Nginx NJS fs.writeFileSync is atomic writing and race condition prevention ?

[Dmitry Volyntsev]

On 19.10.2018 06:33, HENG wrote:
> Hello:
> 
> I am new to Nginx NJS, and I want to write a website with NJS.
> 
> I want to write a simple JSON database with NJS fs.writeFileSync ,just 
> like Node.js LowDB.
> 
> but I have no idea . Does NJS fs.writeFileSync is atomic writing and 
> race condition prevention ?

http://hg.nginx.org/njs/file/tip/njs/njs_fs.c#l649

It simply opens the file, makes several write syscalls into it, and 
closes the file.

So, it is not atomic.

Probably we need here something like

https://www.npmjs.com/package/write-file-atomic

> 
> If NJS fs.writeFileSync is NOT atomic writing, it can NOT be treate as a 
> normal database file write.
> 
> Thank you !
> 
> -- 
> --------------------------------------------------------------------
> Heng
> ---------------------------------------------------------------------
> --
> 
> 
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