summaryrefslogtreecommitdiff
path: root/AK/StringBuilder.cpp
blob: 6c1f3040cdc4757624ce00b42ef0540d4d5dbd98 (plain)
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
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
/*
 * Copyright (c) 2018-2020, Andreas Kling <kling@serenityos.org>
 *
 * SPDX-License-Identifier: BSD-2-Clause
 */

#include <AK/ByteBuffer.h>
#include <AK/Checked.h>
#include <AK/Memory.h>
#include <AK/PrintfImplementation.h>
#include <AK/StdLibExtras.h>
#include <AK/String.h>
#include <AK/StringBuilder.h>
#include <AK/StringView.h>
#include <AK/Utf32View.h>

namespace AK {

inline void StringBuilder::will_append(size_t size)
{
    Checked<size_t> needed_capacity = m_length;
    needed_capacity += size;
    VERIFY(!needed_capacity.has_overflow());
    if (needed_capacity < inline_capacity)
        return;
    Checked<size_t> expanded_capacity = needed_capacity;
    expanded_capacity *= 2;
    VERIFY(!expanded_capacity.has_overflow());
    if (m_buffer.is_null()) {
        m_buffer.grow(expanded_capacity.value());
        memcpy(m_buffer.data(), m_inline_buffer, m_length);
    } else if (needed_capacity.value() > m_buffer.size()) {
        m_buffer.grow(expanded_capacity.value());
    }
}

StringBuilder::StringBuilder(size_t initial_capacity)
{
    if (initial_capacity > inline_capacity)
        m_buffer.grow(initial_capacity);
}

void StringBuilder::append(const StringView& str)
{
    if (str.is_empty())
        return;
    will_append(str.length());
    memcpy(data() + m_length, str.characters_without_null_termination(), str.length());
    m_length += str.length();
}

void StringBuilder::append(const char* characters, size_t length)
{
    append(StringView { characters, length });
}

void StringBuilder::append(char ch)
{
    will_append(1);
    data()[m_length] = ch;
    m_length += 1;
}

void StringBuilder::appendvf(const char* fmt, va_list ap)
{
    printf_internal([this](char*&, char ch) {
        append(ch);
    },
        nullptr, fmt, ap);
}

void StringBuilder::appendf(const char* fmt, ...)
{
    va_list ap;
    va_start(ap, fmt);
    will_append(strlen(fmt));
    appendvf(fmt, ap);
    va_end(ap);
}

ByteBuffer StringBuilder::to_byte_buffer() const
{
    return ByteBuffer::copy(data(), length());
}

String StringBuilder::to_string() const
{
    if (is_empty())
        return String::empty();
    return String((const char*)data(), length());
}

String StringBuilder::build() const
{
    return to_string();
}

StringView StringBuilder::string_view() const
{
    return StringView { data(), m_length };
}

void StringBuilder::clear()
{
    m_buffer.clear();
    m_inline_buffer[0] = '\0';
    m_length = 0;
}

void StringBuilder::append_code_point(u32 code_point)
{
    if (code_point <= 0x7f) {
        append((char)code_point);
    } else if (code_point <= 0x07ff) {
        append((char)(((code_point >> 6) & 0x1f) | 0xc0));
        append((char)(((code_point >> 0) & 0x3f) | 0x80));
    } else if (code_point <= 0xffff) {
        append((char)(((code_point >> 12) & 0x0f) | 0xe0));
        append((char)(((code_point >> 6) & 0x3f) | 0x80));
        append((char)(((code_point >> 0) & 0x3f) | 0x80));
    } else if (code_point <= 0x10ffff) {
        append((char)(((code_point >> 18) & 0x07) | 0xf0));
        append((char)(((code_point >> 12) & 0x3f) | 0x80));
        append((char)(((code_point >> 6) & 0x3f) | 0x80));
        append((char)(((code_point >> 0) & 0x3f) | 0x80));
    } else {
        append(0xef);
        append(0xbf);
        append(0xbd);
    }
}

void StringBuilder::append(const Utf32View& utf32_view)
{
    for (size_t i = 0; i < utf32_view.length(); ++i) {
        auto code_point = utf32_view.code_points()[i];
        append_code_point(code_point);
    }
}

void StringBuilder::append_escaped_for_json(const StringView& string)
{
    for (auto ch : string) {
        switch (ch) {
        case '\e':
            append("\\u001B");
            break;
        case '\b':
            append("\\b");
            break;
        case '\n':
            append("\\n");
            break;
        case '\t':
            append("\\t");
            break;
        case '\"':
            append("\\\"");
            break;
        case '\\':
            append("\\\\");
            break;
        default:
            append(ch);
        }
    }
}

}