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annotate libraries/json/json.c @ 167:84497222db4e

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Decoding of unicode escapes in JSON strings
author jbe
date Fri Aug 01 02:31:13 2014 +0200 (2014-08-01)
parents 7885d1ae35ff
children e618ccd017a3
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@154 5 #include <math.h>
jbe@121 6
jbe@144 7 // maximum number of nested JSON values (objects and arrays):
jbe@150 8 // NOTE: The Lua reference states that the stack may typically contain at least
jbe@150 9 // "a few thousand elements". Since every nested level consumes
jbe@150 10 // 3 elements on the Lua stack (the object/array, its shadow table,
jbe@150 11 // a string key or a placeholder), we limit the number of nested levels
jbe@150 12 // to 500. If a stack overflow would still happen in the import function,
jbe@150 13 // this is detected nevertheless and an error is thrown (instead of
jbe@150 14 // returning nil and an error string).
jbe@150 15 #define JSON_MAXDEPTH 500
jbe@142 16
jbe@155 17 // generate dummy memory addresses that represents null values:
jbe@155 18 char json_nullmark;
jbe@155 19 #define json_isnullmark(L, i) (lua_touserdata((L), (i)) == &json_nullmark)
jbe@155 20 #define json_pushnullmark(L) lua_pushlightuserdata((L), &json_nullmark)
jbe@155 21
jbe@144 22 // macros for usage of Lua registry:
jbe@144 23 #define JSON_REGENT char
jbe@145 24 #define JSON_REGPOINTER void *
jbe@145 25 #define json_regpointer(x) (&json_registry.x)
jbe@151 26 #define json_regfetchpointer(L, x) lua_rawgetp((L), LUA_REGISTRYINDEX, (x))
jbe@151 27 #define json_regfetch(L, x) json_regfetchpointer(L, json_regpointer(x))
jbe@151 28 #define json_regstore(L, x) lua_rawsetp(L, LUA_REGISTRYINDEX, json_regpointer(x))
jbe@145 29
jbe@144 30 // generate dummy memory addresses that represent Lua objects
jbe@145 31 // via lightuserdata keys and LUA_REGISTRYINDEX:
jbe@144 32 static struct {
jbe@145 33 JSON_REGENT shadowtbl; // ephemeron table that maps tables to their corresponding shadow table
jbe@145 34 JSON_REGENT objectmt; // metatable for JSON objects
jbe@145 35 JSON_REGENT arraymt; // metatable for JSON arrays
jbe@144 36 } json_registry;
jbe@138 37
jbe@157 38 // returns the string "<JSON null marker>":
jbe@157 39 static int json_nullmark_tostring(lua_State *L) {
jbe@157 40 lua_pushliteral(L, "<JSON null marker>");
jbe@157 41 return 1;
jbe@157 42 }
jbe@157 43
jbe@145 44 // marks a Lua table as JSON object or JSON array:
jbe@136 45 // (returns its modified argument or a new table if argument is nil)
jbe@145 46 static int json_mark(lua_State *L, JSON_REGPOINTER mt) {
jbe@145 47 // check if argument is nil
jbe@136 48 if (lua_isnoneornil(L, 1)) {
jbe@145 49 // create new table at stack position 1:
jbe@136 50 lua_settop(L, 0);
jbe@136 51 lua_newtable(L);
jbe@145 52 // create shadow table (leaving previously created table on stack position 1):
jbe@144 53 json_regfetch(L, shadowtbl);
jbe@136 54 lua_pushvalue(L, 1);
jbe@136 55 lua_newtable(L);
jbe@143 56 lua_rawset(L, -3);
jbe@143 57 } else {
jbe@166 58 // require argument to be a table:
jbe@166 59 luaL_checktype(L, 1, LUA_TTABLE);
jbe@145 60 // push shadow table on top of stack:
jbe@144 61 json_regfetch(L, shadowtbl);
jbe@143 62 lua_pushvalue(L, 1);
jbe@143 63 lua_rawget(L, -2);
jbe@145 64 // if shadow table does not exist:
jbe@143 65 if (lua_isnil(L, -1)) {
jbe@145 66 // create shadow table and leave it on top of stack:
jbe@143 67 lua_newtable(L);
jbe@143 68 lua_pushvalue(L, 1);
jbe@143 69 lua_pushvalue(L, -2);
jbe@143 70 lua_rawset(L, -5);
jbe@143 71 }
jbe@145 72 // move elements from original table to shadow table (that's expected on top of stack):
jbe@143 73 for(lua_pushnil(L); lua_next(L, 1); lua_pop(L, 1)) {
jbe@143 74 lua_pushvalue(L, -2);
jbe@143 75 lua_pushnil(L);
jbe@143 76 lua_rawset(L, 1);
jbe@143 77 lua_pushvalue(L, -2);
jbe@143 78 lua_pushvalue(L, -2);
jbe@143 79 lua_rawset(L, -5);
jbe@143 80 }
jbe@136 81 }
jbe@138 82 // discard everything but table to return:
jbe@138 83 lua_settop(L, 1);
jbe@136 84 // set metatable:
jbe@145 85 json_regfetchpointer(L, mt);
jbe@136 86 lua_setmetatable(L, 1);
jbe@138 87 // return table:
jbe@136 88 return 1;
jbe@136 89 }
jbe@136 90
jbe@136 91 // marks a table as JSON object:
jbe@136 92 // (returns its modified argument or a new table if argument is nil)
jbe@136 93 static int json_object(lua_State *L) {
jbe@145 94 return json_mark(L, json_regpointer(objectmt));
jbe@136 95 }
jbe@136 96
jbe@136 97 // marks a table as JSON array:
jbe@136 98 // (returns its modified argument or a new table if argument is nil)
jbe@136 99 static int json_array(lua_State *L) {
jbe@145 100 return json_mark(L, json_regpointer(arraymt));
jbe@136 101 }
jbe@136 102
jbe@167 103 #define json_utf16_surrogate(x) ((x) >= 0xD800 && (x) <= 0xDFFF)
jbe@167 104 #define json_utf16_lead(x) ((x) >= 0xD800 && (x) <= 0xDBFF)
jbe@167 105 #define json_utf16_tail(x) ((x) >= 0xDC00 && (x) <= 0xDFFF)
jbe@167 106
jbe@145 107 // internal states of JSON parser:
jbe@124 108 #define JSON_STATE_VALUE 0
jbe@124 109 #define JSON_STATE_OBJECT_KEY 1
jbe@124 110 #define JSON_STATE_OBJECT_KEY_TERMINATOR 2
jbe@124 111 #define JSON_STATE_OBJECT_VALUE 3
jbe@124 112 #define JSON_STATE_OBJECT_SEPARATOR 4
jbe@124 113 #define JSON_STATE_ARRAY_VALUE 5
jbe@124 114 #define JSON_STATE_ARRAY_SEPARATOR 6
jbe@124 115 #define JSON_STATE_END 7
jbe@121 116
jbe@145 117 // special Lua stack indicies for json_import function:
jbe@138 118 #define json_import_objectmt_idx 2
jbe@138 119 #define json_import_arraymt_idx 3
jbe@138 120 #define json_import_shadowtbl_idx 4
jbe@138 121
jbe@167 122 // macro for hex decoding:
jbe@167 123 #define json_import_readhex(x) \
jbe@167 124 do { \
jbe@167 125 x = 0; \
jbe@167 126 for (i=0; i<4; i++) { \
jbe@167 127 x <<= 4; \
jbe@167 128 c = str[pos++]; \
jbe@167 129 if (c >= '0' && c <= '9') x += c - '0'; \
jbe@167 130 else if (c >= 'A' && c <= 'F') x += c - 'A' + 10; \
jbe@167 131 else if (c >= 'a' && c <= 'f') x += c - 'a' + 10; \
jbe@167 132 else if (c == 0) goto json_import_unexpected_eof; \
jbe@167 133 else goto json_import_unexpected_escape; \
jbe@167 134 } \
jbe@167 135 } while (0)
jbe@167 136
jbe@136 137 // decodes a JSON document:
jbe@121 138 static int json_import(lua_State *L) {
jbe@167 139 int i; // loop variable
jbe@136 140 const char *str; // string to parse
jbe@136 141 size_t total; // total length of string to parse
jbe@136 142 size_t pos = 0; // current position in string to parse
jbe@136 143 size_t level = 0; // nested levels of objects/arrays currently being processed
jbe@145 144 int mode = JSON_STATE_VALUE; // state of parser (i.e. "what's expected next?")
