rev |
line source |
jbe@121
|
1 #include <lua.h>
|
jbe@121
|
2 #include <lauxlib.h>
|
jbe@122
|
3 #include <stdlib.h>
|
jbe@121
|
4 #include <string.h>
|
jbe@121
|
5
|
jbe@130
|
6 #define JSON_UPVAL_NULLMARK lua_upvalueindex(1)
|
jbe@130
|
7 #define JSON_UPVAL_SHADOWTBL lua_upvalueindex(2)
|
jbe@130
|
8 #define JSON_UPVAL_TYPES lua_upvalueindex(3)
|
jbe@130
|
9 #define JSON_UPVAL_METATABLE lua_upvalueindex(4)
|
jbe@123
|
10
|
jbe@124
|
11 #define JSON_STATE_VALUE 0
|
jbe@124
|
12 #define JSON_STATE_OBJECT_KEY 1
|
jbe@124
|
13 #define JSON_STATE_OBJECT_KEY_TERMINATOR 2
|
jbe@124
|
14 #define JSON_STATE_OBJECT_VALUE 3
|
jbe@124
|
15 #define JSON_STATE_OBJECT_SEPARATOR 4
|
jbe@124
|
16 #define JSON_STATE_ARRAY_VALUE 5
|
jbe@124
|
17 #define JSON_STATE_ARRAY_SEPARATOR 6
|
jbe@124
|
18 #define JSON_STATE_END 7
|
jbe@121
|
19
|
jbe@121
|
20 static int json_import(lua_State *L) {
|
jbe@121
|
21 const char *str;
|
jbe@121
|
22 size_t total;
|
jbe@121
|
23 size_t pos = 0;
|
jbe@121
|
24 size_t level = 0;
|
jbe@124
|
25 int mode = JSON_STATE_VALUE;
|
jbe@121
|
26 char c;
|
jbe@121
|
27 luaL_Buffer luabuf;
|
jbe@121
|
28 char *cbuf;
|
jbe@121
|
29 size_t writepos;
|
jbe@121
|
30 lua_settop(L, 1);
|
jbe@121
|
31 str = lua_tostring(L, 1);
|
jbe@121
|
32 total = strlen(str);
|
jbe@121
|
33 json_import_loop:
|
jbe@121
|
34 while (c = str[pos], c == ' ' || c == '\n' || c == '\r' || c == '\t' || c == '\f') pos++;
|
jbe@121
|
35 switch (c) {
|
jbe@121
|
36 case 0:
|
jbe@124
|
37 if (mode == JSON_STATE_END) return 1;
|
jbe@121
|
38 json_import_unexpected_eof:
|
jbe@121
|
39 lua_pushnil(L);
|
jbe@121
|
40 if (level == 0) lua_pushliteral(L, "Empty string");
|
jbe@121
|
41 else lua_pushliteral(L, "Unexpected end of JSON document");
|
jbe@121
|
42 return 2;
|
jbe@121
|
43 case '{':
|
jbe@124
|
44 if (mode != JSON_STATE_VALUE && mode != JSON_STATE_OBJECT_VALUE && mode != JSON_STATE_ARRAY_VALUE)
|
jbe@121
|
45 goto json_import_syntax_error;
|
jbe@121
|
46 pos++;
|
jbe@130
|
47 lua_newtable(L); // the external JSON object representation
|
jbe@125
|
48 lua_pushvalue(L, JSON_UPVAL_METATABLE);
|
jbe@125
|
49 lua_setmetatable(L, -2);
|
jbe@127
|
50 lua_pushvalue(L, -1);
|
jbe@127
|
51 lua_pushliteral(L, "object");
|
jbe@127
|
52 lua_rawset(L, JSON_UPVAL_TYPES);
|
jbe@130
|
53 lua_newtable(L); // the internal shadow table
|
jbe@123
|
54 lua_pushvalue(L, -2);
|
jbe@123
|
55 lua_pushvalue(L, -2);
|
jbe@130
|
56 lua_rawset(L, JSON_UPVAL_SHADOWTBL);
