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annotate libraries/json/json.c @ 171:ce208edffcc9

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Code cleanup in json.object and json.array functions
author jbe
date Fri Aug 01 16:40:10 2014 +0200 (2014-08-01)
parents c055d6d64586
children a83164390355
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@171 52 int arrayidx = 0;
jbe@171 53 // determine is argument is given:
jbe@169 54 if (lua_isnoneornil(L, json_convert_source_idx)) {
jbe@171 55 // if no argument is given (or if argument is nil),
jbe@171 56 // create table with shadow table, and leave first table on top of stack:
jbe@144 57 json_regfetch(L, shadowtbl);
jbe@169 58 lua_newtable(L);
jbe@169 59 lua_pushvalue(L, -1);
jbe@169 60 lua_newtable(L);
jbe@169 61 lua_rawset(L, -4);
jbe@169 62 } else {
jbe@171 63 // if an argument was given,
jbe@171 64 // push its iterator function on stack position 2 if existent,
jbe@169 65 // else push null for normal tables:
jbe@171 66 lua_settop(L, 1);
jbe@169 67 if (lua_getmetatable(L, json_convert_source_idx)) {
jbe@169 68 lua_getfield(L, -1, array ? "__ipairs" : "__pairs");
jbe@169 69 if (lua_isnil(L, -1)) luaL_checktype(L, 1, LUA_TTABLE);
jbe@169 70 else if (lua_type(L, -1) != LUA_TFUNCTION)
jbe@169 71 return luaL_error(L, "%s metamethod is not a function", array ? "__ipairs" : "__pairs");
jbe@169 72 lua_replace(L, -2);
jbe@169 73 } else {
jbe@169 74 lua_pushnil(L);
jbe@143 75 }
jbe@171 76 // create result table on stack position 3:
jbe@169 77 lua_newtable(L);
jbe@169 78 // create shadow table on stack position 4:
jbe@169 79 json_regfetch(L, shadowtbl);
jbe@169 80 lua_newtable(L);
jbe@169 81 lua_pushvalue(L, json_convert_output_idx);
jbe@169 82 lua_pushvalue(L, -2);
jbe@169 83 lua_rawset(L, -4);
jbe@169 84 lua_replace(L, -2);
jbe@171 85 // check if iterator function exists:
jbe@169 86 if (lua_isnil(L, json_convert_iterator_idx)) {
jbe@171 87 // if there is no iterator function,
jbe@171 88 // distinguish between objects and arrays:
jbe@171 89 if (array == 0) {
jbe@171 90 // for an object, copy all string key value pairs to shadow table:
jbe@171 91 for (lua_pushnil(L); lua_next(L, json_convert_source_idx); lua_pop(L, 1)) {
jbe@171 92 if (lua_type(L, -2) == LUA_TSTRING) {
jbe@171 93 lua_pushvalue(L, -2);
jbe@171 94 lua_pushvalue(L, -2);
jbe@171 95 lua_rawset(L, json_convert_shadow_idx);
jbe@171 96 }
jbe@171 97 }
jbe@171 98 } else {
jbe@171 99 // for an array, copy consecutive integer value pairs to shadow table:
jbe@171 100 while (1) {
jbe@171 101 // TODO: Lua 5.3 may support more elements
jbe@171 102 if (arrayidx == INT_MAX) {
jbe@171 103 lua_pushnumber(L, (size_t)INT_MAX+1);
jbe@171 104 lua_rawget(L, json_convert_source_idx);
jbe@171 105 if (lua_isnil(L, -1)) break;
jbe@171 106 return luaL_error(L, "Array exceeded length of %d elements", INT_MAX);
jbe@171 107 }
jbe@171 108 arrayidx++;
jbe@171 109 lua_rawgeti(L, json_convert_source_idx, arrayidx);
jbe@171 110 if (lua_isnil(L, -1)) break;
jbe@171 111 lua_rawseti(L, json_convert_shadow_idx, arrayidx);
jbe@171 112 }
jbe@169 113 }
jbe@169 114 } else {
jbe@171 115 // TODO: implement conversion using iterator metamethods
jbe@169 116 return luaL_error(L, "Using %s metamethod not implemented yet", array ? "__ipairs" : "__pairs");
jbe@143 117 }
jbe@171 118 // let result table be on top of stack:
jbe@169 119 lua_settop(L, json_convert_output_idx);
jbe@136 120 }
jbe@171 121 // set metatable (for result table on top of stack):
jbe@171 122 if (array == 0) json_regfetch(L, objectmt);
jbe@171 123 else json_regfetch(L, arraymt);
jbe@169 124 lua_setmetatable(L, -2);
jbe@171 125 // return table on top of stack:
jbe@136 126 return 1;
jbe@136 127 }
jbe@136 128
jbe@136 129 static int json_object(lua_State *L) {
jbe@169 130 return json_convert(L, 0);
jbe@136 131 }
jbe@136 132
jbe@136 133 static int json_array(lua_State *L) {
jbe@169 134 return json_convert(L, 1);
jbe@136 135 }
jbe@136 136
jbe@145 137 // internal states of JSON parser:
jbe@124 138 #define JSON_STATE_VALUE 0
jbe@124 139 #define JSON_STATE_OBJECT_KEY 1
jbe@124 140 #define JSON_STATE_OBJECT_KEY_TERMINATOR 2
jbe@124 141 #define JSON_STATE_OBJECT_VALUE 3
jbe@124 142 #define JSON_STATE_OBJECT_SEPARATOR 4
jbe@124 143 #define JSON_STATE_ARRAY_VALUE 5
jbe@124 144 #define JSON_STATE_ARRAY_SEPARATOR 6
jbe@124 145 #define JSON_STATE_END 7
jbe@121 146
jbe@145 147 // special Lua stack indicies for json_import function:
jbe@138 148 #define json_import_objectmt_idx 2
jbe@138 149 #define json_import_arraymt_idx 3
jbe@138 150 #define json_import_shadowtbl_idx 4
jbe@138 151
jbe@168 152 // macros for hex decoding:
jbe@168 153 #define json_utf16_surrogate(x) ((x) >= 0xD800 && (x) <= 0xDFFF)
jbe@168 154 #define json_utf16_lead(x) ((x) >= 0xD800 && (x) <= 0xDBFF)
jbe@168 155 #define json_utf16_tail(x) ((x) >= 0xDC00 && (x) <= 0xDFFF)
jbe@167 156 #define json_import_readhex(x) \
jbe@167 157 do { \
jbe@167 158 x = 0; \
jbe@167 159 for (i=0; i<4; i++) { \
jbe@167 160 x <<= 4; \
jbe@167 161 c = str[pos++]; \
jbe@167 162 if (c >= '0' && c <= '9') x += c - '0'; \
jbe@167 163 else if (c >= 'A' && c <= 'F') x += c - 'A' + 10; \
jbe@167 164 else if (c >= 'a' && c <= 'f') x += c - 'a' + 10; \
jbe@167 165 else if (c == 0) goto json_import_unexpected_eof; \
jbe@167 166 else goto json_import_unexpected_escape; \
jbe@167 167 } \
jbe@167 168 } while (0)
jbe@167 169
jbe@136 170 // decodes a JSON document:
jbe@121 171 static int json_import(lua_State *L) {
jbe@167 172 int i; // loop variable
jbe@136 173 const char *str; // string to parse
jbe@136 174 size_t total; // total length of string to parse
jbe@136 175 size_t pos = 0; // current position in string to parse
jbe@136 176 size_t level = 0; // nested levels of objects/arrays currently being processed
jbe@145 177 int mode = JSON_STATE_VALUE; // state of parser (i.e. "what's expected next?")
