Renaming minio-demo to erasure-demo

cmd/erasure-demo/decode.go

@@ -0,0 +1,78 @@
+package main
+
+import (
+	"io/ioutil"
+	"log"
+	"os"
+	"strconv"
+	"strings"
+
+	"github.com/codegangsta/cli"
+	"github.com/minio-io/minio/pkgs/erasure"
+)
+
+func decode(c *cli.Context) {
+	// check if minio-encode called without parameters
+	if len(c.Args()) != 1 {
+		cli.ShowCommandHelp(c, "decode")
+		return
+	}
+
+	// get input path
+	inputFilePath := c.Args().Get(0)
+
+	// get output path
+	outputFilePath := inputFilePath
+	if c.String("output") != "" {
+		outputFilePath = c.String("output")
+	}
+
+	protectionLevel := c.String("protection-level")
+	protectionLevelSplit := strings.Split(protectionLevel, ",")
+	if len(protectionLevelSplit) != 2 {
+		log.Fatal("Malformed input for protection-level")
+	}
+
+	k, err := strconv.Atoi(protectionLevelSplit[0])
+	if err != nil {
+		log.Fatal(err)
+	}
+
+	m, err := strconv.Atoi(protectionLevelSplit[1])
+	if err != nil {
+		log.Fatal(err)
+	}
+
+	// get chunks
+	chunks := make([][]byte, k+m)
+	for i := 0; i < k+m; i++ {
+		chunks[i], _ = ioutil.ReadFile(inputFilePath + "." + strconv.Itoa(i))
+	}
+
+	// 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.ParseEncoderParams(k, m, erasure.CAUCHY)
+
+	// decode data
+	decodedData, err := erasure.Decode(chunks, erasureParameters, length)
+	if err != nil {
+		log.Fatal(err)
+	}
+
+	// write decode data out
+	if _, err := os.Stat(outputFilePath); os.IsNotExist(err) {
+		ioutil.WriteFile(outputFilePath, decodedData, 0600)
+	} else {
+		log.Fatal("Output file already exists")
+	}
+}