nodulator
Version:
Complete NodeJS Framework for Restfull APIs
230 lines (214 loc) • 10.1 kB
JavaScript
//+ Jonas Raoni Soares Silva
//@ http://jsfromhell.com/classes/binary-parser [v1.0]
var chr = String.fromCharCode;
var p = exports.BinaryParser = function( bigEndian, allowExceptions ){
this.bigEndian = bigEndian;
this.allowExceptions = allowExceptions;
};
var Buffer = exports.BinaryParser.Buffer = function( bigEndian, buffer ){
this.bigEndian = bigEndian || 0;
this.buffer = [];
this.setBuffer( buffer );
};
Buffer.prototype.setBuffer = function( data ){
if( data ){
for( var l, i = l = data.length, b = this.buffer = new Array( l ); i; b[l - i] = data.charCodeAt( --i ) );
this.bigEndian && b.reverse();
}
};
Buffer.prototype.hasNeededBits = function( neededBits ){
return this.buffer.length >= -( -neededBits >> 3 );
};
Buffer.prototype.checkBuffer = function( neededBits ){
if( !this.hasNeededBits( neededBits ) )
throw new Error( "checkBuffer::missing bytes" );
};
Buffer.prototype.readBits = function( start, length ){
//shl fix: Henri Torgemane ~1996 (compressed by Jonas Raoni)
function shl( a, b ){
for( ; b--; a = ( ( a %= 0x7fffffff + 1 ) & 0x40000000 ) == 0x40000000 ? a * 2 : ( a - 0x40000000 ) * 2 + 0x7fffffff + 1 );
return a;
}
if( start < 0 || length <= 0 )
return 0;
this.checkBuffer( start + length );
for( var offsetLeft, offsetRight = start % 8, curByte = this.buffer.length - ( start >> 3 ) - 1, lastByte = this.buffer.length + ( -( start + length ) >> 3 ), diff = curByte - lastByte, sum = ( ( this.buffer[ curByte ] >> offsetRight ) & ( ( 1 << ( diff ? 8 - offsetRight : length ) ) - 1 ) ) + ( diff && ( offsetLeft = ( start + length ) % 8 ) ? ( this.buffer[ lastByte++ ] & ( ( 1 << offsetLeft ) - 1 ) ) << ( diff-- << 3 ) - offsetRight : 0 ); diff; sum += shl( this.buffer[ lastByte++ ], ( diff-- << 3 ) - offsetRight ) );
return sum;
};
p.warn = function( msg ){
if( this.allowExceptions )
throw new Error( msg );
return 1;
};
p.decodeFloat = function( data, precisionBits, exponentBits ){
var b = new this.Buffer( this.bigEndian, data );
b.checkBuffer( precisionBits + exponentBits + 1 );
var bias = Math.pow( 2, exponentBits - 1 ) - 1, signal = b.readBits( precisionBits + exponentBits, 1 ), exponent = b.readBits( precisionBits, exponentBits ), significand = 0,
divisor = 2, curByte = b.buffer.length + ( -precisionBits >> 3 ) - 1;
do{
for( var byteValue = b.buffer[ ++curByte ], startBit = precisionBits % 8 || 8, mask = 1 << startBit; mask >>= 1; ( byteValue & mask ) && ( significand += 1 / divisor ), divisor *= 2 );
}while( precisionBits -= startBit );
return exponent == ( bias << 1 ) + 1 ? significand ? NaN : signal ? -Infinity : +Infinity : ( 1 + signal * -2 ) * ( exponent || significand ? !exponent ? Math.pow( 2, -bias + 1 ) * significand : Math.pow( 2, exponent - bias ) * ( 1 + significand ) : 0 );
};
p.decodeInt = function( data, bits, signed, forceBigEndian ){
var b = new this.Buffer( this.bigEndian||forceBigEndian, data ), x = b.readBits( 0, bits ), max = Math.pow( 2, bits );
return signed && x >= max / 2 ? x - max : x;
};
p.encodeFloat = function( data, precisionBits, exponentBits ){
