Source/WTF/wtf/glib/FilePathWatcher.h

/*
 * Copyright (C) 2026 Igalia S.L.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY APPLE INC. AND ITS CONTRIBUTORS ``AS IS''
 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
 * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL APPLE INC. OR ITS CONTRIBUTORS
 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
 * THE POSSIBILITY OF SUCH DAMAGE.
 */

#pragma once

#include <gio/gio.h>
#include <wtf/Forward.h>
#include <wtf/Function.h>
#include <wtf/Noncopyable.h>
#include <wtf/TZoneMalloc.h>
#include <wtf/glib/GRefPtr.h>
#include <wtf/text/WTFString.h>

namespace WTF {

// Watches a single filesystem path and runs a handler when the file is created
// or finishes changing. Rename, symlink swap, and in-place rewrite are each
// reported as one call; a bare deletion is not
class FilePathWatcher {
    WTF_MAKE_TZONE_ALLOCATED_EXPORT(FilePathWatcher, WTF_EXPORT_PRIVATE);
    WTF_MAKE_NONCOPYABLE(FilePathWatcher);
public:
    WTF_EXPORT_PRIVATE FilePathWatcher(const String& path, Function<void()>&& handler);
    WTF_EXPORT_PRIVATE ~FilePathWatcher();

    bool isActive() const { return !!m_monitor; }

private:
    static void fileChangedCallback(GFileMonitor*, GFile*, GFile*, GFileMonitorEvent, FilePathWatcher*);

    GRefPtr<GFileMonitor> m_monitor;
    Function<void()> m_handler;
    gulong m_changedHandlerID { 0 };
};

} // namespace WTF

using WTF::FilePathWatcher;