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1/*global Buffer*/2// Named constants with unique integer values3var C = {};4// Tokens5var 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 States17var 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 States38var VALUE   = C.VALUE   = 0x71;39var KEY     = C.KEY     = 0x72;40// Parser Modes41var OBJECT  = C.OBJECT  = 0x81;42var ARRAY   = C.ARRAY   = 0x82;43// Character constants44var 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 data59  this.stringBuffer = Buffer.alloc ? Buffer.alloc(STRING_BUFFER_SIZE) : new Buffer(STRING_BUFFER_SIZE);60  this.stringBufferOffset = 0;61  this.unicode = undefined; // unicode escapes62  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 boundary69  this.bytes_in_sequence = 0; // bytes in multi byte utf8 char to read70  this.temp_buffs = { "2": new Buffer(2), "3": new Buffer(3), "4": new Buffer(4) }; // for rebuilding chars split before boundary is reached71 72  // Stream offset73  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 size106        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;  // t141      }else if(n === 0x66){ this.tState = FALSE1;  // f142      }else if(n === 0x6e){ this.tState = NULL1; // n143      }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) { // 1-9150          this.string = String.fromCharCode(n); this.tState = NUMBER3;151        } else if (n === 0x20 || n === 0x09 || n === 0x0a || n === 0x0d) {152          // whitespace153        } else {154          return this.charError(buffer, i);155        }156      }157    }else if (this.tState === STRING1){ // After open quote158      n = buffer[i]; // get current byte from buffer159      // check for carry over of a multi byte char split between data chunks160      // & fill temp buffer it with start of this data chunk up to the boundary limit set in the last iteration161      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 time170        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 split177          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 chunk179          }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 backslash202      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 codes216      n = buffer[i];217      // 0-9 A-F a-f218      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> - lowSurrogate224            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> - highSurrogate227            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: // 0245          case 0x31: // 1246          case 0x32: // 2247          case 0x33: // 3248          case 0x34: // 4249          case 0x35: // 5250          case 0x36: // 6251          case 0x37: // 7252          case 0x38: // 8253          case 0x39: // 9254          case 0x2e: // .255          case 0x65: // e256          case 0x45: // E257          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 Number272              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){ // r283      if (buffer[i] === 0x72) { this.tState = TRUE2; }284      else { return this.charError(buffer, i); }285    }else if (this.tState === TRUE2){ // u286      if (buffer[i] === 0x75) { this.tState = TRUE3; }287      else { return this.charError(buffer, i); }288    }else if (this.tState === TRUE3){ // e289      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){ // a292      if (buffer[i] === 0x61) { this.tState = FALSE2; }293      else { return this.charError(buffer, i); }294    }else if (this.tState === FALSE2){ // l295      if (buffer[i] === 0x6c) { this.tState = FALSE3; }296      else { return this.charError(buffer, i); }297    }else if (this.tState === FALSE3){ // s298      if (buffer[i] === 0x73) { this.tState = FALSE4; }299      else { return this.charError(buffer, i); }300    }else if (this.tState === FALSE4){ // e301      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){ // u304      if (buffer[i] === 0x75) { this.tState = NULL2; }305      else { return this.charError(buffer, i); }306    }else if (this.tState === NULL2){ // l307      if (buffer[i] === 0x6c) { this.tState = NULL3; }308      else { return this.charError(buffer, i); }309    }else if (this.tState === NULL3){ // l310      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 events317};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 me341};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