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annotate libraries/json/json.c @ 170:c055d6d64586

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Bugfix in json.import function to process bytes >= 128 correctly
author jbe
date Fri Aug 01 13:09:15 2014 +0200 (2014-08-01)
parents 681367a16657
children ce208edffcc9
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@169 44 #define json_convert_source_idx 1
jbe@169 45 #define json_convert_iterator_idx 2
jbe@169 46 #define json_convert_output_idx 3
jbe@169 47 #define json_convert_shadow_idx 4
jbe@169 48
jbe@169 49 // converts a Lua table to a JSON object or JSON array:
jbe@169 50 // (does never modify the argument, returns an empty object or array if argument is nil)
jbe@169 51 static int json_convert(lua_State *L, int array) {
jbe@169 52 lua_settop(L, 1);
jbe@169 53 if (lua_isnoneornil(L, json_convert_source_idx)) {
jbe@144 54 json_regfetch(L, shadowtbl);
jbe@169 55 lua_newtable(L);
jbe@169 56 lua_pushvalue(L, -1);
jbe@169 57 lua_newtable(L);
jbe@169 58 lua_rawset(L, -4);
jbe@169 59 } else {
jbe@169 60 // push iterator function on stack position 2 if existent,
jbe@169 61 // else push null for normal tables:
jbe@169 62 if (lua_getmetatable(L, json_convert_source_idx)) {
jbe@169 63 lua_getfield(L, -1, array ? "__ipairs" : "__pairs");
jbe@169 64 if (lua_isnil(L, -1)) luaL_checktype(L, 1, LUA_TTABLE);
jbe@169 65 else if (lua_type(L, -1) != LUA_TFUNCTION)
jbe@169 66 return luaL_error(L, "%s metamethod is not a function", array ? "__ipairs" : "__pairs");
jbe@169 67 lua_replace(L, -2);
jbe@169 68 } else {
jbe@169 69 lua_pushnil(L);
jbe@143 70 }
jbe@169 71 // create table on stack position 3:
jbe@169 72 lua_newtable(L);
jbe@169 73 // create shadow table on stack position 4:
jbe@169 74 json_regfetch(L, shadowtbl);
jbe@169 75 lua_newtable(L);
jbe@169 76 lua_pushvalue(L, json_convert_output_idx);
jbe@169 77 lua_pushvalue(L, -2);
jbe@169 78 lua_rawset(L, -4);
jbe@169 79 lua_replace(L, -2);
jbe@169 80 if (lua_isnil(L, json_convert_iterator_idx)) {
jbe@169 81 for (lua_pushnil(L); lua_next(L, json_convert_source_idx); lua_pop(L, 1)) {
jbe@169 82 lua_pushvalue(L, -2);
jbe@169 83 lua_pushvalue(L, -2);
jbe@169 84 lua_rawset(L, json_convert_shadow_idx);
jbe@169 85 }
jbe@169 86 } else {
jbe@169 87 return luaL_error(L, "Using %s metamethod not implemented yet", array ? "__ipairs" : "__pairs");
jbe@143 88 }
jbe@169 89 lua_settop(L, json_convert_output_idx);
jbe@136 90 }
jbe@136 91 // set metatable:
jbe@169 92 if (array) json_regfetch(L, arraymt);
jbe@169 93 else json_regfetch(L, objectmt);
jbe@169 94 lua_setmetatable(L, -2);
jbe@138 95 // return table:
jbe@136 96 return 1;
jbe@136 97 }
jbe@136 98
jbe@136 99 static int json_object(lua_State *L) {
jbe@169 100 return json_convert(L, 0);
jbe@136 101 }
jbe@136 102
jbe@136 103 static int json_array(lua_State *L) {
jbe@169 104 return json_convert(L, 1);
jbe@136 105 }
jbe@136 106
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@168 122 // macros for hex decoding:
jbe@168 123 #define json_utf16_surrogate(x) ((x) >= 0xD800 && (x) <= 0xDFFF)
jbe@168 124 #define json_utf16_lead(x) ((x) >= 0xD800 && (x) <= 0xDBFF)
jbe@168 125 #define json_utf16_tail(x) ((x) >= 0xDC00 && (x) <= 0xDFFF)
jbe@167 126 #define json_import_readhex(x) \
jbe@167 127 do { \
jbe@167 128 x = 0; \
jbe@167 129 for (i=0; i<4; i++) { \
jbe@167 130 x <<= 4; \
jbe@167 131 c = str[pos++]; \
jbe@167 132 if (c >= '0' && c <= '9') x += c - '0'; \
jbe@167 133 else if (c >= 'A' && c <= 'F') x += c - 'A' + 10; \
jbe@167 134 else if (c >= 'a' && c <= 'f') x += c - 'a' + 10; \
jbe@167 135 else if (c == 0) goto json_import_unexpected_eof; \
jbe@167 136 else goto json_import_unexpected_escape; \
jbe@167 137 } \
jbe@167 138 } while (0)
jbe@167 139
jbe@136 140 // decodes a JSON document:
jbe@121 141 static int json_import(lua_State *L) {
jbe@167 142 int i; // loop variable
jbe@136 143 const char *str; // string to parse
jbe@136 144 size_t total; // total length of string to parse
jbe@136 145 size_t pos = 0; // current position in string to parse
jbe@136 146 size_t level = 0; // nested levels of objects/arrays currently being processed
jbe@145 147 int mode = JSON_STATE_VALUE; // state of parser (i.e. "what's expected next?")
jbe@170 148 unsigned char c; // variable to store a single character to be processed (unsigned!)
