File size: 9,540 Bytes
d4b77ac
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
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
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
// https://github.com/vivkin/gason - pulled January 10, 2016
#include "gason.h"
#include <stdlib.h>

#define JSON_ZONE_SIZE 4096
#define JSON_STACK_SIZE 32

const char *jsonStrError(int err) {
    switch (err) {
#define XX(no, str) \
    case JSON_##no: \
        return str;
        JSON_ERRNO_MAP(XX)
#undef XX
    default:
        return "unknown";
    }
}

void *JsonAllocator::allocate(size_t size) {
    size = (size + 7) & ~7;

    if (head && head->used + size <= JSON_ZONE_SIZE) {
        char *p = (char *)head + head->used;
        head->used += size;
        return p;
    }

    size_t allocSize = sizeof(Zone) + size;
    Zone *zone = (Zone *)malloc(allocSize <= JSON_ZONE_SIZE ? JSON_ZONE_SIZE : allocSize);
    if (zone == nullptr)
        return nullptr;
    zone->used = allocSize;
    if (allocSize <= JSON_ZONE_SIZE || head == nullptr) {
        zone->next = head;
        head = zone;
    } else {
        zone->next = head->next;
        head->next = zone;
    }
    return (char *)zone + sizeof(Zone);
}

void JsonAllocator::deallocate() {
    while (head) {
        Zone *next = head->next;
        free(head);
        head = next;
    }
}

static inline bool isspace(char c) {
    return c == ' ' || (c >= '\t' && c <= '\r');
}

static inline bool isdelim(char c) {
    return c == ',' || c == ':' || c == ']' || c == '}' || isspace(c) || !c;
}

static inline bool isdigit(char c) {
    return c >= '0' && c <= '9';
}

static inline bool isxdigit(char c) {
    return (c >= '0' && c <= '9') || ((c & ~' ') >= 'A' && (c & ~' ') <= 'F');
}

static inline int char2int(char c) {
    if (c <= '9')
        return c - '0';
    return (c & ~' ') - 'A' + 10;
}

static double string2double(char *s, char **endptr) {
    char ch = *s;
    if (ch == '-')
        ++s;

    double result = 0;
    while (isdigit(*s))
        result = (result * 10) + (*s++ - '0');

    if (*s == '.') {
        ++s;

        double fraction = 1;
        while (isdigit(*s)) {
            fraction *= 0.1;
            result += (*s++ - '0') * fraction;
        }
    }

    if (*s == 'e' || *s == 'E') {
        ++s;

        double base = 10;
        if (*s == '+')
            ++s;
        else if (*s == '-') {
            ++s;
            base = 0.1;
        }

        unsigned int exponent = 0;
        while (isdigit(*s))
            exponent = (exponent * 10) + (*s++ - '0');

        double power = 1;
        for (; exponent; exponent >>= 1, base *= base)
            if (exponent & 1)
                power *= base;

        result *= power;
    }

    *endptr = s;
    return ch == '-' ? -result : result;
}

static inline JsonNode *insertAfter(JsonNode *tail, JsonNode *node) {
    if (!tail)
        return node->next = node;
    node->next = tail->next;
    tail->next = node;
    return node;
}

static inline JsonValue listToValue(JsonTag tag, JsonNode *tail) {
    if (tail) {
        auto head = tail->next;
        tail->next = nullptr;
        return JsonValue(tag, head);
    }
    return JsonValue(tag, nullptr);
}

int jsonParse(char *s, char **endptr, JsonValue *value, JsonAllocator &allocator) {
    JsonNode *tails[JSON_STACK_SIZE];
    JsonTag tags[JSON_STACK_SIZE];
    char *keys[JSON_STACK_SIZE];
    JsonValue o;
    int pos = -1;
    bool separator = true;
    JsonNode *node;
    *endptr = s;