|
jbe@124
|
57 mode = JSON_STATE_OBJECT_KEY;
|
jbe@121
|
58 level++;
|
jbe@121
|
59 goto json_import_loop;
|
jbe@121
|
60 case '[':
|
jbe@124
|
61 if (mode != JSON_STATE_VALUE && mode != JSON_STATE_OBJECT_VALUE && mode != JSON_STATE_ARRAY_VALUE)
|
jbe@121
|
62 goto json_import_syntax_error;
|
jbe@121
|
63 pos++;
|
jbe@130
|
64 lua_newtable(L); // the external JSON array representation
|
jbe@125
|
65 lua_pushvalue(L, JSON_UPVAL_METATABLE);
|
jbe@125
|
66 lua_setmetatable(L, -2);
|
jbe@127
|
67 lua_pushvalue(L, -1);
|
jbe@127
|
68 lua_pushliteral(L, "array");
|
jbe@127
|
69 lua_rawset(L, JSON_UPVAL_TYPES);
|
jbe@130
|
70 lua_newtable(L); // the internal shadow table
|
jbe@123
|
71 lua_pushvalue(L, -2);
|
jbe@123
|
72 lua_pushvalue(L, -2);
|
jbe@130
|
73 lua_rawset(L, JSON_UPVAL_SHADOWTBL);
|
jbe@130
|
74 lua_pushinteger(L, 0); // magic integer to indicate an array
|
jbe@124
|
75 mode = JSON_STATE_ARRAY_VALUE;
|
jbe@121
|
76 level++;
|
jbe@121
|
77 goto json_import_loop;
|
jbe@121
|
78 case '}':
|
jbe@124
|
79 if (mode != JSON_STATE_OBJECT_KEY && mode != JSON_STATE_OBJECT_SEPARATOR)
|
jbe@121
|
80 goto json_import_syntax_error;
|
jbe@121
|
81 goto json_import_close;
|
jbe@121
|
82 case ']':
|
jbe@124
|
83 if (mode != JSON_STATE_ARRAY_VALUE && mode != JSON_STATE_ARRAY_SEPARATOR)
|
jbe@121
|
84 goto json_import_syntax_error;
|
jbe@130
|
85 lua_pop(L, 1); // pop magic integer
|
jbe@121
|
86 json_import_close:
|
jbe@121
|
87 pos++;
|
jbe@130
|
88 lua_pop(L, 1); // pop shadow table
|
jbe@121
|
89 if (--level) {
|
jbe@121
|
90 if (lua_type(L, -2) == LUA_TNUMBER) {
|
jbe@124
|
91 mode = JSON_STATE_ARRAY_VALUE;
|
jbe@121
|
92 } else {
|
jbe@124
|
93 mode = JSON_STATE_OBJECT_VALUE;
|
jbe@121
|
94 }
|
jbe@121
|
95 goto json_import_process_value;
|
jbe@121
|
96 } else {
|
jbe@124
|
97 mode = JSON_STATE_END;
|
jbe@121
|
98 }
|
jbe@121
|
99 goto json_import_loop;
|
jbe@121
|
100 case ':':
|
jbe@124
|
101 if (mode != JSON_STATE_OBJECT_KEY_TERMINATOR)
|
jbe@121
|
102 goto json_import_syntax_error;
|
jbe@121
|
103 pos++;
|
jbe@124
|
104 mode = JSON_STATE_OBJECT_VALUE;
|
jbe@121
|
105 goto json_import_loop;
|
jbe@121
|
106 case ',':
|
jbe@124
|
107 if (mode == JSON_STATE_OBJECT_SEPARATOR) {
|
jbe@124
|
108 mode = JSON_STATE_OBJECT_KEY;
|
jbe@124
|
109 } else if (mode == JSON_STATE_ARRAY_SEPARATOR) {
|
jbe@124
|
110 mode = JSON_STATE_ARRAY_VALUE;
|
jbe@121
|
111 } else {
|
jbe@121
|
112 goto json_import_syntax_error;
|
jbe@121
|
113 }