jbe@145 149 luaL_Buffer luabuf; // Lua buffer to decode JSON string values
jbe@145 150 char *cbuf; // C buffer to decode JSON string values
jbe@162 151 size_t outlen; // maximum length or write position of C buffer
jbe@167 152 long codepoint; // decoded UTF-16 character or higher codepoint
jbe@167 153 long utf16tail; // second decoded UTF-16 character (surrogate tail)
jbe@152 154 size_t arraylen; // variable to temporarily store the array length
jbe@166 155 // require string as argument and convert to C string with length information:
jbe@166 156 str = luaL_checklstring(L, 1, &total);
jbe@166 157 // if string contains a NULL byte, this is a syntax error
jbe@166 158 if (strlen(str) != total) goto json_import_syntax_error;
jbe@147 159 // stack shall contain one function argument:
jbe@138 160 lua_settop(L, 1);
jbe@147 161 // push objectmt onto stack position 2:
jbe@144 162 json_regfetch(L, objectmt);
jbe@147 163 // push arraymt onto stack position 3:
jbe@144 164 json_regfetch(L, arraymt);
jbe@147 165 // push shadowtbl onto stack position 4:
jbe@144 166 json_regfetch(L, shadowtbl);
jbe@136 167 // main loop of parser:
jbe@136 168 json_import_loop:
jbe@136 169 // skip whitespace and store next character in variable 'c':
jbe@146 170 while (c = str[pos],
jbe@146 171 c == ' ' ||
jbe@146 172 c == '\f' ||
jbe@146 173 c == '\n' ||
jbe@146 174 c == '\r' ||
jbe@146 175 c == '\t' ||
jbe@146 176 c == '\v'
jbe@146 177 ) pos++;
jbe@170 178 // NOTE: variable c needs to be unsigned in the following code
jbe@136 179 // switch statement to handle certain (single) characters:
jbe@121 180 switch (c) {
jbe@136 181 // handle end of JSON document:
jbe@121 182 case 0:
jbe@136 183 // if end of JSON document was expected, then return top element of stack as result:
jbe@124 184 if (mode == JSON_STATE_END) return 1;
jbe@136 185 // otherwise, the JSON document was malformed:
jbe@167 186 if (level == 0) {
jbe@167 187 lua_pushnil(L);
jbe@167 188 lua_pushliteral(L, "Empty string");
jbe@167 189 } else {
jbe@167 190 json_import_unexpected_eof:
jbe@167 191 lua_pushnil(L);
jbe@167 192 lua_pushliteral(L, "Unexpected end of JSON document");
jbe@167 193 }
jbe@121 194 return 2;
jbe@136 195 // new JSON object:
jbe@121 196 case '{':
jbe@136 197 // if a JSON object is not expected here, then return an error:
jbe@146 198 if (
jbe@146 199 mode != JSON_STATE_VALUE &&
jbe@146 200 mode != JSON_STATE_OBJECT_VALUE &&
jbe@146 201 mode != JSON_STATE_ARRAY_VALUE
jbe@146 202 ) goto json_import_syntax_error;
jbe@136 203 // create JSON object on stack:
jbe@136 204 lua_newtable(L);
jbe@136 205 // set metatable of JSON object:
jbe@138 206 lua_pushvalue(L, json_import_objectmt_idx);
jbe@125 207 lua_setmetatable(L, -2);
jbe@136 208 // create internal shadow table on stack:
jbe@136 209 lua_newtable(L);
jbe@146 210 // register internal shadow table:
jbe@123 211 lua_pushvalue(L, -2);
jbe@123 212 lua_pushvalue(L, -2);
jbe@138 213 lua_rawset(L, json_import_shadowtbl_idx);
jbe@146 214 // expect object key (or end of object) to follow:
jbe@136 215 mode = JSON_STATE_OBJECT_KEY;
jbe@146 216 // jump to common code for opening JSON object and JSON array:
jbe@142 217 goto json_import_open;
jbe@136 218 // new JSON array:
jbe@121 219 case '[':
jbe@136 220 // if a JSON array is not expected here, then return an error:
jbe@146 221 if (
jbe@146 222 mode != JSON_STATE_VALUE &&
jbe@146 223 mode != JSON_STATE_OBJECT_VALUE &&
jbe@146 224 mode != JSON_STATE_ARRAY_VALUE
jbe@146 225 ) goto json_import_syntax_error;
jbe@136 226 // create JSON array on stack:
jbe@136 227 lua_newtable(L);
jbe@136 228 // set metatable of JSON array:
jbe@138 229 lua_pushvalue(L, json_import_arraymt_idx);
jbe@125 230 lua_setmetatable(L, -2);
jbe@136 231 // create internal shadow table on stack:
jbe@136 232 lua_newtable(L);
jbe@146 233 // register internal shadow table:
jbe@123 234 lua_pushvalue(L, -2);
jbe@123 235 lua_pushvalue(L, -2);
jbe@138 236 lua_rawset(L, json_import_shadowtbl_idx);
jbe@140 237 // add nil as key (needed to keep stack balance) and as magic to detect arrays:
jbe@140 238 lua_pushnil(L);
jbe@146 239 // expect array value (or end of array) to follow:
jbe@142 240 mode = JSON_STATE_ARRAY_VALUE;
jbe@142 241 // continue with common code for opening JSON object and JSON array:
jbe@146 242 // common code for opening JSON object or JSON array:
jbe@142 243 json_import_open:
jbe@142 244 // limit nested levels:
jbe@142 245 if (level >= JSON_MAXDEPTH) {
jbe@142 246 lua_pushnil(L);
jbe@164 247 lua_pushfstring(L, "More than %d nested JSON levels", JSON_MAXDEPTH);
jbe@142 248 return 2;
jbe@142 249 }
jbe@142 250 // additional buffer overflow protection:
jbe@142 251 if (!lua_checkstack(L, LUA_MINSTACK))
jbe@142 252 return luaL_error(L, "Caught stack overflow in JSON import function (too many nested levels and stack size too small)");
jbe@136 253 // increment level:
jbe@121 254 level++;
jbe@142 255 // consume input character:
jbe@142 256 pos++;
jbe@121 257 goto json_import_loop;
jbe@136 258 // end of JSON object:
jbe@121 259 case '}':
jbe@136 260 // if end of JSON object is not expected here, then return an error:
jbe@146 261 if (
jbe@146 262 mode != JSON_STATE_OBJECT_KEY &&
jbe@146 263 mode != JSON_STATE_OBJECT_SEPARATOR
jbe@146 264 ) goto json_import_syntax_error;
jbe@136 265 // jump to common code for end of JSON object and JSON array:
jbe@121 266 goto json_import_close;
jbe@136 267 // end of JSON array:
jbe@121 268 case ']':
jbe@136 269 // if end of JSON array is not expected here, then return an error:
jbe@146 270 if (
jbe@146 271 mode != JSON_STATE_ARRAY_VALUE &&
jbe@146 272 mode != JSON_STATE_ARRAY_SEPARATOR
jbe@146 273 ) goto json_import_syntax_error;
jbe@146 274 // pop nil key/magic (that was needed to keep stack balance):