    while (*s) {
        while (isspace(*s)) {
            ++s;
            if (!*s) break;
        }
        *endptr = s++;
        switch (**endptr) {
        case '-':
            if (!isdigit(*s) && *s != '.') {
                *endptr = s;
                return JSON_BAD_NUMBER;
            }
        case '0':
        case '1':
        case '2':
        case '3':
        case '4':
        case '5':
        case '6':
        case '7':
        case '8':
        case '9':
            o = JsonValue(string2double(*endptr, &s));
            if (!isdelim(*s)) {
                *endptr = s;
                return JSON_BAD_NUMBER;
            }
            break;
        case '"':
            o = JsonValue(JSON_STRING, s);
            for (char *it = s; *s; ++it, ++s) {
                int c = *it = *s;
                if (c == '\\') {
                    c = *++s;
                    switch (c) {
                    case '\\':
                    case '"':
                    case '/':
                        *it = c;
                        break;
                    case 'b':
                        *it = '\b';
                        break;
                    case 'f':
                        *it = '\f';
                        break;
                    case 'n':
                        *it = '\n';
                        break;
                    case 'r':
                        *it = '\r';
                        break;
                    case 't':
                        *it = '\t';
                        break;
                    case 'u':
                        c = 0;
                        for (int i = 0; i < 4; ++i) {
                            if (isxdigit(*++s)) {
                                c = c * 16 + char2int(*s);
                            } else {
                                *endptr = s;
                                return JSON_BAD_STRING;
                            }
                        }
                        if (c < 0x80) {
                            *it = c;
                        } else if (c < 0x800) {
                            *it++ = 0xC0 | (c >> 6);
                            *it = 0x80 | (c & 0x3F);
                        } else {
                            *it++ = 0xE0 | (c >> 12);
                            *it++ = 0x80 | ((c >> 6) & 0x3F);
                            *it = 0x80 | (c & 0x3F);
                        }
                        break;
                    default:
                        *endptr = s;
                        return JSON_BAD_STRING;
                    }
                } else if ((unsigned int)c < ' ' || c == '\x7F') {
                    *endptr = s;
                    return JSON_BAD_STRING;
                } else if (c == '"') {
                    *it = 0;
                    ++s;
                    break;
                }
            }
            if (!isdelim(*s)) {
                *endptr = s;
                return JSON_BAD_STRING;
            }
            break;
        case 't':
            if (!(s[0] == 'r' && s[1] == 'u' && s[2] == 'e' && isdelim(s[3])))
                return JSON_BAD_IDENTIFIER;
            o = JsonValue(JSON_TRUE);
            s += 3;
            break;
        case 'f':
            if (!(s[0] == 'a' && s[1] == 'l' && s[2] == 's' && s[3] == 'e' && isdelim(s[4])))
                return JSON_BAD_IDENTIFIER;
            o = JsonValue(JSON_FALSE);
            s += 4;
            break;
        case 'n':
            if (!(s[0] == 'u' && s[1] == 'l' && s[2] == 'l' && isdelim(s[3])))
                return JSON_BAD_IDENTIFIER;
            o = JsonValue(JSON_NULL);
            s += 3;
            break;
        case ']':
            if (pos == -1)
                return JSON_STACK_UNDERFLOW;
            if (tags[pos] != JSON_ARRAY)
                return JSON_MISMATCH_BRACKET;
            o = listToValue(JSON_ARRAY, tails[pos--]);
            break;
        case '}':
            if (pos == -1)
                return JSON_STACK_UNDERFLOW;
            if (tags[pos] != JSON_OBJECT)
                return JSON_MISMATCH_BRACKET;
            if (keys[pos] != nullptr)
                return JSON_UNEXPECTED_CHARACTER;
            o = listToValue(JSON_OBJECT, tails[pos--]);
            break;
        case '[':
            if (++pos == JSON_STACK_SIZE)
                return JSON_STACK_OVERFLOW;
            tails[pos] = nullptr;
            tags[pos] = JSON_ARRAY;
            keys[pos] = nullptr;
            separator = true;
            continue;
        case '{':
            if (++pos == JSON_STACK_SIZE)
                return JSON_STACK_OVERFLOW;
            tails[pos] = nullptr;
            tags[pos] = JSON_OBJECT;
            keys[pos] = nullptr;
            separator = true;
            continue;
        case ':':
            if (separator || keys[pos] == nullptr)
                return JSON_UNEXPECTED_CHARACTER;
            separator = true;
            continue;
        case ',':
            if (separator || keys[pos] != nullptr)
                return JSON_UNEXPECTED_CHARACTER;
            separator = true;
            continue;
        case '\0':
            continue;
        default:
            return JSON_UNEXPECTED_CHARACTER;
        }

        separator = false;

        if (pos == -1) {
            *endptr = s;
            *value = o;
            return JSON_OK;
        }

        if (tags[pos] == JSON_OBJECT) {
            if (!keys[pos]) {
                if (o.getTag() != JSON_STRING)
                    return JSON_UNQUOTED_KEY;
                keys[pos] = o.toString();
                continue;
            }
            if ((node = (JsonNode *) allocator.allocate(sizeof(JsonNode))) == nullptr)
                return JSON_ALLOCATION_FAILURE;
            tails[pos] = insertAfter(tails[pos], node);
            tails[pos]->key = keys[pos];
            keys[pos] = nullptr;
        } else {
            if ((node = (JsonNode *) allocator.allocate(sizeof(JsonNode) - sizeof(char *))) == nullptr)
                return JSON_ALLOCATION_FAILURE;
            tails[pos] = insertAfter(tails[pos], node);
        }
        tails[pos]->value = o;
    }
    return JSON_BREAKING_BAD;
}