browserfs-zipfs-extras
v1.0.1
Published
Adds EXPLODE, UNSHRINK, and UNREDUCE support to BrowserFS's ZipFS
Downloads
47
Maintainers
Readme
BrowserFS ZipFS Extras v1.0.1
Adds the following decompression algorithms to BrowserFS, which were used in older versions of PKZip:
- EXPLODE and UNSHRINK (ported from Info-Zip's GPL2'd code)
- UNREDUCE (ported from this GPL2 code)
Although BrowserFS is licensed under the MIT license, this add-on library is based on GPL2 code and is provided under the GPL2 license.
Using
Browser
Simply include browserfs.js and browserfs-zipfs-extras.js
on the same page, and BrowserFS will know how to decompress these extra algorithms.
Make sure you include browserfs.js
first.
Node
Add both browserfs
and browserfs-zipfs-extras
as dependencies of your project. Then, simply require
browserfs-zipfs-extras
before you begin using browserfs
.
const BrowserFS = require('browserfs');
require('browserfs-zipfs-extras');
// Now you can use BrowserFS.
Building
Requires a reasonably recent version of Node. Run:
$ npm install
Running Tests
NOTE: You must have Git LFS installed and use it to clone the repository. We use Git LFS to manage our test fixtures, which are a bunch of zip files.
$ npm test
Porting Comments
We emulate pointers and pointer arithmetic with the Ptr
class
, which
takes an array and an offset into the array. extract.ts
and inflate.ts
extensively use pointers into Huffman tables as well as pointer arithmetic
to iterate through table values!
To reduce object allocations, most Ptr
manipulations edit the value of
an existing Ptr
rather than create a new one. As a result, developers
maintaining this project must be cognizant of Ptr
aliasing; if two places
contain the same Ptr
object, then manipulating one will change the other!