1/*global Buffer*/ 2// Named constants with unique integer values 3var C = {}; 4// Tokens 5var LEFT_BRACE = C.LEFT_BRACE = 0x1; 6var RIGHT_BRACE = C.RIGHT_BRACE = 0x2; 7var LEFT_BRACKET = C.LEFT_BRACKET = 0x3; 8var RIGHT_BRACKET = C.RIGHT_BRACKET = 0x4; 9var COLON = C.COLON = 0x5; 10var COMMA = C.COMMA = 0x6; 11var TRUE = C.TRUE = 0x7; 12var FALSE = C.FALSE = 0x8; 13var NULL = C.NULL = 0x9; 14var STRING = C.STRING = 0xa; 15var NUMBER = C.NUMBER = 0xb; 16// Tokenizer States 17var START = C.START = 0x11; 18var STOP = C.STOP = 0x12; 19var TRUE1 = C.TRUE1 = 0x21; 20var TRUE2 = C.TRUE2 = 0x22; 21var TRUE3 = C.TRUE3 = 0x23; 22var FALSE1 = C.FALSE1 = 0x31; 23var FALSE2 = C.FALSE2 = 0x32; 24var FALSE3 = C.FALSE3 = 0x33; 25var FALSE4 = C.FALSE4 = 0x34; 26var NULL1 = C.NULL1 = 0x41; 27var NULL2 = C.NULL2 = 0x42; 28var NULL3 = C.NULL3 = 0x43; 29var NUMBER1 = C.NUMBER1 = 0x51; 30var NUMBER3 = C.NUMBER3 = 0x53; 31var STRING1 = C.STRING1 = 0x61; 32var STRING2 = C.STRING2 = 0x62; 33var STRING3 = C.STRING3 = 0x63; 34var STRING4 = C.STRING4 = 0x64; 35var STRING5 = C.STRING5 = 0x65; 36var STRING6 = C.STRING6 = 0x66; 37// Parser States 38var VALUE = C.VALUE = 0x71; 39var KEY = C.KEY = 0x72; 40// Parser Modes 41var OBJECT = C.OBJECT = 0x81; 42var ARRAY = C.ARRAY = 0x82; 43// Character constants 44var BACK_SLASH = "\\".charCodeAt(0); 45var FORWARD_SLASH = "\/".charCodeAt(0); 46var BACKSPACE = "\b".charCodeAt(0); 47var FORM_FEED = "\f".charCodeAt(0); 48var NEWLINE = "\n".charCodeAt(0); 49var CARRIAGE_RETURN = "\r".charCodeAt(0); 50var TAB = "\t".charCodeAt(0); 51 52var STRING_BUFFER_SIZE = 64 * 1024; 53 54function Parser() { 55 this.tState = START; 56 this.value = undefined; 57 58 this.string = undefined; // string data 59 this.stringBuffer = Buffer.alloc ? Buffer.alloc(STRING_BUFFER_SIZE) : new Buffer(STRING_BUFFER_SIZE); 60 this.stringBufferOffset = 0; 61 this.unicode = undefined; // unicode escapes 62 this.highSurrogate = undefined; 63 64 this.key = undefined; 65 this.mode = undefined; 66 this.stack = []; 67 this.state = VALUE; 68 this.bytes_remaining = 0; // number of bytes remaining in multi byte utf8 char to read after split boundary 69 this.bytes_in_sequence = 0; // bytes in multi byte utf8 char to read 70 this.temp_buffs = { "2": new Buffer(2), "3": new Buffer(3), "4": new Buffer(4) }; // for rebuilding chars split before boundary is reached 71 72 // Stream offset 73 this.offset = -1; 74} 75 76// Slow code to string converter (only used when throwing syntax errors) 77Parser.toknam = function (code) { 78 var keys = Object.keys(C); 79 for (var i = 0, l = keys.length; i < l; i++) { 80 var key = keys[i]; 81 if (C[key] === code) { return key; } 82 } 83 return code && ("0x" + code.toString(16)); 84}; 85 86var proto = Parser.prototype; 87proto.onError = function (err) { throw err; }; 88proto.charError = function (buffer, i) { 89 this.tState = STOP; 90 this.onError(new Error("Unexpected " + JSON.stringify(String.fromCharCode(buffer[i])) + " at position " + i + " in state " + Parser.toknam(this.tState))); 91}; 92proto.appendStringChar = function (char) { 93 if (this.stringBufferOffset >= STRING_BUFFER_SIZE) { 94 this.string += this.stringBuffer.toString('utf8'); 95 this.stringBufferOffset = 0; 96 } 97 98 this.stringBuffer[this.stringBufferOffset++] = char; 99}; 100proto.appendStringBuf = function (buf, start, end) { 101 var size = buf.length; 102 if (typeof start === 'number') { 103 if (typeof end === 'number') { 104 if (end < 0) { 105 // adding a negative end decreeses the size 106 size = buf.length - start + end; 107 } else { 108 size = end - start; 109 } 110 } else { 111 size = buf.length - start; 112 } 113 } 114 115 if (size < 0) { 116 size = 0; 117 } 118 119 