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annotate libraries/json/json.c @ 169:681367a16657

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json.array and json.object functions create a new container rather than marking a table
author jbe
date Fri Aug 01 05:12:21 2014 +0200 (2014-08-01)
parents e618ccd017a3
children c055d6d64586
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@136 148 char c; // variable to store a single character to be processed
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@136 178 // switch statement to handle certain (single) characters:
jbe@121 179 switch (c) {
jbe@136 180 // handle end of JSON document:
jbe@121 181 case 0:
jbe@136 182 // if end of JSON document was expected, then return top element of stack as result:
jbe@124 183 if (mode == JSON_STATE_END) return 1;
jbe@136 184 // otherwise, the JSON document was malformed:
jbe@167 185 if (level == 0) {
jbe@167 186 lua_pushnil(L);
jbe@167 187 lua_pushliteral(L, "Empty string");
jbe@167 188 } else {
jbe@167 189 json_import_unexpected_eof:
jbe@167 190 lua_pushnil(L);
jbe@167 191 lua_pushliteral(L, "Unexpected end of JSON document");
jbe@167 192 }
jbe@121 193 return 2;
jbe@136 194 // new JSON object:
jbe@121 195 case '{':
jbe@136 196 // if a JSON object is not expected here, then return an error:
jbe@146 197 if (
jbe@146 198 mode != JSON_STATE_VALUE &&
jbe@146 199 mode != JSON_STATE_OBJECT_VALUE &&
jbe@146 200 mode != JSON_STATE_ARRAY_VALUE
jbe@146 201 ) goto json_import_syntax_error;
jbe@136 202 // create JSON object on stack:
jbe@136 203 lua_newtable(L);
jbe@136 204 // set metatable of JSON object:
jbe@138 205 lua_pushvalue(L, json_import_objectmt_idx);
jbe@125 206 lua_setmetatable(L, -2);
jbe@136 207 // create internal shadow table on stack:
jbe@136 208 lua_newtable(L);
jbe@146 209 // register internal shadow table:
jbe@123 210 lua_pushvalue(L, -2);
jbe@123 211 lua_pushvalue(L, -2);
jbe@138 212 lua_rawset(L, json_import_shadowtbl_idx);
jbe@146 213 // expect object key (or end of object) to follow:
jbe@136 214 mode = JSON_STATE_OBJECT_KEY;
jbe@146 215 // jump to common code for opening JSON object and JSON array:
jbe@142 216 goto json_import_open;
jbe@136 217 // new JSON array:
jbe@121 218 case '[':
jbe@136 219 // if a JSON array is not expected here, then return an error:
jbe@146 220 if (
jbe@146 221 mode != JSON_STATE_VALUE &&
jbe@146 222 mode != JSON_STATE_OBJECT_VALUE &&
jbe@146 223 mode != JSON_STATE_ARRAY_VALUE
jbe@146 224 ) goto json_import_syntax_error;
jbe@136 225 // create JSON array on stack:
jbe@136 226 lua_newtable(L);
jbe@136 227 // set metatable of JSON array:
jbe@138 228 lua_pushvalue(L, json_import_arraymt_idx);
jbe@125 229 lua_setmetatable(L, -2);
jbe@136 230 // create internal shadow table on stack:
jbe@136 231 lua_newtable(L);
jbe@146 232 // register internal shadow table:
jbe@123 233 lua_pushvalue(L, -2);
jbe@123 234 lua_pushvalue(L, -2);
jbe@138 235 lua_rawset(L, json_import_shadowtbl_idx);
jbe@140 236 // add nil as key (needed to keep stack balance) and as magic to detect arrays:
jbe@140 237 lua_pushnil(L);
jbe@146 238 // expect array value (or end of array) to follow:
jbe@142 239 mode = JSON_STATE_ARRAY_VALUE;
jbe@142 240 // continue with common code for opening JSON object and JSON array:
jbe@146 241 // common code for opening JSON object or JSON array:
jbe@142 242 json_import_open:
jbe@142 243 // limit nested levels:
jbe@142 244 if (level >= JSON_MAXDEPTH) {
jbe@142 245 lua_pushnil(L);
jbe@164 246 lua_pushfstring(L, "More than %d nested JSON levels", JSON_MAXDEPTH);
jbe@142 247 return 2;
jbe@142 248 }
jbe@142 249 // additional buffer overflow protection:
jbe@142 250 if (!lua_checkstack(L, LUA_MINSTACK))
jbe@142 251 return luaL_error(L, "Caught stack overflow in JSON import function (too many nested levels and stack size too small)");
jbe@136 252 // increment level:
jbe@121 253 level++;
jbe@142 254 // consume input character:
jbe@142 255 pos++;
jbe@121 256 goto json_import_loop;
jbe@136 257 // end of JSON object:
jbe@121 258 case '}':
jbe@136 259 // if end of JSON object is not expected here, then return an error:
jbe@146 260 if (
jbe@146 261 mode != JSON_STATE_OBJECT_KEY &&
jbe@146 262 mode != JSON_STATE_OBJECT_SEPARATOR
jbe@146 263 ) goto json_import_syntax_error;
jbe@136 264 // jump to common code for end of JSON object and JSON array:
jbe@121 265 goto json_import_close;
jbe@136 266 // end of JSON array:
jbe@121 267 case ']':
jbe@136 268 // if end of JSON array is not expected here, then return an error:
jbe@146 269 if (
jbe@146 270 mode != JSON_STATE_ARRAY_VALUE &&
jbe@146 271 mode != JSON_STATE_ARRAY_SEPARATOR
jbe@146 272 ) goto json_import_syntax_error;
jbe@146 273 // pop nil key/magic (that was needed to keep stack balance):
jbe@140 274 lua_pop(L, 1);
jbe@136 275 // continue with common code for end of JSON object and JSON array:
jbe@136 276 // common code for end of JSON object or JSON array:
