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
|
/**
* Copyright (C) 2019-present MongoDB, Inc.
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the Server Side Public License, version 1,
* as published by MongoDB, Inc.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* Server Side Public License for more details.
*
* You should have received a copy of the Server Side Public License
* along with this program. If not, see
* <http://www.mongodb.com/licensing/server-side-public-license>.
*
* As a special exception, the copyright holders give permission to link the
* code of portions of this program with the OpenSSL library under certain
* conditions as described in each individual source file and distribute
* linked combinations including the program with the OpenSSL library. You
* must comply with the Server Side Public License in all respects for
* all of the code used other than as permitted herein. If you modify file(s)
* with this exception, you may extend this exception to your version of the
* file(s), but you are not obligated to do so. If you do not wish to do so,
* delete this exception statement from your version. If you delete this
* exception statement from all source files in the program, then also delete
* it in the license file.
*/
#pragma once
#include "mongo/base/string_data.h"
#include <fmt/format.h>
#include <string>
namespace mongo::str {
/**
* Escapes the special characters in 'str' for use as printable text.
*
* The backslash (`\`) character is escaped with another backslash, yielding the
* 2-character sequence {`\`, `\`}.
*
* The single-byte control characters (octets 0x00-0x1f, 0x7f) are generally escaped
* using the format "\xHH", where the 2 `H` characters are replaced by the 2 hex digits
* of the octet. For instance, the octet 0x7f would yield the sequence: {`\`, `x`, `7`, `f`}.
* Exemptions to this rule are the following octets, which are escaped using C-style escape
* sequences:
* 0x00 -> {`\`, `0`}
* 0x07 -> {`\`, `a`}
* 0x08 -> {`\`, `b`}
* 0x09 -> {`\`, `t`}
* 0x0a -> {`\`, `n`}
* 0x0b -> {`\`, `v`}
* 0x0c -> {`\`, `f`}
* 0x0d -> {`\`, `r`}
* 0x1b -> {`\`, `e`}
*
* The two-byte UTF-8 sequences between 0xC280 (U+0080) and 0xC29F (U+009F), inclusive, are
* also escaped as they are considered control characters. The escape sequence for these has
* the format: "\xC2\xHH", where the 2 `H` characters are replaced by the 2 hex digits of the
* second octet.
*
* Invalid bytes found are replaced with the escape sequence following the format: "\xHH",
* similar to how single-byte control characters are escaped.
*
* This writes the escaped output to 'buffer', and stops writing when either the output
* length reaches the 'maxLength', or if appending the next escape sequence will cause the
* output to exceed 'maxLength'. A 'maxLength' value of std::string::npos means unbounded.
*
* The 'wouldWrite' output is updated to contain the total bytes that would have been written
* if there was no length limit.
*/
void escapeForText(fmt::memory_buffer& buffer,
StringData str,
size_t maxLength = std::string::npos,
size_t* wouldWrite = nullptr);
std::string escapeForText(StringData str,
size_t maxLength = std::string::npos,
size_t* wouldWrite = nullptr);
/**
* Escapes the special characters in 'str' for use in JSON.
*
* This differs from escapeForText in that the double-quote character (`"`) is escaped
* with a backslash, yielding the 2-character sequence {`\`, `"`}.
*
* The general format of the escape sequences for single-byte control characters becomes
* "\u00HH", where the 2 `H` characters are replaced by the 2 hex digits of the octet.
* For example, the octet 0x7f would yield the sequence: {`\`, `u`, `0`, `0`, `7`, `f`}.
* The list of octets escaped using C-style escape sequences is also shortened to:
* 0x08 -> {`\`, `b`}
* 0x09 -> {`\`, `t`}
* 0x0a -> {`\`, `n`}
* 0x0c -> {`\`, `f`}
* 0x0d -> {`\`, `r`}
* For two-byte control characters, the format of the escape sequence becomes "\uc2HH",
* where the 2 `H` characters are replaced by the 2 hex digits of the second octet.
* Invalid bytes found are replaced with the sequence: "\ufffd".
*/
void escapeForJSON(fmt::memory_buffer& buffer,
StringData str,
size_t maxLength = std::string::npos,
size_t* wouldWrite = nullptr);
std::string escapeForJSON(StringData str,
size_t maxLength = std::string::npos,
size_t* wouldWrite = nullptr);
} // namespace mongo::str
|
