practice-timer/TimerFileWatcher.c

#include "TimerFileWatcher.h"

#include <glib.h>
#include <glib/gstdio.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <time.h>

struct _TimerFileWatcher {
    GObject parent;

    char *path;

    GThread *thread;
    gboolean running;

    time_t lastTime;
};

G_DEFINE_TYPE(TimerFileWatcher, timer_file_watcher, G_TYPE_OBJECT);

static void timer_file_watcher_tick(TimerFileWatcher *self) {
    gint64 last_tick = 0;
    GStatBuf statbuf;
    while (self->running) {
        gint64 now = g_get_monotonic_time();
        if ((now - last_tick) > (G_USEC_PER_SEC * FILE_WATCHER_POLL_RATE) && g_stat(self->path, &statbuf) == 0) {
            if (self->lastTime != statbuf.st_atime) {
                g_signal_emit_by_name(self, "file-changed");
                self->lastTime = statbuf.st_atime;
            }
            last_tick = now;
        }
        g_usleep(500);
    }
}

TimerFileWatcher *timer_file_watcher_new(const char *path) {
    TimerFileWatcher *fw = g_object_new(TIMER_TYPE_FILE_WATCHER, NULL);
    GStatBuf statbuf;
    if (g_stat(path, &statbuf) == 0) {
        fw->lastTime = statbuf.st_atime;
    }
    fw->path = g_strdup(path);
    fw->running = TRUE;
    fw->thread = g_thread_new(NULL, (GThreadFunc) timer_file_watcher_tick, fw);
    return fw;
}

const char *timer_file_watcher_get_path(TimerFileWatcher* self) {
    return self->path;
}

void timer_file_watcher_pause(TimerFileWatcher *self) {
    if (self->running) {
        self->running = FALSE;
        g_thread_join(self->thread);
        g_thread_unref(self->thread);
    }
}

void timer_file_watcher_resume(TimerFileWatcher *self, gboolean update) {
    if (!self->running) {
        self->running = TRUE;
        if (!update) {
            GStatBuf statbuf;
            if (g_stat(self->path, &statbuf) == 0) {
                self->lastTime = statbuf.st_atime;
            }
        }
        self->thread = g_thread_new(NULL, (GThreadFunc) timer_file_watcher_tick, self);
    }
}

gboolean timer_file_watcher_is_paused(TimerFileWatcher *self) {
    return !self->running;
}

static void timer_file_watcher_finalize(GObject *self) {
    g_free(TIMER_FILE_WATCHER(self)->path);
    timer_file_watcher_pause(TIMER_FILE_WATCHER(self));
    G_OBJECT_CLASS(timer_file_watcher_parent_class)->finalize(self);
}

static void timer_file_watcher_class_init(TimerFileWatcherClass *class) {
    g_signal_new("file-changed", TIMER_TYPE_FILE_WATCHER, G_SIGNAL_RUN_FIRST | G_SIGNAL_ACTION,
                 0, NULL, NULL, NULL, G_TYPE_NONE, 0);
    G_OBJECT_CLASS(class)->finalize = timer_file_watcher_finalize;
}

static void timer_file_watcher_init(TimerFileWatcher *self) {
}