|
jbe@121
|
114 pos++;
|
jbe@121
|
115 goto json_import_loop;
|
jbe@121
|
116 case '"':
|
jbe@121
|
117 cbuf = luaL_buffinitsize(L, &luabuf, total-pos);
|
jbe@121
|
118 writepos = 0;
|
jbe@121
|
119 pos++;
|
jbe@121
|
120 while ((c = str[pos++]) != '"') {
|
jbe@121
|
121 if (c == 0) {
|
jbe@121
|
122 goto json_import_unexpected_eof;
|
jbe@121
|
123 } else if (c < 32 || c == 127) {
|
jbe@121
|
124 lua_pushnil(L);
|
jbe@121
|
125 lua_pushliteral(L, "Unexpected control character in JSON string");
|
jbe@121
|
126 return 2;
|
jbe@121
|
127 } else if (c == '\\') {
|
jbe@121
|
128 c = str[pos++];
|
jbe@121
|
129 switch (c) {
|
jbe@121
|
130 case 0:
|
jbe@121
|
131 goto json_import_unexpected_eof;
|
jbe@121
|
132 case '"':
|
jbe@121
|
133 case '/':
|
jbe@121
|
134 case '\\':
|
jbe@121
|
135 cbuf[writepos++] = c;
|
jbe@121
|
136 break;
|
jbe@121
|
137 case 'b':
|
jbe@121
|
138 cbuf[writepos++] = '\b';
|
jbe@121
|
139 break;
|
jbe@121
|
140 case 'f':
|
jbe@121
|
141 cbuf[writepos++] = '\f';
|
jbe@121
|
142 break;
|
jbe@121
|
143 case 'n':
|
jbe@121
|
144 cbuf[writepos++] = '\n';
|
jbe@121
|
145 break;
|
jbe@121
|
146 case 'r':
|
jbe@121
|
147 cbuf[writepos++] = '\r';
|
jbe@121
|
148 break;
|
jbe@121
|
149 case 't':
|
jbe@121
|
150 cbuf[writepos++] = '\t';
|
jbe@121
|
151 break;
|
jbe@121
|
152 case 'u':
|
jbe@121
|
153 lua_pushnil(L);
|
jbe@121
|
154 lua_pushliteral(L, "JSON unicode escape sequences are not implemented yet"); // TODO
|
jbe@121
|
155 return 2;
|
jbe@121
|
156 default:
|
jbe@121
|
157 lua_pushnil(L);
|
jbe@121
|
158 lua_pushliteral(L, "Unexpected string escape sequence in JSON document");
|
jbe@121
|
159 return 2;
|
jbe@121
|
160 }
|
jbe@121
|
161 } else {
|
jbe@121
|
162 cbuf[writepos++] = c;
|
jbe@121
|
163 }
|
jbe@121
|
164 }
|
jbe@121
|
165 if (!c) goto json_import_unexpected_eof;
|
jbe@121
|
166 luaL_pushresultsize(&luabuf, writepos);
|
jbe@121
|
167 goto json_import_process_value;
|
jbe@121
|
168 }
|
jbe@122
|
169 if (c == '-' || (c >= '0' && c <= '9')) {
|
jbe@122
|
170 char *endptr;
|
jbe@122
|
171 double numval;
|
jbe@122
|
172 numval = strtod(str+pos, &endptr);
|
jbe@122
|
173 if (endptr == str+pos) goto json_import_syntax_error;
|
jbe@122
|
174 pos += endptr - (str+pos);
|
jbe@122
|
175 lua_pushnumber(L, numval);
|
jbe@122
|
176 } else if (!strncmp(str+pos, "true", 4)) {
|
jbe@121
|
177 lua_pushboolean(L, 1);
|
jbe@121
|
178 pos += 4;
|
jbe@121
|
179 } else if (!strncmp(str+pos, "false", 5)) {
|
