1 /*
2 The MIT License (MIT)
3
4 Copyright (c) 2013-2015 Ivan Vashchaev
5
6 Permission is hereby granted, free of charge, to any person obtaining a copy of
7 this software and associated documentation files (the "Software"), to deal in
8 the Software without restriction, including without limitation the rights to
9 use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of
10 the Software, and to permit persons to whom the Software is furnished to do so,
11 subject to the following conditions:
12
13 The above copyright notice and this permission notice shall be included in all
14 copies or substantial portions of the Software.
15
16 THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
17 IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS
18 FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR
19 COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER
20 IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
21 CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
22 */
23
24 #pragma once
25
26 #include <cassert>
27 #include <cstddef>
28 #include <cstdint>
29
30 enum JsonTag
31 {
32 JSON_NUMBER = 0,
33 JSON_STRING,
34 JSON_ARRAY,
35 JSON_OBJECT,
36 JSON_TRUE,
37 JSON_FALSE,
38 JSON_NULL = 0xF
39 };
40
41 struct JsonNode;
42
43 #define JSON_VALUE_PAYLOAD_MASK 0x00007FFFFFFFFFFFULL
44 #define JSON_VALUE_NAN_MASK 0x7FF8000000000000ULL
45 #define JSON_VALUE_TAG_MASK 0xF
46 #define JSON_VALUE_TAG_SHIFT 47
47
48 union JsonValue {
49 uint64_t ival;
50 double fval;
51
JsonValue(double x)52 JsonValue(double x) : fval(x) {}
53 JsonValue(JsonTag tag = JSON_NULL, void *payload = nullptr)
54 {
55 #if !defined(__arm__)
56 assert((uint64_t)(uintptr_t)payload <= JSON_VALUE_PAYLOAD_MASK);
57 #endif
58 ival = JSON_VALUE_NAN_MASK | ((uint64_t)tag << JSON_VALUE_TAG_SHIFT) | (uintptr_t)payload;
59 }
isDouble()60 bool isDouble() const { return (int64_t)ival <= (int64_t)JSON_VALUE_NAN_MASK; }
getTag()61 JsonTag getTag() const
62 {
63 return isDouble() ? JSON_NUMBER : JsonTag((ival >> JSON_VALUE_TAG_SHIFT) & JSON_VALUE_TAG_MASK);
64 }
getPayload()65 uint64_t getPayload() const
66 {
67 assert(!isDouble());
68 return ival & JSON_VALUE_PAYLOAD_MASK;
69 }
toNumber()70 double toNumber() const
71 {
72 assert(getTag() == JSON_NUMBER);
73 return fval;
74 }
toString()75 char *toString() const
76 {
77 assert(getTag() == JSON_STRING);
78 return (char *)getPayload();
79 }
toNode()80 JsonNode *toNode() const
81 {
82 assert(getTag() == JSON_ARRAY || getTag() == JSON_OBJECT);
83 return (JsonNode *)getPayload();
84 }
85 };
86
87 struct JsonNode
88 {
89 JsonValue value;
90 JsonNode *next;
91 char *key;
92 };
93
94 struct JsonIterator
95 {
96 JsonNode *p;
97
98 void operator++() { p = p->next; }
99 bool operator!=(const JsonIterator &x) const { return p != x.p; }
100 JsonNode *operator*() const { return p; }
101 JsonNode *operator->() const { return p; }
102 };
103
begin(JsonValue o)104 inline JsonIterator begin(JsonValue o)
105 {
106 return JsonIterator{ o.toNode() };
107 }
end(JsonValue)108 inline JsonIterator end(JsonValue)
109 {
110 return JsonIterator{ nullptr };
111 }
112
113 #define JSON_ERRNO_MAP(XX) \
114 XX(OK, "ok") \
115 XX(BAD_NUMBER, "bad number") \
116 XX(BAD_STRING, "bad string") \
117 XX(BAD_IDENTIFIER, "bad identifier") \
118 XX(STACK_OVERFLOW, "stack overflow") \
119 XX(STACK_UNDERFLOW, "stack underflow") \
120 XX(MISMATCH_BRACKET, "mismatch bracket") \
121 XX(UNEXPECTED_CHARACTER, "unexpected character") \
122 XX(UNQUOTED_KEY, "unquoted key") \
123 XX(BREAKING_BAD, "breaking bad") \
124 XX(ALLOCATION_FAILURE, "allocation failure")
125
126 enum JsonErrno
127 {
128 #define XX(no, str) JSON_##no,
129 JSON_ERRNO_MAP(XX)
130 #undef XX
131 };
132
133 const char *jsonStrError(int err);
134
135 class JsonAllocator
136 {
137 struct Zone
138 {
139 Zone *next;
140 size_t used;
141 } *head = nullptr;
142
143 public:
144 JsonAllocator() = default;
145 JsonAllocator(const JsonAllocator &) = delete;
146 JsonAllocator &operator=(const JsonAllocator &) = delete;
JsonAllocator(JsonAllocator && x)147 JsonAllocator(JsonAllocator &&x) : head(x.head) { x.head = nullptr; }
148 JsonAllocator &operator=(JsonAllocator &&x)
149 {
150 head = x.head;
151 x.head = nullptr;
152 return *this;
153 }
~JsonAllocator()154 ~JsonAllocator() { deallocate(); }
155 void *allocate(size_t size);
156 void deallocate();
157 };
158
159 int jsonParse(char *str, char **endptr, JsonValue *value, JsonAllocator &allocator);
160