jbe@170 178 unsigned char c; // variable to store a single character to be processed (unsigned!)
jbe@145 179 luaL_Buffer luabuf; // Lua buffer to decode JSON string values
jbe@145 180 char *cbuf; // C buffer to decode JSON string values
jbe@162 181 size_t outlen; // maximum length or write position of C buffer
jbe@167 182 long codepoint; // decoded UTF-16 character or higher codepoint
jbe@167 183 long utf16tail; // second decoded UTF-16 character (surrogate tail)
jbe@152 184 size_t arraylen; // variable to temporarily store the array length
jbe@166 185 // require string as argument and convert to C string with length information:
jbe@166 186 str = luaL_checklstring(L, 1, &total);
jbe@166 187 // if string contains a NULL byte, this is a syntax error
jbe@166 188 if (strlen(str) != total) goto json_import_syntax_error;
jbe@147 189 // stack shall contain one function argument:
jbe@138 190 lua_settop(L, 1);
jbe@147 191 // push objectmt onto stack position 2:
jbe@144 192 json_regfetch(L, objectmt);
jbe@147 193 // push arraymt onto stack position 3:
jbe@144 194 json_regfetch(L, arraymt);
jbe@147 195 // push shadowtbl onto stack position 4:
jbe@144 196 json_regfetch(L, shadowtbl);
jbe@136 197 // main loop of parser:
jbe@136 198 json_import_loop:
jbe@136 199 // skip whitespace and store next character in variable 'c':
jbe@146 200 while (c = str[pos],
jbe@146 201 c == ' ' ||
jbe@146 202 c == '\f' ||
jbe@146 203 c == '\n' ||
jbe@146 204 c == '\r' ||
jbe@146 205 c == '\t' ||
jbe@146 206 c == '\v'
jbe@146 207 ) pos++;
jbe@170 208 // NOTE: variable c needs to be unsigned in the following code
jbe@136 209 // switch statement to handle certain (single) characters:
jbe@121 210 switch (c) {
jbe@136 211 // handle end of JSON document:
jbe@121 212 case 0:
jbe@136 213 // if end of JSON document was expected, then return top element of stack as result:
jbe@124 214 if (mode == JSON_STATE_END) return 1;
jbe@136 215 // otherwise, the JSON document was malformed:
jbe@167 216 if (level == 0) {
jbe@167 217 lua_pushnil(L);
jbe@167 218 lua_pushliteral(L, "Empty string");
jbe@167 219 } else {
jbe@167 220 json_import_unexpected_eof:
jbe@167 221 lua_pushnil(L);
jbe@167 222 lua_pushliteral(L, "Unexpected end of JSON document");
jbe@167 223 }
jbe@121 224 return 2;
jbe@136 225 // new JSON object:
jbe@121 226 case '{':
jbe@136 227 // if a JSON object is not expected here, then return an error:
jbe@146 228 if (
jbe@146 229 mode != JSON_STATE_VALUE &&
jbe@146 230 mode != JSON_STATE_OBJECT_VALUE &&
jbe@146 231 mode != JSON_STATE_ARRAY_VALUE
jbe@146 232 ) goto json_import_syntax_error;
jbe@136 233 // create JSON object on stack:
jbe@136 234 lua_newtable(L);
jbe@136 235 // set metatable of JSON object:
jbe@138 236 lua_pushvalue(L, json_import_objectmt_idx);
jbe@125 237 lua_setmetatable(L, -2);
jbe@136 238 // create internal shadow table on stack:
jbe@136 239 lua_newtable(L);
jbe@146 240 // register internal shadow table:
jbe@123 241 lua_pushvalue(L, -2);
jbe@123 242 lua_pushvalue(L, -2);
jbe@138 243 lua_rawset(L, json_import_shadowtbl_idx);
jbe@146 244 // expect object key (or end of object) to follow:
jbe@136 245 mode = JSON_STATE_OBJECT_KEY;
jbe@146 246 // jump to common code for opening JSON object and JSON array:
jbe@142 247 goto json_import_open;
jbe@136 248 // new JSON array:
jbe@121 249 case '[':
jbe@136 250 // if a JSON array is not expected here, then return an error:
jbe@146 251 if (
jbe@146 252 mode != JSON_STATE_VALUE &&
jbe@146 253 mode != JSON_STATE_OBJECT_VALUE &&
jbe@146 254 mode != JSON_STATE_ARRAY_VALUE
jbe@146 255 ) goto json_import_syntax_error;
jbe@136 256 // create JSON array on stack:
jbe@136 257 lua_newtable(L);
jbe@136 258 // set metatable of JSON array:
jbe@138 259 lua_pushvalue(L, json_import_arraymt_idx);
jbe@125 260 lua_setmetatable(L, -2);
jbe@136 261 // create internal shadow table on stack:
jbe@136 262 lua_newtable(L);
jbe@146 263 // register internal shadow table:
jbe@123 264 lua_pushvalue(L, -2);
jbe@123 265 lua_pushvalue(L, -2);
jbe@138 266 lua_rawset(L, json_import_shadowtbl_idx);
jbe@140 267 // add nil as key (needed to keep stack balance) and as magic to detect arrays:
jbe@140 268 lua_pushnil(L);
jbe@146 269 // expect array value (or end of array) to follow:
jbe@142 270 mode = JSON_STATE_ARRAY_VALUE;
jbe@142 271 // continue with common code for opening JSON object and JSON array:
jbe@146 272 // common code for opening JSON object or JSON array:
jbe@142 273 json_import_open:
jbe@142 274 // limit nested levels:
jbe@142 275 if (level >= JSON_MAXDEPTH) {
jbe@142 276 lua_pushnil(L);
jbe@164 277 lua_pushfstring(L, "More than %d nested JSON levels", JSON_MAXDEPTH);
jbe@142 278 return 2;
jbe@142 279 }
jbe@142 280 // additional buffer overflow protection:
jbe@142 281 if (!lua_checkstack(L, LUA_MINSTACK))
jbe@142 282 return luaL_error(L, "Caught stack overflow in JSON import function (too many nested levels and stack size too small)");
jbe@136 283 // increment level:
jbe@121 284 level++;
jbe@142 285 // consume input character:
jbe@142 286 pos++;
jbe@121 287 goto json_import_loop;
jbe@136 288 // end of JSON object:
jbe@121 289 case '}':
jbe@136 290 // if end of JSON object is not expected here, then return an error:
jbe@146 291 if (
jbe@146 292 mode != JSON_STATE_OBJECT_KEY &&
jbe@146 293 mode != JSON_STATE_OBJECT_SEPARATOR
jbe@146 294 ) goto json_import_syntax_error;
jbe@136 295 // jump to common code for end of JSON object and JSON array:
jbe@121 296 goto json_import_close;
jbe@136 297 // end of JSON array:
jbe@121 298 case ']':
jbe@136 299 // if end of JSON array is not expected here, then return an error:
jbe@146 300 if (
jbe@146 301 mode != JSON_STATE_ARRAY_VALUE &&
jbe@146 302 mode != JSON_STATE_ARRAY_SEPARATOR
jbe@146 303 ) goto json_import_syntax_error;