var bias = Math.pow( 2, exponentBits - 1 ) - 1, minExp = -bias + 1, maxExp = bias, minUnnormExp = minExp - precisionBits,
status = isNaN( n = parseFloat( data ) ) || n == -Infinity || n == +Infinity ? n : 0,
exp = 0, len = 2 * bias + 1 + precisionBits + 3, bin = new Array( len ),
signal = ( n = status !== 0 ? 0 : n ) < 0, n = Math.abs( n ), intPart = Math.floor( n ), floatPart = n - intPart,
i, lastBit, rounded, j, result;
for( i = len; i; bin[--i] = 0 );
for( i = bias + 2; intPart && i; bin[--i] = intPart % 2, intPart = Math.floor( intPart / 2 ) );
for( i = bias + 1; floatPart > 0 && i; ( bin[++i] = ( ( floatPart *= 2 ) >= 1 ) - 0 ) && --floatPart );
for( i = -1; ++i < len && !bin[i]; );
if( bin[( lastBit = precisionBits - 1 + ( i = ( exp = bias + 1 - i ) >= minExp && exp <= maxExp ? i + 1 : bias + 1 - ( exp = minExp - 1 ) ) ) + 1] ){
if( !( rounded = bin[lastBit] ) ){
for( j = lastBit + 2; !rounded && j < len; rounded = bin[j++] );
}
for( j = lastBit + 1; rounded && --j >= 0; ( bin[j] = !bin[j] - 0 ) && ( rounded = 0 ) );
}
for( i = i - 2 < 0 ? -1 : i - 3; ++i < len && !bin[i]; );
if( ( exp = bias + 1 - i ) >= minExp && exp <= maxExp )
++i;
else if( exp < minExp ){
exp != bias + 1 - len && exp < minUnnormExp && this.warn( "encodeFloat::float underflow" );
i = bias + 1 - ( exp = minExp - 1 );
}
if( intPart || status !== 0 ){
this.warn( intPart ? "encodeFloat::float overflow" : "encodeFloat::" + status );
exp = maxExp + 1;
i = bias + 2;
if( status == -Infinity )
signal = 1;
else if( isNaN( status ) )
bin[i] = 1;
}
for( n = Math.abs( exp + bias ), j = exponentBits + 1, result = ""; --j; result = ( n % 2 ) + result, n = n >>= 1 );
for( n = 0, j = 0, i = ( result = ( signal ? "1" : "0" ) + result + bin.slice( i, i + precisionBits ).join( "" ) ).length, r = []; i; j = ( j + 1 ) % 8 ){
n += ( 1 << j ) * result.charAt( --i );
if( j == 7 ){
r[r.length] = String.fromCharCode( n );
n = 0;
}
}
r[r.length] = n ? String.fromCharCode( n ) : "";
return ( this.bigEndian ? r.reverse() : r ).join( "" );
};
p.encodeInt = function( data, bits, signed, forceBigEndian ){
var max = Math.pow( 2, bits );
( data >= max || data < -( max / 2 ) ) && this.warn( "encodeInt::overflow" ) && ( data = 0 );
data < 0 && ( data += max );
for( var r = []; data; r[r.length] = String.fromCharCode( data % 256 ), data = Math.floor( data / 256 ) );
for( bits = -( -bits >> 3 ) - r.length; bits--; r[r.length] = "\0" );
return ( (this.bigEndian||forceBigEndian) ? r.reverse() : r ).join( "" );
};
p.toSmall = function( data ){ return this.decodeInt( data, 8, true ); };
p.fromSmall = function( data ){ return this.encodeInt( data, 8, true ); };
p.toByte = function( data ){ return this.decodeInt( data, 8, false ); };
p.fromByte = function( data ){ return this.encodeInt( data, 8, false ); };
p.toShort = function( data ){ return this.decodeInt( data, 16, true ); };
p.fromShort = function( data ){ return this.encodeInt( data, 16, true ); };
p.toWord = function( data ){ return this.decodeInt( data, 16, false ); };
p.fromWord = function( data ){ return this.encodeInt( data, 16, false ); };
p.toInt = function( data ){ return this.decodeInt( data, 32, true ); };
p.fromInt = function( data ){ return this.encodeInt( data, 32, true ); };