jbe@121 277 json_import_close:
jbe@136 278 // consume input character:
jbe@121 279 pos++;
jbe@136 280 // pop shadow table:
jbe@136 281 lua_pop(L, 1);
jbe@136 282 // check if nested:
jbe@121 283 if (--level) {
jbe@146 284 // if nested,
jbe@146 285 // check if outer(!) structure is an array or object:
jbe@140 286 if (lua_isnil(L, -2)) {
jbe@136 287 // select array value processing:
jbe@124 288 mode = JSON_STATE_ARRAY_VALUE;
jbe@121 289 } else {
jbe@136 290 // select object value processing:
jbe@124 291 mode = JSON_STATE_OBJECT_VALUE;
jbe@121 292 }
jbe@136 293 // store value in outer structure:
jbe@121 294 goto json_import_process_value;
jbe@121 295 }
jbe@136 296 // if not nested, then expect end of JSON document and continue with loop:
jbe@136 297 mode = JSON_STATE_END;
jbe@121 298 goto json_import_loop;
jbe@136 299 // key terminator:
jbe@121 300 case ':':
jbe@136 301 // if key terminator is not expected here, then return an error:
jbe@124 302 if (mode != JSON_STATE_OBJECT_KEY_TERMINATOR)
jbe@121 303 goto json_import_syntax_error;
jbe@136 304 // consume input character:
jbe@121 305 pos++;
jbe@146 306 // expect object value to follow:
jbe@124 307 mode = JSON_STATE_OBJECT_VALUE;
jbe@146 308 // continue with loop:
jbe@121 309 goto json_import_loop;
jbe@136 310 // value terminator (NOTE: trailing comma at end of value or key-value list is tolerated by this parser)
jbe@121 311 case ',':
jbe@146 312 // branch according to parser state:
jbe@124 313 if (mode == JSON_STATE_OBJECT_SEPARATOR) {
jbe@146 314 // expect an object key to follow:
jbe@124 315 mode = JSON_STATE_OBJECT_KEY;
jbe@124 316 } else if (mode == JSON_STATE_ARRAY_SEPARATOR) {
jbe@146 317 // expect an array value to follow:
jbe@124 318 mode = JSON_STATE_ARRAY_VALUE;
jbe@121 319 } else {
jbe@136 320 // if value terminator is not expected here, then return an error:
jbe@136 321 goto json_import_syntax_error;
jbe@121 322 }
jbe@136 323 // consume input character:
jbe@121 324 pos++;
jbe@136 325 // continue with loop:
jbe@121 326 goto json_import_loop;
jbe@136 327 // string literal:
jbe@121 328 case '"':
jbe@146 329 // consume quote character:
jbe@146 330 pos++;
jbe@162 331 // find last character in input string:
jbe@162 332 outlen = pos;
jbe@162 333 while ((c = str[outlen]) != '"') {
jbe@161 334 // consume one character:
jbe@162 335 outlen++;
jbe@161 336 // handle unexpected end of JSON document:
jbe@161 337 if (c == 0) goto json_import_unexpected_eof;
jbe@161 338 // consume one extra character when encountering an escaped quote:
jbe@162 339 else if (c == '\\' && str[outlen] == '"') outlen++;
jbe@161 340 }
jbe@162 341 // determine buffer length:
jbe@162 342 outlen -= pos;
jbe@161 343 // check if string is non empty:
jbe@162 344 if (outlen) {
jbe@161 345 // prepare buffer to decode string (with maximum possible length) and set write position to zero:
jbe@162 346 cbuf = luaL_buffinitsize(L, &luabuf, outlen);
jbe@162 347 outlen = 0;
jbe@161 348 // loop through the characters until encountering end quote:
jbe@161 349 while ((c = str[pos++]) != '"') {
jbe@162 350 // NOTE: unexpected end cannot happen anymore
jbe@162 351 if (c < 32 || c == 127) {
jbe@161 352 // do not allow ASCII control characters:
jbe@161 353 // NOTE: illegal UTF-8 sequences and extended control characters are not sanitized
jbe@161 354 // by this parser to allow different encodings than Unicode
jbe@161 355 lua_pushnil(L);
jbe@161 356 lua_pushliteral(L, "Unexpected control character in JSON string");
jbe@161 357 return 2;
jbe@161 358 } else if (c == '\\') {
jbe@161 359 // read next char after backslash escape:
jbe@161 360 c = str[pos++];
jbe@161 361 switch (c) {
jbe@161 362 // unexpected end-of-string:
jbe@161 363 case 0:
jbe@161 364 goto json_import_unexpected_eof;
jbe@161 365 // unescaping of quotation mark, slash, and backslash:
jbe@161 366 case '"':
jbe@161 367 case '/':
jbe@161 368 case '\\':
jbe@162 369 cbuf[outlen++] = c;
jbe@161 370 break;
jbe@161 371 // unescaping of backspace:
jbe@162 372 case 'b': cbuf[outlen++] = '\b'; break;
jbe@161 373 // unescaping of form-feed:
jbe@162 374 case 'f': cbuf[outlen++] = '\f'; break;
jbe@161 375 // unescaping of new-line:
jbe@162 376 case 'n': cbuf[outlen++] = '\n'; break;
jbe@161 377 // unescaping of carriage-return:
jbe@162 378 case 'r': cbuf[outlen++] = '\r'; break;
jbe@161 379 // unescaping of tabulator:
jbe@162 380 case 't': cbuf[outlen++] = '\t'; break;
jbe@161 381 // unescaping of UTF-16 characters
jbe@161 382 case 'u':
jbe@167 383 // decode 4 hex nibbles:
jbe@167 384 json_import_readhex(codepoint);
jbe@167 385 // handle surrogate character:
jbe@167 386 if (json_utf16_surrogate(codepoint)) {
jbe@167 387 // check if first surrogate is in valid range:
jbe@167 388 if (json_utf16_lead(codepoint)) {
jbe@167 389 // require second surrogate:
jbe@167 390 if ((c = str[pos++]) != '\\' || (c = str[pos++]) != 'u') {
jbe@167 391 if (c == 0) goto json_import_unexpected_eof;
