https://github.com/01alchemist/AS-LZMA

LZMA Decoder written in AssemblyScript
https://github.com/01alchemist/AS-LZMA

assemblyscript data-compression lzma typescript webassembly

Last synced: 3 months ago
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LZMA Decoder written in AssemblyScript

• Host: GitHub
• URL: https://github.com/01alchemist/AS-LZMA
• Owner: 01alchemist
• License: mit
• Created: 2019-02-21T17:21:15.000Z (over 5 years ago)
• Default Branch: master
• Last Pushed: 2019-09-24T17:42:00.000Z (about 5 years ago)
• Last Synced: 2024-07-23T13:32:20.693Z (4 months ago)
• Topics: assemblyscript, data-compression, lzma, typescript, webassembly
• Language: TypeScript
• Size: 10.4 MB
• Stars: 8
• Watchers: 2
• Forks: 4
• Open Issues: 0
• Metadata Files:
  • Readme: README.md
  • License: LICENSE

Awesome Lists containing this project

• awesome-assemblyscript - 01alchemist/as-lzma - LZMA implementation (unmaintained) (Packages)

README

        
LZMA Decoder (AssemblyScript)

============

This is an experimental lzma decoder written in [AssemblyScript](https://github.com/AssemblyScript/assemblyscript)

Example

-------

[example code](/examples)

```javascript

var memory = new WebAssembly.Memory({ initial: 160 })

...

// You know how to instantiate WASM module

var lzma = module.instance.exports

// Get compressed data by fetch or by some other means

var inputData = new Uint8Array(await (await fetch('PATH/TO/COMPRESSED_FILE.lzma')).arrayBuffer())

// Allocate memory to copy input data. 

const inputDataPtr = lzma.newU8Array(inputData.length)

// AssemblyScript ArrayBuffer header length

const AS_ARRAY_OFFSET = 24

// Create an Uint8Array using allocated buffer and set input data

const u8Array = new Uint8Array(

  memory.buffer,

  inputDataPtr + AS_ARRAY_OFFSET,

  inputData.length

)

u8Array.set(inputData)

class DecodeResult {

  constructor(ptr, memory) {

    const result = new Uint32Array(memory.buffer, ptr, 4)

    const [success, error, unpackSize, dataPtr] = result;

    this.success = success

    this.error = error

    if (this.success) {

      this.unpackSize = unpackSize

      this.data = new Uint8Array(

        memory.buffer,

        dataPtr + AS_ARRAY_OFFSET,

        unpackSize

      )

    }

  }

}

// Decode LZMA data

const resultPtr = lzma.decode(inputDataPtr)

const result = new DecodeResult(resultPtr, memory)

// Decompressed data

console.log(result.data)

// If the data is plain text, decode using TextDecoder

// const decoder = new TextDecoder()

// const text = decoder.decode(result.data)

// console.log(text)

```

How to make lzma file

----------------------

Download [lzma sdk] and use following command

```sh

lzma e input_filename.extension output_filename.lzma

```

Developed by [Nidin Vinayakan]

License

----

MIT

[lzma sdk]:http://www.7-zip.org/sdk.html

[Nidin Vinayakan]:https://github.com/nidin