ladybird/Userland/Libraries/LibSQL/Index.h
Jan de Visser 224804b424 LibSQL: BTree index, Heap, and Meta objects for SQL Storage layer
Unfortunately this patch is quite large.

The main functionality included are a BTree index implementation and
the Heap class which manages persistent storage.

Also included are a Key subclass of the Tuple class, which is a
specialization for index key tuples. This "dragged in" the Meta layer,
which has classes defining SQL objects like tables and indexes.
2021-06-19 22:06:45 +02:00

64 lines
1.5 KiB
C++

/*
* Copyright (c) 2021, Jan de Visser <jan@de-visser.net>
*
* SPDX-License-Identifier: BSD-2-Clause
*/
#pragma once
#include <LibCore/Object.h>
#include <LibSQL/Forward.h>
#include <LibSQL/Meta.h>
namespace SQL {
class IndexNode {
public:
virtual ~IndexNode() = default;
[[nodiscard]] u32 pointer() const { return m_pointer; }
virtual void serialize(ByteBuffer&) const = 0;
virtual IndexNode* as_index_node() = 0;
protected:
explicit IndexNode(u32 pointer)
: m_pointer(pointer)
{
}
void set_pointer(u32 pointer) { m_pointer = pointer; }
private:
u32 m_pointer;
};
class Index : public Core::Object {
C_OBJECT_ABSTRACT(Index);
public:
~Index() override = default;
TupleDescriptor descriptor() const { return m_descriptor; }
[[nodiscard]] bool duplicates_allowed() const { return !m_unique; }
[[nodiscard]] bool unique() const { return m_unique; }
[[nodiscard]] u32 pointer() const { return m_pointer; }
protected:
Index(Heap& heap, TupleDescriptor const&, bool unique, u32 pointer);
Index(Heap& heap, TupleDescriptor const&, u32 pointer);
[[nodiscard]] Heap const& heap() const { return m_heap; }
[[nodiscard]] Heap& heap() { return m_heap; }
void set_pointer(u32 pointer) { m_pointer = pointer; }
u32 new_record_pointer() { return m_heap.new_record_pointer(); }
ByteBuffer read_block(u32);
void add_to_write_ahead_log(IndexNode*);
private:
Heap& m_heap;
TupleDescriptor m_descriptor;
bool m_unique { false };
u32 m_pointer { 0 };
};
}