jbe@167 392 else goto json_import_wrong_surrogate;
jbe@167 393 }
jbe@167 394 // read 4 hex nibbles of second surrogate character:
jbe@167 395 json_import_readhex(utf16tail);
jbe@167 396 // check if second surrogate is in valid range:
jbe@167 397 if (!json_utf16_tail(utf16tail)) goto json_import_wrong_surrogate;
jbe@167 398 // calculate codepoint:
jbe@167 399 codepoint = 0x10000 + (utf16tail - 0xDC00) + (codepoint - 0xD800) * 0x400;
jbe@167 400 } else {
jbe@167 401 // throw error for wrong surrogates:
jbe@167 402 json_import_wrong_surrogate:
jbe@167 403 lua_pushnil(L);
jbe@167 404 lua_pushliteral(L, "Illegal UTF-16 surrogate in JSON string escape sequence");
jbe@167 405 return 2;
jbe@167 406 }
jbe@167 407 }
jbe@167 408 // encode as UTF-8:
jbe@167 409 if (codepoint < 0x80) {
jbe@167 410 cbuf[outlen++] = (char)codepoint;
jbe@167 411 } else if (codepoint < 0x800) {
jbe@167 412 cbuf[outlen++] = (char)(0xc0 | (codepoint >> 6));
jbe@167 413 cbuf[outlen++] = (char)(0x80 | (codepoint & 0x3f));
jbe@167 414 } else if (codepoint < 0x10000) {
jbe@167 415 cbuf[outlen++] = (char)(0xe0 | (codepoint >> 12));
jbe@167 416 cbuf[outlen++] = (char)(0x80 | ((codepoint >> 6) & 0x3f));
jbe@167 417 cbuf[outlen++] = (char)(0x80 | (codepoint & 0x3f));
jbe@167 418 } else {
jbe@167 419 cbuf[outlen++] = (char)(0xf0 | (codepoint >> 18));
jbe@167 420 cbuf[outlen++] = (char)(0x80 | ((codepoint >> 12) & 0x3f));
jbe@167 421 cbuf[outlen++] = (char)(0x80 | ((codepoint >> 6) & 0x3f));
jbe@167 422 cbuf[outlen++] = (char)(0x80 | (codepoint & 0x3f));
jbe@167 423 }
jbe@167 424 break;
jbe@161 425 // unexpected escape sequence:
jbe@161 426 default:
jbe@167 427 json_import_unexpected_escape:
jbe@161 428 lua_pushnil(L);
jbe@161 429 lua_pushliteral(L, "Unexpected string escape sequence in JSON document");
jbe@161 430 return 2;
jbe@161 431 }
jbe@161 432 } else {
jbe@161 433 // normal character:
jbe@162 434 cbuf[outlen++] = c;
jbe@121 435 }
jbe@121 436 }
jbe@161 437 // process buffer to Lua string:
jbe@162 438 luaL_pushresultsize(&luabuf, outlen);
jbe@161 439 } else {
jbe@161 440 // if JSON string is empty,
jbe@161 441 // push empty Lua string:
jbe@161 442 lua_pushliteral(L, "");
jbe@167 443 // consume closing quote:
jbe@167 444 pos++;
jbe@121 445 }
jbe@136 446 // continue with processing of decoded string:
jbe@121 447 goto json_import_process_value;
jbe@121 448 }
jbe@136 449 // process values whose type is is not deducible from a single character:
jbe@136 450 if ((c >= '0' && c <= '9') || c == '-' || c == '+') {
jbe@146 451 // for numbers,
jbe@146 452 // use strtod() call to parse a (double precision) floating point number:
jbe@167 453 double numval;
jbe@122 454 char *endptr;
jbe@122 455 numval = strtod(str+pos, &endptr);
jbe@146 456 // catch parsing errors:
jbe@122 457 if (endptr == str+pos) goto json_import_syntax_error;
jbe@146 458 // consume characters that were parsed:
jbe@122 459 pos += endptr - (str+pos);
jbe@146 460 // push parsed (double precision) floating point number on Lua stack:
jbe@122 461 lua_pushnumber(L, numval);
jbe@122 462 } else if (!strncmp(str+pos, "true", 4)) {
jbe@136 463 // consume 4 input characters for "true":
jbe@121 464 pos += 4;
jbe@147 465 // put Lua true value onto stack:
jbe@136 466 lua_pushboolean(L, 1);
jbe@121 467 } else if (!strncmp(str+pos, "false", 5)) {
jbe@136 468 // consume 5 input characters for "false":
jbe@121 469 pos += 5;
jbe@147 470 // put Lua false value onto stack:
jbe@136 471 lua_pushboolean(L, 0);
jbe@121 472 } else if (!strncmp(str+pos, "null", 4)) {
jbe@136 473 // consume 4 input characters for "null":
jbe@136 474 pos += 4;
jbe@153 475 // different behavor for top-level and sub-levels:
jbe@153 476 if (level) {
jbe@153 477 // if sub-level,
jbe@153 478 // push special null-marker onto stack:
jbe@155 479 json_pushnullmark(L);
jbe@153 480 } else {
jbe@153 481 // if top-level,
jbe@153 482 // push nil onto stack:
jbe@153 483 lua_pushnil(L);
jbe@153 484 }
jbe@121 485 } else {
jbe@136 486 // all other cases are a syntax error:
jbe@121 487 goto json_import_syntax_error;
jbe@121 488 }
jbe@136 489 // process a decoded value or key value pair (expected on top of Lua stack):
jbe@136 490 json_import_process_value:
jbe@121 491 switch (mode) {
jbe@136 492 // an object key has been read:
jbe@124 493 case JSON_STATE_OBJECT_KEY:
jbe@136 494 // if an object key is not a string, then this is a syntax error:
jbe@121 495 if (lua_type(L, -1) != LUA_TSTRING) goto json_import_syntax_error;
jbe@146 496 // expect key terminator to follow:
jbe@124 497 mode = JSON_STATE_OBJECT_KEY_TERMINATOR;
jbe@146 498 // continue with loop:
jbe@121 499 goto json_import_loop;
jbe@136 500 // a key value pair has been read:
jbe@124 501 case JSON_STATE_OBJECT_VALUE:
jbe@136 502 // store key value pair in outer shadow table:
jbe@130 503 lua_rawset(L, -3);
jbe@146 504 // expect value terminator (or end of object) to follow:
jbe@124 505 mode = JSON_STATE_OBJECT_SEPARATOR;
jbe@146 506 // continue with loop:
jbe@121 507 goto json_import_loop;
jbe@136 508 // an array value has been read:
jbe@124 509 case JSON_STATE_ARRAY_VALUE:
jbe@152 510 // get current array length:
jbe@152 511 arraylen = lua_rawlen(L, -3);
jbe@152 512 // throw error if array would exceed INT_MAX elements:
jbe@152 513 // TODO: Lua 5.3 may support more elements
jbe@152 514 if (arraylen >= INT_MAX) {
jbe@152 515 lua_pushnil(L);
jbe@152 516 lua_pushfstring(L, "Array exceeded length of %d elements", INT_MAX);
jbe@152 517 }
jbe@136 518 // store value in outer shadow table:
jbe@152 519 lua_rawseti(L, -3, arraylen + 1);
jbe@146 520 // expect value terminator (or end of object) to follow:
jbe@124 521 mode = JSON_STATE_ARRAY_SEPARATOR;
jbe@146 522 // continue with loop
jbe@121 523 goto json_import_loop;
jbe@136 524 // a single value has been read:
jbe@124 525 case JSON_STATE_VALUE:
jbe@136 526 // leave value on top of stack, expect end of JSON document, and continue with loop:
jbe@124 527 mode = JSON_STATE_END;
jbe@121 528 goto json_import_loop;
jbe@121 529 }
jbe@146 530 // syntax error handling (reachable by goto statement):
jbe@136 531 json_import_syntax_error:
jbe@121 532 lua_pushnil(L);
jbe@121 533 lua_pushliteral(L, "Syntax error in JSON document");
jbe@121 534 return 2;
jbe@121 535 }
jbe@121 536
jbe@146 537 // special Lua stack indicies for json_path function:
jbe@138 538 #define json_path_shadowtbl_idx 1
jbe@146 539
jbe@146 540 // stack offset of arguments to json_path function:
jbe@155 541 #define json_path_idxshift 1
jbe@138 542
jbe@146 543 // gets a value or its type from a JSON document (passed as first argument)
jbe@147 544 // using a path (passed as variable number of keys after first argument):
jbe@137 545 static int json_path(lua_State *L, int type_mode) {
jbe@146 546 int stacktop; // stack index of top of stack (after shifting)
jbe@146 547 int idx = 2 + json_path_idxshift; // stack index of current argument to process
jbe@148 548 // insert shadowtbl into stack at position 1 (shifting the arguments):
jbe@144 549 json_regfetch(L, shadowtbl);
jbe@138 550 lua_insert(L, 1);
jbe@146 551 // store stack index of top of stack:
jbe@138 552 stacktop = lua_gettop(L);
jbe@146 553 // use first argument as "current value" (stored on top of stack):
jbe@138 554 lua_pushvalue(L, 1 + json_path_idxshift);
jbe@146 555 // process each "path key" (2nd argument and following arguments):
jbe@138 556 while (idx <= stacktop) {
jbe@146 557 // if "current value" (on top of stack) is nil, then the path cannot be walked and nil is returned:
jbe@137 558 if (lua_isnil(L, -1)) return 1;
jbe@137 559 // try to get shadow table of "current value":
jbe@130 560 lua_pushvalue(L, -1);
jbe@138 561 lua_rawget(L, json_path_shadowtbl_idx);
jbe@126 562 if (lua_isnil(L, -1)) {
jbe@137 563 // if no shadow table is found,
jbe@130 564 if (lua_type(L, -1) == LUA_TTABLE) {
jbe@146 565 // and if "current value" is a table,
jbe@146 566 // drop nil from stack:
jbe@146 567 lua_pop(L, 1);
jbe@137 568 // get "next value" using the "path key":
jbe@130 569 lua_pushvalue(L, idx++);
jbe@130 570 lua_gettable(L, -2);
jbe@130 571 } else {
jbe@137 572 // if "current value" is not a table,
jbe@146 573 // then the path cannot be walked and nil (already on top of stack) is returned:
jbe@137 574 return 1;
jbe@130 575 }
jbe@130 576 } else {
jbe@137 577 // if a shadow table is found,
jbe@137 578 // set "current value" to its shadow table:
jbe@130 579 lua_replace(L, -2);
jbe@137 580 // get "next value" using the "path key":
jbe@130 581 lua_pushvalue(L, idx++);
jbe@130 582 lua_rawget(L, -2);
jbe@126 583 }
jbe@137 584 // the "next value" replaces the "current value":
jbe@130 585 lua_replace(L, -2);
jbe@126 586 }
jbe@137 587 if (!type_mode) {
jbe@137 588 // if a value (and not its type) was requested,
jbe@137 589 // check if value is the null-marker, and store nil on top of Lua stack in that case:
jbe@155 590 if (json_isnullmark(L, -1)) lua_pushnil(L);
jbe@137 591 } else {
jbe@137 592 // if the type was requested,
jbe@137 593 // check if value is the null-marker:
jbe@155 594 if (json_isnullmark(L, -1)) {
jbe@137 595 // if yes, store string "null" on top of Lua stack:
jbe@130 596 lua_pushliteral(L, "null");
jbe@137 597 } else {
jbe@137 598 // otherwise,
jbe@138 599 // check if metatable indicates "object" or "array":
jbe@138 600 if (lua_getmetatable(L, -1)) {
jbe@144 601 json_regfetch(L, objectmt);
jbe@138 602 if (lua_rawequal(L, -2, -1)) {
jbe@146 603 // if value has metatable for JSON objects,
jbe@138 604 // return string "object":
jbe@138 605 lua_pushliteral(L, "object");
jbe@138 606 return 1;
jbe@138 607 }
jbe@144 608 json_regfetch(L, arraymt);
jbe@138 609 if (lua_rawequal(L, -3, -1)) {
jbe@146 610 // if value has metatable for JSON arrays,
jbe@146 611 // return string "object":
jbe@138 612 lua_pushliteral(L, "array");
jbe@138 613 return 1;