if (this.stringBufferOffset + size > STRING_BUFFER_SIZE) { 120 this.string += this.stringBuffer.toString('utf8', 0, this.stringBufferOffset); 121 this.stringBufferOffset = 0; 122 } 123 124 buf.copy(this.stringBuffer, this.stringBufferOffset, start, end); 125 this.stringBufferOffset += size; 126}; 127proto.write = function (buffer) { 128 if (typeof buffer === "string") buffer = new Buffer(buffer); 129 var n; 130 for (var i = 0, l = buffer.length; i < l; i++) { 131 if (this.tState === START){ 132 n = buffer[i]; 133 this.offset++; 134 if(n === 0x7b){ this.onToken(LEFT_BRACE, "{"); // { 135 }else if(n === 0x7d){ this.onToken(RIGHT_BRACE, "}"); // } 136 }else if(n === 0x5b){ this.onToken(LEFT_BRACKET, "["); // [ 137 }else if(n === 0x5d){ this.onToken(RIGHT_BRACKET, "]"); // ] 138 }else if(n === 0x3a){ this.onToken(COLON, ":"); // : 139 }else if(n === 0x2c){ this.onToken(COMMA, ","); // , 140 }else if(n === 0x74){ this.tState = TRUE1; // t 141 }else if(n === 0x66){ this.tState = FALSE1; // f 142 }else if(n === 0x6e){ this.tState = NULL1; // n 143 }else if(n === 0x22){ // " 144 this.string = ""; 145 this.stringBufferOffset = 0; 146 this.tState = STRING1; 147 }else if(n === 0x2d){ this.string = "-"; this.tState = NUMBER1; // - 148 }else{ 149 if (n >= 0x30 && n < 0x40) { // 1-9 150 this.string = String.fromCharCode(n); this.tState = NUMBER3; 151 } else if (n === 0x20 || n === 0x09 || n === 0x0a || n === 0x0d) { 152 // whitespace 153 } else { 154 return this.charError(buffer, i); 155 } 156 } 157 }else if (this.tState === STRING1){ // After open quote 158 n = buffer[i]; // get current byte from buffer 159 // check for carry over of a multi byte char split between data chunks 160 // & fill temp buffer it with start of this data chunk up to the boundary limit set in the last iteration 161 if (this.bytes_remaining > 0) { 162 for (var j = 0; j < this.bytes_remaining; j++) { 163 this.temp_buffs[this.bytes_in_sequence][this.bytes_in_sequence - this.bytes_remaining + j] = buffer[j]; 164 } 165 166 this.appendStringBuf(this.temp_buffs[this.bytes_in_sequence]); 167 this.bytes_in_sequence = this.bytes_remaining = 0; 168 i = i + j - 1; 169 } else if (this.bytes_remaining === 0 && n >= 128) { // else if no remainder bytes carried over, parse multi byte (>=128) chars one at a time 170 if (n <= 193 || n > 244) { 171 return this.onError(new Error("Invalid UTF-8 character at position " + i + " in state " + Parser.toknam(this.tState))); 172 } 173 if ((n >= 194) && (n <= 223)) this.bytes_in_sequence = 2; 174 if ((n >= 224) && (n <= 239)) this.bytes_in_sequence = 3; 175 if ((n >= 240) && (n <= 244)) this.bytes_in_sequence = 4; 176 if ((this.bytes_in_sequence + i) > buffer.length) { // if bytes needed to complete char fall outside buffer length, we have a boundary split 177 for (var k = 0; k <= (buffer.length - 1 - i); k++) { 178 this.temp_buffs[this.bytes_in_sequence][k] = buffer[i + k]; // fill temp buffer of correct size with bytes available in this chunk 179 } 180 this.bytes_remaining = (i + this.bytes_in_sequence) - buffer.length; 181 i = buffer.length - 1; 182 } else { 183 this.appendStringBuf(buffer, i, i + this.bytes_in_sequence); 184 i = i + this.bytes_in_sequence - 1; 185 } 186 } else if (n === 0x22) { 187 this.tState = START; 188 this.string += this.stringBuffer.toString('utf8', 0, this.stringBufferOffset); 189 this.stringBufferOffset = 0; 190 this.onToken(STRING, this.string); 191 this.offset += Buffer.byteLength(this.string, 'utf8') + 1; 192 this.string = undefined; 193 } 194 else if (n === 0x5c) { 195 this.tState = STRING2; 196 } 197 else if (n >= 0x20) { this.appendStringChar(n); } 198 else { 199 return this.charError(buffer, i); 200 } 201 }else if (this.tState === STRING2){ // After backslash 202 n = buffer[i]; 203 if(n === 0x22){ this.appendStringChar(n); this.tState = STRING1; 204 }else if(n === 0x5c){ this.appendStringChar(BACK_SLASH); this.tState = STRING1; 205 }else if(n === 0x2f){ this.appendStringChar(FORWARD_SLASH); this.tState = STRING1; 206 }else if(n === 0x62){ this.appendStringChar(BACKSPACE); this.tState = STRING1; 207 }else if(n === 0x66){ this.appendStringChar(FORM_FEED); this.tState = STRING1; 208 }else if(n === 0x6e){ this.appendStringChar(NEWLINE); this.tState = STRING1; 209 }else if(n === 0x72){ this.appendStringChar(CARRIAGE_RETURN); this.tState = STRING1; 210 }else if(n === 0x74){ this.appendStringChar(TAB); this.tState = STRING1; 211 }else if(n === 0x75){ this.unicode = ""; this.tState = STRING3; 212 }else{ 213 return this.charError(buffer, i); 214 } 215 }else if (this.tState === STRING3 || this.tState === STRING4 || this.tState === STRING5 || this.tState === STRING6){ // unicode hex codes 216 n = buffer[i]; 217 // 0-9 A-F a-f 218 if ((n >= 0x30 && n < 0x40) || (n > 0x40 && n <= 0x46) || (n > 0x60 && n <= 0x66)) { 219 this.unicode += String.fromCharCode(n); 220 if (this.tState++ === STRING6) { 221 var intVal = parseInt(this.unicode, 16); 222 this.unicode = undefined; 223 if (this.highSurrogate !== undefined && intVal >= 0xDC00 && intVal < (0xDFFF + 1)) { //<56320,57343> - lowSurrogate 224 this.appendStringBuf(new Buffer(String.fromCharCode(this.highSurrogate, intVal))); 225 this.highSurrogate = undefined; 226 } else if (this.highSurrogate === undefined && intVal >= 0xD800 && intVal < (0xDBFF + 1)) { //<55296,56319> - highSurrogate 227 this.highSurrogate = intVal; 228 } else { 229 if (this.highSurrogate !== undefined) { 230 this.appendStringBuf(new Buffer(String.fromCharCode(this.highSurrogate))); 231 this.highSurrogate = undefined; 232 } 233 this.appendStringBuf(new Buffer(String.fromCharCode(intVal))); 234 } 235 this.tState = STRING1; 236 } 237 } else { 238 return this.charError(buffer, i); 239 } 240 } else if (this.tState === NUMBER1 || this.tState === NUMBER3) { 241 n = buffer[i]; 242 243 switch (n) { 244 case 0x30: // 0 245 case 0x31: // 1 246 case 0x32: // 2 247 case 0x33: // 3 248 case 0x34: // 4 249 case 0x35: // 5 250 case 0x36: // 6 251 case 0x37: // 7 252 case 0x38: // 8 253 case 0x39: // 9 254 case 0x2e: // . 255 case 0x65: // e 256 case 0x45: // E 257 case 0x2b: // + 258 case 0x2d: // - 259 this.string += String.fromCharCode(n); 260 this.tState = NUMBER3; 261 break; 262 default: 263 this.tState = START; 264 var result = Number(this.string); 265 266 if (isNaN(result)){ 267 return this.charError(buffer, i); 268 } 269 270 if ((this.string.match(/[0-9]+/) == this.string) && (result.toString() != this.string)) { 271 // Long string of digits which is an ID string and not valid and/or safe JavaScript integer Number 272 this.onToken(STRING, this.string); 273 } else { 274 this.onToken(NUMBER, result); 275 } 276 277 this.offset += this.string.length - 1; 278 this.string = undefined; 279 i--; 280 break; 281 } 282 }else if (this.tState === TRUE1){ // r 283 if (buffer[i] === 0x72) { this.tState = TRUE2; } 284 else { return this.charError(buffer, i); } 285 }else if (this.tState === TRUE2){ // u 286 if (buffer[i] === 0x75) { this.tState = TRUE3; } 287 else { return this.charError(buffer, i); } 288 }else if (this.tState === TRUE3){ // e 289 if (buffer[i] === 0x65) { this.tState = START; this.onToken(TRUE, true); this.offset+= 3; } 290 else { return this.charError(buffer, i); } 291 }else if (this.tState === FALSE1){ // a 292 if (buffer[i] === 0x61) { this.tState = FALSE2; } 293 else { return this.charError(buffer, i); } 294 }else if (this.tState === FALSE2){ // l 295 if (buffer[i] === 0x6c) { this.tState = FALSE3; } 296 else { return this.charError(buffer, i); } 297 }else if (this.tState === FALSE3){ // s 298 if (buffer[i] === 0x73) { this.tState = FALSE4; } 299 else { return this.charError(buffer, i); } 300 }else if (this.tState === FALSE4){ // e 301 if (buffer[i] === 0x65) { this.tState = START; this.onToken(FALSE, false); this.offset+= 4; } 302 else { return this.charError(buffer, i); } 303 }else if (this.tState === NULL1){ // u 304 if (buffer[i] === 0x75) { this.tState = NULL2; } 305 else { return this.charError(buffer, i); } 306 }else if (this.tState === NULL2){ // l 307 if (buffer[i] === 0x6c) { this.tState = NULL3; } 308 else { return this.charError(buffer, i); } 309 }else if (this.tState === NULL3){ // l 310 if (buffer[i] === 0x6c) { this.tState = START; this.onToken(NULL, null); this.offset += 3; } 311 else { return this.charError(buffer, i); } 312 } 313 } 314}; 315proto.onToken = function (token, value) { 316 // Override this to get events 317}; 318 319proto.parseError = function (token, value) { 320 this.tState = STOP; 321 this.onError(new Error("Unexpected " + Parser.toknam(token) + (value ? ("(" + JSON.stringify(value) + ")") : "") + " in state " + Parser.toknam(this.state))); 322}; 323proto.push = function () { 324 this.stack.push({value: this.value, key: this.key, mode: this.mode}); 325}; 326proto.pop = function () { 327 var value = this.value; 328 var parent = this.stack.pop(); 329 this.value = parent.value; 330 this.key = parent.key; 331 this.mode = parent.mode; 332 this.emit(value); 333 if (!this.mode) { this.state = VALUE; } 334}; 335proto.emit = function (value) { 336 if (this.mode) { this.state = COMMA; } 337 this.onValue(value); 338}; 339proto.onValue = function (value) { 340 // Override me 341}; 342proto.onToken = function (token, value) { 343 if(this.state === VALUE){ 344 if(token === STRING || token === NUMBER || token === TRUE || token === FALSE || token === NULL){ 345 if (this.value) { 346 this.value[this.key] = value; 347 } 348 this.emit(value); 349 }else if(token === LEFT_BRACE){ 350 this.push(); 351 if (this.value) { 352 this.value = this.value[this.key] = {}; 353 } else { 354 this.value = {}; 355 } 356 this.key = undefined; 357 this.state = KEY; 358 this.mode = OBJECT; 359 }else if(token === LEFT_BRACKET){ 360 this.push(); 361 if (this.value) { 362 this.value = this.value[this.key] = []; 363 } else { 364 this.value = []; 365 } 366 this.key = 0; 367 this.mode = ARRAY; 368 this.state = VALUE; 369 }else if(token === RIGHT_BRACE){ 370 if (this.mode === OBJECT) { 371 this.pop(); 372 } else { 373 return this.parseError(token, value); 374 } 375 }else if(token === RIGHT_BRACKET){ 376 if (this.mode === ARRAY) { 377 this.pop(); 378 } else { 379 return this.parseError(token, value); 380 } 381 }else{ 382 return this.parseError(token, value); 383 } 384 }else if(this.state === KEY){ 385 if (token === STRING) { 386 this.key = value; 387 this.state = COLON; 388 } else if (token === RIGHT_BRACE) { 389 this.pop(); 390 } else { 391 return this.parseError(token, value); 392 } 393 }else if(this.state === COLON){ 394 if (token === COLON) { this.state = VALUE; } 395 else { return this.parseError(token, value); } 396 }else if(this.state === COMMA){ 397 if (token === COMMA) { 398 if (this.mode === ARRAY) { this.key++; this.state = VALUE; } 399 else if (this.mode === OBJECT) { this.state = KEY; } 400 401 } else if (token === RIGHT_BRACKET && this.mode === ARRAY || token === RIGHT_BRACE && this.mode === OBJECT) { 402 this.pop(); 403 } else { 404 return this.parseError(token, value); 405 } 406 }else{ 407 return this.parseError(token, value); 408 } 409}; 410 411Parser.C = C; 412 413module.exports = Parser; 414