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%PDF-
Mini Shell
Mini Shell
/*global Buffer*/
// Named constants with unique integer values
var C = {};
// Tokens
var LEFT_BRACE = C.LEFT_BRACE = 0x1;
var RIGHT_BRACE = C.RIGHT_BRACE = 0x2;
var LEFT_BRACKET = C.LEFT_BRACKET = 0x3;
var RIGHT_BRACKET = C.RIGHT_BRACKET = 0x4;
var COLON = C.COLON = 0x5;
var COMMA = C.COMMA = 0x6;
var TRUE = C.TRUE = 0x7;
var FALSE = C.FALSE = 0x8;
var NULL = C.NULL = 0x9;
var STRING = C.STRING = 0xa;
var NUMBER = C.NUMBER = 0xb;
// Tokenizer States
var START = C.START = 0x11;
var STOP = C.STOP = 0x12;
var TRUE1 = C.TRUE1 = 0x21;
var TRUE2 = C.TRUE2 = 0x22;
var TRUE3 = C.TRUE3 = 0x23;
var FALSE1 = C.FALSE1 = 0x31;
var FALSE2 = C.FALSE2 = 0x32;
var FALSE3 = C.FALSE3 = 0x33;
var FALSE4 = C.FALSE4 = 0x34;
var NULL1 = C.NULL1 = 0x41;
var NULL2 = C.NULL2 = 0x42;
var NULL3 = C.NULL3 = 0x43;
var NUMBER1 = C.NUMBER1 = 0x51;
var NUMBER3 = C.NUMBER3 = 0x53;
var STRING1 = C.STRING1 = 0x61;
var STRING2 = C.STRING2 = 0x62;
var STRING3 = C.STRING3 = 0x63;
var STRING4 = C.STRING4 = 0x64;
var STRING5 = C.STRING5 = 0x65;
var STRING6 = C.STRING6 = 0x66;
// Parser States
var VALUE = C.VALUE = 0x71;
var KEY = C.KEY = 0x72;
// Parser Modes
var OBJECT = C.OBJECT = 0x81;
var ARRAY = C.ARRAY = 0x82;
// Character constants
var BACK_SLASH = "\\".charCodeAt(0);
var FORWARD_SLASH = "\/".charCodeAt(0);
var BACKSPACE = "\b".charCodeAt(0);
var FORM_FEED = "\f".charCodeAt(0);
var NEWLINE = "\n".charCodeAt(0);
var CARRIAGE_RETURN = "\r".charCodeAt(0);
var TAB = "\t".charCodeAt(0);
var STRING_BUFFER_SIZE = 64 * 1024;
function Parser() {
this.tState = START;
this.value = undefined;
this.string = undefined; // string data
this.stringBuffer = Buffer.alloc ? Buffer.alloc(STRING_BUFFER_SIZE) : new Buffer(STRING_BUFFER_SIZE);
this.stringBufferOffset = 0;
this.unicode = undefined; // unicode escapes
this.highSurrogate = undefined;
this.key = undefined;
this.mode = undefined;
this.stack = [];
this.state = VALUE;
this.bytes_remaining = 0; // number of bytes remaining in multi byte utf8 char to read after split boundary
this.bytes_in_sequence = 0; // bytes in multi byte utf8 char to read
this.temp_buffs = { "2": new Buffer(2), "3": new Buffer(3), "4": new Buffer(4) }; // for rebuilding chars split before boundary is reached
// Stream offset
this.offset = -1;
}
// Slow code to string converter (only used when throwing syntax errors)
Parser.toknam = function (code) {
var keys = Object.keys(C);
for (var i = 0, l = keys.length; i < l; i++) {
var key = keys[i];
if (C[key] === code) { return key; }
}
return code && ("0x" + code.toString(16));
};
var proto = Parser.prototype;
proto.onError = function (err) { throw err; };
proto.charError = function (buffer, i) {
this.tState = STOP;
this.onError(new Error("Unexpected " + JSON.stringify(String.fromCharCode(buffer[i])) + " at position " + i + " in state " + Parser.toknam(this.tState)));
};
proto.appendStringChar = function (char) {
if (this.stringBufferOffset >= STRING_BUFFER_SIZE) {
