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Unable to decompress Snappy JSON file using golang/snappy

Open raihan26 opened this issue 2 years ago • 1 comments

I've encountered an issue with the golang/snappy library where I'm unable to decompress a Snappy compressed JSON file. The error I receive is Failed to decompress content: snappy: corrupt input. However, I've verified that the file is not corrupt by successfully decompressing it using the snzip tool.

Steps to Reproduce:

  1. Compress a JSON file using Spark job by using this parameter .option("compression", "snappy") and write it to s3.
  2. Attempt to decompress the file from s3 using the following Go code:
package main

import (
	"bytes"
	"fmt"
	"io/ioutil"
	"log"
	"github.com/golang/snappy"
)

func main() {
	// Read the compressed file
	content, err := ioutil.ReadFile("path_to_your_snappy_file.snappy")
	if err != nil {
		log.Fatalf("Failed to read file: %v", err)
	}

	// Decompress using golang/snappy
	decompressed, err := snappy.Decode(nil, content)
	if err != nil {
		log.Fatalf("Failed to decompress content: %v", err)
	}

	// Print the decompressed content
	fmt.Println(string(decompressed))
}

Observe the error: Failed to decompress content: snappy: corrupt input.

Expected Behavior:

The Snappy compressed JSON file should be decompressed without errors.

Actual Behavior:

Received an error indicating the input is corrupt, even though other tools like snzip can decompress the file without issues.

Additional Information:

The Snappy compressed file is a JSON file where each line is a separate JSON object. I've verified the integrity of the file by decompressing it using snzip. The issue might be related to the specific Snappy format or framing used, but I'm not certain.

raihan26 avatar Aug 22 '23 19:08 raihan26

You are using the block decompressor to decode what is probably a stream. There are unique formats (streams contains wrapped blocks). Try with a Reader.

klauspost avatar Dec 07 '23 20:12 klauspost