63 lines
2.2 KiB
Markdown
63 lines
2.2 KiB
Markdown
---
|
|
title: "Crazy Experiment: Ship the Frontend as an asar document"
|
|
date: "2017-01-09"
|
|
tags:
|
|
- asar
|
|
- frontend
|
|
---
|
|
|
|
Today's crazy experiment is using an [asar archive](https://github.com/electron/asar) for shipping around
|
|
and mounting frontend Javascript applications. This is something I feel is worth doing because it allows
|
|
the web frontend developer (or team) give the backend team a single "binary" that can be dropped into the
|
|
deployment process without having to build the frontend code as part of CI.
|
|
|
|
asar is an interesting file format because it allows for random access of the data inside the archive.
|
|
This allows an HTTP server to be able to concurrently serve files out of it without having to lock or
|
|
incur an additional open file descriptor.
|
|
|
|
In order to implement this, I have created a Go package named [asarfs](https://github.com/Xe/asarfs) that
|
|
exposes the contents of an asar archive as a standard http.Handler.
|
|
|
|
Example Usage:
|
|
|
|
```go
|
|
package main
|
|
|
|
import (
|
|
"log"
|
|
"net/http"
|
|
"os"
|
|
|
|
"github.com/Xe/asarfs"
|
|
)
|
|
|
|
func do404(w http.ResponseWriter, r *http.Request) {
|
|
http.Error(w, "Not found", http.StatusNotFound)
|
|
}
|
|
|
|
func main() {
|
|
fs, err := asarfs.New("./static.asar", http.HandlerFunc(do404))
|
|
if err != nil {
|
|
log.Fatal(err)
|
|
}
|
|
|
|
http.ListenAndServe(":"+os.Getenv("PORT"), fs)
|
|
}
|
|
```
|
|
|
|
I made some contrived benchmarks using some sample data (lots of large json files from mongodb dumps)
|
|
I had laying around and ran them a few times. The results were very promising:
|
|
|
|
```console
|
|
[~/g/s/g/X/asarfs] : go1.8beta2 test -bench=. -benchmem
|
|
BenchmarkHTTPFileSystem-8 20000 66481 ns/op 3219 B/op 58 allocs/op
|
|
BenchmarkASARfs-8 20000 72084 ns/op 3549 B/op 77 allocs/op
|
|
BenchmarkPreloadedASARfs-8 20000 62894 ns/op 3218 B/op 58 allocs/op
|
|
PASS
|
|
ok github.com/Xe/asarfs 5.636s
|
|
```
|
|
|
|
Amazingly, the performance and memory usage differences between serving the files over an asar archive
|
|
and off of the filesystem are negligible. I've implemented it in the latest release of my personal website
|
|
and hopefully end users should be seeing no difference in page load times.
|