jbe@140 275 lua_pop(L, 1);
jbe@136 276 // continue with common code for end of JSON object and JSON array:
jbe@136 277 // common code for end of JSON object or JSON array:
jbe@121 278 json_import_close:
jbe@136 279 // consume input character:
jbe@121 280 pos++;
jbe@136 281 // pop shadow table:
jbe@136 282 lua_pop(L, 1);
jbe@136 283 // check if nested:
jbe@121 284 if (--level) {
jbe@146 285 // if nested,
jbe@146 286 // check if outer(!) structure is an array or object:
jbe@140 287 if (lua_isnil(L, -2)) {
jbe@136 288 // select array value processing:
jbe@124 289 mode = JSON_STATE_ARRAY_VALUE;
jbe@121 290 } else {
jbe@136 291 // select object value processing:
jbe@124 292 mode = JSON_STATE_OBJECT_VALUE;
jbe@121 293 }
jbe@136 294 // store value in outer structure:
jbe@121 295 goto json_import_process_value;
jbe@121 296 }
jbe@136 297 // if not nested, then expect end of JSON document and continue with loop:
jbe@136 298 mode = JSON_STATE_END;
jbe@121 299 goto json_import_loop;
jbe@136 300 // key terminator:
jbe@121 301 case ':':
jbe@136 302 // if key terminator is not expected here, then return an error:
jbe@124 303 if (mode != JSON_STATE_OBJECT_KEY_TERMINATOR)
jbe@121 304 goto json_import_syntax_error;
jbe@136 305 // consume input character:
jbe@121 306 pos++;
jbe@146 307 // expect object value to follow:
jbe@124 308 mode = JSON_STATE_OBJECT_VALUE;
jbe@146 309 // continue with loop:
jbe@121 310 goto json_import_loop;
jbe@136 311 // value terminator (NOTE: trailing comma at end of value or key-value list is tolerated by this parser)
jbe@121 312 case ',':
jbe@146 313 // branch according to parser state:
jbe@124 314 if (mode == JSON_STATE_OBJECT_SEPARATOR) {
jbe@146 315 // expect an object key to follow:
jbe@124 316 mode = JSON_STATE_OBJECT_KEY;
jbe@124 317 } else if (mode == JSON_STATE_ARRAY_SEPARATOR) {
jbe@146 318 // expect an array value to follow:
jbe@124 319 mode = JSON_STATE_ARRAY_VALUE;
jbe@121 320 } else {
jbe@136 321 // if value terminator is not expected here, then return an error:
jbe@136 322 goto json_import_syntax_error;
jbe@121 323 }
jbe@136 324 // consume input character:
jbe@121 325 pos++;
jbe@136 326 // continue with loop:
jbe@121 327 goto json_import_loop;
jbe@136 328 // string literal:
jbe@121 329 case '"':
jbe@146 330 // consume quote character:
jbe@146 331 pos++;
jbe@162 332 // find last character in input string:
jbe@162 333 outlen = pos;
jbe@162 334 while ((c = str[outlen]) != '"') {
jbe@161 335 // consume one character:
jbe@162 336 outlen++;
jbe@161 337 // handle unexpected end of JSON document:
jbe@161 338 if (c == 0) goto json_import_unexpected_eof;
jbe@161 339 // consume one extra character when encountering an escaped quote:
jbe@162 340 else if (c == '\\' && str[outlen] == '"') outlen++;
jbe@161 341 }
jbe@162 342 // determine buffer length:
jbe@162 343 outlen -= pos;
jbe@161 344 // check if string is non empty:
jbe@162 345 if (outlen) {
jbe@161 346 // prepare buffer to decode string (with maximum possible length) and set write position to zero:
jbe@162 347 cbuf = luaL_buffinitsize(L, &luabuf, outlen);
jbe@162 348 outlen = 0;
jbe@161 349 // loop through the characters until encountering end quote:
jbe@161 350 while ((c = str[pos++]) != '"') {
jbe@162 351 // NOTE: unexpected end cannot happen anymore
jbe@162 352 if (c < 32 || c == 127) {
jbe@161 353 // do not allow ASCII control characters:
jbe@161 354 // NOTE: illegal UTF-8 sequences and extended control characters are not sanitized
jbe@161 355 // by this parser to allow different encodings than Unicode
jbe@161 356 lua_pushnil(L);
jbe@161 357 lua_pushliteral(L, "Unexpected control character in JSON string");
jbe@161 358 return 2;
jbe@161 359 } else if (c == '\\') {
jbe@161 360 // read next char after backslash escape:
jbe@161 361 c = str[pos++];
jbe@161 362 switch (c) {
jbe@161 363 // unexpected end-of-string:
jbe@161 364 case 0:
jbe@161 365 goto json_import_unexpected_eof;
jbe@161 366 // unescaping of quotation mark, slash, and backslash:
jbe@161 367 case '"':
jbe@161 368 case '/':
jbe@161 369 case '\\':
jbe@162 370 cbuf[outlen++] = c;
jbe@161 371 break;
jbe@161 372 // unescaping of backspace:
jbe@162 373 case 'b': cbuf[outlen++] = '\b'; break;
jbe@161 374 // unescaping of form-feed:
jbe@162 375 case 'f': cbuf[outlen++] = '\f'; break;
jbe@161 376 // unescaping of new-line:
jbe@162 377 case 'n': cbuf[outlen++] = '\n'; break;
jbe@161 378 // unescaping of carriage-return:
jbe@162 379 case 'r': cbuf[outlen++] = '\r'; break;
jbe@161 380 // unescaping of tabulator:
jbe@162 381 case 't': cbuf[outlen++] = '\t'; break;
jbe@161 382 // unescaping of UTF-16 characters
jbe@161 383 case 'u':
jbe@167 384 // decode 4 hex nibbles:
jbe@167 385 json_import_readhex(codepoint);
jbe@167 386 // handle surrogate character:
jbe@167 387 if (json_utf16_surrogate(codepoint)) {
jbe@167 388 // check if first surrogate is in valid range:
jbe@167 389 if (json_utf16_lead(codepoint)) {
jbe@167 390 // require second surrogate:
jbe@167 391 if ((c = str[pos++]) != '\\' || (c = str[pos++]) != 'u') {
jbe@167 392 if (c == 0) goto json_import_unexpected_eof;
jbe@167 393 else goto json_import_wrong_surrogate;
jbe@167 394 }
jbe@167 395 // read 4 hex nibbles of second surrogate character:
jbe@167 396 json_import_readhex(utf16tail);
jbe@167 397 // check if second surrogate is in valid range:
jbe@167 398 if (!json_utf16_tail(utf16tail)) goto json_import_wrong_surrogate;
jbe@167 399 // calculate codepoint:
jbe@167 400 codepoint = 0x10000 + (utf16tail - 0xDC00) + (codepoint - 0xD800) * 0x400;
jbe@167 401 } else {
jbe@167 402 // throw error for wrong surrogates:
jbe@167 403 json_import_wrong_surrogate:
jbe@167 404 lua_pushnil(L);
jbe@167 405 lua_pushliteral(L, "Illegal UTF-16 surrogate in JSON string escape sequence");