jbe@136 145 char c; // variable to store a single character to be processed
jbe@145 146 luaL_Buffer luabuf; // Lua buffer to decode JSON string values
jbe@145 147 char *cbuf; // C buffer to decode JSON string values
jbe@162 148 size_t outlen; // maximum length or write position of C buffer
jbe@167 149 long codepoint; // decoded UTF-16 character or higher codepoint
jbe@167 150 long utf16tail; // second decoded UTF-16 character (surrogate tail)
jbe@152 151 size_t arraylen; // variable to temporarily store the array length
jbe@166 152 // require string as argument and convert to C string with length information:
jbe@166 153 str = luaL_checklstring(L, 1, &total);
jbe@166 154 // if string contains a NULL byte, this is a syntax error
jbe@166 155 if (strlen(str) != total) goto json_import_syntax_error;
jbe@147 156 // stack shall contain one function argument:
jbe@138 157 lua_settop(L, 1);
jbe@147 158 // push objectmt onto stack position 2:
jbe@144 159 json_regfetch(L, objectmt);
jbe@147 160 // push arraymt onto stack position 3:
jbe@144 161 json_regfetch(L, arraymt);
jbe@147 162 // push shadowtbl onto stack position 4:
jbe@144 163 json_regfetch(L, shadowtbl);
jbe@136 164 // main loop of parser:
jbe@136 165 json_import_loop:
jbe@136 166 // skip whitespace and store next character in variable 'c':
jbe@146 167 while (c = str[pos],
jbe@146 168 c == ' ' ||
jbe@146 169 c == '\f' ||
jbe@146 170 c == '\n' ||
jbe@146 171 c == '\r' ||
jbe@146 172 c == '\t' ||
jbe@146 173 c == '\v'
jbe@146 174 ) pos++;
jbe@136 175 // switch statement to handle certain (single) characters:
jbe@121 176 switch (c) {
jbe@136 177 // handle end of JSON document:
jbe@121 178 case 0:
jbe@136 179 // if end of JSON document was expected, then return top element of stack as result:
jbe@124 180 if (mode == JSON_STATE_END) return 1;
jbe@136 181 // otherwise, the JSON document was malformed:
jbe@167 182 if (level == 0) {
jbe@167 183 lua_pushnil(L);
jbe@167 184 lua_pushliteral(L, "Empty string");
jbe@167 185 } else {
jbe@167 186 json_import_unexpected_eof:
jbe@167 187 lua_pushnil(L);
jbe@167 188 lua_pushliteral(L, "Unexpected end of JSON document");
jbe@167 189 }
jbe@121 190 return 2;
jbe@136 191 // new JSON object:
jbe@121 192 case '{':
jbe@136 193 // if a JSON object is not expected here, then return an error:
jbe@146 194 if (
jbe@146 195 mode != JSON_STATE_VALUE &&
jbe@146 196 mode != JSON_STATE_OBJECT_VALUE &&
jbe@146 197 mode != JSON_STATE_ARRAY_VALUE
jbe@146 198 ) goto json_import_syntax_error;
jbe@136 199 // create JSON object on stack:
jbe@136 200 lua_newtable(L);
jbe@136 201 // set metatable of JSON object:
jbe@138 202 lua_pushvalue(L, json_import_objectmt_idx);
jbe@125 203 lua_setmetatable(L, -2);
jbe@136 204 // create internal shadow table on stack:
jbe@136 205 lua_newtable(L);
jbe@146 206 // register internal shadow table:
jbe@123 207 lua_pushvalue(L, -2);
jbe@123 208 lua_pushvalue(L, -2);
jbe@138 209 lua_rawset(L, json_import_shadowtbl_idx);
jbe@146 210 // expect object key (or end of object) to follow:
jbe@136 211 mode = JSON_STATE_OBJECT_KEY;
jbe@146 212 // jump to common code for opening JSON object and JSON array:
jbe@142 213 goto json_import_open;
jbe@136 214 // new JSON array:
jbe@121 215 case '[':
jbe@136 216 // if a JSON array is not expected here, then return an error:
jbe@146 217 if (
jbe@146 218 mode != JSON_STATE_VALUE &&
jbe@146 219 mode != JSON_STATE_OBJECT_VALUE &&
jbe@146 220 mode != JSON_STATE_ARRAY_VALUE
jbe@146 221 ) goto json_import_syntax_error;
jbe@136 222 // create JSON array on stack:
jbe@136 223 lua_newtable(L);
jbe@136 224 // set metatable of JSON array:
jbe@138 225 lua_pushvalue(L, json_import_arraymt_idx);
jbe@125 226 lua_setmetatable(L, -2);
jbe@136 227 // create internal shadow table on stack:
jbe@136 228 lua_newtable(L);
jbe@146 229 // register internal shadow table:
jbe@123 230 lua_pushvalue(L, -2);
jbe@123 231 lua_pushvalue(L, -2);
jbe@138 232 lua_rawset(L, json_import_shadowtbl_idx);
jbe@140 233 // add nil as key (needed to keep stack balance) and as magic to detect arrays:
jbe@140 234 lua_pushnil(L);
jbe@146 235 // expect array value (or end of array) to follow:
jbe@142 236 mode = JSON_STATE_ARRAY_VALUE;
jbe@142 237 // continue with common code for opening JSON object and JSON array:
jbe@146 238 // common code for opening JSON object or JSON array:
jbe@142 239 json_import_open:
jbe@142 240 // limit nested levels:
jbe@142 241 if (level >= JSON_MAXDEPTH) {
jbe@142 242 lua_pushnil(L);
jbe@164 243 lua_pushfstring(L, "More than %d nested JSON levels", JSON_MAXDEPTH);
jbe@142 244 return 2;
jbe@142 245 }
jbe@142 246 // additional buffer overflow protection:
jbe@142 247 if (!lua_checkstack(L, LUA_MINSTACK))
jbe@142 248 return luaL_error(L, "Caught stack overflow in JSON import function (too many nested levels and stack size too small)");
jbe@136 249 // increment level:
jbe@121 250 level++;
jbe@142 251 // consume input character:
jbe@142 252 pos++;
jbe@121 253 goto json_import_loop;
jbe@136 254 // end of JSON object:
jbe@121 255 case '}':
jbe@136 256 // if end of JSON object is not expected here, then return an error:
jbe@146 257 if (
jbe@146 258 mode != JSON_STATE_OBJECT_KEY &&
jbe@146 259 mode != JSON_STATE_OBJECT_SEPARATOR
jbe@146 260 ) goto json_import_syntax_error;
jbe@136 261 // jump to common code for end of JSON object and JSON array:
jbe@121 262 goto json_import_close;
jbe@136 263 // end of JSON array:
jbe@121 264 case ']':
jbe@136 265 // if end of JSON array is not expected here, then return an error:
jbe@146 266 if (
jbe@146 267 mode != JSON_STATE_ARRAY_VALUE &&
jbe@146 268 mode != JSON_STATE_ARRAY_SEPARATOR
jbe@146 269 ) goto json_import_syntax_error;
jbe@146 270 // pop nil key/magic (that was needed to keep stack balance):
jbe@140 271 lua_pop(L, 1);