jbe@146 304 // pop nil key/magic (that was needed to keep stack balance):
jbe@140 305 lua_pop(L, 1);
jbe@136 306 // continue with common code for end of JSON object and JSON array:
jbe@136 307 // common code for end of JSON object or JSON array:
jbe@121 308 json_import_close:
jbe@136 309 // consume input character:
jbe@121 310 pos++;
jbe@136 311 // pop shadow table:
jbe@136 312 lua_pop(L, 1);
jbe@136 313 // check if nested:
jbe@121 314 if (--level) {
jbe@146 315 // if nested,
jbe@146 316 // check if outer(!) structure is an array or object:
jbe@140 317 if (lua_isnil(L, -2)) {
jbe@136 318 // select array value processing:
jbe@124 319 mode = JSON_STATE_ARRAY_VALUE;
jbe@121 320 } else {
jbe@136 321 // select object value processing:
jbe@124 322 mode = JSON_STATE_OBJECT_VALUE;
jbe@121 323 }
jbe@136 324 // store value in outer structure:
jbe@121 325 goto json_import_process_value;
jbe@121 326 }
jbe@136 327 // if not nested, then expect end of JSON document and continue with loop:
jbe@136 328 mode = JSON_STATE_END;
jbe@121 329 goto json_import_loop;
jbe@136 330 // key terminator:
jbe@121 331 case ':':
jbe@136 332 // if key terminator is not expected here, then return an error:
jbe@124 333 if (mode != JSON_STATE_OBJECT_KEY_TERMINATOR)
jbe@121 334 goto json_import_syntax_error;
jbe@136 335 // consume input character:
jbe@121 336 pos++;
jbe@146 337 // expect object value to follow:
jbe@124 338 mode = JSON_STATE_OBJECT_VALUE;
jbe@146 339 // continue with loop:
jbe@121 340 goto json_import_loop;
jbe@136 341 // value terminator (NOTE: trailing comma at end of value or key-value list is tolerated by this parser)
jbe@121 342 case ',':
jbe@146 343 // branch according to parser state:
jbe@124 344 if (mode == JSON_STATE_OBJECT_SEPARATOR) {
jbe@146 345 // expect an object key to follow:
jbe@124 346 mode = JSON_STATE_OBJECT_KEY;
jbe@124 347 } else if (mode == JSON_STATE_ARRAY_SEPARATOR) {
jbe@146 348 // expect an array value to follow:
jbe@124 349 mode = JSON_STATE_ARRAY_VALUE;
jbe@121 350 } else {
jbe@136 351 // if value terminator is not expected here, then return an error:
jbe@136 352 goto json_import_syntax_error;
jbe@121 353 }
jbe@136 354 // consume input character:
jbe@121 355 pos++;
jbe@136 356 // continue with loop:
jbe@121 357 goto json_import_loop;
jbe@136 358 // string literal:
jbe@121 359 case '"':
jbe@146 360 // consume quote character:
jbe@146 361 pos++;
jbe@162 362 // find last character in input string:
jbe@162 363 outlen = pos;
jbe@162 364 while ((c = str[outlen]) != '"') {
jbe@161 365 // consume one character:
jbe@162 366 outlen++;
jbe@161 367 // handle unexpected end of JSON document:
jbe@161 368 if (c == 0) goto json_import_unexpected_eof;
jbe@161 369 // consume one extra character when encountering an escaped quote:
jbe@162 370 else if (c == '\\' && str[outlen] == '"') outlen++;
jbe@161 371 }
jbe@162 372 // determine buffer length:
jbe@162 373 outlen -= pos;
jbe@161 374 // check if string is non empty:
jbe@162 375 if (outlen) {
jbe@161 376 // prepare buffer to decode string (with maximum possible length) and set write position to zero:
jbe@162 377 cbuf = luaL_buffinitsize(L, &luabuf, outlen);
jbe@162 378 outlen = 0;
jbe@161 379 // loop through the characters until encountering end quote:
jbe@161 380 while ((c = str[pos++]) != '"') {
jbe@162 381 // NOTE: unexpected end cannot happen anymore
jbe@162 382 if (c < 32 || c == 127) {
jbe@161 383 // do not allow ASCII control characters:
jbe@161 384 // NOTE: illegal UTF-8 sequences and extended control characters are not sanitized
jbe@161 385 // by this parser to allow different encodings than Unicode
jbe@161 386 lua_pushnil(L);
jbe@161 387 lua_pushliteral(L, "Unexpected control character in JSON string");
jbe@161 388 return 2;
jbe@161 389 } else if (c == '\\') {
jbe@161 390 // read next char after backslash escape:
jbe@161 391 c = str[pos++];
jbe@161 392 switch (c) {
jbe@161 393 // unexpected end-of-string:
jbe@161 394 case 0:
jbe@161 395 goto json_import_unexpected_eof;
jbe@161 396 // unescaping of quotation mark, slash, and backslash:
jbe@161 397 case '"':
jbe@161 398 case '/':
jbe@161 399 case '\\':
jbe@162 400 cbuf[outlen++] = c;
jbe@161 401 break;
jbe@161 402 // unescaping of backspace:
jbe@162 403 case 'b': cbuf[outlen++] = '\b'; break;
jbe@161 404 // unescaping of form-feed:
jbe@162 405 case 'f': cbuf[outlen++] = '\f'; break;
jbe@161 406 // unescaping of new-line:
jbe@162 407 case 'n': cbuf[outlen++] = '\n'; break;
jbe@161 408 // unescaping of carriage-return:
jbe@162 409 case 'r': cbuf[outlen++] = '\r'; break;
jbe@161 410 // unescaping of tabulator:
jbe@162 411 case 't': cbuf[outlen++] = '\t'; break;
jbe@161 412 // unescaping of UTF-16 characters
jbe@161 413 case 'u':
jbe@167 414 // decode 4 hex nibbles:
jbe@167 415 json_import_readhex(codepoint);
jbe@167 416 // handle surrogate character:
jbe@167 417 if (json_utf16_surrogate(codepoint)) {
jbe@167 418 // check if first surrogate is in valid range:
jbe@167 419 if (json_utf16_lead(codepoint)) {
jbe@167 420 // require second surrogate:
jbe@167 421 if ((c = str[pos++]) != '\\' || (c = str[pos++]) != 'u') {
jbe@167 422 if (c == 0) goto json_import_unexpected_eof;
jbe@167 423 else goto json_import_wrong_surrogate;
jbe@167 424 }
jbe@167 425 // read 4 hex nibbles of second surrogate character:
jbe@167 426 json_import_readhex(utf16tail);
jbe@167 427 // check if second surrogate is in valid range:
jbe@167 428 if (!json_utf16_tail(utf16tail)) goto json_import_wrong_surrogate;
jbe@167 429 // calculate codepoint:
jbe@167 430 codepoint = 0x10000 + (utf16tail - 0xDC00) + (codepoint - 0xD800) * 0x400;
jbe@167 431 } else {
jbe@167 432 // throw error for wrong surrogates:
jbe@167 433 json_import_wrong_surrogate:
jbe@167 434 lua_pushnil(L);
