fsdecomp

FSDecomp

FSDecomp is a Go library that wraps any io.fs.FS implementation and provides transparent decompression of compressed files. When a file is requested, FSDecomp first tries to open it directly, and if not found, it attempts to locate and decompress a compressed version with a supported extension.

Features

• Transparently access compressed files without specifying the compression extension
• Automatically decompress files on-the-fly
• Preserve proper file metadata (with compression extensions removed from names)
• Support for multiple compression formats:
  • gzip (.gz)
  • bzip2 (.bz2)
  • zstandard (.zst)
  • LZ4 (.lz4)

Installation

go get github.com/AndreRenaud/fsdecomp

Usage

Apply automatic file decompression to any fs.FS object by wrapping it in a fsdecomp.DecompressFS.

package main

import (
	"fmt"
	"io"
	"io/fs"
	"log"
	"os"

	"github.com/AndreRenaud/fsdecomp"
)

func main() {
	// Create a decompressing filesystem wrapper around os.DirFS
	fsys := fsdecomp.DecompressFS{os.DirFS("./data")}

	// Open a file - if data/config.json doesn't exist but data/config.json.gz does,
	// it will be transparently decompressed
	file, err := fsys.Open("config.json")
	if err != nil {
		log.Fatal(err)
	}
	defer file.Close()

	// Read and use the file as if it were a normal uncompressed file
	content, err := io.ReadAll(file)
	if err != nil {
		log.Fatal(err)
	}

	fmt.Println(string(content))
}

Limitations

• Write operations are not supported (follows the read-only fs.FS interface)
• The library prioritizes the uncompressed version if both compressed and uncompressed versions exist
• Directory operations follow the behavior of the underlying filesystem

License

Zero-Clause BSD - See LICENSE file for details.

Contributing

Contributions are welcome! Feel free to submit issues or pull requests.