@ltd/j-gzip v2.4.0

@ltd/j-gzip

Compression/decompression is a kind of CPU intensive operation.

Originally, this module tried to make full use of multi-core CPU and avoid blocking the main process through spawn sub-process; later, it was found that the native gzip / unzip callback interface was originally implemented by derived threads, so now this module is only a simple encapsulation of the original method.

Firstly, based on the callback interface, the promisify interface is added.

Secondly, the compression parameter options is simplified to level; the compression occupied memory level memLevel is the highest, and other options are default.

压缩/解压缩是一类 CPU 密集运算。

本来本模块尝试通过 spawn 子进程，实现对多核 CPU 的充分利用、避免阻塞主进程；后来发现原生 gzip / unzip 回调接口原本就是派生线程实现的，所以现在本模块只是对原生方法的简单封装。

首先，基于回调接口，增加了 promisify 接口。

其次，压缩选项参数 options 被简化为压缩等级参数 level；压缩占用内存等级 memLevel 为最高，其它选项值缺省。

API

type Level = -1 | 0 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9;

function gzipAsync  (data :Buffer | string, level :Level                    ) :Promise<Buffer>;
function gzipSync   (data :Buffer | string, level :Level                    ) :Buffer;
function gzip       (data :Buffer | string, level :Level, callback :Callback) :void;

function unzipAsync (data :Buffer                                           ) :Promise<Buffer>
function unzipSync  (data :Buffer                                           ) :Buffer;
function unzip      (data :Buffer,                        callback :Callback) :void;

type Callback = {
    (error :Error             ) :void
    (error :null, data :Buffer) :void
};