jbe@167 435 lua_pushliteral(L, "Illegal UTF-16 surrogate in JSON string escape sequence");
jbe@167 436 return 2;
jbe@167 437 }
jbe@167 438 }
jbe@167 439 // encode as UTF-8:
jbe@167 440 if (codepoint < 0x80) {
jbe@167 441 cbuf[outlen++] = (char)codepoint;
jbe@167 442 } else if (codepoint < 0x800) {
jbe@167 443 cbuf[outlen++] = (char)(0xc0 | (codepoint >> 6));
jbe@167 444 cbuf[outlen++] = (char)(0x80 | (codepoint & 0x3f));
jbe@167 445 } else if (codepoint < 0x10000) {
jbe@167 446 cbuf[outlen++] = (char)(0xe0 | (codepoint >> 12));
jbe@167 447 cbuf[outlen++] = (char)(0x80 | ((codepoint >> 6) & 0x3f));
jbe@167 448 cbuf[outlen++] = (char)(0x80 | (codepoint & 0x3f));
jbe@167 449 } else {
jbe@167 450 cbuf[outlen++] = (char)(0xf0 | (codepoint >> 18));
jbe@167 451 cbuf[outlen++] = (char)(0x80 | ((codepoint >> 12) & 0x3f));
jbe@167 452 cbuf[outlen++] = (char)(0x80 | ((codepoint >> 6) & 0x3f));
jbe@167 453 cbuf[outlen++] = (char)(0x80 | (codepoint & 0x3f));
jbe@167 454 }
jbe@167 455 break;
jbe@161 456 // unexpected escape sequence:
jbe@161 457 default:
jbe@167 458 json_import_unexpected_escape:
jbe@161 459 lua_pushnil(L);
jbe@161 460 lua_pushliteral(L, "Unexpected string escape sequence in JSON document");
jbe@161 461 return 2;
jbe@161 462 }
jbe@161 463 } else {
jbe@161 464 // normal character:
jbe@162 465 cbuf[outlen++] = c;
jbe@121 466 }
jbe@121 467 }
jbe@161 468 // process buffer to Lua string:
jbe@162 469 luaL_pushresultsize(&luabuf, outlen);
jbe@161 470 } else {
jbe@161 471 // if JSON string is empty,
jbe@161 472 // push empty Lua string:
jbe@161 473 lua_pushliteral(L, "");
jbe@167 474 // consume closing quote:
jbe@167 475 pos++;
jbe@121 476 }
jbe@136 477 // continue with processing of decoded string:
jbe@121 478 goto json_import_process_value;
jbe@121 479 }
jbe@136 480 // process values whose type is is not deducible from a single character:
jbe@136 481 if ((c >= '0' && c <= '9') || c == '-' || c == '+') {
jbe@146 482 // for numbers,
jbe@146 483 // use strtod() call to parse a (double precision) floating point number:
jbe@167 484 double numval;
jbe@122 485 char *endptr;
jbe@122 486 numval = strtod(str+pos, &endptr);
jbe@146 487 // catch parsing errors:
jbe@122 488 if (endptr == str+pos) goto json_import_syntax_error;
jbe@146 489 // consume characters that were parsed:
jbe@122 490 pos += endptr - (str+pos);
jbe@146 491 // push parsed (double precision) floating point number on Lua stack:
jbe@122 492 lua_pushnumber(L, numval);
jbe@122 493 } else if (!strncmp(str+pos, "true", 4)) {
jbe@136 494 // consume 4 input characters for "true":
jbe@121 495 pos += 4;
jbe@147 496 // put Lua true value onto stack:
jbe@136 497 lua_pushboolean(L, 1);
jbe@121 498 } else if (!strncmp(str+pos, "false", 5)) {
jbe@136 499 // consume 5 input characters for "false":
jbe@121 500 pos += 5;
jbe@147 501 // put Lua false value onto stack:
jbe@136 502 lua_pushboolean(L, 0);
jbe@121 503 } else if (!strncmp(str+pos, "null", 4)) {
jbe@136 504 // consume 4 input characters for "null":
jbe@136 505 pos += 4;
jbe@153 506 // different behavor for top-level and sub-levels:
jbe@153 507 if (level) {
jbe@153 508 // if sub-level,
jbe@153 509 // push special null-marker onto stack:
jbe@155 510 json_pushnullmark(L);
jbe@153 511 } else {
jbe@153 512 // if top-level,
jbe@153 513 // push nil onto stack:
jbe@153 514 lua_pushnil(L);
jbe@153 515 }
jbe@121 516 } else {
jbe@136 517 // all other cases are a syntax error:
jbe@121 518 goto json_import_syntax_error;
jbe@121 519 }
jbe@136 520 // process a decoded value or key value pair (expected on top of Lua stack):
jbe@136 521 json_import_process_value:
jbe@121 522 switch (mode) {
jbe@136 523 // an object key has been read:
jbe@124 524 case JSON_STATE_OBJECT_KEY:
jbe@136 525 // if an object key is not a string, then this is a syntax error:
jbe@121 526 if (lua_type(L, -1) != LUA_TSTRING) goto json_import_syntax_error;
jbe@146 527 // expect key terminator to follow:
jbe@124 528 mode = JSON_STATE_OBJECT_KEY_TERMINATOR;
jbe@146 529 // continue with loop:
jbe@121 530 goto json_import_loop;
jbe@136 531 // a key value pair has been read:
jbe@124 532 case JSON_STATE_OBJECT_VALUE:
jbe@136 533 // store key value pair in outer shadow table:
jbe@130 534 lua_rawset(L, -3);
jbe@146 535 // expect value terminator (or end of object) to follow:
jbe@124 536 mode = JSON_STATE_OBJECT_SEPARATOR;
jbe@146 537 // continue with loop:
jbe@121 538 goto json_import_loop;
jbe@136 539 // an array value has been read:
jbe@124 540 case JSON_STATE_ARRAY_VALUE:
jbe@152 541 // get current array length:
jbe@152 542 arraylen = lua_rawlen(L, -3);
jbe@152 543 // throw error if array would exceed INT_MAX elements:
jbe@152 544 // TODO: Lua 5.3 may support more elements
jbe@152 545 if (arraylen >= INT_MAX) {
jbe@152 546 lua_pushnil(L);
jbe@152 547 lua_pushfstring(L, "Array exceeded length of %d elements", INT_MAX);
jbe@152 548 }
jbe@136 549 // store value in outer shadow table:
jbe@152 550 lua_rawseti(L, -3, arraylen + 1);
jbe@146 551 // expect value terminator (or end of object) to follow:
jbe@124 552 mode = JSON_STATE_ARRAY_SEPARATOR;
jbe@146 553 // continue with loop
jbe@121 554 goto json_import_loop;
jbe@136 555 // a single value has been read:
jbe@124 556 case JSON_STATE_VALUE:
jbe@136 557 // leave value on top of stack, expect end of JSON document, and continue with loop:
jbe@124 558 mode = JSON_STATE_END;
jbe@121 559 goto json_import_loop;
jbe@121 560 }
jbe@146 561 // syntax error handling (reachable by goto statement):
jbe@136 562 json_import_syntax_error:
jbe@121 563 lua_pushnil(L);
jbe@121 564 lua_pushliteral(L, "Syntax error in JSON document");
jbe@121 565 return 2;
jbe@121 566 }
jbe@121 567
jbe@146 568 // special Lua stack indicies for json_path function:
jbe@138 569 #define json_path_shadowtbl_idx 1
