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// Copyright (c) FIRST and other WPILib contributors.
// Open Source Software; you can modify and/or share it under the terms of
// the WPILib BSD license file in the root directory of this project.
#pragma once
#include <functional>
#include <string_view>
#include <thread>
#include "wpi/DataLog.h"
namespace wpi {
/**
* A class version of `tail -f`, otherwise known as `tail -f` at home. Watches
* a file and puts the data somewhere else. Only works on Linux-based platforms.
*/
class FileLogger {
public:
FileLogger() = default;
/**
* Construct a FileLogger. When the specified file is modified, the callback
* will be called with the appended changes.
*
* @param file The path to the file.
* @param callback A callback that accepts the appended file data.
*/
FileLogger(std::string_view file,
std::function<void(std::string_view)> callback);
/**
* Construct a FileLogger. When the specified file is modified, appended data
* will be appended to the specified data log.
*
* @param file The path to the file.
* @param log A data log.
* @param key The log key to append data to.
*/
FileLogger(std::string_view file, log::DataLog& log, std::string_view key);
FileLogger(FileLogger&& other);
FileLogger& operator=(FileLogger&& rhs);
~FileLogger();
/**
* Creates a function that chunks incoming data into blocks of whole lines and
* stores incomplete lines to add to the next block of data.
*
* @param callback A callback that accepts the blocks of whole lines.
* @return The function.
*/
static std::function<void(std::string_view)> Buffer(
std::function<void(std::string_view)> callback);
private:
#ifdef __linux__
int m_fileHandle = -1;
int m_inotifyHandle = -1;
int m_inotifyWatchHandle = -1;
std::thread m_thread;
#endif
};
} // namespace wpi