watcher.h

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#ifndef FS_WATCHER_H
#define FS_WATCHER_H
 
#include <atomic>
#include <chrono>
#include <condition_variable>
#include <functional>
#include <map>
#include <memory>
#include <mutex>
#include <string>
#include <thread>
 
#include "filesystem.h"
#include "pattern_filter.h"
 
namespace fs
{
 
class watcher
{
public:
    enum entry_status
    {
        created,
        modified,
        removed,
        renamed,
        unmodified,
    };
 
    struct entry
    {
        fs::path path;
        fs::path last_path;
        entry_status status = unmodified;
        fs::file_time_type last_mod_time;
        std::uintmax_t size = 0;
        fs::file_type type;
    };
 
    using notify_callback = std::function<void(const std::vector<entry>&, bool)>;
    using clock_t = std::chrono::steady_clock;
    //-----------------------------------------------------------------------------
    //  Name : watch ()
    //-----------------------------------------------------------------------------
    static auto watch(const fs::path& path,
                      const pattern_filter& filter,
                      bool recursive,
                      bool initial_list,
                      clock_t::duration poll_interval,
                      notify_callback callback) -> std::uint64_t;
 
    // Backward compatible overload
    static auto watch(const fs::path& path,
                      const std::string& filter_pattern,
                      bool recursive,
                      bool initial_list,
                      clock_t::duration poll_interval,
                      notify_callback callback) -> std::uint64_t;
 
    //-----------------------------------------------------------------------------
    //  Name : unwatch ()
    //-----------------------------------------------------------------------------
    static void unwatch(std::uint64_t key);
 
    //-----------------------------------------------------------------------------
    //  Name : unwatch_all ()
    //-----------------------------------------------------------------------------
    static void unwatch_all();
 
    //-----------------------------------------------------------------------------
    //  Name : touch ()
    //-----------------------------------------------------------------------------
    static void touch(const fs::path& path, bool recursive, fs::file_time_type time = fs::now());
 
    //-----------------------------------------------------------------------------
    //  Name : ~watcher ()
    //-----------------------------------------------------------------------------
    ~watcher();
    watcher() = default;
 
    static void pause();
    static void resume();
 
protected:
    //-----------------------------------------------------------------------------
    //  Name : close ()
    //-----------------------------------------------------------------------------
    void close();
 
    //-----------------------------------------------------------------------------
    //  Name : start ()
    //-----------------------------------------------------------------------------
    void start();
 
    //-----------------------------------------------------------------------------
    //  Name : watch_impl ()
    //-----------------------------------------------------------------------------
    static auto watch_impl(const fs::path& path,
                           const pattern_filter& filter,
                           bool recursive,
                           bool initial_list,
                           clock_t::duration poll_interval,
                           notify_callback& list_callback) -> std::uint64_t;
 
    static void unwatch_impl(std::uint64_t key);
 
    static void unwatch_all_impl();
 
    std::mutex mutex_;
    std::atomic<bool> watching_ = {false};
 
    std::condition_variable cv_;
    std::thread thread_;
    class impl;
    std::map<std::uint64_t, std::shared_ptr<impl>> watchers_;
};
 
auto to_string(const watcher::entry& e) -> std::string;
 
} // namespace fs
 
#endif