jbe@146 570
jbe@146 571 // stack offset of arguments to json_path function:
jbe@155 572 #define json_path_idxshift 1
jbe@138 573
jbe@146 574 // gets a value or its type from a JSON document (passed as first argument)
jbe@147 575 // using a path (passed as variable number of keys after first argument):
jbe@137 576 static int json_path(lua_State *L, int type_mode) {
jbe@146 577 int stacktop; // stack index of top of stack (after shifting)
jbe@146 578 int idx = 2 + json_path_idxshift; // stack index of current argument to process
jbe@148 579 // insert shadowtbl into stack at position 1 (shifting the arguments):
jbe@144 580 json_regfetch(L, shadowtbl);
jbe@138 581 lua_insert(L, 1);
jbe@146 582 // store stack index of top of stack:
jbe@138 583 stacktop = lua_gettop(L);
jbe@146 584 // use first argument as "current value" (stored on top of stack):
jbe@138 585 lua_pushvalue(L, 1 + json_path_idxshift);
jbe@146 586 // process each "path key" (2nd argument and following arguments):
jbe@138 587 while (idx <= stacktop) {
jbe@146 588 // if "current value" (on top of stack) is nil, then the path cannot be walked and nil is returned:
jbe@137 589 if (lua_isnil(L, -1)) return 1;
jbe@137 590 // try to get shadow table of "current value":
jbe@130 591 lua_pushvalue(L, -1);
jbe@138 592 lua_rawget(L, json_path_shadowtbl_idx);
jbe@126 593 if (lua_isnil(L, -1)) {
jbe@137 594 // if no shadow table is found,
jbe@130 595 if (lua_type(L, -1) == LUA_TTABLE) {
jbe@146 596 // and if "current value" is a table,
jbe@146 597 // drop nil from stack:
jbe@146 598 lua_pop(L, 1);
jbe@137 599 // get "next value" using the "path key":
jbe@130 600 lua_pushvalue(L, idx++);
jbe@130 601 lua_gettable(L, -2);
jbe@130 602 } else {
jbe@137 603 // if "current value" is not a table,
jbe@146 604 // then the path cannot be walked and nil (already on top of stack) is returned:
jbe@137 605 return 1;
jbe@130 606 }
jbe@130 607 } else {
jbe@137 608 // if a shadow table is found,
jbe@137 609 // set "current value" to its shadow table:
jbe@130 610 lua_replace(L, -2);
jbe@137 611 // get "next value" using the "path key":
jbe@130 612 lua_pushvalue(L, idx++);
jbe@130 613 lua_rawget(L, -2);
jbe@126 614 }
jbe@137 615 // the "next value" replaces the "current value":
jbe@130 616 lua_replace(L, -2);
jbe@126 617 }
jbe@137 618 if (!type_mode) {
jbe@137 619 // if a value (and not its type) was requested,
jbe@137 620 // check if value is the null-marker, and store nil on top of Lua stack in that case:
jbe@155 621 if (json_isnullmark(L, -1)) lua_pushnil(L);
jbe@137 622 } else {
jbe@137 623 // if the type was requested,
jbe@137 624 // check if value is the null-marker:
jbe@155 625 if (json_isnullmark(L, -1)) {
jbe@137 626 // if yes, store string "null" on top of Lua stack:
jbe@130 627 lua_pushliteral(L, "null");
jbe@137 628 } else {
jbe@137 629 // otherwise,
jbe@138 630 // check if metatable indicates "object" or "array":
jbe@138 631 if (lua_getmetatable(L, -1)) {
jbe@144 632 json_regfetch(L, objectmt);
jbe@138 633 if (lua_rawequal(L, -2, -1)) {
jbe@146 634 // if value has metatable for JSON objects,
jbe@138 635 // return string "object":
jbe@138 636 lua_pushliteral(L, "object");
jbe@138 637 return 1;
jbe@138 638 }
jbe@144 639 json_regfetch(L, arraymt);
jbe@138 640 if (lua_rawequal(L, -3, -1)) {
jbe@146 641 // if value has metatable for JSON arrays,
jbe@146 642 // return string "object":
jbe@138 643 lua_pushliteral(L, "array");
jbe@138 644 return 1;
jbe@138 645 }
jbe@146 646 // remove 3 metatables (one of the value, two for comparison) from stack:
jbe@138 647 lua_pop(L, 3);
jbe@138 648 }
jbe@138 649 // otherwise, get the Lua type:
jbe@138 650 lua_pushstring(L, lua_typename(L, lua_type(L, -1)));
jbe@126 651 }
jbe@126 652 }
jbe@137 653 // return the top most value on the Lua stack:
jbe@137 654 return 1;
jbe@130 655 }
jbe@130 656
jbe@147 657 // gets a value from a JSON document (passed as first argument)
jbe@147 658 // using a path (passed as variable number of keys after first argument):
jbe@130 659 static int json_get(lua_State *L) {
jbe@137 660 return json_path(L, 0);
jbe@130 661 }
jbe@130 662
jbe@147 663 // gets a value's type from a JSON document (passed as first argument)
jbe@147 664 // using a path (variable number of keys after first argument):
jbe@130 665 static int json_type(lua_State *L) {
jbe@137 666 return json_path(L, 1);
jbe@130 667 }
jbe@130 668
jbe@147 669 // returns the length of a JSON array (or zero for a table without numeric keys):
jbe@130 670 static int json_len(lua_State *L) {
jbe@147 671 // stack shall contain one function argument:
jbe@130 672 lua_settop(L, 1);
jbe@148 673 // try to get corresponding shadow table for first argument:
jbe@144 674 json_regfetch(L, shadowtbl);
jbe@130 675 lua_pushvalue(L, 1);
jbe@138 676 lua_rawget(L, -2);
jbe@147 677 // if shadow table does not exist, return length of argument, else length of shadow table:
jbe@147 678 lua_pushnumber(L, lua_rawlen(L, lua_isnil(L, -1) ? 1 : -1));
jbe@123 679 return 1;
jbe@123 680 }
jbe@123 681
jbe@130 682 static int json_index(lua_State *L) {
jbe@148 683 // stack shall contain two function arguments:
jbe@130 684 lua_settop(L, 2);
jbe@155 685 // get corresponding shadow table for first argument:
jbe@144 686 json_regfetch(L, shadowtbl);
jbe@130 687 lua_pushvalue(L, 1);
jbe@155 688 lua_rawget(L, -2);
jbe@148 689 // throw error if no shadow table was found:
jbe@139 690 if (lua_isnil(L, -1)) return luaL_error(L, "Shadow table not found");
jbe@148 691 // use key passed as second argument to lookup value in shadow table:
jbe@130 692 lua_pushvalue(L, 2);
jbe@130 693 lua_rawget(L, -2);
jbe@148 694 // if value is null-marker, then push nil onto stack:
jbe@155 695 if (json_isnullmark(L, -1)) lua_pushnil(L);
jbe@148 696 // return either looked up value, or nil
