VulpesOS/assets/webapps/gallery.gaiamobile.org/shared/js/blobview.js

;'use strict';var BlobView=(function(){function fail(msg){throw Error(msg);}
var decoderCache={};function getDecoder(encoding){if(encoding in decoderCache){return decoderCache[encoding];}
var decoder=decoderCache[encoding]=new TextDecoder(encoding);return decoder;}
function BlobView(blob,sliceOffset,sliceLength,slice,viewOffset,viewLength,littleEndian)
{this.blob=blob;this.sliceOffset=sliceOffset;this.sliceLength=sliceLength;this.slice=slice;this.viewOffset=viewOffset;this.viewLength=viewLength;this.littleEndian=littleEndian;this.view=new DataView(slice,viewOffset,viewLength);this.buffer=slice;this.byteLength=viewLength;this.byteOffset=viewOffset;this.index=0;}
BlobView.get=function(blob,offset,length,callback,littleEndian){if(offset<0){fail('negative offset');}
if(length<0){fail('negative length');}
if(offset>blob.size){fail('offset larger than blob size');}
if(offset+length>blob.size){length=blob.size-offset;}
var slice=blob.slice(offset,offset+length);var reader=new FileReader();reader.readAsArrayBuffer(slice);reader.onloadend=function(){var result=null;if(reader.result){result=new BlobView(blob,offset,length,reader.result,0,length,littleEndian||false);}
callback(result,reader.error);};};BlobView.getFromArrayBuffer=function(buffer,offset,length,littleEndian){return new BlobView(null,offset,length,buffer,offset,length,littleEndian);};BlobView.prototype={constructor:BlobView,getMore:function(offset,length,callback){if(!this.blob){fail('no blob backing this BlobView');}
if(offset>=this.sliceOffset&&offset+length<=this.sliceOffset+this.sliceLength){callback(new BlobView(this.blob,this.sliceOffset,this.sliceLength,this.slice,offset-this.sliceOffset,length,this.littleEndian));}
else{BlobView.get(this.blob,offset,length,callback,this.littleEndian);}},littleEndian:function(){this.littleEndian=true;},bigEndian:function(){this.littleEndian=false;},getUint8:function(offset){return this.view.getUint8(offset);},getInt8:function(offset){return this.view.getInt8(offset);},getUint16:function(offset,le){return this.view.getUint16(offset,le!==undefined?le:this.littleEndian);},getInt16:function(offset,le){return this.view.getInt16(offset,le!==undefined?le:this.littleEndian);},getUint32:function(offset,le){return this.view.getUint32(offset,le!==undefined?le:this.littleEndian);},getInt32:function(offset,le){return this.view.getInt32(offset,le!==undefined?le:this.littleEndian);},getFloat32:function(offset,le){return this.view.getFloat32(offset,le!==undefined?le:this.littleEndian);},getFloat64:function(offset,le){return this.view.getFloat64(offset,le!==undefined?le:this.littleEndian);},readByte:function(){return this.view.getInt8(this.index++);},readUnsignedByte:function(){return this.view.getUint8(this.index++);},readShort:function(le){var val=this.view.getInt16(this.index,le!==undefined?le:this.littleEndian);this.index+=2;return val;},readUnsignedShort:function(le){var val=this.view.getUint16(this.index,le!==undefined?le:this.littleEndian);this.index+=2;return val;},readInt:function(le){var val=this.view.getInt32(this.index,le!==undefined?le:this.littleEndian);this.index+=4;return val;},readUnsignedInt:function(le){var val=this.view.getUint32(this.index,le!==undefined?le:this.littleEndian);this.index+=4;return val;},readFloat:function(le){var val=this.view.getFloat32(this.index,le!==undefined?le:this.littleEndian);this.index+=4;return val;},readDouble:function(le){var val=this.view.getFloat64(this.index,le!==undefined?le:this.littleEndian);this.index+=8;return val;},tell:function(){return this.index;},remaining:function(){return this.byteLength-this.index;},seek:function(index){if(index<0){fail('negative index');}
