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.cpp

@@ -0,0 +1,74 @@
+/*
+ * Copyright (c) 2018-2021, Andreas Kling <andreas@ladybird.org>
+ * Copyright (c) 2023, kleines Filmröllchen <filmroellchen@serenityos.org>
+ *
+ * SPDX-License-Identifier: BSD-2-Clause
+ */
+
+#include <AK/ScopeGuard.h>
+#include <LibCore/File.h>
+#include <LibCore/MappedFile.h>
+#include <LibCore/System.h>
+#include <fcntl.h>
+#include <sys/mman.h>
+#include <unistd.h>
+
+namespace Core {
+
+ErrorOr<NonnullOwnPtr<MappedFile>> MappedFile::map(StringView path, Mode mode)
+{
+    auto const file_mode = mode == Mode::ReadOnly ? O_RDONLY : O_RDWR;
+    auto fd = TRY(Core::System::open(path, file_mode | O_CLOEXEC, 0));
+    return map_from_fd_and_close(fd, path, mode);
+}
+
+ErrorOr<NonnullOwnPtr<MappedFile>> MappedFile::map_from_file(NonnullOwnPtr<Core::File> stream, StringView path)
+{
+    return map_from_fd_and_close(stream->leak_fd(Badge<MappedFile> {}), path);
+}
+
+ErrorOr<NonnullOwnPtr<MappedFile>> MappedFile::map_from_fd_and_close(int fd, [[maybe_unused]] StringView path, Mode mode)
+{
+    TRY(Core::System::fcntl(fd, F_SETFD, FD_CLOEXEC));
+
+    ScopeGuard fd_close_guard = [fd] {
+        ::close(fd);
+    };
+
+    auto stat = TRY(Core::System::fstat(fd));
+    auto size = stat.st_size;
+
+    int protection;
+    int flags;
+    switch (mode) {
+    case Mode::ReadOnly:
+        protection = PROT_READ;
+        flags = MAP_SHARED;
+        break;
+    case Mode::ReadWrite:
+        protection = PROT_READ | PROT_WRITE;
+        // Don't map a read-write mapping shared as a precaution.
+        flags = MAP_PRIVATE;
+        break;
+    }
+
+    auto* ptr = TRY(Core::System::mmap(nullptr, size, protection, flags, fd, 0, 0, path));
+
+    return adopt_own(*new MappedFile(ptr, size, mode));
+}
+
+MappedFile::MappedFile(void* ptr, size_t size, Mode mode)
+    : FixedMemoryStream(Bytes { ptr, size }, mode)
+    , m_data(ptr)
+    , m_size(size)
+{
+}
+
+MappedFile::~MappedFile()
+{
+    auto res = Core::System::munmap(m_data, m_size);
+    if (res.is_error())
+        dbgln("Failed to unmap MappedFile (@ {:p}): {}", m_data, res.error());
+}
+
+}