jbe@121
|
180 lua_pushboolean(L, 0);
|
jbe@121
|
181 pos += 5;
|
jbe@121
|
182 } else if (!strncmp(str+pos, "null", 4)) {
|
jbe@130
|
183 lua_pushvalue(L, JSON_UPVAL_NULLMARK);
|
jbe@121
|
184 pos += 4;
|
jbe@121
|
185 } else {
|
jbe@121
|
186 goto json_import_syntax_error;
|
jbe@121
|
187 }
|
jbe@121
|
188 json_import_process_value:
|
jbe@121
|
189 switch (mode) {
|
jbe@124
|
190 case JSON_STATE_OBJECT_KEY:
|
jbe@121
|
191 if (lua_type(L, -1) != LUA_TSTRING) goto json_import_syntax_error;
|
jbe@124
|
192 mode = JSON_STATE_OBJECT_KEY_TERMINATOR;
|
jbe@121
|
193 goto json_import_loop;
|
jbe@124
|
194 case JSON_STATE_OBJECT_VALUE:
|
jbe@130
|
195 lua_rawset(L, -3);
|
jbe@124
|
196 mode = JSON_STATE_OBJECT_SEPARATOR;
|
jbe@121
|
197 goto json_import_loop;
|
jbe@124
|
198 case JSON_STATE_ARRAY_VALUE:
|
jbe@130
|
199 lua_rawseti(L, -3, lua_rawlen(L, -3) + 1);
|
jbe@124
|
200 mode = JSON_STATE_ARRAY_SEPARATOR;
|
jbe@121
|
201 goto json_import_loop;
|
jbe@124
|
202 case JSON_STATE_VALUE:
|
jbe@124
|
203 mode = JSON_STATE_END;
|
jbe@121
|
204 goto json_import_loop;
|
jbe@121
|
205 }
|
jbe@121
|
206 json_import_syntax_error:
|
jbe@121
|
207 lua_pushnil(L);
|
jbe@121
|
208 lua_pushliteral(L, "Syntax error in JSON document");
|
jbe@121
|
209 return 2;
|
jbe@121
|
210 }
|
jbe@121
|
211
|
jbe@130
|
212 #define JSON_PATH_GET 1
|
jbe@130
|
213 #define JSON_PATH_TYPE 2
|
jbe@130
|
214 #define JSON_PATH_ISNULL 3
|
jbe@130
|
215
|
jbe@130
|
216 static int json_path(lua_State *L, int mode) {
|
jbe@130
|
217 int argc;
|
jbe@130
|
218 int idx = 2;
|
jbe@130
|
219 argc = lua_gettop(L);
|
jbe@126
|
220 lua_pushvalue(L, 1);
|
jbe@130
|
221 while (idx <= argc) {
|
jbe@132
|
222 if (lua_isnil(L, -1)) {
|
jbe@132
|
223 if (mode == JSON_PATH_ISNULL) lua_pushboolean(L, 0);
|
jbe@132
|
224 return 1;
|
jbe@132
|
225 }
|
jbe@130
|
226 lua_pushvalue(L, -1);
|
jbe@130
|
227 lua_rawget(L, JSON_UPVAL_SHADOWTBL);
|
jbe@126
|
228 if (lua_isnil(L, -1)) {
|
jbe@126
|
229 lua_pop(L, 1);
|
jbe@130
|
230 if (lua_type(L, -1) == LUA_TTABLE) {
|
jbe@130
|
231 lua_pushvalue(L, idx++);
|
jbe@130
|
232 lua_gettable(L, -2);
|
jbe@130
|
233 } else {
|
jbe@130
|
234 lua_pushnil(L);
|
jbe@130
|
235 }
|
jbe@130
|
236 } else {
|
jbe@130
|
237 lua_replace(L, -2);
|
jbe@130
|
238 lua_pushvalue(L, idx++);
|
jbe@130
|
239 lua_rawget(L, -2);
|
jbe@126
|
240 }
|
jbe@130
|
241 lua_replace(L, -2);
|
jbe@126
|
242 }
|
jbe@130
|
243 switch (mode) {
|
jbe@130
|
244 case JSON_PATH_GET:
|
jbe@130
|
245 if (lua_rawequal(L, -1, JSON_UPVAL_NULLMARK)) lua_pushnil(L);
|
jbe@130
|
246 return 1;
|
jbe@130
|
247 case JSON_PATH_TYPE:
|
jbe@130
|
248 if (lua_rawequal(L, -1, JSON_UPVAL_NULLMARK)) {
|
jbe@130
|
249 lua_pushliteral(L, "null");
|
jbe@130
|
250 return 1;
|
jbe@126
|
251 }
|
jbe@130
|
252 lua_pushvalue(L, -1);
|
jbe@130
|
253 lua_rawget(L, JSON_UPVAL_TYPES);
|
jbe@130
|
254 if (lua_isnil(L, -1)) lua_pushstring(L, lua_typename(L, lua_type(L, -2)));
|
jbe@130
|
255 return 1;
|
jbe@130
|
256 case JSON_PATH_ISNULL:
|
jbe@130
|
257 lua_pushboolean(L, lua_rawequal(L, -1, JSON_UPVAL_NULLMARK));
|
jbe@130
|
258 return 1;
|
jbe@126
|
259 }
|
jbe@130
|
260 return 0;
|
jbe@130
|
261 }
|
jbe@130
|
262
|
jbe@130
|
263 static int json_get(lua_State *L) {
|
jbe@130
|
264 return json_path(L, JSON_PATH_GET);
|
jbe@130
|
265 }
|
jbe@130
|
266
|
jbe@130
|
267 static int json_type(lua_State *L) {
|
jbe@130
|
268 return json_path(L, JSON_PATH_TYPE);
|
jbe@130
|
269 }
|
jbe@130
|
270
|
jbe@130
|
271 static int json_isnull(lua_State *L) {
|
jbe@130
|
272 return json_path(L, JSON_PATH_ISNULL);
|
jbe@130
|
273 }
|
jbe@130
|
274
|
jbe@131
|
275 static int json_setnull(lua_State *L) {
|
jbe@131
|
276 lua_settop(L, 2);
|
jbe@131
|
277 lua_pushvalue(L, JSON_UPVAL_METATABLE);
|
jbe@131
|
278 lua_setmetatable(L, 1);
|
jbe@131
|
279 lua_pushvalue(L, 1);
|
jbe@131
|
280 lua_rawget(L, JSON_UPVAL_SHADOWTBL);
|
jbe@131
|
281 if (lua_isnil(L, -1)) {
|
jbe@131
|
282 lua_newtable(L);
|
jbe@131
|
283 lua_pushvalue(L, 1);
|
jbe@131
|
284 lua_pushvalue(L, -2);
|
jbe@131
|
285 lua_rawset(L, JSON_UPVAL_SHADOWTBL);
|
jbe@131
|
286 }
|
jbe@131
|
287 lua_pushvalue(L, 2);
|
jbe@131
|
288 lua_pushvalue(L, JSON_UPVAL_NULLMARK);
|
jbe@131
|
289 lua_rawset(L, -3);
|
jbe@131
|
290 return 0;
|
jbe@131
|
291 }
|
jbe@131
|
292
|
jbe@130
|
293 static int json_len(lua_State *L) {
|
jbe@130
|
294 lua_settop(L, 1);
|
jbe@130
|
295 lua_pushvalue(L, 1);
|
jbe@130
|
296 lua_rawget(L, JSON_UPVAL_SHADOWTBL);
|
jbe@130
|
297 if (lua_isnil(L, -1)) lua_pop(L, 1);
|
jbe@130
|
298 lua_pushinteger(L, lua_rawlen(L, -1));
|
jbe@123
|
299 return 1;
|
jbe@123
|
300 }
|
jbe@123
|
301
|
jbe@130
|
302 static int json_index(lua_State *L) {
|
jbe@130
|
303 lua_settop(L, 2);
|
jbe@130
|
304 lua_pushvalue(L, 1);
|
jbe@130
|
305 lua_rawget(L, JSON_UPVAL_SHADOWTBL);
|
jbe@130
|
306 if (lua_isnil(L, -1)) return 1;
|
jbe@130
|
307 lua_pushvalue(L, 2);
|
jbe@130
|
308 lua_rawget(L, -2);