jbe@167 406 return 2;
jbe@167 407 }
jbe@167 408 }
jbe@167 409 // encode as UTF-8:
jbe@167 410 if (codepoint < 0x80) {
jbe@167 411 cbuf[outlen++] = (char)codepoint;
jbe@167 412 } else if (codepoint < 0x800) {
jbe@167 413 cbuf[outlen++] = (char)(0xc0 | (codepoint >> 6));
jbe@167 414 cbuf[outlen++] = (char)(0x80 | (codepoint & 0x3f));
jbe@167 415 } else if (codepoint < 0x10000) {
jbe@167 416 cbuf[outlen++] = (char)(0xe0 | (codepoint >> 12));
jbe@167 417 cbuf[outlen++] = (char)(0x80 | ((codepoint >> 6) & 0x3f));
jbe@167 418 cbuf[outlen++] = (char)(0x80 | (codepoint & 0x3f));
jbe@167 419 } else {
jbe@167 420 cbuf[outlen++] = (char)(0xf0 | (codepoint >> 18));
jbe@167 421 cbuf[outlen++] = (char)(0x80 | ((codepoint >> 12) & 0x3f));
jbe@167 422 cbuf[outlen++] = (char)(0x80 | ((codepoint >> 6) & 0x3f));
jbe@167 423 cbuf[outlen++] = (char)(0x80 | (codepoint & 0x3f));
jbe@167 424 }
jbe@167 425 break;
jbe@161 426 // unexpected escape sequence:
jbe@161 427 default:
jbe@167 428 json_import_unexpected_escape:
jbe@161 429 lua_pushnil(L);
jbe@161 430 lua_pushliteral(L, "Unexpected string escape sequence in JSON document");
jbe@161 431 return 2;
jbe@161 432 }
jbe@161 433 } else {
jbe@161 434 // normal character:
jbe@162 435 cbuf[outlen++] = c;
jbe@121 436 }
jbe@121 437 }
jbe@161 438 // process buffer to Lua string:
jbe@162 439 luaL_pushresultsize(&luabuf, outlen);
jbe@161 440 } else {
jbe@161 441 // if JSON string is empty,
jbe@161 442 // push empty Lua string:
jbe@161 443 lua_pushliteral(L, "");
jbe@167 444 // consume closing quote:
jbe@167 445 pos++;
jbe@121 446 }
jbe@136 447 // continue with processing of decoded string:
jbe@121 448 goto json_import_process_value;
jbe@121 449 }
jbe@136 450 // process values whose type is is not deducible from a single character:
jbe@136 451 if ((c >= '0' && c <= '9') || c == '-' || c == '+') {
jbe@146 452 // for numbers,
jbe@146 453 // use strtod() call to parse a (double precision) floating point number:
jbe@167 454 double numval;
jbe@122 455 char *endptr;
jbe@122 456 numval = strtod(str+pos, &endptr);
jbe@146 457 // catch parsing errors:
jbe@122 458 if (endptr == str+pos) goto json_import_syntax_error;
jbe@146 459 // consume characters that were parsed:
jbe@122 460 pos += endptr - (str+pos);
jbe@146 461 // push parsed (double precision) floating point number on Lua stack:
jbe@122 462 lua_pushnumber(L, numval);
jbe@122 463 } else if (!strncmp(str+pos, "true", 4)) {
jbe@136 464 // consume 4 input characters for "true":
jbe@121 465 pos += 4;
jbe@147 466 // put Lua true value onto stack:
jbe@136 467 lua_pushboolean(L, 1);
jbe@121 468 } else if (!strncmp(str+pos, "false", 5)) {
jbe@136 469 // consume 5 input characters for "false":
jbe@121 470 pos += 5;
jbe@147 471 // put Lua false value onto stack:
jbe@136 472 lua_pushboolean(L, 0);
jbe@121 473 } else if (!strncmp(str+pos, "null", 4)) {
jbe@136 474 // consume 4 input characters for "null":
jbe@136 475 pos += 4;
jbe@153 476 // different behavor for top-level and sub-levels:
jbe@153 477 if (level) {
jbe@153 478 // if sub-level,
jbe@153 479 // push special null-marker onto stack:
jbe@155 480 json_pushnullmark(L);
jbe@153 481 } else {
jbe@153 482 // if top-level,
jbe@153 483 // push nil onto stack:
jbe@153 484 lua_pushnil(L);
jbe@153 485 }
jbe@121 486 } else {
jbe@136 487 // all other cases are a syntax error:
jbe@121 488 goto json_import_syntax_error;
jbe@121 489 }
jbe@136 490 // process a decoded value or key value pair (expected on top of Lua stack):
jbe@136 491 json_import_process_value:
jbe@121 492 switch (mode) {
jbe@136 493 // an object key has been read:
jbe@124 494 case JSON_STATE_OBJECT_KEY:
jbe@136 495 // if an object key is not a string, then this is a syntax error:
jbe@121 496 if (lua_type(L, -1) != LUA_TSTRING) goto json_import_syntax_error;
jbe@146 497 // expect key terminator to follow:
jbe@124 498 mode = JSON_STATE_OBJECT_KEY_TERMINATOR;
jbe@146 499 // continue with loop:
jbe@121 500 goto json_import_loop;
jbe@136 501 // a key value pair has been read:
jbe@124 502 case JSON_STATE_OBJECT_VALUE:
jbe@136 503 // store key value pair in outer shadow table:
jbe@130 504 lua_rawset(L, -3);
jbe@146 505 // expect value terminator (or end of object) to follow:
jbe@124 506 mode = JSON_STATE_OBJECT_SEPARATOR;
jbe@146 507 // continue with loop:
jbe@121 508 goto json_import_loop;
jbe@136 509 // an array value has been read:
jbe@124 510 case JSON_STATE_ARRAY_VALUE:
jbe@152 511 // get current array length:
jbe@152 512 arraylen = lua_rawlen(L, -3);
jbe@152 513 // throw error if array would exceed INT_MAX elements:
jbe@152 514 // TODO: Lua 5.3 may support more elements
jbe@152 515 if (arraylen >= INT_MAX) {
jbe@152 516 lua_pushnil(L);
jbe@152 517 lua_pushfstring(L, "Array exceeded length of %d elements", INT_MAX);
jbe@152 518 }
jbe@136 519 // store value in outer shadow table:
jbe@152 520 lua_rawseti(L, -3, arraylen + 1);
jbe@146 521 // expect value terminator (or end of object) to follow:
jbe@124 522 mode = JSON_STATE_ARRAY_SEPARATOR;
jbe@146 523 // continue with loop
jbe@121 524 goto json_import_loop;
jbe@136 525 // a single value has been read:
jbe@124 526 case JSON_STATE_VALUE:
jbe@136 527 // leave value on top of stack, expect end of JSON document, and continue with loop:
jbe@124 528 mode = JSON_STATE_END;
jbe@121 529 goto json_import_loop;
jbe@121 530 }
jbe@146 531 // syntax error handling (reachable by goto statement):
jbe@136 532 json_import_syntax_error:
jbe@121 533 lua_pushnil(L);
jbe@121 534 lua_pushliteral(L, "Syntax error in JSON document");
jbe@121 535 return 2;
jbe@121 536 }
jbe@121 537
jbe@146 538 // special Lua stack indicies for json_path function:
jbe@138 539 #define json_path_shadowtbl_idx 1
jbe@146 540
jbe@146 541 // stack offset of arguments to json_path function:
jbe@155 542 #define json_path_idxshift 1
jbe@138 543
jbe@146 544 // gets a value or its type from a JSON document (passed as first argument)
jbe@147 545 // using a path (passed as variable number of keys after first argument):
jbe@137 546 static int json_path(lua_State *L, int type_mode) {
jbe@146 547 int stacktop; // stack index of top of stack (after shifting)
jbe@146 548 int idx = 2 + json_path_idxshift; // stack index of current argument to process
jbe@148 549 // insert shadowtbl into stack at position 1 (shifting the arguments):
jbe@144 550 json_regfetch(L, shadowtbl);
jbe@138 551 lua_insert(L, 1);
jbe@146 552 // store stack index of top of stack:
jbe@138 553 stacktop = lua_gettop(L);
jbe@146 554 // use first argument as "current value" (stored on top of stack):
jbe@138 555 lua_pushvalue(L, 1 + json_path_idxshift);
jbe@146 556 // process each "path key" (2nd argument and following arguments):
jbe@138 557 while (idx <= stacktop) {
jbe@146 558 // if "current value" (on top of stack) is nil, then the path cannot be walked and nil is returned:
jbe@137 559 if (lua_isnil(L, -1)) return 1;
jbe@137 560 // try to get shadow table of "current value":
jbe@130 561 lua_pushvalue(L, -1);
jbe@138 562 lua_rawget(L, json_path_shadowtbl_idx);
jbe@126 563 if (lua_isnil(L, -1)) {
jbe@137 564 // if no shadow table is found,
jbe@130 565 if (lua_type(L, -1) == LUA_TTABLE) {
jbe@146 566 // and if "current value" is a table,
jbe@146 567 // drop nil from stack:
jbe@146 568 lua_pop(L, 1);
jbe@137 569 // get "next value" using the "path key":
jbe@130 570 lua_pushvalue(L, idx++);
jbe@130 571 lua_gettable(L, -2);
jbe@130 572 } else {
jbe@137 573 // if "current value" is not a table,
jbe@146 574 // then the path cannot be walked and nil (already on top of stack) is returned:
jbe@137 575 return 1;
jbe@130 576 }
jbe@130 577 } else {
jbe@137 578 // if a shadow table is found,
jbe@137 579 // set "current value" to its shadow table:
jbe@130 580 lua_replace(L, -2);
jbe@137 581 // get "next value" using the "path key":
jbe@130 582 lua_pushvalue(L, idx++);
jbe@130 583 lua_rawget(L, -2);
jbe@126 584 }
jbe@137 585 // the "next value" replaces the "current value":
jbe@130 586 lua_replace(L, -2);
jbe@126 587 }
jbe@137 588 if (!type_mode) {
jbe@137 589 // if a value (and not its type) was requested,
jbe@137 590 // check if value is the null-marker, and store nil on top of Lua stack in that case:
jbe@155 591 if (json_isnullmark(L, -1)) lua_pushnil(L);
jbe@137 592 } else {
jbe@137 593 // if the type was requested,
jbe@137 594 // check if value is the null-marker:
jbe@155 595 if (json_isnullmark(L, -1)) {
jbe@137 596 // if yes, store string "null" on top of Lua stack:
jbe@130 597 lua_pushliteral(L, "null");
jbe@137 598 } else {
jbe@137 599 // otherwise,
jbe@138 600 // check if metatable indicates "object" or "array":
jbe@138 601 if (lua_getmetatable(L, -1)) {
jbe@144 602 json_regfetch(L, objectmt);
jbe@138 603 if (lua_rawequal(L, -2, -1)) {
jbe@146 604 // if value has metatable for JSON objects,
jbe@138 605 // return string "object":
jbe@138 606 lua_pushliteral(L, "object");
jbe@138 607 return 1;
jbe@138 608 }
jbe@144 609 json_regfetch(L, arraymt);
jbe@138 610 if (lua_rawequal(L, -3, -1)) {
jbe@146 611 // if value has metatable for JSON arrays,
jbe@146 612 // return string "object":
jbe@138 613 lua_pushliteral(L, "array");
jbe@138 614 return 1;
jbe@138 615 }
jbe@146 616 // remove 3 metatables (one of the value, two for comparison) from stack:
jbe@138 617 lua_pop(L, 3);
jbe@138 618 }
jbe@138 619 // otherwise, get the Lua type:
jbe@138 620 lua_pushstring(L, lua_typename(L, lua_type(L, -1)));
jbe@126 621 }
jbe@126 622 }
jbe@137 623 // return the top most value on the Lua stack:
jbe@137 624 return 1;
jbe@130 625 }
jbe@130 626
jbe@147 627 // gets a value from a JSON document (passed as first argument)
jbe@147 628 // using a path (passed as variable number of keys after first argument):
jbe@130 629 static int json_get(lua_State *L) {
jbe@137 630 return json_path(L, 0);
jbe@130 631 }
jbe@130 632
jbe@147 633 // gets a value's type from a JSON document (passed as first argument)
jbe@147 634 // using a path (variable number of keys after first argument):
jbe@130 635 static int json_type(lua_State *L) {
jbe@137 636 return json_path(L, 1);
jbe@130 637 }
jbe@130 638
jbe@147 639 // returns the length of a JSON array (or zero for a table without numeric keys):
jbe@130 640 static int json_len(lua_State *L) {
jbe@147 641 // stack shall contain one function argument:
jbe@130 642 lua_settop(L, 1);
jbe@148 643 // try to get corresponding shadow table for first argument:
jbe@144 644 json_regfetch(L, shadowtbl);
jbe@130 645 lua_pushvalue(L, 1);
jbe@138 646 lua_rawget(L, -2);
jbe@147 647 // if shadow table does not exist, return length of argument, else length of shadow table:
jbe@147 648 lua_pushnumber(L, lua_rawlen(L, lua_isnil(L, -1) ? 1 : -1));
jbe@123 649 return 1;
jbe@123 650 }
jbe@123 651
jbe@130 652 static int json_index(lua_State *L) {
jbe@148 653 // stack shall contain two function arguments:
jbe@130 654 lua_settop(L, 2);
jbe@155 655 // get corresponding shadow table for first argument:
jbe@144 656 json_regfetch(L, shadowtbl);
jbe@130 657 lua_pushvalue(L, 1);
jbe@155 658 lua_rawget(L, -2);
jbe@148 659 // throw error if no shadow table was found:
jbe@139 660 if (lua_isnil(L, -1)) return luaL_error(L, "Shadow table not found");
jbe@148 661 // use key passed as second argument to lookup value in shadow table:
jbe@130 662 lua_pushvalue(L, 2);
jbe@130 663 lua_rawget(L, -2);
jbe@148 664 // if value is null-marker, then push nil onto stack:
jbe@155 665 if (json_isnullmark(L, -1)) lua_pushnil(L);
jbe@148 666 // return either looked up value, or nil
jbe@127 667 return 1;
jbe@127 668 }
jbe@127 669