jbe@127 697 return 1;
jbe@127 698 }
jbe@127 699
jbe@130 700 static int json_newindex(lua_State *L) {
jbe@148 701 // stack shall contain three function arguments:
jbe@130 702 lua_settop(L, 3);
jbe@148 703 // get corresponding shadow table for first argument:
jbe@144 704 json_regfetch(L, shadowtbl);
jbe@123 705 lua_pushvalue(L, 1);
jbe@143 706 lua_rawget(L, -2);
jbe@148 707 // throw error if no shadow table was found:
jbe@130 708 if (lua_isnil(L, -1)) return luaL_error(L, "Shadow table not found");
jbe@148 709 // replace first argument with shadow table:
jbe@130 710 lua_replace(L, 1);
jbe@148 711 // reset stack and use second and third argument to write to shadow table:
jbe@139 712 lua_settop(L, 3);
jbe@130 713 lua_rawset(L, 1);
jbe@148 714 // return nothing:
jbe@148 715 return 0;
jbe@121 716 }
jbe@121 717
jbe@135 718 static int json_pairs_iterfunc(lua_State *L) {
jbe@149 719 // stack shall contain two function arguments:
jbe@135 720 lua_settop(L, 2);
jbe@155 721 // get corresponding shadow table for first argument:
jbe@144 722 json_regfetch(L, shadowtbl);
jbe@135 723 lua_pushvalue(L, 1);
jbe@155 724 lua_rawget(L, -2);
jbe@149 725 // throw error if no shadow table was found:
jbe@135 726 if (lua_isnil(L, -1)) return luaL_error(L, "Shadow table not found");
jbe@149 727 // get next key value pair from shadow table (using previous key from argument 2)
jbe@149 728 // and return nothing if there is no next pair:
jbe@135 729 lua_pushvalue(L, 2);
jbe@135 730 if (!lua_next(L, -2)) return 0;
jbe@149 731 // replace null-marker with nil:
jbe@155 732 if (json_isnullmark(L, -1)) {
jbe@135 733 lua_pop(L, 1);
jbe@135 734 lua_pushnil(L);
jbe@135 735 }
jbe@149 736 // return key and value (or key and nil, if null-marker was found):
jbe@135 737 return 2;
jbe@135 738 }
jbe@135 739
jbe@149 740 // returns a triple such that 'for key, value in pairs(obj) do ... end'
jbe@149 741 // iterates through all key value pairs (including JSON null keys represented as Lua nil):
jbe@135 742 static int json_pairs(lua_State *L) {
jbe@149 743 // return triple of function json_pairs_iterfunc, first argument, and nil:
jbe@139 744 lua_pushcfunction(L, json_pairs_iterfunc);
jbe@135 745 lua_pushvalue(L, 1);
jbe@135 746 lua_pushnil(L);
jbe@135 747 return 3;
jbe@135 748 }
jbe@135 749
jbe@134 750 static int json_ipairs_iterfunc(lua_State *L) {
jbe@152 751 lua_Integer idx;
jbe@149 752 // stack shall contain two function arguments:
jbe@134 753 lua_settop(L, 2);
jbe@149 754 // calculate new index by incrementing second argument:
jbe@134 755 idx = lua_tointeger(L, 2) + 1;
jbe@149 756 // get corresponding shadow table for first argument:
jbe@155 757 json_regfetch(L, shadowtbl);
jbe@134 758 lua_pushvalue(L, 1);
jbe@155 759 lua_rawget(L, -2);
jbe@149 760 // throw error if no shadow table was found:
jbe@134 761 if (lua_isnil(L, -1)) return luaL_error(L, "Shadow table not found");
jbe@149 762 // do integer lookup in shadow table:
jbe@134 763 lua_rawgeti(L, -1, idx);
jbe@149 764 // return nothing if there was no value:
jbe@134 765 if (lua_isnil(L, -1)) return 0;
jbe@149 766 // return new index and
jbe@149 767 // either the looked up value if it is not equal to the null-marker
jbe@149 768 // or nil instead of null-marker:
jbe@134 769 lua_pushinteger(L, idx);
jbe@155 770 if (json_isnullmark(L, -2)) lua_pushnil(L);
jbe@134 771 else lua_pushvalue(L, -2);
jbe@134 772 return 2;
jbe@134 773 }
jbe@134 774
jbe@149 775 // returns a triple such that 'for idx, value in ipairs(ary) do ... end'
jbe@149 776 // iterates through all values (including JSON null represented as Lua nil):
jbe@134 777 static int json_ipairs(lua_State *L) {
jbe@149 778 // return triple of function json_ipairs_iterfunc, first argument, and zero:
jbe@139 779 lua_pushcfunction(L, json_ipairs_iterfunc);
jbe@134 780 lua_pushvalue(L, 1);
jbe@134 781 lua_pushinteger(L, 0);
jbe@134 782 return 3;
jbe@134 783 }
jbe@134 784
jbe@163 785 typedef struct {
jbe@163 786 size_t length;
jbe@163 787 const char *data;
jbe@163 788 } json_key_t;
jbe@163 789
jbe@163 790 static int json_key_cmp(json_key_t *key1, json_key_t *key2) {
jbe@163 791 size_t pos = 0;
jbe@163 792 unsigned char c1, c2;
jbe@163 793 while (1) {
jbe@163 794 if (key1->length > pos) {
jbe@163 795 if (key2->length > pos) {
jbe@163 796 c1 = key1->data[pos];
jbe@163 797 c2 = key2->data[pos];
jbe@163 798 if (c1 < c2) return -1;
jbe@163 799 else if (c1 > c2) return 1;
jbe@163 800 } else {
jbe@163 801 return 1;
jbe@163 802 }
jbe@163 803 } else {
jbe@163 804 if (key2->length > pos) {
jbe@163 805 return -1;
jbe@163 806 } else {
jbe@163 807 return 0;
jbe@163 808 }
jbe@163 809 }
jbe@163 810 pos++;
jbe@163 811 }
jbe@163 812 }
jbe@163 813
jbe@154 814 #define JSON_TABLETYPE_UNKNOWN 0
jbe@154 815 #define JSON_TABLETYPE_OBJECT 1
jbe@154 816 #define JSON_TABLETYPE_ARRAY 2
jbe@154 817
jbe@164 818 #define json_export_internal_indentstring_idx 1
jbe@164 819 #define json_export_internal_level_idx 2
jbe@164 820 #define json_export_internal_value_idx 3
jbe@164 821 #define json_export_internal_tmp_idx 4
jbe@164 822
jbe@164 823 static int json_export_internal(lua_State *L) {
jbe@164 824 int level;
jbe@164 825 int pretty;
jbe@164 826 int i;
jbe@154 827 lua_Number num;
jbe@154 828 const char *str;
jbe@154 829 unsigned char c;
jbe@154 830 size_t strlen;
jbe@154 831 size_t pos = 0;
jbe@154 832 luaL_Buffer buf;
jbe@154 833 char hexcode[7]; // backslash, character 'u', 4 hex digits, and terminating NULL byte
jbe@154 834 int tabletype = JSON_TABLETYPE_UNKNOWN;
jbe@164 835 int anyelement = 0;
jbe@163 836 size_t keycount = 0;
jbe@163 837 size_t keypos = 0;
jbe@165 838 json_key_t *keybuf = NULL;
jbe@154 839 lua_Integer idx;
jbe@164 840 lua_settop(L, json_export_internal_value_idx);
