/*
* BinaryFile over XMLHttpRequest
* Part of the javascriptRRD package
* Copyright (c) 2009 Frank Wuerthwein, fkw@ucsd.edu
* MIT License [http://www.opensource.org/licenses/mit-license.php]
*
* Original repository: http://javascriptrrd.sourceforge.net/
*
* Based on:
* Binary Ajax 0.1.5
* Copyright (c) 2008 Jacob Seidelin, cupboy@gmail.com, http://blog.nihilogic.dk/
* MIT License [http://www.opensource.org/licenses/mit-license.php]
*/
// ============================================================
// Exception class
function InvalidBinaryFile(msg) {
this.message=msg;
this.name="Invalid BinaryFile";
}
// pretty print
InvalidBinaryFile.prototype.toString = function() {
return this.name + ': "' + this.message + '"';
}
// =====================================================================
// BinaryFile class
// Allows access to element inside a binary stream
function BinaryFile(strData, iDataOffset, iDataLength) {
var data = strData;
var dataOffset = iDataOffset || 0;
var dataLength = 0;
// added
var doubleMantExpHi=Math.pow(2,-28);
var doubleMantExpLo=Math.pow(2,-52);
var doubleMantExpFast=Math.pow(2,-20);
var switch_endian = false;
this.getRawData = function() {
return data;
}
if (typeof strData == "string") {
dataLength = iDataLength || data.length;
this.getByteAt = function(iOffset) {
return data.charCodeAt(iOffset + dataOffset) & 0xFF;
}
} else if (typeof strData == "unknown") {
dataLength = iDataLength || IEBinary_getLength(data);
this.getByteAt = function(iOffset) {
return IEBinary_getByteAt(data, iOffset + dataOffset);
}
} else {
throw new InvalidBinaryFile("Unsupported type " + (typeof strData));
}
this.getEndianByteAt = function(iOffset,width,delta) {
if (this.switch_endian)
return this.getByteAt(iOffset+width-delta-1);
else
return this.getByteAt(iOffset+delta);
}
this.getLength = function() {
return dataLength;
}
this.getSByteAt = function(iOffset) {
var iByte = this.getByteAt(iOffset);
if (iByte > 127)
return iByte - 256;
else
return iByte;
}
this.getShortAt = function(iOffset) {
var iShort = (this.getEndianByteAt(iOffset,2,1) << 8) + this.getEndianByteAt(iOffset,2,0)
if (iShort < 0) iShort += 65536;
return iShort;
}
this.getSShortAt = function(iOffset) {
var iUShort = this.getShortAt(iOffset);
if (iUShort > 32767)
return iUShort - 65536;
else
return iUShort;
}
this.getLongAt = function(iOffset) {
var iByte1 = this.getEndianByteAt(iOffset,4,0),
iByte2 = this.getEndianByteAt(iOffset,4,1),
iByte3 = this.getEndianByteAt(iOffset,4,2),
iByte4 = this.getEndianByteAt(iOffset,4,3);
var iLong = (((((iByte4 << 8) + iByte3) << 8) + iByte2) << 8) + iByte1;
if (iLong < 0) iLong += 4294967296;
return iLong;
}
this.getSLongAt = function(iOffset) {
var iULong = this.getLongAt(iOffset);
if (iULong > 2147483647)
return iULong - 4294967296;
else
return iULong;
}
this.getStringAt = function(iOffset, iLength) {
var aStr = [];
for (var i=iOffset,j=0;i<iOffset+iLength;i++,j++) {
aStr[j] = String.fromCharCode(this.getByteAt(i));
}
return aStr.join("");
}
// Added
this.getCStringAt = function(iOffset, iMaxLength) {
var aStr = [];
for (var i=iOffset,j=0;(i<iOffset+iMaxLength) && (this.getByteAt(i)>0);i++,j++) {
aStr[j] = String.fromCharCode(this.getByteAt(i));
}
return aStr.join("");
}
// Added
this.getDoubleAt = function(iOffset) {
var iByte1 = this.getEndianByteAt(iOffset,8,0),
iByte2 = this.getEndianByteAt(iOffset,8,1),