jbe@138 614 }
jbe@146 615 // remove 3 metatables (one of the value, two for comparison) from stack:
jbe@138 616 lua_pop(L, 3);
jbe@138 617 }
jbe@138 618 // otherwise, get the Lua type:
jbe@138 619 lua_pushstring(L, lua_typename(L, lua_type(L, -1)));
jbe@126 620 }
jbe@126 621 }
jbe@137 622 // return the top most value on the Lua stack:
jbe@137 623 return 1;
jbe@130 624 }
jbe@130 625
jbe@147 626 // gets a value from a JSON document (passed as first argument)
jbe@147 627 // using a path (passed as variable number of keys after first argument):
jbe@130 628 static int json_get(lua_State *L) {
jbe@137 629 return json_path(L, 0);
jbe@130 630 }
jbe@130 631
jbe@147 632 // gets a value's type from a JSON document (passed as first argument)
jbe@147 633 // using a path (variable number of keys after first argument):
jbe@130 634 static int json_type(lua_State *L) {
jbe@137 635 return json_path(L, 1);
jbe@130 636 }
jbe@130 637
jbe@147 638 // returns the length of a JSON array (or zero for a table without numeric keys):
jbe@130 639 static int json_len(lua_State *L) {
jbe@147 640 // stack shall contain one function argument:
jbe@130 641 lua_settop(L, 1);
jbe@148 642 // try to get corresponding shadow table for first argument:
jbe@144 643 json_regfetch(L, shadowtbl);
jbe@130 644 lua_pushvalue(L, 1);
jbe@138 645 lua_rawget(L, -2);
jbe@147 646 // if shadow table does not exist, return length of argument, else length of shadow table:
jbe@147 647 lua_pushnumber(L, lua_rawlen(L, lua_isnil(L, -1) ? 1 : -1));
jbe@123 648 return 1;
jbe@123 649 }
jbe@123 650
jbe@130 651 static int json_index(lua_State *L) {
jbe@148 652 // stack shall contain two function arguments:
jbe@130 653 lua_settop(L, 2);
jbe@155 654 // get corresponding shadow table for first argument:
jbe@144 655 json_regfetch(L, shadowtbl);
jbe@130 656 lua_pushvalue(L, 1);
jbe@155 657 lua_rawget(L, -2);
jbe@148 658 // throw error if no shadow table was found:
jbe@139 659 if (lua_isnil(L, -1)) return luaL_error(L, "Shadow table not found");
jbe@148 660 // use key passed as second argument to lookup value in shadow table:
jbe@130 661 lua_pushvalue(L, 2);
jbe@130 662 lua_rawget(L, -2);
jbe@148 663 // if value is null-marker, then push nil onto stack:
jbe@155 664 if (json_isnullmark(L, -1)) lua_pushnil(L);
jbe@148 665 // return either looked up value, or nil
jbe@127 666 return 1;
jbe@127 667 }
jbe@127 668
jbe@130 669 static int json_newindex(lua_State *L) {
jbe@148 670 // stack shall contain three function arguments:
jbe@130 671 lua_settop(L, 3);
jbe@148 672 // get corresponding shadow table for first argument:
jbe@144 673 json_regfetch(L, shadowtbl);
jbe@123 674 lua_pushvalue(L, 1);
jbe@143 675 lua_rawget(L, -2);
jbe@148 676 // throw error if no shadow table was found:
jbe@130 677 if (lua_isnil(L, -1)) return luaL_error(L, "Shadow table not found");
jbe@148 678 // replace first argument with shadow table:
jbe@130 679 lua_replace(L, 1);
jbe@148 680 // reset stack and use second and third argument to write to shadow table:
jbe@139 681 lua_settop(L, 3);
jbe@130 682 lua_rawset(L, 1);
jbe@148 683 // return nothing:
jbe@148 684 return 0;
jbe@121 685 }
jbe@121 686
jbe@135 687 static int json_pairs_iterfunc(lua_State *L) {
jbe@149 688 // stack shall contain two function arguments:
jbe@135 689 lua_settop(L, 2);
jbe@155 690 // get corresponding shadow table for first argument:
jbe@144 691 json_regfetch(L, shadowtbl);
jbe@135 692 lua_pushvalue(L, 1);
jbe@155 693 lua_rawget(L, -2);
jbe@149 694 // throw error if no shadow table was found:
jbe@135 695 if (lua_isnil(L, -1)) return luaL_error(L, "Shadow table not found");
jbe@149 696 // get next key value pair from shadow table (using previous key from argument 2)
jbe@149 697 // and return nothing if there is no next pair:
jbe@135 698 lua_pushvalue(L, 2);
jbe@135 699 if (!lua_next(L, -2)) return 0;
jbe@149 700 // replace null-marker with nil:
jbe@155 701 if (json_isnullmark(L, -1)) {
jbe@135 702 lua_pop(L, 1);
jbe@135 703 lua_pushnil(L);
jbe@135 704 }
jbe@149 705 // return key and value (or key and nil, if null-marker was found):
jbe@135 706 return 2;
jbe@135 707 }
jbe@135 708
jbe@149 709 // returns a triple such that 'for key, value in pairs(obj) do ... end'
jbe@149 710 // iterates through all key value pairs (including JSON null keys represented as Lua nil):
jbe@135 711 static int json_pairs(lua_State *L) {
jbe@149 712 // return triple of function json_pairs_iterfunc, first argument, and nil:
jbe@139 713 lua_pushcfunction(L, json_pairs_iterfunc);
jbe@135 714 lua_pushvalue(L, 1);
jbe@135 715 lua_pushnil(L);
jbe@135 716 return 3;
jbe@135 717 }
jbe@135 718
jbe@134 719 static int json_ipairs_iterfunc(lua_State *L) {
jbe@152 720 lua_Integer idx;
jbe@149 721 // stack shall contain two function arguments:
jbe@134 722 lua_settop(L, 2);
jbe@149 723 // calculate new index by incrementing second argument:
jbe@134 724 idx = lua_tointeger(L, 2) + 1;