jbe@130 670 static int json_newindex(lua_State *L) {
jbe@148 671 // stack shall contain three function arguments:
jbe@130 672 lua_settop(L, 3);
jbe@148 673 // get corresponding shadow table for first argument:
jbe@144 674 json_regfetch(L, shadowtbl);
jbe@123 675 lua_pushvalue(L, 1);
jbe@143 676 lua_rawget(L, -2);
jbe@148 677 // throw error if no shadow table was found:
jbe@130 678 if (lua_isnil(L, -1)) return luaL_error(L, "Shadow table not found");
jbe@148 679 // replace first argument with shadow table:
jbe@130 680 lua_replace(L, 1);
jbe@148 681 // reset stack and use second and third argument to write to shadow table:
jbe@139 682 lua_settop(L, 3);
jbe@130 683 lua_rawset(L, 1);
jbe@148 684 // return nothing:
jbe@148 685 return 0;
jbe@121 686 }
jbe@121 687
jbe@135 688 static int json_pairs_iterfunc(lua_State *L) {
jbe@149 689 // stack shall contain two function arguments:
jbe@135 690 lua_settop(L, 2);
jbe@155 691 // get corresponding shadow table for first argument:
jbe@144 692 json_regfetch(L, shadowtbl);
jbe@135 693 lua_pushvalue(L, 1);
jbe@155 694 lua_rawget(L, -2);
jbe@149 695 // throw error if no shadow table was found:
jbe@135 696 if (lua_isnil(L, -1)) return luaL_error(L, "Shadow table not found");
jbe@149 697 // get next key value pair from shadow table (using previous key from argument 2)
jbe@149 698 // and return nothing if there is no next pair:
jbe@135 699 lua_pushvalue(L, 2);
jbe@135 700 if (!lua_next(L, -2)) return 0;
jbe@149 701 // replace null-marker with nil:
jbe@155 702 if (json_isnullmark(L, -1)) {
jbe@135 703 lua_pop(L, 1);
jbe@135 704 lua_pushnil(L);
jbe@135 705 }
jbe@149 706 // return key and value (or key and nil, if null-marker was found):
jbe@135 707 return 2;
jbe@135 708 }
jbe@135 709
jbe@149 710 // returns a triple such that 'for key, value in pairs(obj) do ... end'
jbe@149 711 // iterates through all key value pairs (including JSON null keys represented as Lua nil):
jbe@135 712 static int json_pairs(lua_State *L) {
jbe@149 713 // return triple of function json_pairs_iterfunc, first argument, and nil:
jbe@139 714 lua_pushcfunction(L, json_pairs_iterfunc);
jbe@135 715 lua_pushvalue(L, 1);
jbe@135 716 lua_pushnil(L);
jbe@135 717 return 3;
jbe@135 718 }
jbe@135 719
jbe@134 720 static int json_ipairs_iterfunc(lua_State *L) {
jbe@152 721 lua_Integer idx;
jbe@149 722 // stack shall contain two function arguments:
jbe@134 723 lua_settop(L, 2);
jbe@149 724 // calculate new index by incrementing second argument:
jbe@134 725 idx = lua_tointeger(L, 2) + 1;
jbe@149 726 // get corresponding shadow table for first argument:
jbe@155 727 json_regfetch(L, shadowtbl);
jbe@134 728 lua_pushvalue(L, 1);
jbe@155 729 lua_rawget(L, -2);
jbe@149 730 // throw error if no shadow table was found:
jbe@134 731 if (lua_isnil(L, -1)) return luaL_error(L, "Shadow table not found");
jbe@149 732 // do integer lookup in shadow table:
jbe@134 733 lua_rawgeti(L, -1, idx);
jbe@149 734 // return nothing if there was no value:
jbe@134 735 if (lua_isnil(L, -1)) return 0;
jbe@149 736 // return new index and
jbe@149 737 // either the looked up value if it is not equal to the null-marker
jbe@149 738 // or nil instead of null-marker:
jbe@134 739 lua_pushinteger(L, idx);
jbe@155 740 if (json_isnullmark(L, -2)) lua_pushnil(L);
jbe@134 741 else lua_pushvalue(L, -2);
jbe@134 742 return 2;
jbe@134 743 }
jbe@134 744
jbe@149 745 // returns a triple such that 'for idx, value in ipairs(ary) do ... end'
jbe@149 746 // iterates through all values (including JSON null represented as Lua nil):
jbe@134 747 static int json_ipairs(lua_State *L) {
jbe@149 748 // return triple of function json_ipairs_iterfunc, first argument, and zero:
jbe@139 749 lua_pushcfunction(L, json_ipairs_iterfunc);
jbe@134 750 lua_pushvalue(L, 1);
jbe@134 751 lua_pushinteger(L, 0);
jbe@134 752 return 3;
jbe@134 753 }
jbe@134 754
jbe@163 755 typedef struct {
jbe@163 756 size_t length;
jbe@163 757 const char *data;
jbe@163 758 } json_key_t;
jbe@163 759
jbe@163 760 static int json_key_cmp(json_key_t *key1, json_key_t *key2) {
jbe@163 761 size_t pos = 0;
jbe@163 762 unsigned char c1, c2;
jbe@163 763 while (1) {
jbe@163 764 if (key1->length > pos) {
jbe@163 765 if (key2->length > pos) {
jbe@163 766 c1 = key1->data[pos];
jbe@163 767 c2 = key2->data[pos];
jbe@163 768 if (c1 < c2) return -1;
jbe@163 769 else if (c1 > c2) return 1;
jbe@163 770 } else {
jbe@163 771 return 1;
jbe@163 772 }
jbe@163 773 } else {
jbe@163 774 if (key2->length > pos) {
jbe@163 775 return -1;
jbe@163 776 } else {
jbe@163 777 return 0;
jbe@163 778 }
jbe@163 779 }
jbe@163 780 pos++;
jbe@163 781 }
jbe@163 782 }
jbe@163 783
jbe@154 784 #define JSON_TABLETYPE_UNKNOWN 0
jbe@154 785 #define JSON_TABLETYPE_OBJECT 1
jbe@154 786 #define JSON_TABLETYPE_ARRAY 2
jbe@154 787
jbe@164 788 #define json_export_internal_indentstring_idx 1
jbe@164 789 #define json_export_internal_level_idx 2
jbe@164 790 #define json_export_internal_value_idx 3
jbe@164 791 #define json_export_internal_tmp_idx 4
jbe@164 792
jbe@164 793 static int json_export_internal(lua_State *L) {
jbe@164 794 int level;
jbe@164 795 int pretty;
jbe@164 796 int i;
jbe@154 797 lua_Number num;
jbe@154 798 const char *str;
jbe@154 799 unsigned char c;
jbe@154 800 size_t strlen;
jbe@154 801 size_t pos = 0;
jbe@154 802 luaL_Buffer buf;
jbe@154 803 char hexcode[7]; // backslash, character 'u', 4 hex digits, and terminating NULL byte
jbe@154 804 int tabletype = JSON_TABLETYPE_UNKNOWN;
jbe@164 805 int anyelement = 0;
jbe@163 806 size_t keycount = 0;
jbe@163 807 size_t keypos = 0;
jbe@165 808 json_key_t *keybuf = NULL;
jbe@154 809 lua_Integer idx;
jbe@164 810 lua_settop(L, json_export_internal_value_idx);
jbe@164 811 if (json_isnullmark(L, json_export_internal_value_idx)) {
jbe@164 812 lua_pop(L, 1);
