Everywhere: Hoist the Libraries folder to the top-level

Author: https://github.com/trflynn89
Commit: 93712b24bf
Pull-request: https://github.com/LadybirdBrowser/ladybird/pull/2256
Reviewed-by: https://github.com/sideshowbarker

Libraries/LibCore/MappedFile.h

@@ -0,0 +1,56 @@
+/*
+ * Copyright (c) 2018-2021, Andreas Kling <andreas@ladybird.org>
+ * Copyright (c) 2023, kleines Filmröllchen <filmroellchen@serenityos.org>
+ *
+ * SPDX-License-Identifier: BSD-2-Clause
+ */
+
+#pragma once
+
+#include <AK/ByteBuffer.h>
+#include <AK/Error.h>
+#include <AK/MemoryStream.h>
+#include <AK/Noncopyable.h>
+#include <AK/NonnullOwnPtr.h>
+#include <AK/RefCounted.h>
+#include <LibCore/Forward.h>
+
+namespace Core {
+
+class MappedFile : public FixedMemoryStream {
+    AK_MAKE_NONCOPYABLE(MappedFile);
+    AK_MAKE_NONMOVABLE(MappedFile);
+
+public:
+    static ErrorOr<NonnullOwnPtr<MappedFile>> map(StringView path, Mode mode = Mode::ReadOnly);
+    static ErrorOr<NonnullOwnPtr<MappedFile>> map_from_file(NonnullOwnPtr<Core::File>, StringView path);
+    static ErrorOr<NonnullOwnPtr<MappedFile>> map_from_fd_and_close(int fd, StringView path, Mode mode = Mode::ReadOnly);
+    virtual ~MappedFile();
+
+    // Non-stream APIs for using MappedFile as a simple POSIX API wrapper.
+    void* data() { return m_data; }
+    void const* data() const { return m_data; }
+    ReadonlyBytes bytes() const { return { m_data, m_size }; }
+
+private:
+    explicit MappedFile(void*, size_t, Mode);
+
+    void* m_data { nullptr };
+    size_t m_size { 0 };
+};
+
+class SharedMappedFile : public RefCounted<SharedMappedFile> {
+public:
+    explicit SharedMappedFile(NonnullOwnPtr<MappedFile> file)
+        : m_file(move(file))
+    {
+    }
+
+    MappedFile const& operator->() const { return *m_file; }
+    MappedFile& operator->() { return *m_file; }
+
+private:
+    NonnullOwnPtr<MappedFile> m_file;
+};
+
+}