this.string += this.stringBuffer.toString('utf8');
this.stringBufferOffset = 0;
}
this.stringBuffer[this.stringBufferOffset++] = char;
};
proto.appendStringBuf = function (buf, start, end) {
var size = buf.length;
if (typeof start === 'number') {
if (typeof end === 'number') {
if (end < 0) {
// adding a negative end decreeses the size
size = buf.length - start + end;
} else {
size = end - start;
}
} else {
size = buf.length - start;
}
}
if (size < 0) {
size = 0;
}
if (this.stringBufferOffset + size > STRING_BUFFER_SIZE) {
this.string += this.stringBuffer.toString('utf8', 0, this.stringBufferOffset);
this.stringBufferOffset = 0;
}
buf.copy(this.stringBuffer, this.stringBufferOffset, start, end);
this.stringBufferOffset += size;
};
proto.write = function (buffer) {
if (typeof buffer === "string") buffer = new Buffer(buffer);
var n;
for (var i = 0, l = buffer.length; i < l; i++) {
if (this.tState === START){
n = buffer[i];
this.offset++;
if(n === 0x7b){ this.onToken(LEFT_BRACE, "{"); // {
}else if(n === 0x7d){ this.onToken(RIGHT_BRACE, "}"); // }
}else if(n === 0x5b){ this.onToken(LEFT_BRACKET, "["); // [
}else if(n === 0x5d){ this.onToken(RIGHT_BRACKET, "]"); // ]
}else if(n === 0x3a){ this.onToken(COLON, ":"); // :
}else if(n === 0x2c){ this.onToken(COMMA, ","); // ,
}else if(n === 0x74){ this.tState = TRUE1; // t
}else if(n === 0x66){ this.tState = FALSE1; // f
}else if(n === 0x6e){ this.tState = NULL1; // n
}else if(n === 0x22){ // "
this.string = "";
this.stringBufferOffset = 0;
this.tState = STRING1;
}else if(n === 0x2d){ this.string = "-"; this.tState = NUMBER1; // -
}else{
if (n >= 0x30 && n < 0x40) { // 1-9
this.string = String.fromCharCode(n); this.tState = NUMBER3;
} else if (n === 0x20 || n === 0x09 || n === 0x0a || n === 0x0d) {
// whitespace
} else {
return this.charError(buffer, i);
}
}
}else if (this.tState === STRING1){ // After open quote
n = buffer[i]; // get current byte from buffer
// check for carry over of a multi byte char split between data chunks
// & fill temp buffer it with start of this data chunk up to the boundary limit set in the last iteration
if (this.bytes_remaining > 0) {
for (var j = 0; j < this.bytes_remaining; j++) {
this.temp_buffs[this.bytes_in_sequence][this.bytes_in_sequence - this.bytes_remaining + j] = buffer[j];
}
this.appendStringBuf(this.temp_buffs[this.bytes_in_sequence]);
this.bytes_in_sequence = this.bytes_remaining = 0;
i = i + j - 1;
} else if (this.bytes_remaining === 0 && n >= 128) { // else if no remainder bytes carried over, parse multi byte (>=128) chars one at a time
if (n <= 193 || n > 244) {
return this.onError(new Error("Invalid UTF-8 character at position " + i + " in state " + Parser.toknam(this.tState)));
}
if ((n >= 194) && (n <= 223)) this.bytes_in_sequence = 2;
if ((n >= 224) && (n <= 239)) this.bytes_in_sequence = 3;
if ((n >= 240) && (n <= 244)) this.bytes_in_sequence = 4;
if ((this.bytes_in_sequence + i) > buffer.length) { // if bytes needed to complete char fall outside buffer length, we have a boundary split
