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Serenity Operating System
1/*
2 * Copyright (c) 2021, Jan de Visser <jan@de-visser.net>
3 *
4 * SPDX-License-Identifier: BSD-2-Clause
5 */
6
7#pragma once
8
9#include <AK/Vector.h>
10#include <LibSQL/Forward.h>
11#include <LibSQL/TupleDescriptor.h>
12#include <LibSQL/Value.h>
13
14namespace SQL {
15
16/**
17 * A Tuple is an element of a random-access data structure persisted in a Heap.
18 * Tuple objects stored in such a structure have a definition controlling the
19 * number of parts or columns the tuple has, the types of the parts, and the
20 * sort order of these parts. Besides having an optional definition, a Tuple
21 * consists of one Value object per part. In addition, tuples have a u32 pointer
22 * member which points to a Heap location.
23 *
24 * Tuple is a base class; concrete subclasses are Key, which implements the
25 * elements of an index, and Row, which implements the rows in a table.
26 */
27class Tuple {
28public:
29 Tuple();
30 explicit Tuple(NonnullRefPtr<TupleDescriptor> const&, u32 pointer = 0);
31 Tuple(NonnullRefPtr<TupleDescriptor> const&, Serializer&);
32 Tuple(Tuple const&);
33 virtual ~Tuple() = default;
34
35 Tuple& operator=(Tuple const&);
36
37 [[nodiscard]] DeprecatedString to_deprecated_string() const;
38 explicit operator DeprecatedString() const { return to_deprecated_string(); }
39
40 bool operator<(Tuple const& other) const { return compare(other) < 0; }
41 bool operator<=(Tuple const& other) const { return compare(other) <= 0; }
42 bool operator==(Tuple const& other) const { return compare(other) == 0; }
43 bool operator!=(Tuple const& other) const { return compare(other) != 0; }
44 bool operator>(Tuple const& other) const { return compare(other) > 0; }
45 bool operator>=(Tuple const& other) const { return compare(other) >= 0; }
46
47 [[nodiscard]] bool is_null() const { return m_data.is_empty(); }
48 [[nodiscard]] bool has(DeprecatedString const& name) const { return index_of(name).has_value(); }
49
50 Value const& operator[](size_t ix) const { return m_data[ix]; }
51 Value& operator[](size_t ix) { return m_data[ix]; }
52 Value const& operator[](DeprecatedString const& name) const;
53 Value& operator[](DeprecatedString const& name);
54 void append(Value const&);
55 Tuple& operator+=(Value const&);
56 void extend(Tuple const&);
57 [[nodiscard]] bool is_compatible(Tuple const&) const;
58
59 [[nodiscard]] u32 pointer() const { return m_pointer; }
60 void set_pointer(u32 ptr) { m_pointer = ptr; }
61
62 [[nodiscard]] size_t size() const { return m_data.size(); }
63 [[nodiscard]] virtual size_t length() const;
64 void clear() { m_data.clear(); }
65 [[nodiscard]] NonnullRefPtr<TupleDescriptor> descriptor() const { return m_descriptor; }
66 [[nodiscard]] int compare(Tuple const&) const;
67 [[nodiscard]] int match(Tuple const&) const;
68 [[nodiscard]] u32 hash() const;
69
70 [[nodiscard]] Vector<Value> take_data() { return move(m_data); }
71
72protected:
73 [[nodiscard]] Optional<size_t> index_of(StringView) const;
74 void copy_from(Tuple const&);
75 virtual void serialize(Serializer&) const;
76 virtual void deserialize(Serializer&);
77
78private:
79 NonnullRefPtr<TupleDescriptor> m_descriptor;
80 Vector<Value> m_data;
81 u32 m_pointer { 2 * sizeof(u32) };
82
83 friend Serializer;
84};
85
86}