GDAL

cpl_json_streaming_parser.h
1/******************************************************************************
2 *
3 * Project: CPL - Common Portability Library
4 * Purpose: JSon streaming parser
5 * Author: Even Rouault, even.rouault at spatialys.com
6 *
7 ******************************************************************************
8 * Copyright (c) 2017, Even Rouault <even.rouault at spatialys.com>
9 *
10 * Permission is hereby granted, free of charge, to any person obtaining a
11 * copy of this software and associated documentation files (the "Software"),
12 * to deal in the Software without restriction, including without limitation
13 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
14 * and/or sell copies of the Software, and to permit persons to whom the
15 * Software is furnished to do so, subject to the following conditions:
16 *
17 * The above copyright notice and this permission notice shall be included
18 * in all copies or substantial portions of the Software.
19 *
20 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
21 * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
22 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
23 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
24 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
25 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
26 * DEALINGS IN THE SOFTWARE.
27 ****************************************************************************/
28
29#ifndef CPL_JSON_STREAMIN_PARSER_H
30#define CPL_JSON_STREAMIN_PARSER_H
31
34#if defined(__cplusplus) && !defined(CPL_SUPRESS_CPLUSPLUS)
35
36#include <vector>
37#include <string>
38#include "cpl_port.h"
39
40 class CPL_DLL CPLJSonStreamingParser
41{
42 CPL_DISALLOW_COPY_ASSIGN(CPLJSonStreamingParser)
43
44 enum State
45 {
46 INIT,
47 OBJECT,
48 ARRAY,
49 STRING,
50 NUMBER,
51 STATE_TRUE,
52 STATE_FALSE,
53 STATE_NULL
54 };
55
56 bool m_bExceptionOccurred = false;
57 bool m_bElementFound = false;
58 bool m_bStopParsing = false;
59 int m_nLastChar = 0;
60 int m_nLineCounter = 1;
61 int m_nCharCounter = 1;
62 std::vector<State> m_aState{};
63 std::string m_osToken{};
64 enum class ArrayState
65 {
66 INIT,
67 AFTER_COMMA,
68 AFTER_VALUE
69 };
70 std::vector<ArrayState> m_abArrayState{};
71 bool m_bInStringEscape = false;
72 bool m_bInUnicode = false;
73 std::string m_osUnicodeHex{};
74 size_t m_nMaxDepth = 1024;
75 size_t m_nMaxStringSize = 10000000;
76
77 enum MemberState
78 {
79 WAITING_KEY,
80 IN_KEY,
81 KEY_FINISHED,
82 IN_VALUE
83 };
84
85 std::vector<MemberState> m_aeObjectState{};
86
87 enum State currentState()
88 {
89 return m_aState.back();
90 }
91
92 void SkipSpace(const char *&pStr, size_t &nLength);
93 void AdvanceChar(const char *&pStr, size_t &nLength);
94 bool EmitUnexpectedChar(char ch, const char *pszExpecting = nullptr);
95 bool StartNewToken(const char *&pStr, size_t &nLength);
96 bool CheckAndEmitTrueFalseOrNull(char ch);
97 bool CheckStackEmpty();
98 void DecodeUnicode();
99
100 protected:
101 bool EmitException(const char *pszMessage);
102 void StopParsing();
103
104 public:
105 CPLJSonStreamingParser();
106 virtual ~CPLJSonStreamingParser();
107
108 void SetMaxDepth(size_t nVal);
109 void SetMaxStringSize(size_t nVal);
110
111 bool ExceptionOccurred() const
112 {
113 return m_bExceptionOccurred;
114 }
115
116 static std::string GetSerializedString(const char *pszStr);
117
118 virtual void Reset();
119 virtual bool Parse(const char *pStr, size_t nLength, bool bFinished);
120
121 virtual void String(const char * /*pszValue*/, size_t /*nLength*/)
122 {
123 }
124
125 virtual void Number(const char * /*pszValue*/, size_t /*nLength*/)
126 {
127 }
128
129 virtual void Boolean(bool /*b*/)
130 {
131 }
132
133 virtual void Null()
134 {
135 }
136
137 virtual void StartObject()
138 {
139 }
140
141 virtual void EndObject()
142 {
143 }
144
145 virtual void StartObjectMember(const char * /*pszKey*/, size_t /*nLength*/)
146 {
147 }
148
149 virtual void StartArray()
150 {
151 }
152
153 virtual void EndArray()
154 {
155 }
156
157 virtual void StartArrayMember()
158 {
159 }
160
161 virtual void Exception(const char * /*pszMessage*/)
162 {
163 }
164};
165
166#endif // __cplusplus
167
170#endif // CPL_JSON_STREAMIN_PARSER_H
cpl_port.h
Core portability definitions for CPL.
CPL_DISALLOW_COPY_ASSIGN
#define CPL_DISALLOW_COPY_ASSIGN(ClassName)
Helper to remove the copy and assignment constructors so that the compiler will not generate the defa...
Definition cpl_port.h:1042