jbe@136 272 // continue with common code for end of JSON object and JSON array:
jbe@136 273 // common code for end of JSON object or JSON array:
jbe@121 274 json_import_close:
jbe@136 275 // consume input character:
jbe@121 276 pos++;
jbe@136 277 // pop shadow table:
jbe@136 278 lua_pop(L, 1);
jbe@136 279 // check if nested:
jbe@121 280 if (--level) {
jbe@146 281 // if nested,
jbe@146 282 // check if outer(!) structure is an array or object:
jbe@140 283 if (lua_isnil(L, -2)) {
jbe@136 284 // select array value processing:
jbe@124 285 mode = JSON_STATE_ARRAY_VALUE;
jbe@121 286 } else {
jbe@136 287 // select object value processing:
jbe@124 288 mode = JSON_STATE_OBJECT_VALUE;
jbe@121 289 }
jbe@136 290 // store value in outer structure:
jbe@121 291 goto json_import_process_value;
jbe@121 292 }
jbe@136 293 // if not nested, then expect end of JSON document and continue with loop:
jbe@136 294 mode = JSON_STATE_END;
jbe@121 295 goto json_import_loop;
jbe@136 296 // key terminator:
jbe@121 297 case ':':
jbe@136 298 // if key terminator is not expected here, then return an error:
jbe@124 299 if (mode != JSON_STATE_OBJECT_KEY_TERMINATOR)
jbe@121 300 goto json_import_syntax_error;
jbe@136 301 // consume input character:
jbe@121 302 pos++;
jbe@146 303 // expect object value to follow:
jbe@124 304 mode = JSON_STATE_OBJECT_VALUE;
jbe@146 305 // continue with loop:
jbe@121 306 goto json_import_loop;
jbe@136 307 // value terminator (NOTE: trailing comma at end of value or key-value list is tolerated by this parser)
jbe@121 308 case ',':
jbe@146 309 // branch according to parser state:
jbe@124 310 if (mode == JSON_STATE_OBJECT_SEPARATOR) {
jbe@146 311 // expect an object key to follow:
jbe@124 312 mode = JSON_STATE_OBJECT_KEY;
jbe@124 313 } else if (mode == JSON_STATE_ARRAY_SEPARATOR) {
jbe@146 314 // expect an array value to follow:
jbe@124 315 mode = JSON_STATE_ARRAY_VALUE;
jbe@121 316 } else {
jbe@136 317 // if value terminator is not expected here, then return an error:
jbe@136 318 goto json_import_syntax_error;
jbe@121 319 }
jbe@136 320 // consume input character:
jbe@121 321 pos++;
jbe@136 322 // continue with loop:
jbe@121 323 goto json_import_loop;
jbe@136 324 // string literal:
jbe@121 325 case '"':
jbe@146 326 // consume quote character:
jbe@146 327 pos++;
jbe@162 328 // find last character in input string:
jbe@162 329 outlen = pos;
jbe@162 330 while ((c = str[outlen]) != '"') {
jbe@161 331 // consume one character:
jbe@162 332 outlen++;
jbe@161 333 // handle unexpected end of JSON document:
jbe@161 334 if (c == 0) goto json_import_unexpected_eof;
jbe@161 335 // consume one extra character when encountering an escaped quote:
jbe@162 336 else if (c == '\\' && str[outlen] == '"') outlen++;
jbe@161 337 }
jbe@162 338 // determine buffer length:
jbe@162 339 outlen -= pos;
jbe@161 340 // check if string is non empty:
jbe@162 341 if (outlen) {
jbe@161 342 // prepare buffer to decode string (with maximum possible length) and set write position to zero:
jbe@162 343 cbuf = luaL_buffinitsize(L, &luabuf, outlen);
jbe@162 344 outlen = 0;
jbe@161 345 // loop through the characters until encountering end quote:
jbe@161 346 while ((c = str[pos++]) != '"') {
jbe@162 347 // NOTE: unexpected end cannot happen anymore
jbe@162 348 if (c < 32 || c == 127) {
jbe@161 349 // do not allow ASCII control characters:
jbe@161 350 // NOTE: illegal UTF-8 sequences and extended control characters are not sanitized
jbe@161 351 // by this parser to allow different encodings than Unicode
jbe@161 352 lua_pushnil(L);
jbe@161 353 lua_pushliteral(L, "Unexpected control character in JSON string");
jbe@161 354 return 2;
jbe@161 355 } else if (c == '\\') {
jbe@161 356 // read next char after backslash escape:
jbe@161 357 c = str[pos++];
jbe@161 358 switch (c) {
jbe@161 359 // unexpected end-of-string:
jbe@161 360 case 0:
jbe@161 361 goto json_import_unexpected_eof;
jbe@161 362 // unescaping of quotation mark, slash, and backslash:
jbe@161 363 case '"':
jbe@161 364 case '/':
jbe@161 365 case '\\':
jbe@162 366 cbuf[outlen++] = c;
jbe@161 367 break;
jbe@161 368 // unescaping of backspace:
jbe@162 369 case 'b': cbuf[outlen++] = '\b'; break;
jbe@161 370 // unescaping of form-feed:
jbe@162 371 case 'f': cbuf[outlen++] = '\f'; break;
jbe@161 372 // unescaping of new-line:
jbe@162 373 case 'n': cbuf[outlen++] = '\n'; break;
jbe@161 374 // unescaping of carriage-return:
jbe@162 375 case 'r': cbuf[outlen++] = '\r'; break;
jbe@161 376 // unescaping of tabulator:
jbe@162 377 case 't': cbuf[outlen++] = '\t'; break;
jbe@161 378 // unescaping of UTF-16 characters
jbe@161 379 case 'u':
jbe@167 380 // decode 4 hex nibbles:
jbe@167 381 json_import_readhex(codepoint);
jbe@167 382 // handle surrogate character:
jbe@167 383 if (json_utf16_surrogate(codepoint)) {
jbe@167 384 // check if first surrogate is in valid range:
jbe@167 385 if (json_utf16_lead(codepoint)) {
jbe@167 386 // require second surrogate:
jbe@167 387 if ((c = str[pos++]) != '\\' || (c = str[pos++]) != 'u') {
jbe@167 388 if (c == 0) goto json_import_unexpected_eof;
jbe@167 389 else goto json_import_wrong_surrogate;
jbe@167 390 }
jbe@167 391 // read 4 hex nibbles of second surrogate character:
jbe@167 392 json_import_readhex(utf16tail);
jbe@167 393 // check if second surrogate is in valid range:
jbe@167 394 if (!json_utf16_tail(utf16tail)) goto json_import_wrong_surrogate;
jbe@167 395 // calculate codepoint:
jbe@167 396 codepoint = 0x10000 + (utf16tail - 0xDC00) + (codepoint - 0xD800) * 0x400;
jbe@167 397 } else {
jbe@167 398 // throw error for wrong surrogates:
jbe@167 399 json_import_wrong_surrogate:
jbe@167 400 lua_pushnil(L);
jbe@167 401 lua_pushliteral(L, "Illegal UTF-16 surrogate in JSON string escape sequence");
jbe@167 402 return 2;
jbe@167 403 }