jbe@164 841 if (json_isnullmark(L, json_export_internal_value_idx)) {
jbe@164 842 lua_pop(L, 1);
jbe@157 843 lua_pushnil(L);
jbe@157 844 }
jbe@164 845 switch (lua_type(L, json_export_internal_value_idx)) {
jbe@154 846 case LUA_TNIL:
jbe@154 847 lua_pushliteral(L, "null");
jbe@154 848 return 1;
jbe@154 849 case LUA_TNUMBER:
jbe@164 850 num = lua_tonumber(L, json_export_internal_value_idx);
jbe@154 851 if (isnan(num)) return luaL_error(L, "JSON export not possible for NaN value");
jbe@154 852 if (isinf(num)) return luaL_error(L, "JSON export not possible for infinite numbers");
jbe@164 853 lua_tostring(L, json_export_internal_value_idx);
jbe@154 854 return 1;
jbe@154 855 case LUA_TBOOLEAN:
jbe@164 856 if (lua_toboolean(L, json_export_internal_value_idx)) {
jbe@164 857 lua_pushliteral(L, "true");
jbe@164 858 } else {
jbe@164 859 lua_pushliteral(L, "false");
jbe@164 860 }
jbe@154 861 return 1;
jbe@154 862 case LUA_TSTRING:
jbe@164 863 str = lua_tolstring(L, 3, &strlen);
jbe@154 864 luaL_buffinit(L, &buf);
jbe@154 865 luaL_addchar(&buf, '"');
jbe@154 866 while (pos < strlen) {
jbe@154 867 c = str[pos++];
jbe@154 868 if (c == '"') luaL_addstring(&buf, "\\\"");
jbe@154 869 else if (c == '\\') luaL_addstring(&buf, "\\\\");
jbe@154 870 else if (c == 127) luaL_addstring(&buf, "\\u007F");
jbe@154 871 else if (c >= 32) luaL_addchar(&buf, c);
jbe@154 872 else if (c == '\b') luaL_addstring(&buf, "\\b");
jbe@154 873 else if (c == '\f') luaL_addstring(&buf, "\\f");
jbe@154 874 else if (c == '\n') luaL_addstring(&buf, "\\n");
jbe@154 875 else if (c == '\r') luaL_addstring(&buf, "\\r");
jbe@154 876 else if (c == '\t') luaL_addstring(&buf, "\\t");
jbe@154 877 else if (c == '\v') luaL_addstring(&buf, "\\v");
jbe@154 878 else {
jbe@154 879 sprintf(hexcode, "\\u%04X", c);
jbe@154 880 luaL_addstring(&buf, hexcode);
jbe@154 881 }
jbe@154 882 }
jbe@154 883 luaL_addchar(&buf, '"');
jbe@154 884 luaL_pushresult(&buf);
jbe@154 885 return 1;
jbe@154 886 case LUA_TTABLE:
jbe@164 887 if (lua_getmetatable(L, json_export_internal_value_idx)) {
jbe@154 888 json_regfetch(L, objectmt);
jbe@154 889 if (lua_rawequal(L, -2, -1)) {
jbe@154 890 tabletype = JSON_TABLETYPE_OBJECT;
jbe@154 891 } else {
jbe@154 892 json_regfetch(L, arraymt);
jbe@164 893 if (lua_rawequal(L, -3, -1)) {
jbe@164 894 tabletype = JSON_TABLETYPE_ARRAY;
jbe@164 895 } else {
jbe@164 896 return luaL_error(L, "JSON export not possible for tables with nonsupported metatable");
jbe@164 897 }
jbe@154 898 }
jbe@154 899 }
jbe@154 900 json_regfetch(L, shadowtbl);
jbe@164 901 lua_pushvalue(L, json_export_internal_value_idx);
jbe@154 902 lua_rawget(L, -2);
jbe@164 903 if (!lua_isnil(L, -1)) lua_replace(L, json_export_internal_value_idx);
jbe@164 904 lua_settop(L, json_export_internal_value_idx);
jbe@154 905 if (tabletype == JSON_TABLETYPE_UNKNOWN) {
jbe@164 906 for (lua_pushnil(L); lua_next(L, json_export_internal_value_idx); lua_pop(L, 1)) {
jbe@164 907 switch (lua_type(L, -2)) {
jbe@164 908 case LUA_TSTRING:
jbe@164 909 keycount++;
jbe@164 910 if (tabletype == JSON_TABLETYPE_UNKNOWN) tabletype = JSON_TABLETYPE_OBJECT;
jbe@164 911 else if (tabletype == JSON_TABLETYPE_ARRAY) goto json_export_tabletype_error;
jbe@164 912 break;
jbe@164 913 case LUA_TNUMBER:
jbe@164 914 if (tabletype == JSON_TABLETYPE_UNKNOWN) tabletype = JSON_TABLETYPE_ARRAY;
jbe@164 915 else if (tabletype == JSON_TABLETYPE_OBJECT) goto json_export_tabletype_error;
jbe@164 916 break;
jbe@154 917 }
jbe@154 918 }
jbe@154 919 }
jbe@164 920 pretty = lua_toboolean(L, json_export_internal_indentstring_idx);
jbe@164 921 level = lua_tointeger(L, json_export_internal_level_idx) + 1;
jbe@164 922 if (level > JSON_MAXDEPTH) {
jbe@164 923 return luaL_error(L, "More than %d nested JSON levels", JSON_MAXDEPTH);
jbe@164 924 }
jbe@154 925 switch (tabletype) {
jbe@154 926 case JSON_TABLETYPE_OBJECT:
jbe@164 927 if (!keycount) {
jbe@164 928 for (lua_pushnil(L); lua_next(L, json_export_internal_value_idx); lua_pop(L, 1)) {
jbe@164 929 if (lua_type(L, -2) == LUA_TSTRING) keycount++;
jbe@164 930 }
jbe@163 931 }
jbe@163 932 if (keycount) {
jbe@163 933 keybuf = calloc(keycount, sizeof(json_key_t));
jbe@163 934 if (!keybuf) return luaL_error(L, "Memory allocation failed in JSON library");
jbe@164 935 for (lua_pushnil(L); lua_next(L, json_export_internal_value_idx); lua_pop(L, 1)) {
jbe@163 936 if (lua_type(L, -2) == LUA_TSTRING) {
jbe@163 937 json_key_t *key = keybuf + (keypos++);
jbe@163 938 key->data = lua_tolstring(L, -2, &key->length);
jbe@163 939 }
jbe@163 940 }
jbe@163 941 qsort(keybuf, keycount, sizeof(json_key_t), (void *)json_key_cmp);
jbe@163 942 }
jbe@154 943 luaL_buffinit(L, &buf);
jbe@154 944 luaL_addchar(&buf, '{');
jbe@163 945 for (keypos=0; keypos<keycount; keypos++) {
jbe@163 946 json_key_t *key = keybuf + keypos;
jbe@163 947 if (keypos) luaL_addchar(&buf, ',');
jbe@164 948 if (pretty) {
jbe@164 949 luaL_addchar(&buf, '\n');
jbe@164 950 for (i=0; i<level; 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@164 955 lua_pushcfunction(L, json_export_internal);
jbe@164 956 lua_pushvalue(L, json_export_internal_indentstring_idx);
jbe@164 957 lua_pushinteger(L, level);
jbe@163 958 lua_pushlstring(L, key->data, key->length);
jbe@164 959 if (lua_pcall(L, 3, 1, 0)) {
jbe@163 960 if (keybuf) free(keybuf);
jbe@163 961 return lua_error(L);
jbe@154 962 }
jbe@163 963 luaL_addvalue(&buf);
jbe@163 964 luaL_addchar(&buf, ':');
jbe@164 965 if (pretty) luaL_addchar(&buf, ' ');
jbe@164 966 lua_pushcfunction(L, json_export_internal);
jbe@164 967 lua_pushvalue(L, json_export_internal_indentstring_idx);
jbe@164 968 lua_pushinteger(L, level);
jbe@163 969 lua_pushlstring(L, key->data, key->length);
jbe@164 970 lua_rawget(L, json_export_internal_value_idx);
jbe@164 971 if (lua_pcall(L, 3, 1, 0)) {