if(index>this.byteLength){fail('index greater than buffer size');}
this.index=index;},advance:function(n){var index=this.index+n;if(index<0){fail('advance past beginning of buffer');}
if(index>this.byteLength){fail('advance past end of buffer');}
this.index=index;},getUnsignedByteArray:function(offset,n){return new Uint8Array(this.buffer,offset+this.viewOffset,n);},readUnsignedByteArray:function(n){var val=new Uint8Array(this.buffer,this.index+this.viewOffset,n);this.index+=n;return val;},getBit:function(offset,bit){var byte=this.view.getUint8(offset);return(byte&(1<<bit))!==0;},getUint24:function(offset,le){var b1,b2,b3;if(le!==undefined?le:this.littleEndian){b1=this.view.getUint8(offset);b2=this.view.getUint8(offset+1);b3=this.view.getUint8(offset+2);}
else{b3=this.view.getUint8(offset);b2=this.view.getUint8(offset+1);b1=this.view.getUint8(offset+2);}
return(b3<<16)+(b2<<8)+b1;},readUint24:function(le){var value=this.getUint24(this.index,le);this.index+=3;return value;},getBinaryText:function(offset,len){var bytes=new Uint8Array(this.buffer,offset+this.viewOffset,len);return String.fromCharCode.apply(String,bytes);},readBinaryText:function(len){var s=this.getBinaryText(this.index,len);this.index+=len;return s;},getLatin1Text:function(offset,len){var bytes=new Uint8Array(this.buffer,offset+this.viewOffset,len);return getDecoder('latin1').decode(bytes);},readLatin1Text:function(len){var s=this.getLatin1Text(this.index,len);this.index+=len;return s;},getUTF8Text:function(offset,len){var bytes=new Uint8Array(this.buffer,offset+this.viewOffset,len);return getDecoder('utf-8').decode(bytes);},readUTF8Text:function(len){var s=this.getUTF8Text(this.index,len);this.index+=len;return s;},getUTF16Text:function(offset,len,le){if(len%2){fail('len must be a multiple of two');}
var bytes=new Uint8Array(this.buffer,offset+this.viewOffset,len);if(le===null||le===undefined){var BOM=(bytes[0]<<8)+bytes[1];if(BOM===0xFEFF){bytes=bytes.subarray(2);le=false;}else if(BOM===0xFFFE){bytes=bytes.subarray(2);le=true;}else{le=true;}}
var encoding=le?'utf-16le':'utf-16be';return getDecoder(encoding).decode(bytes);},readUTF16Text:function(len,le){var s=this.getUTF16Text(this.index,len,le);this.index+=len;return s;},getID3Uint28BE:function(offset){var b1=this.view.getUint8(offset)&0x7f;var b2=this.view.getUint8(offset+1)&0x7f;var b3=this.view.getUint8(offset+2)&0x7f;var b4=this.view.getUint8(offset+3)&0x7f;return(b1<<21)|(b2<<14)|(b3<<7)|b4;},readID3Uint28BE:function(){var value=this.getID3Uint28BE(this.index);this.index+=4;return value;},readNullTerminatedLatin1Text:function(size,advance_by_size=false){var bytes=new Uint8Array(this.buffer,this.viewOffset+this.index,size);var nil=bytes.indexOf(0);if(nil!==-1){bytes=bytes.subarray(0,nil);}
var s=getDecoder('latin1').decode(bytes);if(nil===-1||advance_by_size){this.index+=size;}else{this.index+=nil+1;}
return s;},readNullTerminatedUTF8Text:function(size,advance_by_size=false){var bytes=new Uint8Array(this.buffer,this.viewOffset+this.index,size);var nil=bytes.indexOf(0);if(nil!==-1){bytes=bytes.subarray(0,nil);}
var s=getDecoder('utf-8').decode(bytes);if(nil===-1||advance_by_size){this.index+=size;}else{this.index+=nil+1;}
return s;},readNullTerminatedUTF16Text:function(size,le,advance_by_size=false){if(size%2){fail('size must be a multiple of two');}
for(var len=0;len<size;len+=2){if(this.getUint16(this.index+len,le)===0){break;}}
var s=this.getUTF16Text(this.index,len,le);if(len===size||advance_by_size){this.index+=size;}else{this.index+=len+2;}
return s;}};return{get:BlobView.get,getFromArrayBuffer:BlobView.getFromArrayBuffer};}());