for (var k = 0; k <= (buffer.length - 1 - i); k++) {
this.temp_buffs[this.bytes_in_sequence][k] = buffer[i + k]; // fill temp buffer of correct size with bytes available in this chunk
}
this.bytes_remaining = (i + this.bytes_in_sequence) - buffer.length;
i = buffer.length - 1;
} else {
this.appendStringBuf(buffer, i, i + this.bytes_in_sequence);
i = i + this.bytes_in_sequence - 1;
}
} else if (n === 0x22) {
this.tState = START;
this.string += this.stringBuffer.toString('utf8', 0, this.stringBufferOffset);
this.stringBufferOffset = 0;
this.onToken(STRING, this.string);
this.offset += Buffer.byteLength(this.string, 'utf8') + 1;
this.string = undefined;
}
else if (n === 0x5c) {
this.tState = STRING2;
}
else if (n >= 0x20) { this.appendStringChar(n); }
else {
return this.charError(buffer, i);
}
}else if (this.tState === STRING2){ // After backslash
n = buffer[i];
if(n === 0x22){ this.appendStringChar(n); this.tState = STRING1;
}else if(n === 0x5c){ this.appendStringChar(BACK_SLASH); this.tState = STRING1;
}else if(n === 0x2f){ this.appendStringChar(FORWARD_SLASH); this.tState = STRING1;
}else if(n === 0x62){ this.appendStringChar(BACKSPACE); this.tState = STRING1;
}else if(n === 0x66){ this.appendStringChar(FORM_FEED); this.tState = STRING1;
}else if(n === 0x6e){ this.appendStringChar(NEWLINE); this.tState = STRING1;
}else if(n === 0x72){ this.appendStringChar(CARRIAGE_RETURN); this.tState = STRING1;
}else if(n === 0x74){ this.appendStringChar(TAB); this.tState = STRING1;
}else if(n === 0x75){ this.unicode = ""; this.tState = STRING3;
}else{
return this.charError(buffer, i);
}
}else if (this.tState === STRING3 || this.tState === STRING4 || this.tState === STRING5 || this.tState === STRING6){ // unicode hex codes
n = buffer[i];
// 0-9 A-F a-f
if ((n >= 0x30 && n < 0x40) || (n > 0x40 && n <= 0x46) || (n > 0x60 && n <= 0x66)) {
this.unicode += String.fromCharCode(n);
if (this.tState++ === STRING6) {
var intVal = parseInt(this.unicode, 16);
this.unicode = undefined;
if (this.highSurrogate !== undefined && intVal >= 0xDC00 && intVal < (0xDFFF + 1)) { //<56320,57343> - lowSurrogate
this.appendStringBuf(new Buffer(String.fromCharCode(this.highSurrogate, intVal)));
this.highSurrogate = undefined;
} else if (this.highSurrogate === undefined && intVal >= 0xD800 && intVal < (0xDBFF + 1)) { //<55296,56319> - highSurrogate
this.highSurrogate = intVal;
} else {
if (this.highSurrogate !== undefined) {
this.appendStringBuf(new Buffer(String.fromCharCode(this.highSurrogate)));
this.highSurrogate = undefined;
}
this.appendStringBuf(new Buffer(String.fromCharCode(intVal)));
}
this.tState = STRING1;
}
} else {
return this.charError(buffer, i);
}
} else if (this.tState === NUMBER1 || this.tState === NUMBER3) {
n = buffer[i];
switch (n) {
case 0x30: // 0
case 0x31: // 1
case 0x32: // 2
case 0x33: // 3
case 0x34: // 4
case 0x35: // 5
case 0x36: // 6
case 0x37: // 7
case 0x38: // 8
case 0x39: // 9
case 0x2e: // .