iByte3 = this.getEndianByteAt(iOffset,8,2),
iByte4 = this.getEndianByteAt(iOffset,8,3),
iByte5 = this.getEndianByteAt(iOffset,8,4),
iByte6 = this.getEndianByteAt(iOffset,8,5),
iByte7 = this.getEndianByteAt(iOffset,8,6),
iByte8 = this.getEndianByteAt(iOffset,8,7);
var iSign=iByte8 >> 7;
var iExpRaw=((iByte8 & 0x7F)<< 4) + (iByte7 >> 4);
var iMantHi=((((((iByte7 & 0x0F) << 8) + iByte6) << 8) + iByte5) << 8) + iByte4;
var iMantLo=((((iByte3) << 8) + iByte2) << 8) + iByte1;
if (iExpRaw==0) return 0.0;
if (iExpRaw==0x7ff) return undefined;
var iExp=(iExpRaw & 0x7FF)-1023;
var dDouble = ((iSign==1)?-1:1)*Math.pow(2,iExp)*(1.0 + iMantLo*doubleMantExpLo + iMantHi*doubleMantExpHi);
return dDouble;
}
// added
// Extracts only 4 bytes out of 8, loosing in precision (20 bit mantissa)
this.getFastDoubleAt = function(iOffset) {
var iByte5 = this.getEndianByteAt(iOffset,8,4),
iByte6 = this.getEndianByteAt(iOffset,8,5),
iByte7 = this.getEndianByteAt(iOffset,8,6),
iByte8 = this.getEndianByteAt(iOffset,8,7);
var iSign=iByte8 >> 7;
var iExpRaw=((iByte8 & 0x7F)<< 4) + (iByte7 >> 4);
var iMant=((((iByte7 & 0x0F) << 8) + iByte6) << 8) + iByte5;
if (iExpRaw==0) return 0.0;
if (iExpRaw==0x7ff) return undefined;
var iExp=(iExpRaw & 0x7FF)-1023;
var dDouble = ((iSign==1)?-1:1)*Math.pow(2,iExp)*(1.0 + iMant*doubleMantExpFast);
return dDouble;
}
this.getCharAt = function(iOffset) {
return String.fromCharCode(this.getByteAt(iOffset));
}
}
document.write(
"<script type='text/vbscript'>\r\n"
+ "Function IEBinary_getByteAt(strBinary, iOffset)\r\n"
+ " IEBinary_getByteAt = AscB(MidB(strBinary,iOffset+1,1))\r\n"
+ "End Function\r\n"
+ "Function IEBinary_getLength(strBinary)\r\n"
+ " IEBinary_getLength = LenB(strBinary)\r\n"
+ "End Function\r\n"
+ "</script>\r\n"
);
// ===============================================================
// Load a binary file from the specified URL
// Will return an object of type BinaryFile
function FetchBinaryURL(url) {
var request = new XMLHttpRequest();
request.open("GET", url,false);
try {
request.overrideMimeType('text/plain; charset=x-user-defined');
} catch (err) {
// ignore any error, just to make both FF and IE work
}
request.send(null);
var response=request.responseBody;
if (response==undefined){ // responseBody is non standard, but the only way to make it work in IE
response=request.responseText;
}
var bf=new BinaryFile(response);
return bf;
}
// ===============================================================
// Asyncronously load a binary file from the specified URL
//
// callback must be a function with one or two arguments:
// - bf = an object of type BinaryFile
// - optional argument object (used only if callback_arg not undefined)
function FetchBinaryURLAsync(url, callback, callback_arg) {
var callback_wrapper = function() {
if(this.readyState == 4) {
var response=this.responseBody;
if (response==undefined){ // responseBody is non standard, but the only way to make it work in IE
response=this.responseText;
}
var bf=new BinaryFile(response);
if (callback_arg!=null) {
callback(bf,callback_arg);
} else {
callback(bf);
}
}
}
var request = new XMLHttpRequest();
request.onreadystatechange = callback_wrapper;
request.open("GET", url,true);
try {
request.overrideMimeType('text/plain; charset=x-user-defined');
} catch (err) {
// ignore any error, just to make both FF and IE work
}
request.send(null);
return request
}