p.toLong = function( data ){ return this.decodeInt( data, 64, true ); };
p.fromLong = function( data ){ return this.encodeInt( data, 64, true ); };
p.toDWord = function( data ){ return this.decodeInt( data, 32, false ); };
p.fromDWord = function( data ){ return this.encodeInt( data, 32, false ); };
p.toQWord = function( data ){ return this.decodeInt( data, 64, true ); };
p.fromQWord = function( data ){ return this.encodeInt( data, 64, true ); };
p.toFloat = function( data ){ return this.decodeFloat( data, 23, 8 ); };
p.fromFloat = function( data ){ return this.encodeFloat( data, 23, 8 ); };
p.toDouble = function( data ){ return this.decodeFloat( data, 52, 11 ); };
p.fromDouble = function( data ){ return this.encodeFloat( data, 52, 11 ); };
// Factor out the encode so it can be shared by add_header and push_int32
p.encode_int32 = function(number) {
var a, b, c, d, unsigned;
unsigned = (number < 0) ? (number + 0x100000000) : number;
a = Math.floor(unsigned / 0xffffff);
unsigned &= 0xffffff;
b = Math.floor(unsigned / 0xffff);
unsigned &= 0xffff;
c = Math.floor(unsigned / 0xff);
unsigned &= 0xff;
d = Math.floor(unsigned);
return chr(a) + chr(b) + chr(c) + chr(d);
};
p.encode_int64 = function(number) {
var a, b, c, d, e, f, g, h, unsigned;
unsigned = (number < 0) ? (number + 0x10000000000000000) : number;
a = Math.floor(unsigned / 0xffffffffffffff);
unsigned &= 0xffffffffffffff;
b = Math.floor(unsigned / 0xffffffffffff);
unsigned &= 0xffffffffffff;
c = Math.floor(unsigned / 0xffffffffff);
unsigned &= 0xffffffffff;
d = Math.floor(unsigned / 0xffffffff);
unsigned &= 0xffffffff;
e = Math.floor(unsigned / 0xffffff);
unsigned &= 0xffffff;
f = Math.floor(unsigned / 0xffff);
unsigned &= 0xffff;
g = Math.floor(unsigned / 0xff);
unsigned &= 0xff;
h = Math.floor(unsigned);
return chr(a) + chr(b) + chr(c) + chr(d) + chr(e) + chr(f) + chr(g) + chr(h);
};
/**
UTF8 methods
**/
// Take a raw binary string and return a utf8 string
p.decode_utf8 = function(a) {
var string = "";
var i = 0;
var c = c1 = c2 = 0;
while ( i < a.length ) {
c = a.charCodeAt(i);
if (c < 128) {
string += String.fromCharCode(c);
i++;
} else if((c > 191) && (c < 224)) {
c2 = a.charCodeAt(i+1);
string += String.fromCharCode(((c & 31) << 6) | (c2 & 63));
i += 2;
} else {
c2 = a.charCodeAt(i+1);
c3 = a.charCodeAt(i+2);
string += String.fromCharCode(((c & 15) << 12) | ((c2 & 63) << 6) | (c3 & 63));
i += 3;
}
}
return string;
};
// Encode a cstring correctly
p.encode_cstring = function(s) {
return unescape(encodeURIComponent(s)) + p.fromByte(0);
};
// Take a utf8 string and return a binary string
p.encode_utf8 = function(s) {
var a="";
for (var n=0; n< s.length; n++) {
var c=s.charCodeAt(n);
if (c<128) {
a += String.fromCharCode(c);
} else if ((c>127)&&(c<2048)) {
a += String.fromCharCode( (c>>6) | 192) ;
a += String.fromCharCode( (c&63) | 128);
} else {
a += String.fromCharCode( (c>>12) | 224);
a += String.fromCharCode( ((c>>6) & 63) | 128);
a += String.fromCharCode( (c&63) | 128);
}
}
return a;
};
p.pprint = function(s) {
for (var i=0; i<s.length; i++) {
if (s.charCodeAt(i)<32) {sys.puts(s.charCodeAt(i)+' : ');}
else {sys.puts(s.charCodeAt(i)+' : '+ s.charAt(i));}
}
};