jbe@157 813 lua_pushnil(L);
jbe@157 814 }
jbe@164 815 switch (lua_type(L, json_export_internal_value_idx)) {
jbe@154 816 case LUA_TNIL:
jbe@154 817 lua_pushliteral(L, "null");
jbe@154 818 return 1;
jbe@154 819 case LUA_TNUMBER:
jbe@164 820 num = lua_tonumber(L, json_export_internal_value_idx);
jbe@154 821 if (isnan(num)) return luaL_error(L, "JSON export not possible for NaN value");
jbe@154 822 if (isinf(num)) return luaL_error(L, "JSON export not possible for infinite numbers");
jbe@164 823 lua_tostring(L, json_export_internal_value_idx);
jbe@154 824 return 1;
jbe@154 825 case LUA_TBOOLEAN:
jbe@164 826 if (lua_toboolean(L, json_export_internal_value_idx)) {
jbe@164 827 lua_pushliteral(L, "true");
jbe@164 828 } else {
jbe@164 829 lua_pushliteral(L, "false");
jbe@164 830 }
jbe@154 831 return 1;
jbe@154 832 case LUA_TSTRING:
jbe@164 833 str = lua_tolstring(L, 3, &strlen);
jbe@154 834 luaL_buffinit(L, &buf);
jbe@154 835 luaL_addchar(&buf, '"');
jbe@154 836 while (pos < strlen) {
jbe@154 837 c = str[pos++];
jbe@154 838 if (c == '"') luaL_addstring(&buf, "\\\"");
jbe@154 839 else if (c == '\\') luaL_addstring(&buf, "\\\\");
jbe@154 840 else if (c == 127) luaL_addstring(&buf, "\\u007F");
jbe@154 841 else if (c >= 32) luaL_addchar(&buf, c);
jbe@154 842 else if (c == '\b') luaL_addstring(&buf, "\\b");
jbe@154 843 else if (c == '\f') luaL_addstring(&buf, "\\f");
jbe@154 844 else if (c == '\n') luaL_addstring(&buf, "\\n");
jbe@154 845 else if (c == '\r') luaL_addstring(&buf, "\\r");
jbe@154 846 else if (c == '\t') luaL_addstring(&buf, "\\t");
jbe@154 847 else if (c == '\v') luaL_addstring(&buf, "\\v");
jbe@154 848 else {
jbe@154 849 sprintf(hexcode, "\\u%04X", c);
jbe@154 850 luaL_addstring(&buf, hexcode);
jbe@154 851 }
jbe@154 852 }
jbe@154 853 luaL_addchar(&buf, '"');
jbe@154 854 luaL_pushresult(&buf);
jbe@154 855 return 1;
jbe@154 856 case LUA_TTABLE:
jbe@164 857 if (lua_getmetatable(L, json_export_internal_value_idx)) {
jbe@154 858 json_regfetch(L, objectmt);
jbe@154 859 if (lua_rawequal(L, -2, -1)) {
jbe@154 860 tabletype = JSON_TABLETYPE_OBJECT;
jbe@154 861 } else {
jbe@154 862 json_regfetch(L, arraymt);
jbe@164 863 if (lua_rawequal(L, -3, -1)) {
jbe@164 864 tabletype = JSON_TABLETYPE_ARRAY;
jbe@164 865 } else {
jbe@164 866 return luaL_error(L, "JSON export not possible for tables with nonsupported metatable");
jbe@164 867 }
jbe@154 868 }
jbe@154 869 }
jbe@154 870 json_regfetch(L, shadowtbl);
jbe@164 871 lua_pushvalue(L, json_export_internal_value_idx);
jbe@154 872 lua_rawget(L, -2);
jbe@164 873 if (!lua_isnil(L, -1)) lua_replace(L, json_export_internal_value_idx);
jbe@164 874 lua_settop(L, json_export_internal_value_idx);
jbe@154 875 if (tabletype == JSON_TABLETYPE_UNKNOWN) {
jbe@164 876 for (lua_pushnil(L); lua_next(L, json_export_internal_value_idx); lua_pop(L, 1)) {
jbe@164 877 switch (lua_type(L, -2)) {
jbe@164 878 case LUA_TSTRING:
jbe@164 879 keycount++;
jbe@164 880 if (tabletype == JSON_TABLETYPE_UNKNOWN) tabletype = JSON_TABLETYPE_OBJECT;
jbe@164 881 else if (tabletype == JSON_TABLETYPE_ARRAY) goto json_export_tabletype_error;
jbe@164 882 break;
jbe@164 883 case LUA_TNUMBER:
jbe@164 884 if (tabletype == JSON_TABLETYPE_UNKNOWN) tabletype = JSON_TABLETYPE_ARRAY;
jbe@164 885 else if (tabletype == JSON_TABLETYPE_OBJECT) goto json_export_tabletype_error;
jbe@164 886 break;
jbe@154 887 }
jbe@154 888 }
jbe@154 889 }
jbe@164 890 pretty = lua_toboolean(L, json_export_internal_indentstring_idx);
jbe@164 891 level = lua_tointeger(L, json_export_internal_level_idx) + 1;
jbe@164 892 if (level > JSON_MAXDEPTH) {
jbe@164 893 return luaL_error(L, "More than %d nested JSON levels", JSON_MAXDEPTH);
jbe@164 894 }
jbe@154 895 switch (tabletype) {
jbe@154 896 case JSON_TABLETYPE_OBJECT:
jbe@164 897 if (!keycount) {
jbe@164 898 for (lua_pushnil(L); lua_next(L, json_export_internal_value_idx); lua_pop(L, 1)) {
jbe@164 899 if (lua_type(L, -2) == LUA_TSTRING) keycount++;
jbe@164 900 }
jbe@163 901 }
jbe@163 902 if (keycount) {
jbe@163 903 keybuf = calloc(keycount, sizeof(json_key_t));
jbe@163 904 if (!keybuf) return luaL_error(L, "Memory allocation failed in JSON library");
jbe@164 905 for (lua_pushnil(L); lua_next(L, json_export_internal_value_idx); lua_pop(L, 1)) {
jbe@163 906 if (lua_type(L, -2) == LUA_TSTRING) {
jbe@163 907 json_key_t *key = keybuf + (keypos++);
jbe@163 908 key->data = lua_tolstring(L, -2, &key->length);
jbe@163 909 }
jbe@163 910 }
jbe@163 911 qsort(keybuf, keycount, sizeof(json_key_t), (void *)json_key_cmp);
jbe@163 912 }
jbe@154 913 luaL_buffinit(L, &buf);
jbe@154 914 luaL_addchar(&buf, '{');
jbe@163 915 for (keypos=0; keypos<keycount; keypos++) {
jbe@163 916 json_key_t *key = keybuf + keypos;
jbe@163 917 if (keypos) luaL_addchar(&buf, ',');
jbe@164 918 if (pretty) {
jbe@164 919 luaL_addchar(&buf, '\n');
jbe@164 920 for (i=0; i<level; i++) {
jbe@164 921 lua_pushvalue(L, json_export_internal_indentstring_idx);
jbe@164 922 luaL_addvalue(&buf);
jbe@164 923 }
jbe@164 924 }
jbe@164 925 lua_pushcfunction(L, json_export_internal);
jbe@164 926 lua_pushvalue(L, json_export_internal_indentstring_idx);
jbe@164 927 lua_pushinteger(L, level);
jbe@163 928 lua_pushlstring(L, key->data, key->length);
jbe@164 929 if (lua_pcall(L, 3, 1, 0)) {
jbe@163 930 if (keybuf) free(keybuf);
jbe@163 931 return lua_error(L);
jbe@154 932 }
jbe@163 933 luaL_addvalue(&buf);
jbe@163 934 luaL_addchar(&buf, ':');
jbe@164 935 if (pretty) luaL_addchar(&buf, ' ');
jbe@164 936 lua_pushcfunction(L, json_export_internal);
jbe@164 937 lua_pushvalue(L, json_export_internal_indentstring_idx);
jbe@164 938 lua_pushinteger(L, level);
jbe@163 939 lua_pushlstring(L, key->data, key->length);
jbe@164 940 lua_rawget(L, json_export_internal_value_idx);
jbe@164 941 if (lua_pcall(L, 3, 1, 0)) {