case 0x65: // e
case 0x45: // E
case 0x2b: // +
case 0x2d: // -
this.string += String.fromCharCode(n);
this.tState = NUMBER3;
break;
default:
this.tState = START;
var result = Number(this.string);
if (isNaN(result)){
return this.charError(buffer, i);
}
if ((this.string.match(/[0-9]+/) == this.string) && (result.toString() != this.string)) {
// Long string of digits which is an ID string and not valid and/or safe JavaScript integer Number
this.onToken(STRING, this.string);
} else {
this.onToken(NUMBER, result);
}
this.offset += this.string.length - 1;
this.string = undefined;
i--;
break;
}
}else if (this.tState === TRUE1){ // r
if (buffer[i] === 0x72) { this.tState = TRUE2; }
else { return this.charError(buffer, i); }
}else if (this.tState === TRUE2){ // u
if (buffer[i] === 0x75) { this.tState = TRUE3; }
else { return this.charError(buffer, i); }
}else if (this.tState === TRUE3){ // e
if (buffer[i] === 0x65) { this.tState = START; this.onToken(TRUE, true); this.offset+= 3; }
else { return this.charError(buffer, i); }
}else if (this.tState === FALSE1){ // a
if (buffer[i] === 0x61) { this.tState = FALSE2; }
else { return this.charError(buffer, i); }
}else if (this.tState === FALSE2){ // l
if (buffer[i] === 0x6c) { this.tState = FALSE3; }
else { return this.charError(buffer, i); }
}else if (this.tState === FALSE3){ // s
if (buffer[i] === 0x73) { this.tState = FALSE4; }
else { return this.charError(buffer, i); }
}else if (this.tState === FALSE4){ // e
if (buffer[i] === 0x65) { this.tState = START; this.onToken(FALSE, false); this.offset+= 4; }
else { return this.charError(buffer, i); }
}else if (this.tState === NULL1){ // u
if (buffer[i] === 0x75) { this.tState = NULL2; }
else { return this.charError(buffer, i); }
}else if (this.tState === NULL2){ // l
if (buffer[i] === 0x6c) { this.tState = NULL3; }
else { return this.charError(buffer, i); }
}else if (this.tState === NULL3){ // l
if (buffer[i] === 0x6c) { this.tState = START; this.onToken(NULL, null); this.offset += 3; }
else { return this.charError(buffer, i); }
}
}
};
proto.onToken = function (token, value) {
// Override this to get events
};
proto.parseError = function (token, value) {
this.tState = STOP;
this.onError(new Error("Unexpected " + Parser.toknam(token) + (value ? ("(" + JSON.stringify(value) + ")") : "") + " in state " + Parser.toknam(this.state)));
};
proto.push = function () {
this.stack.push({value: this.value, key: this.key, mode: this.mode});
};
proto.pop = function () {
var value = this.value;
var parent = this.stack.pop();
this.value = parent.value;
this.key = parent.key;
this.mode = parent.mode;
this.emit(value);
if (!this.mode) { this.state = VALUE; }
};
proto.emit = function (value) {
if (this.mode) { this.state = COMMA; }
this.onValue(value);
};
proto.onValue = function (value) {
// Override me
};
proto.onToken = function (token, value) {
if(this.state === VALUE){
if(token === STRING || token === NUMBER || token === TRUE || token === FALSE || token === NULL){
if (this.value) {
this.value[this.key] = value;
}
this.emit(value);
}else if(token === LEFT_BRACE){
this.push();
if (this.value) {
this.value = this.value[this.key] = {};
} else {
this.value = {};
}
this.key = undefined;
this.state = KEY;
this.mode = OBJECT;
}else if(token === LEFT_BRACKET){
this.push();
if (this.value) {
this.value = this.value[this.key] = [];
} else {
this.value = [];
}
this.key = 0;
this.mode = ARRAY;
this.state = VALUE;
}else if(token === RIGHT_BRACE){
if (this.mode === OBJECT) {
this.pop();
} else {
return this.parseError(token, value);
}
}else if(token === RIGHT_BRACKET){
if (this.mode === ARRAY) {
this.pop();
} else {
return this.parseError(token, value);
}
}else{
return this.parseError(token, value);
}
}else if(this.state === KEY){
if (token === STRING) {
this.key = value;
this.state = COLON;
} else if (token === RIGHT_BRACE) {
this.pop();
} else {
return this.parseError(token, value);
}
}else if(this.state === COLON){
if (token === COLON) { this.state = VALUE; }
else { return this.parseError(token, value); }
}else if(this.state === COMMA){
if (token === COMMA) {
if (this.mode === ARRAY) { this.key++; this.state = VALUE; }
else if (this.mode === OBJECT) { this.state = KEY; }
} else if (token === RIGHT_BRACKET && this.mode === ARRAY || token === RIGHT_BRACE && this.mode === OBJECT) {
this.pop();
} else {
return this.parseError(token, value);
}
}else{
return this.parseError(token, value);
}
};
Parser.C = C;
module.exports = Parser;
Zerion Mini Shell 1.0