minio/cmd/minio-decode/main.go
2014-11-24 07:16:54 -08:00

95 lines
1.8 KiB
Go

package main
import (
"io/ioutil"
"log"
"os"
"strconv"
"github.com/codegangsta/cli"
"github.com/minio-io/minio/erasure"
)
func main() {
app := cli.NewApp()
app.Name = "minio-decode"
app.Usage = "erasure decode a byte stream"
app.Flags = []cli.Flag{
cli.StringFlag{
Name: "input,i",
Value: "",
Usage: "Input file",
},
cli.StringFlag{
Name: "output,o",
Value: "",
Usage: "Output file",
},
cli.IntFlag{
Name: "k",
Value: 10,
Usage: "k value of encoder parameters",
},
cli.IntFlag{
Name: "m",
Value: 5,
Usage: "m value of encoder parameters",
},
}
app.Action = func(c *cli.Context) {
// check if minio-encode called without parameters
if len(c.Args()) == 1 {
cli.ShowAppHelp(c)
}
// get input path
if c.String("input") == "" {
log.Fatal("No input specified")
}
inputFilePath := c.String("input")
// get output path
outputFilePath := inputFilePath
if c.String("output") != "" {
outputFilePath = c.String("output")
}
k := c.Int("k")
m := c.Int("m")
// get chunks
chunks := make([][]byte, k+m)
for i := 0; i < k+m; i++ {
var err error
chunks[i], err = ioutil.ReadFile(inputFilePath + "." + strconv.Itoa(i))
if err != nil {
continue
}
}
// get length
lengthBytes, err := ioutil.ReadFile(inputFilePath + ".length")
if err != nil {
log.Fatal(err)
}
lengthString := string(lengthBytes)
length, err := strconv.Atoi(lengthString)
if err != nil {
log.Fatal(err)
}
// set up encoder
erasureParameters, _ := erasure.ValidateParams(k, m, 8, erasure.CAUCHY)
// decode data
decodedData, err := erasure.Decode(chunks, erasureParameters, length)
if err != nil {
log.Fatal(err)
}
// write decode data out
ioutil.WriteFile(outputFilePath, decodedData, 0600)
}
app.Run(os.Args)
}