apple2js/js/formats/prodos/directory.js

88 lines
3.6 KiB
JavaScript

import { dateToUint32, readFileName, writeFileName, uint32ToDate } from './utils';
import { readEntries, writeEntries } from './file_entry';
import { STORAGE_TYPES, ACCESS_TYPES } from './constants';
export function Directory(volume, fileEntry) {
var _fileEntry = fileEntry;
var DIRECTORY_OFFSETS = {
PREV: 0x00,
NEXT: 0x02,
STORAGE_TYPE: 0x04,
NAME_LENGTH: 0x04,
VOLUME_NAME: 0x05,
RESERVED_1: 0x14,
CREATION: 0x1C,
VERSION: 0x20,
MIN_VERSION: 0x21,
ACCESS: 0x22,
ENTRY_LENGTH: 0x23,
ENTRIES_PER_BLOCK: 0x24,
FILE_COUNT: 0x25,
PARENT: 0x27,
PARENT_ENTRY_NUMBER: 0x29,
PARENT_ENTRY_LENGTH: 0x2A
};
var blocks = volume.blocks();
return {
prev: 0,
next: 0,
storageType: STORAGE_TYPES.DIRECTORY,
name: 'Untitled',
creation: new Date(),
access: ACCESS_TYPES.ALL,
entryLength: 0x27,
entriesPerBlock: 23,
fileCount: 0,
parent: 0,
parentEntryLength: 0,
parentEntryNumber: 0,
entries: [],
read: function(fileEntry) {
fileEntry = fileEntry || _fileEntry;
var block = new DataView(blocks[fileEntry.keyPointer].buffer);
this.prev = block.getUint16(DIRECTORY_OFFSETS.PREV, true);
this.next = block.getUint16(DIRECTORY_OFFSETS.NEXT, true);
this.storageType = block.getUint8(DIRECTORY_OFFSETS.STORAGE_TYPE) >> 4;
var nameLength = block.getUint8(DIRECTORY_OFFSETS.NAME_LENGTH) & 0xF;
var caseBits = block.getUint8(DIRECTORY_OFFSETS.CASE_BITS);
this.name = readFileName(block, DIRECTORY_OFFSETS.VOLUME_NAME, nameLength, caseBits);
this.creation = uint32ToDate(block.getUint32(DIRECTORY_OFFSETS.CREATION, true));
this.access = block.getUint8(DIRECTORY_OFFSETS.ACCESS);
this.entryLength = block.getUint8(DIRECTORY_OFFSETS.ENTRY_LENGTH);
this.entriesPerBlock = block.getUint8(DIRECTORY_OFFSETS.ENTRIES_PER_BLOCK);
this.fileCount = block.getUint16(DIRECTORY_OFFSETS.FILE_COUNT, true);
this.parent = block.getUint16(DIRECTORY_OFFSETS.PARENT, true);
this.parentEntryNumber = block.getUint8(DIRECTORY_OFFSETS.PARENT_ENTRY_NUMBER);
this.parentEntryLength = block.getUint8(DIRECTORY_OFFSETS.PARENT_ENTRY_LENGTH);
this.entries = readEntries(volume, block, this);
},
write: function() {
var block = new DataView(blocks[fileEntry.keyPointer].buffer);
var nameLength = name.length & 0x0f;
block.setUint8(DIRECTORY_OFFSETS.STORAGE_TYPE, this.storageType << 4 & nameLength);
var caseBits = writeFileName(block, DIRECTORY_OFFSETS.FILE_NAME, this.name);
block.setUint32(DIRECTORY_OFFSETS.CREATION, dateToUint32(this.creation), true);
block.setUint16(DIRECTORY_OFFSETS.CASE_BITS, caseBits);
block.setUint8(DIRECTORY_OFFSETS.ACCESS, this.access);
block.setUint8(DIRECTORY_OFFSETS.ENTRY_LENGTH, this.entryLength);
block.setUint8(DIRECTORY_OFFSETS.ENTRIES_PER_BLOCK, this.entriesPerBlock);
block.setUint16(DIRECTORY_OFFSETS.FILE_COUNT, this.fileCount, true);
block.setUint16(DIRECTORY_OFFSETS.PARENT, this.parent, true);
block.setUint8(DIRECTORY_OFFSETS.PARENT_ENTRY_NUMBER, this.parentEntryNumber);
block.setUint8(DIRECTORY_OFFSETS.PARENT_ENTRY_LENGTH, this.parentEntryLength);
writeEntries(volume, block, this);
}
};
}