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
|
/*
* Copyright (c) 2018-2021, Andreas Kling <kling@serenityos.org>
*
* SPDX-License-Identifier: BSD-2-Clause
*/
#include <AK/StdLibExtras.h>
#include <Kernel/KBufferBuilder.h>
namespace Kernel {
inline bool KBufferBuilder::check_expand(size_t size)
{
if (!m_buffer)
return false;
if ((m_size + size) < m_buffer->capacity())
return true;
if (Checked<size_t>::addition_would_overflow(m_size, size))
return false;
size_t new_buffer_size = m_size + size;
if (Checked<size_t>::addition_would_overflow(new_buffer_size, 1 * MiB))
return false;
auto rounded_new_buffer_size_or_error = Memory::page_round_up(new_buffer_size + 1 * MiB);
if (rounded_new_buffer_size_or_error.is_error()) {
return false;
}
auto new_buffer_or_error = KBuffer::try_create_with_size(rounded_new_buffer_size_or_error.value());
if (new_buffer_or_error.is_error())
return false;
auto new_buffer = new_buffer_or_error.release_value();
memcpy(new_buffer->data(), m_buffer->data(), m_buffer->size());
m_buffer = move(new_buffer);
return true;
}
bool KBufferBuilder::flush()
{
if (!m_buffer)
return false;
m_buffer->set_size(m_size);
return true;
}
OwnPtr<KBuffer> KBufferBuilder::build()
{
if (!flush())
return {};
return move(m_buffer);
}
ErrorOr<KBufferBuilder> KBufferBuilder::try_create()
{
auto buffer = TRY(KBuffer::try_create_with_size(4 * MiB, Memory::Region::Access::ReadWrite));
return KBufferBuilder { move(buffer) };
}
KBufferBuilder::KBufferBuilder(NonnullOwnPtr<KBuffer> buffer)
: m_buffer(move(buffer))
{
}
ErrorOr<void> KBufferBuilder::append_bytes(ReadonlyBytes bytes)
{
if (!check_expand(bytes.size()))
return ENOMEM;
memcpy(insertion_ptr(), bytes.data(), bytes.size());
m_size += bytes.size();
return {};
}
ErrorOr<void> KBufferBuilder::append(StringView str)
{
if (str.is_empty())
return {};
if (!check_expand(str.length()))
return ENOMEM;
memcpy(insertion_ptr(), str.characters_without_null_termination(), str.length());
m_size += str.length();
return {};
}
ErrorOr<void> KBufferBuilder::append(const char* characters, int length)
{
if (!length)
return {};
if (!check_expand(length))
return ENOMEM;
memcpy(insertion_ptr(), characters, length);
m_size += length;
return {};
}
ErrorOr<void> KBufferBuilder::append(char ch)
{
if (!check_expand(1))
return ENOMEM;
insertion_ptr()[0] = ch;
m_size += 1;
return {};
}
ErrorOr<void> KBufferBuilder::append_escaped_for_json(StringView string)
{
for (auto ch : string) {
switch (ch) {
case '\b':
TRY(append("\\b"));
break;
case '\n':
TRY(append("\\n"));
break;
case '\t':
TRY(append("\\t"));
break;
case '\"':
TRY(append("\\\""));
break;
case '\\':
TRY(append("\\\\"));
break;
default:
if (ch >= 0 && ch <= 0x1f)
TRY(appendff("\\u{:04x}", ch));
else
TRY(append(ch));
}
}
return {};
}
}
|