|
jbe@130
|
309 if (lua_rawequal(L, -1, JSON_UPVAL_NULLMARK)) lua_pushnil(L);
|
jbe@127
|
310 return 1;
|
jbe@127
|
311 }
|
jbe@127
|
312
|
jbe@130
|
313 static int json_newindex(lua_State *L) {
|
jbe@130
|
314 lua_settop(L, 3);
|
jbe@123
|
315 lua_pushvalue(L, 1);
|
jbe@130
|
316 lua_rawget(L, JSON_UPVAL_SHADOWTBL);
|
jbe@130
|
317 if (lua_isnil(L, -1)) return luaL_error(L, "Shadow table not found");
|
jbe@130
|
318 lua_replace(L, 1);
|
jbe@130
|
319 lua_rawset(L, 1);
|
jbe@121
|
320 return 1;
|
jbe@121
|
321 }
|
jbe@121
|
322
|
jbe@121
|
323 static const struct luaL_Reg json_module_functions[] = {
|
jbe@121
|
324 {"import", json_import},
|
jbe@130
|
325 {"get", json_get},
|
jbe@127
|
326 {"type", json_type},
|
jbe@123
|
327 {"isnull", json_isnull},
|
jbe@131
|
328 {"setnull", json_setnull},
|
jbe@121
|
329 {NULL, NULL}
|
jbe@121
|
330 };
|
jbe@121
|
331
|
jbe@126
|
332 static const struct luaL_Reg json_metatable_functions[] = {
|
jbe@130
|
333 {"__len", json_len},
|
jbe@130
|
334 {"__index", json_index},
|
jbe@130
|
335 {"__newindex", json_newindex},
|
jbe@126
|
336 {NULL, NULL}
|
jbe@126
|
337 };
|
jbe@126
|
338
|
jbe@121
|
339 int luaopen_json(lua_State *L) {
|
jbe@126
|
340 lua_settop(L, 0);
|
jbe@126
|
341 lua_newtable(L); // 1: library table on stack position
|
jbe@130
|
342 lua_newtable(L); // 2: table used as JSON NULL value in internal shadow tables
|
jbe@130
|
343 lua_newtable(L); // 3: ephemeron table to store shadow tables for each JSON object/array to allow NULL values returned as nil
|
jbe@130
|
344 lua_newtable(L); // 4: ephemeron table to store the type of the JSON object/array
|
jbe@130
|
345 lua_newtable(L); // 5: metatable for ephemeron tables
|
jbe@121
|
346 lua_pushliteral(L, "__mode");
|
jbe@121
|
347 lua_pushliteral(L, "k");
|
jbe@130
|
348 lua_rawset(L, 5);
|
jbe@130
|
349 lua_pushvalue(L, 5); // 6: cloned metatable reference
|
jbe@127
|
350 lua_setmetatable(L, 3);
|
jbe@130
|
351 lua_setmetatable(L, 4);
|
jbe@130
|
352 lua_newtable(L); // 5: metatable for JSON objects and JSON arrays
|
jbe@130
|
353 lua_pushvalue(L, 5);
|
jbe@126
|
354 lua_setfield(L, 1, "metatable");
|
jbe@126
|
355 lua_pushvalue(L, 2);
|
jbe@126
|
356 lua_pushvalue(L, 3);
|
jbe@127
|
357 lua_pushvalue(L, 4);
|
jbe@130
|
358 lua_pushvalue(L, 5);
|
jbe@130
|
359 luaL_setfuncs(L, json_metatable_functions, 4);
|
jbe@130
|
360 luaL_setfuncs(L, json_module_functions, 4);
|
jbe@121
|
361 return 1;
|
jbe@121
|
362 }
|