1// Copyright (C) 2016 The Qt Company Ltd.
2// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR LGPL-3.0-only OR GPL-2.0-only OR GPL-3.0-only
3
4#ifndef QDATABUFFER_P_H
5#define QDATABUFFER_P_H
6
7//
8// W A R N I N G
9// -------------
10//
11// This file is not part of the Qt API. It exists for the convenience
12// of other Qt classes. This header file may change from version to
13// version without notice, or even be removed.
14//
15// We mean it.
16//
17
18#include <QtGui/private/qtguiglobal_p.h>
19
20#include "QtCore/qalloc.h"
21#include "QtCore/qbytearray.h"
22#include "QtCore/qtypeinfo.h"
23
24#include <stdlib.h>
25
26QT_BEGIN_NAMESPACE
27
28template <typename Type> class QDataBuffer
29{
30 Q_DISABLE_COPY_MOVE(QDataBuffer)
31public:
32 explicit QDataBuffer(qsizetype res)
33 {
34 capacity = res;
35 if (res) {
36 QT_WARNING_PUSH
37 QT_WARNING_DISABLE_GCC("-Walloc-size-larger-than=")
38 buffer = (Type*) QtPrivate::fittedMalloc(headerSize: 0, capacity: &capacity, elementSize: sizeof(Type));
39 QT_WARNING_POP
40 Q_CHECK_PTR(buffer);
41 } else {
42 buffer = nullptr;
43 }
44 siz = 0;
45 }
46
47 ~QDataBuffer()
48 {
49 static_assert(!QTypeInfo<Type>::isComplex);
50 if (buffer)
51 QtPrivate::sizedFree(buffer, capacity, sizeof(Type));
52 }
53
54 inline void reset() { siz = 0; }
55
56 inline bool isEmpty() const { return siz==0; }
57
58 qsizetype size() const { return siz; }
59 inline Type *data() const { return buffer; }
60
61 Type &at(qsizetype i) { Q_ASSERT(i >= 0 && i < siz); return buffer[i]; }
62 const Type &at(qsizetype i) const { Q_ASSERT(i >= 0 && i < siz); return buffer[i]; }
63 inline Type &last() { Q_ASSERT(!isEmpty()); return buffer[siz-1]; }
64 inline const Type &last() const { Q_ASSERT(!isEmpty()); return buffer[siz-1]; }
65 inline Type &first() { Q_ASSERT(!isEmpty()); return buffer[0]; }
66 inline const Type &first() const { Q_ASSERT(!isEmpty()); return buffer[0]; }
67
68 inline void add(const Type &t) {
69 reserve(size: siz + 1);
70 buffer[siz] = t;
71 ++siz;
72 }
73
74 inline void pop_back() {
75 Q_ASSERT(siz > 0);
76 --siz;
77 }
78
79 void resize(qsizetype size) {
80 reserve(size);
81 siz = size;
82 }
83
84 void reserve(qsizetype size) {
85 if (size > capacity) {
86 if (capacity == 0)
87 capacity = 1;
88 while (capacity < size)
89 capacity *= 2;
90 auto ptr = QtPrivate::fittedRealloc(ptr: static_cast<void*>(buffer), headerSize: 0, capacity: &capacity, elementSize: sizeof(Type));
91 Q_CHECK_PTR(ptr);
92 buffer = static_cast<Type*>(ptr);
93 }
94 }
95
96 void shrink(qsizetype size) {
97 Q_ASSERT(capacity >= size);
98 if (size) {
99 capacity = size;
100 const auto ptr = QtPrivate::fittedRealloc(ptr: static_cast<void*>(buffer), headerSize: 0, capacity: &capacity, elementSize: sizeof(Type));
101 Q_CHECK_PTR(ptr);
102 buffer = static_cast<Type*>(ptr);
103 siz = std::min(a: siz, b: size);
104 } else {
105 QtPrivate::sizedFree(buffer, capacity, sizeof(Type));
106 capacity = size;
107 buffer = nullptr;
108 siz = 0;
109 }
110 }
111
112 inline void swap(QDataBuffer<Type> &other) {
113 qSwap(value1&: capacity, value2&: other.capacity);
114 qSwap(value1&: siz, value2&: other.siz);
115 qSwap(buffer, other.buffer);
116 }
117
118 inline QDataBuffer &operator<<(const Type &t) { add(t); return *this; }
119
120private:
121 qsizetype capacity;
122 qsizetype siz;
123 Type *buffer;
124};
125
126QT_END_NAMESPACE
127
128#endif // QDATABUFFER_P_H
129

source code of qtbase/src/gui/painting/qdatabuffer_p.h