jbe@167 404 }
jbe@167 405 // encode as UTF-8:
jbe@167 406 if (codepoint < 0x80) {
jbe@167 407 cbuf[outlen++] = (char)codepoint;
jbe@167 408 } else if (codepoint < 0x800) {
jbe@167 409 cbuf[outlen++] = (char)(0xc0 | (codepoint >> 6));
jbe@167 410 cbuf[outlen++] = (char)(0x80 | (codepoint & 0x3f));
jbe@167 411 } else if (codepoint < 0x10000) {
jbe@167 412 cbuf[outlen++] = (char)(0xe0 | (codepoint >> 12));
jbe@167 413 cbuf[outlen++] = (char)(0x80 | ((codepoint >> 6) & 0x3f));
jbe@167 414 cbuf[outlen++] = (char)(0x80 | (codepoint & 0x3f));
jbe@167 415 } else {
jbe@167 416 cbuf[outlen++] = (char)(0xf0 | (codepoint >> 18));
jbe@167 417 cbuf[outlen++] = (char)(0x80 | ((codepoint >> 12) & 0x3f));
jbe@167 418 cbuf[outlen++] = (char)(0x80 | ((codepoint >> 6) & 0x3f));
jbe@167 419 cbuf[outlen++] = (char)(0x80 | (codepoint & 0x3f));
jbe@167 420 }
jbe@167 421 break;
jbe@161 422 // unexpected escape sequence:
jbe@161 423 default:
jbe@167 424 json_import_unexpected_escape:
jbe@161 425 lua_pushnil(L);
jbe@161 426 lua_pushliteral(L, "Unexpected string escape sequence in JSON document");
jbe@161 427 return 2;
jbe@161 428 }
jbe@161 429 } else {
jbe@161 430 // normal character:
jbe@162 431 cbuf[outlen++] = c;
jbe@121 432 }
jbe@121 433 }
jbe@161 434 // process buffer to Lua string:
jbe@162 435 luaL_pushresultsize(&luabuf, outlen);
jbe@161 436 } else {
jbe@161 437 // if JSON string is empty,
jbe@161 438 // push empty Lua string:
jbe@161 439 lua_pushliteral(L, "");
jbe@167 440 // consume closing quote:
jbe@167 441 pos++;
jbe@121 442 }
jbe@136 443 // continue with processing of decoded string:
jbe@121 444 goto json_import_process_value;
jbe@121 445 }
jbe@136 446 // process values whose type is is not deducible from a single character:
jbe@136 447 if ((c >= '0' && c <= '9') || c == '-' || c == '+') {
jbe@146 448 // for numbers,
jbe@146 449 // use strtod() call to parse a (double precision) floating point number:
jbe@167 450 double numval;
jbe@122 451 char *endptr;
jbe@122 452 numval = strtod(str+pos, &endptr);
jbe@146 453 // catch parsing errors:
jbe@122 454 if (endptr == str+pos) goto json_import_syntax_error;
jbe@146 455 // consume characters that were parsed:
jbe@122 456 pos += endptr - (str+pos);
jbe@146 457 // push parsed (double precision) floating point number on Lua stack:
jbe@122 458 lua_pushnumber(L, numval);
jbe@122 459 } else if (!strncmp(str+pos, "true", 4)) {
jbe@136 460 // consume 4 input characters for "true":
jbe@121 461 pos += 4;
jbe@147 462 // put Lua true value onto stack:
jbe@136 463 lua_pushboolean(L, 1);
jbe@121 464 } else if (!strncmp(str+pos, "false", 5)) {
jbe@136 465 // consume 5 input characters for "false":
jbe@121 466 pos += 5;
jbe@147 467 // put Lua false value onto stack:
jbe@136 468 lua_pushboolean(L, 0);
jbe@121 469 } else if (!strncmp(str+pos, "null", 4)) {
jbe@136 470 // consume 4 input characters for "null":
jbe@136 471 pos += 4;
jbe@153 472 // different behavor for top-level and sub-levels:
jbe@153 473 if (level) {
jbe@153 474 // if sub-level,
jbe@153 475 // push special null-marker onto stack:
jbe@155 476 json_pushnullmark(L);
jbe@153 477 } else {
jbe@153 478 // if top-level,
jbe@153 479 // push nil onto stack:
jbe@153 480 lua_pushnil(L);
jbe@153 481 }
jbe@121 482 } else {
jbe@136 483 // all other cases are a syntax error:
jbe@121 484 goto json_import_syntax_error;
jbe@121 485 }
jbe@136 486 // process a decoded value or key value pair (expected on top of Lua stack):
jbe@136 487 json_import_process_value:
jbe@121 488 switch (mode) {
jbe@136 489 // an object key has been read:
jbe@124 490 case JSON_STATE_OBJECT_KEY:
jbe@136 491 // if an object key is not a string, then this is a syntax error:
jbe@121 492 if (lua_type(L, -1) != LUA_TSTRING) goto json_import_syntax_error;
jbe@146 493 // expect key terminator to follow:
jbe@124 494 mode = JSON_STATE_OBJECT_KEY_TERMINATOR;
jbe@146 495 // continue with loop:
jbe@121 496 goto json_import_loop;
jbe@136 497 // a key value pair has been read:
jbe@124 498 case JSON_STATE_OBJECT_VALUE:
jbe@136 499 // store key value pair in outer shadow table:
jbe@130 500 lua_rawset(L, -3);
jbe@146 501 // expect value terminator (or end of object) to follow:
jbe@124 502 mode = JSON_STATE_OBJECT_SEPARATOR;
jbe@146 503 // continue with loop:
jbe@121 504 goto json_import_loop;
jbe@136 505 // an array value has been read:
jbe@124 506 case JSON_STATE_ARRAY_VALUE:
jbe@152 507 // get current array length:
jbe@152 508 arraylen = lua_rawlen(L, -3);
jbe@152 509 // throw error if array would exceed INT_MAX elements:
jbe@152 510 // TODO: Lua 5.3 may support more elements
jbe@152 511 if (arraylen >= INT_MAX) {
jbe@152 512 lua_pushnil(L);
jbe@152 513 lua_pushfstring(L, "Array exceeded length of %d elements", INT_MAX);
jbe@152 514 }
jbe@136 515 // store value in outer shadow table:
jbe@152 516 lua_rawseti(L, -3, arraylen + 1);
jbe@146 517 // expect value terminator (or end of object) to follow:
jbe@124 518 mode = JSON_STATE_ARRAY_SEPARATOR;
jbe@146 519 // continue with loop
jbe@121 520 goto json_import_loop;
jbe@136 521 // a single value has been read:
jbe@124 522 case JSON_STATE_VALUE:
jbe@136 523 // leave value on top of stack, expect end of JSON document, and continue with loop:
jbe@124 524 mode = JSON_STATE_END;
jbe@121 525 goto json_import_loop;
jbe@121 526 }
jbe@146 527 // syntax error handling (reachable by goto statement):
jbe@136 528 json_import_syntax_error:
jbe@121 529 lua_pushnil(L);
jbe@121 530 lua_pushliteral(L, "Syntax error in JSON document");
jbe@121 531 return 2;
jbe@121 532 }
jbe@121 533
jbe@146 534 // special Lua stack indicies for json_path function:
jbe@138 535 #define json_path_shadowtbl_idx 1
jbe@146 536
jbe@146 537 // stack offset of arguments to json_path function:
jbe@155 538 #define json_path_idxshift 1
