Atmosphere/libraries/libstratosphere/include/stratosphere/fssystem/fssystem_bucket_tree_utils.hpp

/*
 * Copyright (c) 2018-2020 Atmosphère-NX
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms and conditions of the GNU General Public License,
 * version 2, as published by the Free Software Foundation.
 *
 * This program is distributed in the hope it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
 * more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */
#pragma once
#include <stratosphere/fssystem/fssystem_bucket_tree.hpp>

namespace ams::fssystem::impl {

    class SafeValue {
        public:
            static ALWAYS_INLINE s64 GetInt64(const void *ptr) {
                s64 value;
                std::memcpy(std::addressof(value), ptr, sizeof(s64));
                return value;
            }

            static ALWAYS_INLINE s64 GetInt64(const s64 *ptr) {
                return GetInt64(static_cast<const void *>(ptr));
            }

            static ALWAYS_INLINE s64 GetInt64(const s64 &v) {
                return GetInt64(std::addressof(v));
            }

            static ALWAYS_INLINE void SetInt64(void *dst, const void *src) {
                std::memcpy(dst, src, sizeof(s64));
            }

            static ALWAYS_INLINE void SetInt64(void *dst, const s64 *src) {
                return SetInt64(dst, static_cast<const void *>(src));
            }

            static ALWAYS_INLINE void SetInt64(void *dst, const s64 &v) {
                return SetInt64(dst, std::addressof(v));
            }
    };

    template<typename IteratorType>
    struct BucketTreeNode {
        using Header = BucketTree::NodeHeader;

        Header header;

        s32 GetCount() const { return this->header.count; }

        void *GetArray() { return std::addressof(this->header) + 1; }
        template<typename T> T *GetArray() { return reinterpret_cast<T *>(this->GetArray()); }
        const void *GetArray() const { return std::addressof(this->header) + 1; }
        template<typename T> const T *GetArray() const { return reinterpret_cast<const T *>(this->GetArray()); }

        s64 GetBeginOffset() const { return *this->GetArray<s64>(); }
        s64 GetEndOffset() const { return this->header.offset; }

        IteratorType GetBegin() { return IteratorType(this->GetArray<s64>()); }
        IteratorType GetEnd() { return IteratorType(this->GetArray<s64>()) + this->header.count; }
        IteratorType GetBegin() const { return IteratorType(this->GetArray<s64>()); }
        IteratorType GetEnd() const { return IteratorType(this->GetArray<s64>()) + this->header.count; }

        IteratorType GetBegin(size_t entry_size) { return IteratorType(this->GetArray(), entry_size); }
        IteratorType GetEnd(size_t entry_size) { return IteratorType(this->GetArray(), entry_size) + this->header.count; }
        IteratorType GetBegin(size_t entry_size) const { return IteratorType(this->GetArray(), entry_size); }
        IteratorType GetEnd(size_t entry_size) const { return IteratorType(this->GetArray(), entry_size) + this->header.count; }
    };

    constexpr inline s64 GetBucketTreeEntryOffset(s64 entry_set_offset, size_t entry_size, s32 entry_index) {
        return entry_set_offset + sizeof(BucketTree::NodeHeader) + entry_index * static_cast<s64>(entry_size);
    }

    constexpr inline s64 GetBucketTreeEntryOffset(s32 entry_set_index, size_t node_size, size_t entry_size, s32 entry_index) {
        return GetBucketTreeEntryOffset(entry_set_index * static_cast<s64>(node_size), entry_size, entry_index);
    }

}