apple2js/js/formats/prodos/seedling_file.js

41 lines
1.2 KiB
JavaScript

import { STORAGE_TYPES } from './constants';
export function SeedlingFile (volume, fileEntry) {
var blocks = volume.blocks();
var bitMap = volume.bitMap();
return {
getBlockPointers() {
var pointers = [fileEntry.keyPointer];
return pointers;
},
read: function () {
var seedlingBlock = blocks[fileEntry.keyPointer];
var data = new Uint8Array(fileEntry.eof);
data.set(seedlingBlock.slice(0, fileEntry.eof));
return data;
},
write: function(data) {
if (fileEntry.keyPointer) {
this.delete();
}
fileEntry.storageType = STORAGE_TYPES.SEEDLING;
fileEntry.keyPointer = bitMap.allocBlock();
fileEntry.eof = data.byteLength;
var seedlingBlock = blocks[fileEntry.keyPointer];
seedlingBlock.set(data);
fileEntry.write();
},
delete: function() {
var pointers = this.getBlockPointers();
for (var idx; idx < pointers.length; idx++) {
bitMap.freeBlock(pointers[idx]);
}
}
};
}