1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
|
////////////////////////////////////////////////////////////
//
// SFML - Simple and Fast Multimedia Library
// Copyright (C) 2007-2025 Laurent Gomila (laurent@sfml-dev.org)
//
// This software is provided 'as-is', without any express or implied warranty.
// In no event will the authors be held liable for any damages arising from the use of this software.
//
// Permission is granted to anyone to use this software for any purpose,
// including commercial applications, and to alter it and redistribute it freely,
// subject to the following restrictions:
//
// 1. The origin of this software must not be misrepresented;
// you must not claim that you wrote the original software.
// If you use this software in a product, an acknowledgment
// in the product documentation would be appreciated but is not required.
//
// 2. Altered source versions must be plainly marked as such,
// and must not be misrepresented as being the original software.
//
// 3. This notice may not be removed or altered from any source distribution.
//
////////////////////////////////////////////////////////////
#pragma once
////////////////////////////////////////////////////////////
// Headers
////////////////////////////////////////////////////////////
#include <SFML/Config.hpp>
#include <SFML/System/Export.hpp>
#include <SFML/System/InputStream.hpp>
#include <cstddef>
#include <cstdint>
namespace sf
{
////////////////////////////////////////////////////////////
/// \brief Implementation of input stream based on a memory chunk
///
////////////////////////////////////////////////////////////
class SFML_SYSTEM_API MemoryInputStream : public InputStream
{
public:
////////////////////////////////////////////////////////////
/// \brief Construct the stream from its data
///
/// \param data Pointer to the data in memory
/// \param sizeInBytes Size of the data, in bytes
///
////////////////////////////////////////////////////////////
MemoryInputStream(const void* data, std::size_t sizeInBytes);
////////////////////////////////////////////////////////////
/// \brief Read data from the stream
///
/// After reading, the stream's reading position must be
/// advanced by the amount of bytes read.
///
/// \param data Buffer where to copy the read data
/// \param size Desired number of bytes to read
///
/// \return The number of bytes actually read, or `std::nullopt` on error
///
////////////////////////////////////////////////////////////
[[nodiscard]] std::optional<std::size_t> read(void* data, std::size_t size) override;
////////////////////////////////////////////////////////////
/// \brief Change the current reading position
///
/// \param position The position to seek to, from the beginning
///
/// \return The position actually sought to, or `std::nullopt` on error
///
////////////////////////////////////////////////////////////
[[nodiscard]] std::optional<std::size_t> seek(std::size_t position) override;
////////////////////////////////////////////////////////////
/// \brief Get the current reading position in the stream
///
/// \return The current position, or `std::nullopt` on error.
///
////////////////////////////////////////////////////////////
[[nodiscard]] std::optional<std::size_t> tell() override;
////////////////////////////////////////////////////////////
/// \brief Return the size of the stream
///
/// \return The total number of bytes available in the stream, or `std::nullopt` on error
///
////////////////////////////////////////////////////////////
std::optional<std::size_t> getSize() override;
private:
////////////////////////////////////////////////////////////
// Member data
////////////////////////////////////////////////////////////
const std::byte* m_data{}; //!< Pointer to the data in memory
std::size_t m_size{}; //!< Total size of the data
std::size_t m_offset{}; //!< Current reading position
};
} // namespace sf
////////////////////////////////////////////////////////////
/// \class sf::MemoryInputStream
/// \ingroup system
///
/// This class is a specialization of `InputStream` that
/// reads from data in memory.
///
/// It wraps a memory chunk in the common `InputStream` interface
/// and therefore allows to use generic classes or functions
/// that accept such a stream, with content already loaded in memory.
///
/// In addition to the virtual functions inherited from
/// `InputStream`, `MemoryInputStream` adds a function to
/// specify the pointer and size of the data in memory.
///
/// SFML resource classes can usually be loaded directly from
/// memory, so this class shouldn't be useful to you unless
/// you create your own algorithms that operate on an InputStream.
///
/// Usage example:
/// \code
/// void process(InputStream& stream);
///
/// MemoryInputStream stream(thePtr, theSize);
/// process(stream);
/// \endcode
///
/// \see `InputStream`, `FileInputStream`
///
////////////////////////////////////////////////////////////
|