jbe@163 972 if (keybuf) free(keybuf);
jbe@163 973 return lua_error(L);
jbe@163 974 }
jbe@163 975 luaL_addvalue(&buf);
jbe@154 976 }
jbe@163 977 if (keybuf) free(keybuf);
jbe@164 978 if (pretty && keycount != 0) {
jbe@164 979 luaL_addchar(&buf, '\n');
jbe@164 980 for (i=0; i<level-1; i++) {
jbe@164 981 lua_pushvalue(L, json_export_internal_indentstring_idx);
jbe@164 982 luaL_addvalue(&buf);
jbe@164 983 }
jbe@164 984 }
jbe@154 985 luaL_addchar(&buf, '}');
jbe@164 986 if (pretty && level == 1) luaL_addchar(&buf, '\n');
jbe@154 987 luaL_pushresult(&buf);
jbe@154 988 return 1;
jbe@154 989 case JSON_TABLETYPE_ARRAY:
jbe@164 990 lua_settop(L, json_export_internal_tmp_idx);
jbe@154 991 luaL_buffinit(L, &buf);
jbe@154 992 luaL_addchar(&buf, '[');
jbe@154 993 for (idx = 1; ; idx++) {
jbe@164 994 lua_rawgeti(L, json_export_internal_value_idx, idx);
jbe@154 995 if (lua_isnil(L, -1)) {
jbe@154 996 lua_pop(L, 1);
jbe@154 997 break;
jbe@154 998 }
jbe@164 999 lua_replace(L, json_export_internal_tmp_idx);
jbe@164 1000 if (anyelement) luaL_addchar(&buf, ',');
jbe@164 1001 anyelement = 1;
jbe@164 1002 if (pretty) {
jbe@164 1003 luaL_addchar(&buf, '\n');
jbe@164 1004 for (i=0; i<level; i++) {
jbe@164 1005 lua_pushvalue(L, json_export_internal_indentstring_idx);
jbe@164 1006 luaL_addvalue(&buf);
jbe@164 1007 }
jbe@164 1008 }
jbe@164 1009 lua_pushcfunction(L, json_export_internal);
jbe@164 1010 lua_pushvalue(L, json_export_internal_indentstring_idx);
jbe@164 1011 lua_pushinteger(L, level);
jbe@164 1012 lua_pushvalue(L, json_export_internal_tmp_idx);
jbe@164 1013 lua_call(L, 3, 1);
jbe@154 1014 luaL_addvalue(&buf);
jbe@154 1015 }
jbe@164 1016 if (pretty && anyelement) {
jbe@164 1017 luaL_addchar(&buf, '\n');
jbe@164 1018 for (i=0; i<level-1; i++) {
jbe@164 1019 lua_pushvalue(L, json_export_internal_indentstring_idx);
jbe@164 1020 luaL_addvalue(&buf);
jbe@164 1021 }
jbe@164 1022 }
jbe@154 1023 luaL_addchar(&buf, ']');
jbe@164 1024 if (pretty && level == 1) luaL_addchar(&buf, '\n');
jbe@154 1025 luaL_pushresult(&buf);
jbe@154 1026 return 1;
jbe@154 1027 }
jbe@154 1028 json_export_tabletype_error:
jbe@154 1029 return luaL_error(L, "JSON export not possible for ambiguous table (cannot decide whether it is an object or array)");
jbe@154 1030 }
jbe@166 1031 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 1032 }
jbe@154 1033
jbe@164 1034 static int json_export(lua_State *L) {
jbe@164 1035 lua_settop(L, 1);
jbe@164 1036 lua_pushcfunction(L, json_export_internal);
jbe@164 1037 lua_pushnil(L);
jbe@164 1038 lua_pushinteger(L, 0);
jbe@164 1039 lua_pushvalue(L, 1);
jbe@164 1040 lua_call(L, 3, 1);
jbe@164 1041 return 1;
jbe@164 1042 }
jbe@164 1043
jbe@164 1044 static int json_pretty(lua_State *L) {
jbe@164 1045 lua_settop(L, 2);
jbe@164 1046 lua_pushcfunction(L, json_export_internal);
jbe@164 1047 if (lua_isnil(L, 2)) lua_pushliteral(L, " ");
jbe@164 1048 else lua_pushvalue(L, 2);
jbe@164 1049 lua_pushinteger(L, 0);
jbe@164 1050 lua_pushvalue(L, 1);
jbe@164 1051 lua_call(L, 3, 1);
jbe@164 1052 return 1;
jbe@164 1053 }
jbe@164 1054
jbe@149 1055 // functions in library module:
jbe@121 1056 static const struct luaL_Reg json_module_functions[] = {
jbe@133 1057 {"object", json_object},
jbe@133 1058 {"array", json_array},
jbe@121 1059 {"import", json_import},
jbe@154 1060 {"export", json_export},
jbe@164 1061 {"pretty", json_pretty},
jbe@130 1062 {"get", json_get},
jbe@127 1063 {"type", json_type},
jbe@121 1064 {NULL, NULL}
jbe@121 1065 };
jbe@121 1066
jbe@149 1067 // metamethods for JSON objects, JSON arrays, and unknown JSON collections (object or array):
jbe@126 1068 static const struct luaL_Reg json_metatable_functions[] = {
jbe@130 1069 {"__len", json_len},
jbe@130 1070 {"__index", json_index},
jbe@130 1071 {"__newindex", json_newindex},
jbe@135 1072 {"__pairs", json_pairs},
jbe@134 1073 {"__ipairs", json_ipairs},
jbe@160 1074 {"__tostring", json_export},
jbe@126 1075 {NULL, NULL}
jbe@126 1076 };
jbe@126 1077
jbe@157 1078 // metamethods for JSON null marker:
jbe@157 1079 static const struct luaL_Reg json_nullmark_metamethods[] = {
jbe@157 1080 {"__tostring", json_nullmark_tostring},
jbe@157 1081 {NULL, NULL}
jbe@157 1082 };
jbe@157 1083
jbe@149 1084 // initializes json library:
jbe@121 1085 int luaopen_json(lua_State *L) {
jbe@149 1086 // empty stack:
jbe@126 1087 lua_settop(L, 0);
jbe@149 1088 // push library module onto stack position 1:
jbe@149 1089 lua_newtable(L);
jbe@149 1090 // register library functions:
jbe@149 1091 luaL_setfuncs(L, json_module_functions, 0);
jbe@149 1092 // create and store objectmt:
jbe@138 1093 lua_newtable(L);
jbe@138 1094 luaL_setfuncs(L, json_metatable_functions, 0);
jbe@144 1095 json_regstore(L, objectmt);
jbe@149 1096 // create and store arraymt:
jbe@138 1097 lua_newtable(L);
jbe@138 1098 luaL_setfuncs(L, json_metatable_functions, 0);
jbe@144 1099 json_regstore(L, arraymt);
jbe@149 1100 // create and store ephemeron table to store shadow tables for each JSON object/array
jbe@149 1101 // to allow NULL values returned as nil
jbe@149 1102 lua_newtable(L);
jbe@138 1103 lua_newtable(L); // metatable for ephemeron table
jbe@121 1104 lua_pushliteral(L, "__mode");
jbe@121 1105 lua_pushliteral(L, "k");
jbe@138 1106 lua_rawset(L, -3);
jbe@138 1107 lua_setmetatable(L, -2);
jbe@144 1108 json_regstore(L, shadowtbl);
jbe@157 1109 // set metatable of null marker and make it available through library module:
jbe@157 1110 json_pushnullmark(L);
jbe@157 1111 lua_newtable(L);
jbe@157 1112 luaL_setfuncs(L, json_nullmark_metamethods, 0);
jbe@157 1113 lua_setmetatable(L, -2);
jbe@157 1114 lua_setfield(L, 1, "null");
jbe@157 1115 // return library module (that's expected on top of stack):
jbe@121 1116 return 1;
jbe@121 1117 }

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