jbe@138 539
jbe@146 540 // gets a value or its type from a JSON document (passed as first argument)
jbe@147 541 // using a path (passed as variable number of keys after first argument):
jbe@137 542 static int json_path(lua_State *L, int type_mode) {
jbe@146 543 int stacktop; // stack index of top of stack (after shifting)
jbe@146 544 int idx = 2 + json_path_idxshift; // stack index of current argument to process
jbe@148 545 // insert shadowtbl into stack at position 1 (shifting the arguments):
jbe@144 546 json_regfetch(L, shadowtbl);
jbe@138 547 lua_insert(L, 1);
jbe@146 548 // store stack index of top of stack:
jbe@138 549 stacktop = lua_gettop(L);
jbe@146 550 // use first argument as "current value" (stored on top of stack):
jbe@138 551 lua_pushvalue(L, 1 + json_path_idxshift);
jbe@146 552 // process each "path key" (2nd argument and following arguments):
jbe@138 553 while (idx <= stacktop) {
jbe@146 554 // if "current value" (on top of stack) is nil, then the path cannot be walked and nil is returned:
jbe@137 555 if (lua_isnil(L, -1)) return 1;
jbe@137 556 // try to get shadow table of "current value":
jbe@130 557 lua_pushvalue(L, -1);
jbe@138 558 lua_rawget(L, json_path_shadowtbl_idx);
jbe@126 559 if (lua_isnil(L, -1)) {
jbe@137 560 // if no shadow table is found,
jbe@130 561 if (lua_type(L, -1) == LUA_TTABLE) {
jbe@146 562 // and if "current value" is a table,
jbe@146 563 // drop nil from stack:
jbe@146 564 lua_pop(L, 1);
jbe@137 565 // get "next value" using the "path key":
jbe@130 566 lua_pushvalue(L, idx++);
jbe@130 567 lua_gettable(L, -2);
jbe@130 568 } else {
jbe@137 569 // if "current value" is not a table,
jbe@146 570 // then the path cannot be walked and nil (already on top of stack) is returned:
jbe@137 571 return 1;
jbe@130 572 }
jbe@130 573 } else {
jbe@137 574 // if a shadow table is found,
jbe@137 575 // set "current value" to its shadow table:
jbe@130 576 lua_replace(L, -2);
jbe@137 577 // get "next value" using the "path key":
jbe@130 578 lua_pushvalue(L, idx++);
jbe@130 579 lua_rawget(L, -2);
jbe@126 580 }
jbe@137 581 // the "next value" replaces the "current value":
jbe@130 582 lua_replace(L, -2);
jbe@126 583 }
jbe@137 584 if (!type_mode) {
jbe@137 585 // if a value (and not its type) was requested,
jbe@137 586 // check if value is the null-marker, and store nil on top of Lua stack in that case:
jbe@155 587 if (json_isnullmark(L, -1)) lua_pushnil(L);
jbe@137 588 } else {
jbe@137 589 // if the type was requested,
jbe@137 590 // check if value is the null-marker:
jbe@155 591 if (json_isnullmark(L, -1)) {
jbe@137 592 // if yes, store string "null" on top of Lua stack:
jbe@130 593 lua_pushliteral(L, "null");
jbe@137 594 } else {
jbe@137 595 // otherwise,
jbe@138 596 // check if metatable indicates "object" or "array":
jbe@138 597 if (lua_getmetatable(L, -1)) {
jbe@144 598 json_regfetch(L, objectmt);
jbe@138 599 if (lua_rawequal(L, -2, -1)) {
jbe@146 600 // if value has metatable for JSON objects,
jbe@138 601 // return string "object":
jbe@138 602 lua_pushliteral(L, "object");
jbe@138 603 return 1;
jbe@138 604 }
jbe@144 605 json_regfetch(L, arraymt);
jbe@138 606 if (lua_rawequal(L, -3, -1)) {
jbe@146 607 // if value has metatable for JSON arrays,
jbe@146 608 // return string "object":
jbe@138 609 lua_pushliteral(L, "array");
jbe@138 610 return 1;
jbe@138 611 }
jbe@146 612 // remove 3 metatables (one of the value, two for comparison) from stack:
jbe@138 613 lua_pop(L, 3);
jbe@138 614 }
jbe@138 615 // otherwise, get the Lua type:
jbe@138 616 lua_pushstring(L, lua_typename(L, lua_type(L, -1)));
jbe@126 617 }
jbe@126 618 }
jbe@137 619 // return the top most value on the Lua stack:
jbe@137 620 return 1;
jbe@130 621 }
jbe@130 622
jbe@147 623 // gets a value from a JSON document (passed as first argument)
jbe@147 624 // using a path (passed as variable number of keys after first argument):
jbe@130 625 static int json_get(lua_State *L) {
jbe@137 626 return json_path(L, 0);
jbe@130 627 }
jbe@130 628
jbe@147 629 // gets a value's type from a JSON document (passed as first argument)
jbe@147 630 // using a path (variable number of keys after first argument):
jbe@130 631 static int json_type(lua_State *L) {
jbe@137 632 return json_path(L, 1);
jbe@130 633 }
jbe@130 634
jbe@147 635 // returns the length of a JSON array (or zero for a table without numeric keys):
jbe@130 636 static int json_len(lua_State *L) {
jbe@147 637 // stack shall contain one function argument:
jbe@130 638 lua_settop(L, 1);
jbe@148 639 // try to get corresponding shadow table for first argument:
jbe@144 640 json_regfetch(L, shadowtbl);
jbe@130 641 lua_pushvalue(L, 1);
jbe@138 642 lua_rawget(L, -2);
jbe@147 643 // if shadow table does not exist, return length of argument, else length of shadow table:
jbe@147 644 lua_pushnumber(L, lua_rawlen(L, lua_isnil(L, -1) ? 1 : -1));
jbe@123 645 return 1;
jbe@123 646 }
jbe@123 647
jbe@130 648 static int json_index(lua_State *L) {
jbe@148 649 // stack shall contain two function arguments:
jbe@130 650 lua_settop(L, 2);
jbe@155 651 // get corresponding shadow table for first argument:
jbe@144 652 json_regfetch(L, shadowtbl);
jbe@130 653 lua_pushvalue(L, 1);
jbe@155 654 lua_rawget(L, -2);
jbe@148 655 // throw error if no shadow table was found:
jbe@139 656 if (lua_isnil(L, -1)) return luaL_error(L, "Shadow table not found");
jbe@148 657 // use key passed as second argument to lookup value in shadow table:
jbe@130 658 lua_pushvalue(L, 2);
jbe@130 659 lua_rawget(L, -2);
jbe@148 660 // if value is null-marker, then push nil onto stack:
jbe@155 661 if (json_isnullmark(L, -1)) lua_pushnil(L);
jbe@148 662 // return either looked up value, or nil
jbe@127 663 return 1;
jbe@127 664 }
jbe@127 665
jbe@130 666 static int json_newindex(lua_State *L) {
