::updateLastPrintedMessage(const std::string& message)
{
    if (mEnded)
    {
        throw std::runtime_error(
                "Attempted to use progress bar after having terminated it");
    }

    std::cout << "\r\033[F"
        << std::left
        << std::setw(mLengthOfLastPrintedMessage)
        << message << "\n";
    mLengthOfLastPrintedMessage = message.size();
}

void ProgressBar::endProgressBar()
{
    if (!mEnded)
    {
        std::cout << std::string(2, '\n');
    }
    mEnded = true;
}

如何使用它

以下是两段代码,展示了如何使用它以及预期的输出:

正在更新。清洁石油产品

#include "ProgressBar.h"
#include <unistd.h>

#define ITERATIONS 10

int main()
{
    ProgressBar progress(ITERATIONS, "No odd number found");
    for (size_t i = 0; i < ITERATIONS; ++i)
    {
        // Sleep for 0.5s so that the gif is clear enough
        usleep(500000);

        if (i%2 != 0)
        {
            progress.updateLastPrintedMessage(
                    "New odd number found: " + std::to_string(i));
        }

        ++progress;
    }
}

#include "ProgressBar.h"
#include <unistd.h>

#define ITERATIONS 10

int main()
{
    ProgressBar progress(ITERATIONS, "Looking for odd numbers...");
    for (size_t i = 0; i < ITERATIONS; ++i)
    {
        // Sleep for 0.5s so that the gif is clear enough
        usleep(500000);

        if (i%2 != 0)
        {
            progress.printNewMessage(
                    "New odd number found: " + std::to_string(i));
        }

        ++progress;
    }
}

追加的输出。清洁石油产品