jbe@163 942 if (keybuf) free(keybuf);
jbe@163 943 return lua_error(L);
jbe@163 944 }
jbe@163 945 luaL_addvalue(&buf);
jbe@154 946 }
jbe@163 947 if (keybuf) free(keybuf);
jbe@164 948 if (pretty && keycount != 0) {
jbe@164 949 luaL_addchar(&buf, '\n');
jbe@164 950 for (i=0; i<level-1; i++) {
jbe@164 951 lua_pushvalue(L, json_export_internal_indentstring_idx);
jbe@164 952 luaL_addvalue(&buf);
jbe@164 953 }
jbe@164 954 }
jbe@154 955 luaL_addchar(&buf, '}');
jbe@164 956 if (pretty && level == 1) luaL_addchar(&buf, '\n');
jbe@154 957 luaL_pushresult(&buf);
jbe@154 958 return 1;
jbe@154 959 case JSON_TABLETYPE_ARRAY:
jbe@164 960 lua_settop(L, json_export_internal_tmp_idx);
jbe@154 961 luaL_buffinit(L, &buf);
jbe@154 962 luaL_addchar(&buf, '[');
jbe@154 963 for (idx = 1; ; idx++) {
jbe@164 964 lua_rawgeti(L, json_export_internal_value_idx, idx);
jbe@154 965 if (lua_isnil(L, -1)) {
jbe@154 966 lua_pop(L, 1);
jbe@154 967 break;
jbe@154 968 }
jbe@164 969 lua_replace(L, json_export_internal_tmp_idx);
jbe@164 970 if (anyelement) luaL_addchar(&buf, ',');
jbe@164 971 anyelement = 1;
jbe@164 972 if (pretty) {
jbe@164 973 luaL_addchar(&buf, '\n');
jbe@164 974 for (i=0; i<level; i++) {
jbe@164 975 lua_pushvalue(L, json_export_internal_indentstring_idx);
jbe@164 976 luaL_addvalue(&buf);
jbe@164 977 }
jbe@164 978 }
jbe@164 979 lua_pushcfunction(L, json_export_internal);
jbe@164 980 lua_pushvalue(L, json_export_internal_indentstring_idx);
jbe@164 981 lua_pushinteger(L, level);
jbe@164 982 lua_pushvalue(L, json_export_internal_tmp_idx);
jbe@164 983 lua_call(L, 3, 1);
jbe@154 984 luaL_addvalue(&buf);
jbe@154 985 }
jbe@164 986 if (pretty && anyelement) {
jbe@164 987 luaL_addchar(&buf, '\n');
jbe@164 988 for (i=0; i<level-1; i++) {
jbe@164 989 lua_pushvalue(L, json_export_internal_indentstring_idx);
jbe@164 990 luaL_addvalue(&buf);
jbe@164 991 }
jbe@164 992 }
jbe@154 993 luaL_addchar(&buf, ']');
jbe@164 994 if (pretty && level == 1) luaL_addchar(&buf, '\n');
jbe@154 995 luaL_pushresult(&buf);
jbe@154 996 return 1;
jbe@154 997 }
jbe@154 998 json_export_tabletype_error:
jbe@154 999 return luaL_error(L, "JSON export not possible for ambiguous table (cannot decide whether it is an object or array)");
jbe@154 1000 }
jbe@166 1001 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 1002 }
jbe@154 1003
jbe@164 1004 static int json_export(lua_State *L) {
jbe@164 1005 lua_settop(L, 1);
jbe@164 1006 lua_pushcfunction(L, json_export_internal);
jbe@164 1007 lua_pushnil(L);
jbe@164 1008 lua_pushinteger(L, 0);
jbe@164 1009 lua_pushvalue(L, 1);
jbe@164 1010 lua_call(L, 3, 1);
jbe@164 1011 return 1;
jbe@164 1012 }
jbe@164 1013
jbe@164 1014 static int json_pretty(lua_State *L) {
jbe@164 1015 lua_settop(L, 2);
jbe@164 1016 lua_pushcfunction(L, json_export_internal);
jbe@164 1017 if (lua_isnil(L, 2)) lua_pushliteral(L, " ");
jbe@164 1018 else lua_pushvalue(L, 2);
jbe@164 1019 lua_pushinteger(L, 0);
jbe@164 1020 lua_pushvalue(L, 1);
jbe@164 1021 lua_call(L, 3, 1);
jbe@164 1022 return 1;
jbe@164 1023 }
jbe@164 1024
jbe@149 1025 // functions in library module:
jbe@121 1026 static const struct luaL_Reg json_module_functions[] = {
jbe@133 1027 {"object", json_object},
jbe@133 1028 {"array", json_array},
jbe@121 1029 {"import", json_import},
jbe@154 1030 {"export", json_export},
jbe@164 1031 {"pretty", json_pretty},
jbe@130 1032 {"get", json_get},
jbe@127 1033 {"type", json_type},
jbe@121 1034 {NULL, NULL}
jbe@121 1035 };
jbe@121 1036
jbe@149 1037 // metamethods for JSON objects, JSON arrays, and unknown JSON collections (object or array):
jbe@126 1038 static const struct luaL_Reg json_metatable_functions[] = {
jbe@130 1039 {"__len", json_len},
jbe@130 1040 {"__index", json_index},
jbe@130 1041 {"__newindex", json_newindex},
jbe@135 1042 {"__pairs", json_pairs},
jbe@134 1043 {"__ipairs", json_ipairs},
jbe@160 1044 {"__tostring", json_export},
jbe@126 1045 {NULL, NULL}
jbe@126 1046 };
jbe@126 1047
jbe@157 1048 // metamethods for JSON null marker:
jbe@157 1049 static const struct luaL_Reg json_nullmark_metamethods[] = {
jbe@157 1050 {"__tostring", json_nullmark_tostring},
jbe@157 1051 {NULL, NULL}
jbe@157 1052 };
jbe@157 1053
jbe@149 1054 // initializes json library:
jbe@121 1055 int luaopen_json(lua_State *L) {
jbe@149 1056 // empty stack:
jbe@126 1057 lua_settop(L, 0);
jbe@149 1058 // push library module onto stack position 1:
jbe@149 1059 lua_newtable(L);
jbe@149 1060 // register library functions:
jbe@149 1061 luaL_setfuncs(L, json_module_functions, 0);
jbe@149 1062 // create and store objectmt:
jbe@138 1063 lua_newtable(L);
jbe@138 1064 luaL_setfuncs(L, json_metatable_functions, 0);
jbe@144 1065 json_regstore(L, objectmt);
jbe@149 1066 // create and store arraymt:
jbe@138 1067 lua_newtable(L);
jbe@138 1068 luaL_setfuncs(L, json_metatable_functions, 0);
jbe@144 1069 json_regstore(L, arraymt);
jbe@149 1070 // create and store ephemeron table to store shadow tables for each JSON object/array
jbe@149 1071 // to allow NULL values returned as nil
jbe@149 1072 lua_newtable(L);
jbe@138 1073 lua_newtable(L); // metatable for ephemeron table
jbe@121 1074 lua_pushliteral(L, "__mode");
jbe@121 1075 lua_pushliteral(L, "k");
jbe@138 1076 lua_rawset(L, -3);
jbe@138 1077 lua_setmetatable(L, -2);
jbe@144 1078 json_regstore(L, shadowtbl);
jbe@157 1079 // set metatable of null marker and make it available through library module:
jbe@157 1080 json_pushnullmark(L);
jbe@157 1081 lua_newtable(L);
jbe@157 1082 luaL_setfuncs(L, json_nullmark_metamethods, 0);
jbe@157 1083 lua_setmetatable(L, -2);
jbe@157 1084 lua_setfield(L, 1, "null");
jbe@157 1085 // return library module (that's expected on top of stack):
jbe@121 1086 return 1;
jbe@121 1087 }

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