jbe@149 725 // get corresponding shadow table for first argument:
jbe@155 726 json_regfetch(L, shadowtbl);
jbe@134 727 lua_pushvalue(L, 1);
jbe@155 728 lua_rawget(L, -2);
jbe@149 729 // throw error if no shadow table was found:
jbe@134 730 if (lua_isnil(L, -1)) return luaL_error(L, "Shadow table not found");
jbe@149 731 // do integer lookup in shadow table:
jbe@134 732 lua_rawgeti(L, -1, idx);
jbe@149 733 // return nothing if there was no value:
jbe@134 734 if (lua_isnil(L, -1)) return 0;
jbe@149 735 // return new index and
jbe@149 736 // either the looked up value if it is not equal to the null-marker
jbe@149 737 // or nil instead of null-marker:
jbe@134 738 lua_pushinteger(L, idx);
jbe@155 739 if (json_isnullmark(L, -2)) lua_pushnil(L);
jbe@134 740 else lua_pushvalue(L, -2);
jbe@134 741 return 2;
jbe@134 742 }
jbe@134 743
jbe@149 744 // returns a triple such that 'for idx, value in ipairs(ary) do ... end'
jbe@149 745 // iterates through all values (including JSON null represented as Lua nil):
jbe@134 746 static int json_ipairs(lua_State *L) {
jbe@149 747 // return triple of function json_ipairs_iterfunc, first argument, and zero:
jbe@139 748 lua_pushcfunction(L, json_ipairs_iterfunc);
jbe@134 749 lua_pushvalue(L, 1);
jbe@134 750 lua_pushinteger(L, 0);
jbe@134 751 return 3;
jbe@134 752 }
jbe@134 753
jbe@163 754 typedef struct {
jbe@163 755 size_t length;
jbe@163 756 const char *data;
jbe@163 757 } json_key_t;
jbe@163 758
jbe@163 759 static int json_key_cmp(json_key_t *key1, json_key_t *key2) {
jbe@163 760 size_t pos = 0;
jbe@163 761 unsigned char c1, c2;
jbe@163 762 while (1) {
jbe@163 763 if (key1->length > pos) {
jbe@163 764 if (key2->length > pos) {
jbe@163 765 c1 = key1->data[pos];
jbe@163 766 c2 = key2->data[pos];
jbe@163 767 if (c1 < c2) return -1;
jbe@163 768 else if (c1 > c2) return 1;
jbe@163 769 } else {
jbe@163 770 return 1;
jbe@163 771 }
jbe@163 772 } else {
jbe@163 773 if (key2->length > pos) {
jbe@163 774 return -1;
jbe@163 775 } else {
jbe@163 776 return 0;
jbe@163 777 }
jbe@163 778 }
jbe@163 779 pos++;
jbe@163 780 }
jbe@163 781 }
jbe@163 782
jbe@154 783 #define JSON_TABLETYPE_UNKNOWN 0
jbe@154 784 #define JSON_TABLETYPE_OBJECT 1
jbe@154 785 #define JSON_TABLETYPE_ARRAY 2
jbe@154 786
jbe@164 787 #define json_export_internal_indentstring_idx 1
jbe@164 788 #define json_export_internal_level_idx 2
jbe@164 789 #define json_export_internal_value_idx 3
jbe@164 790 #define json_export_internal_tmp_idx 4
jbe@164 791
jbe@164 792 static int json_export_internal(lua_State *L) {
jbe@164 793 int level;
jbe@164 794 int pretty;
jbe@164 795 int i;
jbe@154 796 lua_Number num;
jbe@154 797 const char *str;
jbe@154 798 unsigned char c;
jbe@154 799 size_t strlen;
jbe@154 800 size_t pos = 0;
jbe@154 801 luaL_Buffer buf;
jbe@154 802 char hexcode[7]; // backslash, character 'u', 4 hex digits, and terminating NULL byte
jbe@154 803 int tabletype = JSON_TABLETYPE_UNKNOWN;
jbe@164 804 int anyelement = 0;
jbe@163 805 size_t keycount = 0;
jbe@163 806 size_t keypos = 0;
jbe@165 807 json_key_t *keybuf = NULL;
jbe@154 808 lua_Integer idx;
jbe@164 809 lua_settop(L, json_export_internal_value_idx);
jbe@164 810 if (json_isnullmark(L, json_export_internal_value_idx)) {
jbe@164 811 lua_pop(L, 1);
jbe@157 812 lua_pushnil(L);
jbe@157 813 }
jbe@164 814 switch (lua_type(L, json_export_internal_value_idx)) {
jbe@154 815 case LUA_TNIL:
jbe@154 816 lua_pushliteral(L, "null");
jbe@154 817 return 1;
jbe@154 818 case LUA_TNUMBER:
jbe@164 819 num = lua_tonumber(L, json_export_internal_value_idx);
jbe@154 820 if (isnan(num)) return luaL_error(L, "JSON export not possible for NaN value");
jbe@154 821 if (isinf(num)) return luaL_error(L, "JSON export not possible for infinite numbers");
jbe@164 822 lua_tostring(L, json_export_internal_value_idx);
jbe@154 823 return 1;
jbe@154 824 case LUA_TBOOLEAN:
jbe@164 825 if (lua_toboolean(L, json_export_internal_value_idx)) {
jbe@164 826 lua_pushliteral(L, "true");
jbe@164 827 } else {
jbe@164 828 lua_pushliteral(L, "false");
jbe@164 829 }
jbe@154 830 return 1;
jbe@154 831 case LUA_TSTRING:
jbe@164 832 str = lua_tolstring(L, 3, &strlen);
jbe@154 833 luaL_buffinit(L, &buf);
jbe@154 834 luaL_addchar(&buf, '"');
jbe@154 835 while (pos < strlen) {
jbe@154 836 c = str[pos++];
jbe@154 837 if (c == '"') luaL_addstring(&buf, "\\\"");
jbe@154 838 else if (c == '\\') luaL_addstring(&buf, "\\\\");
jbe@154 839 else if (c == 127) luaL_addstring(&buf, "\\u007F");
jbe@154 840 else if (c >= 32) luaL_addchar(&buf, c);
jbe@154 841 else if (c == '\b') luaL_addstring(&buf, "\\b");
jbe@154 842 else if (c == '\f') luaL_addstring(&buf, "\\f");
jbe@154 843 else if (c == '\n') luaL_addstring(&buf, "\\n");
jbe@154 844 else if (c == '\r') luaL_addstring(&buf, "\\r");
jbe@154 845 else if (c == '\t') luaL_addstring(&buf, "\\t");
jbe@154 846 else if (c == '\v') luaL_addstring(&buf, "\\v");
jbe@154 847 else {
jbe@154 848 sprintf(hexcode, "\\u%04X", c);