jbe@148 667 // stack shall contain three function arguments:
jbe@130 668 lua_settop(L, 3);
jbe@148 669 // get corresponding shadow table for first argument:
jbe@144 670 json_regfetch(L, shadowtbl);
jbe@123 671 lua_pushvalue(L, 1);
jbe@143 672 lua_rawget(L, -2);
jbe@148 673 // throw error if no shadow table was found:
jbe@130 674 if (lua_isnil(L, -1)) return luaL_error(L, "Shadow table not found");
jbe@148 675 // replace first argument with shadow table:
jbe@130 676 lua_replace(L, 1);
jbe@148 677 // reset stack and use second and third argument to write to shadow table:
jbe@139 678 lua_settop(L, 3);
jbe@130 679 lua_rawset(L, 1);
jbe@148 680 // return nothing:
jbe@148 681 return 0;
jbe@121 682 }
jbe@121 683
jbe@135 684 static int json_pairs_iterfunc(lua_State *L) {
jbe@149 685 // stack shall contain two function arguments:
jbe@135 686 lua_settop(L, 2);
jbe@155 687 // get corresponding shadow table for first argument:
jbe@144 688 json_regfetch(L, shadowtbl);
jbe@135 689 lua_pushvalue(L, 1);
jbe@155 690 lua_rawget(L, -2);
jbe@149 691 // throw error if no shadow table was found:
jbe@135 692 if (lua_isnil(L, -1)) return luaL_error(L, "Shadow table not found");
jbe@149 693 // get next key value pair from shadow table (using previous key from argument 2)
jbe@149 694 // and return nothing if there is no next pair:
jbe@135 695 lua_pushvalue(L, 2);
jbe@135 696 if (!lua_next(L, -2)) return 0;
jbe@149 697 // replace null-marker with nil:
jbe@155 698 if (json_isnullmark(L, -1)) {
jbe@135 699 lua_pop(L, 1);
jbe@135 700 lua_pushnil(L);
jbe@135 701 }
jbe@149 702 // return key and value (or key and nil, if null-marker was found):
jbe@135 703 return 2;
jbe@135 704 }
jbe@135 705
jbe@149 706 // returns a triple such that 'for key, value in pairs(obj) do ... end'
jbe@149 707 // iterates through all key value pairs (including JSON null keys represented as Lua nil):
jbe@135 708 static int json_pairs(lua_State *L) {
jbe@149 709 // return triple of function json_pairs_iterfunc, first argument, and nil:
jbe@139 710 lua_pushcfunction(L, json_pairs_iterfunc);
jbe@135 711 lua_pushvalue(L, 1);
jbe@135 712 lua_pushnil(L);
jbe@135 713 return 3;
jbe@135 714 }
jbe@135 715
jbe@134 716 static int json_ipairs_iterfunc(lua_State *L) {
jbe@152 717 lua_Integer idx;
jbe@149 718 // stack shall contain two function arguments:
jbe@134 719 lua_settop(L, 2);
jbe@149 720 // calculate new index by incrementing second argument:
jbe@134 721 idx = lua_tointeger(L, 2) + 1;
jbe@149 722 // get corresponding shadow table for first argument:
jbe@155 723 json_regfetch(L, shadowtbl);
jbe@134 724 lua_pushvalue(L, 1);
jbe@155 725 lua_rawget(L, -2);
jbe@149 726 // throw error if no shadow table was found:
jbe@134 727 if (lua_isnil(L, -1)) return luaL_error(L, "Shadow table not found");
jbe@149 728 // do integer lookup in shadow table:
jbe@134 729 lua_rawgeti(L, -1, idx);
jbe@149 730 // return nothing if there was no value:
jbe@134 731 if (lua_isnil(L, -1)) return 0;
jbe@149 732 // return new index and
jbe@149 733 // either the looked up value if it is not equal to the null-marker
jbe@149 734 // or nil instead of null-marker:
jbe@134 735 lua_pushinteger(L, idx);
jbe@155 736 if (json_isnullmark(L, -2)) lua_pushnil(L);
jbe@134 737 else lua_pushvalue(L, -2);
jbe@134 738 return 2;
jbe@134 739 }
jbe@134 740
jbe@149 741 // returns a triple such that 'for idx, value in ipairs(ary) do ... end'
jbe@149 742 // iterates through all values (including JSON null represented as Lua nil):
jbe@134 743 static int json_ipairs(lua_State *L) {
jbe@149 744 // return triple of function json_ipairs_iterfunc, first argument, and zero:
jbe@139 745 lua_pushcfunction(L, json_ipairs_iterfunc);
jbe@134 746 lua_pushvalue(L, 1);
jbe@134 747 lua_pushinteger(L, 0);
jbe@134 748 return 3;
jbe@134 749 }
jbe@134 750
jbe@163 751 typedef struct {
jbe@163 752 size_t length;
jbe@163 753 const char *data;
jbe@163 754 } json_key_t;
jbe@163 755
jbe@163 756 static int json_key_cmp(json_key_t *key1, json_key_t *key2) {
jbe@163 757 size_t pos = 0;
jbe@163 758 unsigned char c1, c2;
jbe@163 759 while (1) {
jbe@163 760 if (key1->length > pos) {
jbe@163 761 if (key2->length > pos) {
jbe@163 762 c1 = key1->data[pos];
jbe@163 763 c2 = key2->data[pos];
jbe@163 764 if (c1 < c2) return -1;
jbe@163 765 else if (c1 > c2) return 1;
jbe@163 766 } else {
jbe@163 767 return 1;
jbe@163 768 }
jbe@163 769 } else {
jbe@163 770 if (key2->length > pos) {
jbe@163 771 return -1;
jbe@163 772 } else {
jbe@163 773 return 0;
jbe@163 774 }
jbe@163 775 }
jbe@163 776 pos++;
jbe@163 777 }
jbe@163 778 }
jbe@163 779
jbe@154 780 #define JSON_TABLETYPE_UNKNOWN 0
jbe@154 781 #define JSON_TABLETYPE_OBJECT 1
jbe@154 782 #define JSON_TABLETYPE_ARRAY 2
jbe@154 783
jbe@164 784 #define json_export_internal_indentstring_idx 1
jbe@164 785 #define json_export_internal_level_idx 2
jbe@164 786 #define json_export_internal_value_idx 3
jbe@164 787 #define json_export_internal_tmp_idx 4
jbe@164 788
jbe@164 789 static int json_export_internal(lua_State *L) {
jbe@164 790 int level;
jbe@164 791 int pretty;
jbe@164 792 int i;
jbe@154 793 lua_Number num;
jbe@154 794 const char *str;
jbe@154 795 unsigned char c;
jbe@154 796 size_t strlen;
jbe@154 797 size_t pos = 0;
jbe@154 798 luaL_Buffer buf;
jbe@154 799 char hexcode[7]; // backslash, character 'u', 4 hex digits, and terminating NULL byte
jbe@154 800 int tabletype = JSON_TABLETYPE_UNKNOWN;
jbe@164 801 int anyelement = 0;
jbe@163 802 size_t keycount = 0;
jbe@163 803 size_t keypos = 0;
jbe@165 804 json_key_t *keybuf = NULL;
jbe@154 805 lua_Integer idx;
jbe@164 806 lua_settop(L, json_export_internal_value_idx);
jbe@164 807 if (json_isnullmark(L, json_export_internal_value_idx)) {
jbe@164 808 lua_pop(L, 1);
jbe@157 809 lua_pushnil(L);
jbe@157 810 }
