Implementation of http.FileSystem where the files stay in memory.
It uses fsnotify to keep the cache updated.
Example:
github.com/ranveerkunal/memfs/example $ go build memfs_code.go
github.com/ranveerkunal/memfs/example $ ./memfs_code
package main
import (
"flag"
"log"
"net/http"
"github.com/ranveerkunal/memfs"
)
func main() {
path := flag.String("path", "./", "")
addr := flag.String("addr", ":9999", "")
verbose := flag.Bool("verbose", true, "")
flag.Parse()
fs, err := memfs.New(*path)
if err != nil {
log.Fatalf("Failed to create memfs: %s err: %v", *path, err)
}
if (*verbose) {
log.Printf("logging to stderr ...")
memfs.SetLogger(memfs.Verbose)
}
http.Handle("/memfs/", http.StripPrefix("/memfs/", http.FileServer(fs)))
log.Printf("path: %s addr:%s", *path, *addr)
log.Fatal(http.ListenAndServe(*addr, nil))
}Benchmark on mac: darwin 64 ~/ranveerkunal/memfs % go test memfs_test.go -bench=. -cpu=4 -parallel=4 temp dir: /tmp/memfs406771321 writing small file writing big file ready to benchmark ... testing: warning: no tests to run PASS BenchmarkNonExistentMemFS-4 5000000 700 ns/op BenchmarkNonExistentDiskFS-4 500000 3996 ns/op BenchmarkSmallFileMemFS-4 10000 111634 ns/op BenchmarkSmallFileDiskFS-4 10000 128475 ns/op BenchmarkBigFileMemFS-4 20 83455262 ns/op BenchmarkBigFileDiskFS-4 20 96320175 ns/op ok command-line-arguments 26.610s
Benchmark on linux: ~/kamphaus/memfs % go test memfs_test.go -bench=. -cpu=4 -parallel=4 temp dir: /tmp/memfs018986335 writing small file writing medium file writing big file ready to benchmark ... goos: linux goarch: amd64 BenchmarkNonExistentMemFS-4 5259802 223 ns/op BenchmarkNonExistentDiskFS-4 870788 1422 ns/op BenchmarkSmallFileMemFS-4 21523 54604 ns/op BenchmarkSmallFileDiskFS-4 18241 65965 ns/op BenchmarkMediumFileMemFS-4 426 2790326 ns/op BenchmarkMediumFileDiskFS-4 458 2603583 ns/op BenchmarkBigFileMemFS-4 24 46187587 ns/op BenchmarkBigFileDiskFS-4 33 35086878 ns/op PASS ok command-line-arguments 19.123s
It looks it's a speedup for small or non existent files. As soon as there are medium sized files (5 MiB) it's more efficient if the kernel takes care of caching the files.