jbe@154 849 luaL_addstring(&buf, hexcode);
jbe@154 850 }
jbe@154 851 }
jbe@154 852 luaL_addchar(&buf, '"');
jbe@154 853 luaL_pushresult(&buf);
jbe@154 854 return 1;
jbe@154 855 case LUA_TTABLE:
jbe@164 856 if (lua_getmetatable(L, json_export_internal_value_idx)) {
jbe@154 857 json_regfetch(L, objectmt);
jbe@154 858 if (lua_rawequal(L, -2, -1)) {
jbe@154 859 tabletype = JSON_TABLETYPE_OBJECT;
jbe@154 860 } else {
jbe@154 861 json_regfetch(L, arraymt);
jbe@164 862 if (lua_rawequal(L, -3, -1)) {
jbe@164 863 tabletype = JSON_TABLETYPE_ARRAY;
jbe@164 864 } else {
jbe@164 865 return luaL_error(L, "JSON export not possible for tables with nonsupported metatable");
jbe@164 866 }
jbe@154 867 }
jbe@154 868 }
jbe@154 869 json_regfetch(L, shadowtbl);
jbe@164 870 lua_pushvalue(L, json_export_internal_value_idx);
jbe@154 871 lua_rawget(L, -2);
jbe@164 872 if (!lua_isnil(L, -1)) lua_replace(L, json_export_internal_value_idx);
jbe@164 873 lua_settop(L, json_export_internal_value_idx);
jbe@154 874 if (tabletype == JSON_TABLETYPE_UNKNOWN) {
jbe@164 875 for (lua_pushnil(L); lua_next(L, json_export_internal_value_idx); lua_pop(L, 1)) {
jbe@164 876 switch (lua_type(L, -2)) {
jbe@164 877 case LUA_TSTRING:
jbe@164 878 keycount++;
jbe@164 879 if (tabletype == JSON_TABLETYPE_UNKNOWN) tabletype = JSON_TABLETYPE_OBJECT;
jbe@164 880 else if (tabletype == JSON_TABLETYPE_ARRAY) goto json_export_tabletype_error;
jbe@164 881 break;
jbe@164 882 case LUA_TNUMBER:
jbe@164 883 if (tabletype == JSON_TABLETYPE_UNKNOWN) tabletype = JSON_TABLETYPE_ARRAY;
jbe@164 884 else if (tabletype == JSON_TABLETYPE_OBJECT) goto json_export_tabletype_error;
jbe@164 885 break;
jbe@154 886 }
jbe@154 887 }
jbe@154 888 }
jbe@164 889 pretty = lua_toboolean(L, json_export_internal_indentstring_idx);
jbe@164 890 level = lua_tointeger(L, json_export_internal_level_idx) + 1;
jbe@164 891 if (level > JSON_MAXDEPTH) {
jbe@164 892 return luaL_error(L, "More than %d nested JSON levels", JSON_MAXDEPTH);
jbe@164 893 }
jbe@154 894 switch (tabletype) {
jbe@154 895 case JSON_TABLETYPE_OBJECT:
jbe@164 896 if (!keycount) {
jbe@164 897 for (lua_pushnil(L); lua_next(L, json_export_internal_value_idx); lua_pop(L, 1)) {
jbe@164 898 if (lua_type(L, -2) == LUA_TSTRING) keycount++;
jbe@164 899 }
jbe@163 900 }
jbe@163 901 if (keycount) {
jbe@163 902 keybuf = calloc(keycount, sizeof(json_key_t));
jbe@163 903 if (!keybuf) return luaL_error(L, "Memory allocation failed in JSON library");
jbe@164 904 for (lua_pushnil(L); lua_next(L, json_export_internal_value_idx); lua_pop(L, 1)) {
jbe@163 905 if (lua_type(L, -2) == LUA_TSTRING) {
jbe@163 906 json_key_t *key = keybuf + (keypos++);
jbe@163 907 key->data = lua_tolstring(L, -2, &key->length);
jbe@163 908 }
jbe@163 909 }
jbe@163 910 qsort(keybuf, keycount, sizeof(json_key_t), (void *)json_key_cmp);
jbe@163 911 }
jbe@154 912 luaL_buffinit(L, &buf);
jbe@154 913 luaL_addchar(&buf, '{');
jbe@163 914 for (keypos=0; keypos<keycount; keypos++) {
jbe@163 915 json_key_t *key = keybuf + keypos;
jbe@163 916 if (keypos) luaL_addchar(&buf, ',');
jbe@164 917 if (pretty) {
jbe@164 918 luaL_addchar(&buf, '\n');
jbe@164 919 for (i=0; i<level; i++) {
jbe@164 920 lua_pushvalue(L, json_export_internal_indentstring_idx);
jbe@164 921 luaL_addvalue(&buf);
jbe@164 922 }
jbe@164 923 }
jbe@164 924 lua_pushcfunction(L, json_export_internal);
jbe@164 925 lua_pushvalue(L, json_export_internal_indentstring_idx);
jbe@164 926 lua_pushinteger(L, level);
jbe@163 927 lua_pushlstring(L, key->data, key->length);
jbe@164 928 if (lua_pcall(L, 3, 1, 0)) {
jbe@163 929 if (keybuf) free(keybuf);
jbe@163 930 return lua_error(L);
jbe@154 931 }
jbe@163 932 luaL_addvalue(&buf);
jbe@163 933 luaL_addchar(&buf, ':');
jbe@164 934 if (pretty) luaL_addchar(&buf, ' ');
jbe@164 935 lua_pushcfunction(L, json_export_internal);
jbe@164 936 lua_pushvalue(L, json_export_internal_indentstring_idx);
jbe@164 937 lua_pushinteger(L, level);
jbe@163 938 lua_pushlstring(L, key->data, key->length);
jbe@164 939 lua_rawget(L, json_export_internal_value_idx);
jbe@164 940 if (lua_pcall(L, 3, 1, 0)) {
jbe@163 941 if (keybuf) free(keybuf);
jbe@163 942 return lua_error(L);
jbe@163 943 }
jbe@163 944 luaL_addvalue(&buf);
jbe@154 945 }
jbe@163 946 if (keybuf) free(keybuf);
jbe@164 947 if (pretty && keycount != 0) {
jbe@164 948 luaL_addchar(&buf, '\n');
jbe@164 949 for (i=0; i<level-1; i++) {
jbe@164 950 lua_pushvalue(L, json_export_internal_indentstring_idx);
jbe@164 951 luaL_addvalue(&buf);
jbe@164 952 }
jbe@164 953 }
jbe@154 954 luaL_addchar(&buf, '}');
jbe@164 955 if (pretty && level == 1) luaL_addchar(&buf, '\n');
jbe@154 956 luaL_pushresult(&buf);
jbe@154 957 return 1;
jbe@154 958 case JSON_TABLETYPE_ARRAY:
jbe@164 959 lua_settop(L, json_export_internal_tmp_idx);
jbe@154 960 luaL_buffinit(L, &buf);
jbe@154 961 luaL_addchar(&buf, '[');
jbe@154 962 for (idx = 1; ; idx++) {
jbe@164 963 lua_rawgeti(L, json_export_internal_value_idx, idx);