jbe@164 811 switch (lua_type(L, json_export_internal_value_idx)) {
jbe@154 812 case LUA_TNIL:
jbe@154 813 lua_pushliteral(L, "null");
jbe@154 814 return 1;
jbe@154 815 case LUA_TNUMBER:
jbe@164 816 num = lua_tonumber(L, json_export_internal_value_idx);
jbe@154 817 if (isnan(num)) return luaL_error(L, "JSON export not possible for NaN value");
jbe@154 818 if (isinf(num)) return luaL_error(L, "JSON export not possible for infinite numbers");
jbe@164 819 lua_tostring(L, json_export_internal_value_idx);
jbe@154 820 return 1;
jbe@154 821 case LUA_TBOOLEAN:
jbe@164 822 if (lua_toboolean(L, json_export_internal_value_idx)) {
jbe@164 823 lua_pushliteral(L, "true");
jbe@164 824 } else {
jbe@164 825 lua_pushliteral(L, "false");
jbe@164 826 }
jbe@154 827 return 1;
jbe@154 828 case LUA_TSTRING:
jbe@164 829 str = lua_tolstring(L, 3, &strlen);
jbe@154 830 luaL_buffinit(L, &buf);
jbe@154 831 luaL_addchar(&buf, '"');
jbe@154 832 while (pos < strlen) {
jbe@154 833 c = str[pos++];
jbe@154 834 if (c == '"') luaL_addstring(&buf, "\\\"");
jbe@154 835 else if (c == '\\') luaL_addstring(&buf, "\\\\");
jbe@154 836 else if (c == 127) luaL_addstring(&buf, "\\u007F");
jbe@154 837 else if (c >= 32) luaL_addchar(&buf, c);
jbe@154 838 else if (c == '\b') luaL_addstring(&buf, "\\b");
jbe@154 839 else if (c == '\f') luaL_addstring(&buf, "\\f");
jbe@154 840 else if (c == '\n') luaL_addstring(&buf, "\\n");
jbe@154 841 else if (c == '\r') luaL_addstring(&buf, "\\r");
jbe@154 842 else if (c == '\t') luaL_addstring(&buf, "\\t");
jbe@154 843 else if (c == '\v') luaL_addstring(&buf, "\\v");
jbe@154 844 else {
jbe@154 845 sprintf(hexcode, "\\u%04X", c);
jbe@154 846 luaL_addstring(&buf, hexcode);
jbe@154 847 }
jbe@154 848 }
jbe@154 849 luaL_addchar(&buf, '"');
jbe@154 850 luaL_pushresult(&buf);
jbe@154 851 return 1;
jbe@154 852 case LUA_TTABLE:
jbe@164 853 if (lua_getmetatable(L, json_export_internal_value_idx)) {
jbe@154 854 json_regfetch(L, objectmt);
jbe@154 855 if (lua_rawequal(L, -2, -1)) {
jbe@154 856 tabletype = JSON_TABLETYPE_OBJECT;
jbe@154 857 } else {
jbe@154 858 json_regfetch(L, arraymt);
jbe@164 859 if (lua_rawequal(L, -3, -1)) {
jbe@164 860 tabletype = JSON_TABLETYPE_ARRAY;
jbe@164 861 } else {
jbe@164 862 return luaL_error(L, "JSON export not possible for tables with nonsupported metatable");
jbe@164 863 }
jbe@154 864 }
jbe@154 865 }
jbe@154 866 json_regfetch(L, shadowtbl);
jbe@164 867 lua_pushvalue(L, json_export_internal_value_idx);
jbe@154 868 lua_rawget(L, -2);
jbe@164 869 if (!lua_isnil(L, -1)) lua_replace(L, json_export_internal_value_idx);
jbe@164 870 lua_settop(L, json_export_internal_value_idx);
jbe@154 871 if (tabletype == JSON_TABLETYPE_UNKNOWN) {
jbe@164 872 for (lua_pushnil(L); lua_next(L, json_export_internal_value_idx); lua_pop(L, 1)) {
jbe@164 873 switch (lua_type(L, -2)) {
jbe@164 874 case LUA_TSTRING:
jbe@164 875 keycount++;
jbe@164 876 if (tabletype == JSON_TABLETYPE_UNKNOWN) tabletype = JSON_TABLETYPE_OBJECT;
jbe@164 877 else if (tabletype == JSON_TABLETYPE_ARRAY) goto json_export_tabletype_error;
jbe@164 878 break;
jbe@164 879 case LUA_TNUMBER:
jbe@164 880 if (tabletype == JSON_TABLETYPE_UNKNOWN) tabletype = JSON_TABLETYPE_ARRAY;
jbe@164 881 else if (tabletype == JSON_TABLETYPE_OBJECT) goto json_export_tabletype_error;
jbe@164 882 break;
jbe@154 883 }
jbe@154 884 }
jbe@154 885 }
jbe@164 886 pretty = lua_toboolean(L, json_export_internal_indentstring_idx);
jbe@164 887 level = lua_tointeger(L, json_export_internal_level_idx) + 1;
jbe@164 888 if (level > JSON_MAXDEPTH) {
jbe@164 889 return luaL_error(L, "More than %d nested JSON levels", JSON_MAXDEPTH);
jbe@164 890 }
jbe@154 891 switch (tabletype) {
jbe@154 892 case JSON_TABLETYPE_OBJECT:
jbe@164 893 if (!keycount) {
jbe@164 894 for (lua_pushnil(L); lua_next(L, json_export_internal_value_idx); lua_pop(L, 1)) {
jbe@164 895 if (lua_type(L, -2) == LUA_TSTRING) keycount++;
jbe@164 896 }
jbe@163 897 }
jbe@163 898 if (keycount) {
jbe@163 899 keybuf = calloc(keycount, sizeof(json_key_t));
jbe@163 900 if (!keybuf) return luaL_error(L, "Memory allocation failed in JSON library");
jbe@164 901 for (lua_pushnil(L); lua_next(L, json_export_internal_value_idx); lua_pop(L, 1)) {
jbe@163 902 if (lua_type(L, -2) == LUA_TSTRING) {
jbe@163 903 json_key_t *key = keybuf + (keypos++);
jbe@163 904 key->data = lua_tolstring(L, -2, &key->length);
jbe@163 905 }
jbe@163 906 }
jbe@163 907 qsort(keybuf, keycount, sizeof(json_key_t), (void *)json_key_cmp);
jbe@163 908 }
jbe@154 909 luaL_buffinit(L, &buf);
jbe@154 910 luaL_addchar(&buf, '{');
jbe@163 911 for (keypos=0; keypos<keycount; keypos++) {
jbe@163 912 json_key_t *key = keybuf + keypos;
jbe@163 913 if (keypos) luaL_addchar(&buf, ',');
jbe@164 914 if (pretty) {
jbe@164 915 luaL_addchar(&buf, '\n');
jbe@164 916 for (i=0; i<level; i++) {
jbe@164 917 lua_pushvalue(L, json_export_internal_indentstring_idx);
jbe@164 918 luaL_addvalue(&buf);
jbe@164 919 }
jbe@164 920 }
jbe@164 921 lua_pushcfunction(L, json_export_internal);
jbe@164 922 lua_pushvalue(L, json_export_internal_indentstring_idx);
jbe@164 923 lua_pushinteger(L, level);
jbe@163 924 lua_pushlstring(L, key->data, key->length);
jbe@164 925 if (lua_pcall(L, 3, 1, 0)) {
jbe@163 926 if (keybuf) free(keybuf);
jbe@163 927 return lua_error(L);
jbe@154 928 }
jbe@163 929 luaL_addvalue(&buf);
jbe@163 930 luaL_addchar(&buf, ':');
jbe@164 931 if (pretty) luaL_addchar(&buf, ' ');
jbe@164 932 lua_pushcfunction(L, json_export_internal);
jbe@164 933 lua_pushvalue(L, json_export_internal_indentstring_idx);
jbe@164 934 lua_pushinteger(L, level);
jbe@163 935 lua_pushlstring(L, key->data, key->length);
jbe@164 936 lua_rawget(L, json_export_internal_value_idx);
jbe@164 937 if (lua_pcall(L, 3, 1, 0)) {
jbe@163 938 if (keybuf) free(keybuf);
jbe@163 939 return lua_error(L);
