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Joeywp/nbt.js

Created May 23, 2015 15:48
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A NBT reader for JavaScript making use of jDataViewer to read binary files. Originally made for use in an online schematic viewer that was cancelled
Raw
nbt.js
var NBT = function(data)
{
this.data = data;
this.viewer = new jDataView(data);
this.tags = {
TAG_END: 0,
TAG_BYTE: 1,
TAG_SHORT: 2,
TAG_INT: 3,
TAG_LONG: 4,
TAG_FLOAT: 5,
TAG_DOUBLE: 6,
TAG_BYTE_ARRAY: 7,
TAG_STRING: 8,
TAG_LIST: 9,
TAG_COMPOUND: 10,
TAG_INT_ARRAY: 11
};
this.read = function()
{
var data = {};
data.values = [];
data.datasize = this.data.length;
try
{
this.traverse(data);
//document.write("<pre>" + JSON.stringify(data, undefined, 2) + "</pre>");
} catch (e)
{
console.log(e);
return null;
}
return data.values;
};
this.traverse = function(parent, sentType)
{
var data = {};
if(sentType === undefined)
data.type = this.viewer.getUint8();
else
data.type = sentType;
var readName = (sentType === undefined) ? true : false;
switch(data.type)
{
case this.tags.TAG_END:
break;
case this.tags.TAG_BYTE:
if(readName)
data.name = this._getString();
data.values = this.viewer.getUint8();
break;
case this.tags.TAG_SHORT:
if(readName)
data.name = this._getString();
data.values = this.viewer.getUint16();
break;
case this.tags.TAG_INT:
if(readName)
data.name = this._getString();
data.values = this.viewer.getUint32();
break;
case this.tags.TAG_LONG:
if(readName)
data.name = this._getString();
data.values = this.viewer.getUint64();
break;
case this.tags.TAG_FLOAT:
if(readName)
data.name = this._getString();
data.values = this.viewer.getFloat32();
break;
case this.tags.TAG_DOUBLE:
if(readName)
data.name = this._getString();
data.values = this.viewer.getFloat64();
break;
case this.tags.TAG_BYTE_ARRAY:
if(readName)
data.name = this._getString();
data.length = this.viewer.getUint32();
data.values = [];
for(var i = 0; i < data.length; i++)
{
data.values.push(this.viewer.getUint8());
}
break;
case this.tags.TAG_STRING:
if(readName)
data.name = this._getString();
data.values = this._getString();
break;
case this.tags.TAG_LIST:
if(readName)
data.name = this._getString();
data.listtype = this.viewer.getUint8();
data.length = this.viewer.getInt32();
data.values = [];
for(var i = 0; i < data.length; i++)
{
if(data.listtype == this.tags.TAG_COMPOUND)
{
var type = null;
while(type != this.tags.TAG_END)
{
type = this.traverse(data);
}
} else
{
this.traverse(data, data.listtype);
}
}
break;
case this.tags.TAG_COMPOUND:
if(readName)
data.name = this._getString();
data.values = [];
var type = null;
while(type != this.tags.TAG_END)
{
type = this.traverse(data);
}
break;
case this.tags.TAG_INT_ARRAY:
//console.log("TAG_INT_ARRAY");
if(readName)
data.name = this._getString();
data.length = this.viewer.getUint32();
data.values = [];
for(var i = 0; i < data.length; i++)
{
data.values.push(this.viewer.getUint32());
}
//throw "Tagtype not implemented yet";
break;
default:
throw "Unknown datatype: " + data.type;
break;
}
if(data.type != this.tags.TAG_END)
parent.values.push(data);
return data.type;
};
this._getString = function()
{
var length = this.viewer.getUint16();
return this.viewer.getString(length);
}
};
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