jbe@154 964 if (lua_isnil(L, -1)) {
jbe@154 965 lua_pop(L, 1);
jbe@154 966 break;
jbe@154 967 }
jbe@164 968 lua_replace(L, json_export_internal_tmp_idx);
jbe@164 969 if (anyelement) luaL_addchar(&buf, ',');
jbe@164 970 anyelement = 1;
jbe@164 971 if (pretty) {
jbe@164 972 luaL_addchar(&buf, '\n');
jbe@164 973 for (i=0; i<level; i++) {
jbe@164 974 lua_pushvalue(L, json_export_internal_indentstring_idx);
jbe@164 975 luaL_addvalue(&buf);
jbe@164 976 }
jbe@164 977 }
jbe@164 978 lua_pushcfunction(L, json_export_internal);
jbe@164 979 lua_pushvalue(L, json_export_internal_indentstring_idx);
jbe@164 980 lua_pushinteger(L, level);
jbe@164 981 lua_pushvalue(L, json_export_internal_tmp_idx);
jbe@164 982 lua_call(L, 3, 1);
jbe@154 983 luaL_addvalue(&buf);
jbe@154 984 }
jbe@164 985 if (pretty && anyelement) {
jbe@164 986 luaL_addchar(&buf, '\n');
jbe@164 987 for (i=0; i<level-1; i++) {
jbe@164 988 lua_pushvalue(L, json_export_internal_indentstring_idx);
jbe@164 989 luaL_addvalue(&buf);
jbe@164 990 }
jbe@164 991 }
jbe@154 992 luaL_addchar(&buf, ']');
jbe@164 993 if (pretty && level == 1) luaL_addchar(&buf, '\n');
jbe@154 994 luaL_pushresult(&buf);
jbe@154 995 return 1;
jbe@154 996 }
jbe@154 997 json_export_tabletype_error:
jbe@154 998 return luaL_error(L, "JSON export not possible for ambiguous table (cannot decide whether it is an object or array)");
jbe@154 999 }
jbe@166 1000 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 1001 }
jbe@154 1002
jbe@164 1003 static int json_export(lua_State *L) {
jbe@164 1004 lua_settop(L, 1);
jbe@164 1005 lua_pushcfunction(L, json_export_internal);
jbe@164 1006 lua_pushnil(L);
jbe@164 1007 lua_pushinteger(L, 0);
jbe@164 1008 lua_pushvalue(L, 1);
jbe@164 1009 lua_call(L, 3, 1);
jbe@164 1010 return 1;
jbe@164 1011 }
jbe@164 1012
jbe@164 1013 static int json_pretty(lua_State *L) {
jbe@164 1014 lua_settop(L, 2);
jbe@164 1015 lua_pushcfunction(L, json_export_internal);
jbe@164 1016 if (lua_isnil(L, 2)) lua_pushliteral(L, " ");
jbe@164 1017 else lua_pushvalue(L, 2);
jbe@164 1018 lua_pushinteger(L, 0);
jbe@164 1019 lua_pushvalue(L, 1);
jbe@164 1020 lua_call(L, 3, 1);
jbe@164 1021 return 1;
jbe@164 1022 }
jbe@164 1023
jbe@149 1024 // functions in library module:
jbe@121 1025 static const struct luaL_Reg json_module_functions[] = {
jbe@133 1026 {"object", json_object},
jbe@133 1027 {"array", json_array},
jbe@121 1028 {"import", json_import},
jbe@154 1029 {"export", json_export},
jbe@164 1030 {"pretty", json_pretty},
jbe@130 1031 {"get", json_get},
jbe@127 1032 {"type", json_type},
jbe@121 1033 {NULL, NULL}
jbe@121 1034 };
jbe@121 1035
jbe@149 1036 // metamethods for JSON objects, JSON arrays, and unknown JSON collections (object or array):
jbe@126 1037 static const struct luaL_Reg json_metatable_functions[] = {
jbe@130 1038 {"__len", json_len},
jbe@130 1039 {"__index", json_index},
jbe@130 1040 {"__newindex", json_newindex},
jbe@135 1041 {"__pairs", json_pairs},
jbe@134 1042 {"__ipairs", json_ipairs},
jbe@160 1043 {"__tostring", json_export},
jbe@126 1044 {NULL, NULL}
jbe@126 1045 };
jbe@126 1046
jbe@157 1047 // metamethods for JSON null marker:
jbe@157 1048 static const struct luaL_Reg json_nullmark_metamethods[] = {
jbe@157 1049 {"__tostring", json_nullmark_tostring},
jbe@157 1050 {NULL, NULL}
jbe@157 1051 };
jbe@157 1052
jbe@149 1053 // initializes json library:
jbe@121 1054 int luaopen_json(lua_State *L) {
jbe@149 1055 // empty stack:
jbe@126 1056 lua_settop(L, 0);
jbe@149 1057 // push library module onto stack position 1:
jbe@149 1058 lua_newtable(L);
jbe@149 1059 // register library functions:
jbe@149 1060 luaL_setfuncs(L, json_module_functions, 0);
jbe@149 1061 // create and store objectmt:
jbe@138 1062 lua_newtable(L);
jbe@138 1063 luaL_setfuncs(L, json_metatable_functions, 0);
jbe@144 1064 json_regstore(L, objectmt);
jbe@149 1065 // create and store arraymt:
jbe@138 1066 lua_newtable(L);
jbe@138 1067 luaL_setfuncs(L, json_metatable_functions, 0);
jbe@144 1068 json_regstore(L, arraymt);
jbe@149 1069 // create and store ephemeron table to store shadow tables for each JSON object/array
jbe@149 1070 // to allow NULL values returned as nil
jbe@149 1071 lua_newtable(L);
jbe@138 1072 lua_newtable(L); // metatable for ephemeron table
jbe@121 1073 lua_pushliteral(L, "__mode");
jbe@121 1074 lua_pushliteral(L, "k");
jbe@138 1075 lua_rawset(L, -3);
jbe@138 1076 lua_setmetatable(L, -2);
jbe@144 1077 json_regstore(L, shadowtbl);
jbe@157 1078 // set metatable of null marker and make it available through library module:
jbe@157 1079 json_pushnullmark(L);
jbe@157 1080 lua_newtable(L);
jbe@157 1081 luaL_setfuncs(L, json_nullmark_metamethods, 0);
jbe@157 1082 lua_setmetatable(L, -2);
jbe@157 1083 lua_setfield(L, 1, "null");
jbe@157 1084 // return library module (that's expected on top of stack):
jbe@121 1085 return 1;
jbe@121 1086 }

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