apple2js/js/formats/prodos/tree_file.js
Will Scullin b647b3c2bb
CFFA (#20)
* CFFA

* CFFA multi-disk and write functionaliity.

* Clean up multi-devices/partition behavior.

* ProDOS WIP

* Update against refactored codebase.

* WIP

* Wait until disks load, show progress.

* Don't wait so long to boot floppies.

* Forgot to save :|.

* Credit.
2020-01-02 11:11:04 -08:00

117 lines
4.5 KiB
JavaScript

/* Copyright 2010-2019 Will Scullin <scullin@scullinsteel.com>
*
* Permission to use, copy, modify, distribute, and sell this software and its
* documentation for any purpose is hereby granted without fee, provided that
* the above copyright notice appear in all copies and that both that
* copyright notice and this permission notice appear in supporting
* documentation. No representations are made about the suitability of this
* software for any purpose. It is provided "as is" without express or
* implied warranty.
*/
import { BLOCK_SIZE, STORAGE_TYPES } from './constants';
export function TreeFile (volume, fileEntry) {
var blocks = volume.blocks();
var bitMap = volume.bitMap();
return {
getBlockPointers() {
var treeBlock = blocks[fileEntry.keyPointer];
var saplingPointers = new DataView(treeBlock);
var pointers = [];
for (var idx = 0; idx < 256; idx++) {
var saplingPointer = saplingPointers.getUint16(idx * 2);
if (saplingPointer) {
pointers.push(saplingPointer);
var seedlingPointers = new DataView(blocks[saplingPointer]);
for (var jdx = 0; jdx < 256; jdx++) {
var seedlingPointer = seedlingPointers.getUint16(idx * 2);
if (seedlingPointer) {
pointers.push(seedlingPointer);
}
}
}
}
return pointers;
},
read: function() {
var treeBlock = blocks[fileEntry.keyPointer];
var saplingPointers = new DataView(treeBlock);
var remainingLength = fileEntry.eof;
var data = new Uint8Array(remainingLength);
var offset = 0;
var idx = 0;
while (remainingLength > 0) {
var saplingPointer = saplingPointers.getUint16(idx * 2, true);
var jdx = 0;
if (saplingPointer) {
var saplingBlock = blocks[saplingPointer];
var seedlingPointers = new DataView(saplingBlock);
while (jdx < 256 && remainingLength > 0) {
var seedlingPointer = seedlingPointers.getUint16(idx * 2, true);
if (seedlingPointer) {
var seedlingBlock = blocks[seedlingPointer];
var bytes = seedlingBlock.slice(Math.min(BLOCK_SIZE, remainingLength));
data.set(bytes, offset);
}
jdx++;
offset += BLOCK_SIZE;
remainingLength -= BLOCK_SIZE;
}
} else {
offset += BLOCK_SIZE * 256;
remainingLength -= BLOCK_SIZE * 256;
}
idx++;
}
return data;
},
write: function(data) {
fileEntry.storageType = STORAGE_TYPES.TREE;
fileEntry.keyPointer = bitMap.allocBlock();
fileEntry.eof = data.byteLength;
var treeBlock = blocks[fileEntry.keyPointer];
var saplingPointers = new DataView(treeBlock);
var remainingLength = fileEntry.eof;
var offset = 0;
var idx = 0;
while (remainingLength > 0) {
var saplingPointer = bitMap.allocBlock();
var saplingBlock = blocks[saplingPointer];
saplingPointers.setUint16(idx * 2, saplingPointer, true);
var seedlingPointers = new DataView(saplingBlock);
var jdx = 0;
while (jdx < 256 && remainingLength > 0) {
var seedlingPointer = bitMap.allocBlock();
seedlingPointers.setUint16(idx * 2, seedlingPointer, true);
var seedlingBlock = blocks[seedlingPointer];
seedlingBlock.set(data.slice(offset, Math.min(BLOCK_SIZE, remainingLength)));
jdx++;
offset += BLOCK_SIZE;
remainingLength -= BLOCK_SIZE;
}
idx++;
}
fileEntry.write();
},
delete: function() {
var pointers = this.getBlockPointers();
for (var idx; idx < pointers.length; idx++) {
bitMap.freeBlock(pointers[idx]);
}
}
};
}