jbe@163 940 }
jbe@163 941 luaL_addvalue(&buf);
jbe@154 942 }
jbe@163 943 if (keybuf) free(keybuf);
jbe@164 944 if (pretty && keycount != 0) {
jbe@164 945 luaL_addchar(&buf, '\n');
jbe@164 946 for (i=0; i<level-1; i++) {
jbe@164 947 lua_pushvalue(L, json_export_internal_indentstring_idx);
jbe@164 948 luaL_addvalue(&buf);
jbe@164 949 }
jbe@164 950 }
jbe@154 951 luaL_addchar(&buf, '}');
jbe@164 952 if (pretty && level == 1) luaL_addchar(&buf, '\n');
jbe@154 953 luaL_pushresult(&buf);
jbe@154 954 return 1;
jbe@154 955 case JSON_TABLETYPE_ARRAY:
jbe@164 956 lua_settop(L, json_export_internal_tmp_idx);
jbe@154 957 luaL_buffinit(L, &buf);
jbe@154 958 luaL_addchar(&buf, '[');
jbe@154 959 for (idx = 1; ; idx++) {
jbe@164 960 lua_rawgeti(L, json_export_internal_value_idx, idx);
jbe@154 961 if (lua_isnil(L, -1)) {
jbe@154 962 lua_pop(L, 1);
jbe@154 963 break;
jbe@154 964 }
jbe@164 965 lua_replace(L, json_export_internal_tmp_idx);
jbe@164 966 if (anyelement) luaL_addchar(&buf, ',');
jbe@164 967 anyelement = 1;
jbe@164 968 if (pretty) {
jbe@164 969 luaL_addchar(&buf, '\n');
jbe@164 970 for (i=0; i<level; i++) {
jbe@164 971 lua_pushvalue(L, json_export_internal_indentstring_idx);
jbe@164 972 luaL_addvalue(&buf);
jbe@164 973 }
jbe@164 974 }
jbe@164 975 lua_pushcfunction(L, json_export_internal);
jbe@164 976 lua_pushvalue(L, json_export_internal_indentstring_idx);
jbe@164 977 lua_pushinteger(L, level);
jbe@164 978 lua_pushvalue(L, json_export_internal_tmp_idx);
jbe@164 979 lua_call(L, 3, 1);
jbe@154 980 luaL_addvalue(&buf);
jbe@154 981 }
jbe@164 982 if (pretty && anyelement) {
jbe@164 983 luaL_addchar(&buf, '\n');
jbe@164 984 for (i=0; i<level-1; i++) {
jbe@164 985 lua_pushvalue(L, json_export_internal_indentstring_idx);
jbe@164 986 luaL_addvalue(&buf);
jbe@164 987 }
jbe@164 988 }
jbe@154 989 luaL_addchar(&buf, ']');
jbe@164 990 if (pretty && level == 1) luaL_addchar(&buf, '\n');
jbe@154 991 luaL_pushresult(&buf);
jbe@154 992 return 1;
jbe@154 993 }
jbe@154 994 json_export_tabletype_error:
jbe@154 995 return luaL_error(L, "JSON export not possible for ambiguous table (cannot decide whether it is an object or array)");
jbe@154 996 }
jbe@166 997 return luaL_error(L, "JSON export not possible for values of type \"%s\"", lua_typename(L, lua_type(L, json_export_internal_value_idx)));
jbe@154 998 }
jbe@154 999
jbe@164 1000 static int json_export(lua_State *L) {
jbe@164 1001 lua_settop(L, 1);
jbe@164 1002 lua_pushcfunction(L, json_export_internal);
jbe@164 1003 lua_pushnil(L);
jbe@164 1004 lua_pushinteger(L, 0);
jbe@164 1005 lua_pushvalue(L, 1);
jbe@164 1006 lua_call(L, 3, 1);
jbe@164 1007 return 1;
jbe@164 1008 }
jbe@164 1009
jbe@164 1010 static int json_pretty(lua_State *L) {
jbe@164 1011 lua_settop(L, 2);
jbe@164 1012 lua_pushcfunction(L, json_export_internal);
jbe@164 1013 if (lua_isnil(L, 2)) lua_pushliteral(L, " ");
jbe@164 1014 else lua_pushvalue(L, 2);
jbe@164 1015 lua_pushinteger(L, 0);
jbe@164 1016 lua_pushvalue(L, 1);
jbe@164 1017 lua_call(L, 3, 1);
jbe@164 1018 return 1;
jbe@164 1019 }
jbe@164 1020
jbe@149 1021 // functions in library module:
jbe@121 1022 static const struct luaL_Reg json_module_functions[] = {
jbe@133 1023 {"object", json_object},
jbe@133 1024 {"array", json_array},
jbe@121 1025 {"import", json_import},
jbe@154 1026 {"export", json_export},
jbe@164 1027 {"pretty", json_pretty},
jbe@130 1028 {"get", json_get},
jbe@127 1029 {"type", json_type},
jbe@121 1030 {NULL, NULL}
jbe@121 1031 };
jbe@121 1032
jbe@149 1033 // metamethods for JSON objects, JSON arrays, and unknown JSON collections (object or array):
jbe@126 1034 static const struct luaL_Reg json_metatable_functions[] = {
jbe@130 1035 {"__len", json_len},
jbe@130 1036 {"__index", json_index},
jbe@130 1037 {"__newindex", json_newindex},
jbe@135 1038 {"__pairs", json_pairs},
jbe@134 1039 {"__ipairs", json_ipairs},
jbe@160 1040 {"__tostring", json_export},
jbe@126 1041 {NULL, NULL}
jbe@126 1042 };
jbe@126 1043
jbe@157 1044 // metamethods for JSON null marker:
jbe@157 1045 static const struct luaL_Reg json_nullmark_metamethods[] = {
jbe@157 1046 {"__tostring", json_nullmark_tostring},
jbe@157 1047 {NULL, NULL}
jbe@157 1048 };
jbe@157 1049
jbe@149 1050 // initializes json library:
jbe@121 1051 int luaopen_json(lua_State *L) {
jbe@149 1052 // empty stack:
jbe@126 1053 lua_settop(L, 0);
jbe@149 1054 // push library module onto stack position 1:
jbe@149 1055 lua_newtable(L);
jbe@149 1056 // register library functions:
jbe@149 1057 luaL_setfuncs(L, json_module_functions, 0);
jbe@149 1058 // create and store objectmt:
jbe@138 1059 lua_newtable(L);
jbe@138 1060 luaL_setfuncs(L, json_metatable_functions, 0);
jbe@144 1061 json_regstore(L, objectmt);
jbe@149 1062 // create and store arraymt:
jbe@138 1063 lua_newtable(L);
jbe@138 1064 luaL_setfuncs(L, json_metatable_functions, 0);
jbe@144 1065 json_regstore(L, arraymt);
jbe@149 1066 // create and store ephemeron table to store shadow tables for each JSON object/array
jbe@149 1067 // to allow NULL values returned as nil
jbe@149 1068 lua_newtable(L);
jbe@138 1069 lua_newtable(L); // metatable for ephemeron table
jbe@121 1070 lua_pushliteral(L, "__mode");
jbe@121 1071 lua_pushliteral(L, "k");
jbe@138 1072 lua_rawset(L, -3);
jbe@138 1073 lua_setmetatable(L, -2);
jbe@144 1074 json_regstore(L, shadowtbl);
jbe@157 1075 // set metatable of null marker and make it available through library module:
jbe@157 1076 json_pushnullmark(L);
jbe@157 1077 lua_newtable(L);
jbe@157 1078 luaL_setfuncs(L, json_nullmark_metamethods, 0);
jbe@157 1079 lua_setmetatable(L, -2);
jbe@157 1080 lua_setfield(L, 1, "null");
jbe@157 1081 // return library module (that's expected on top of stack):
jbe@121 1082 return 1;
jbe@121 1083 }

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