92 lines
1.9 KiB
Go
92 lines
1.9 KiB
Go
package main
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import (
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"io/ioutil"
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"log"
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"os"
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"strconv"
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"github.com/codegangsta/cli"
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"github.com/minio-io/minio/pkgs/erasure"
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)
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func decode(c *cli.Context) {
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// check if minio-encode called without parameters
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if len(c.Args()) != 1 {
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cli.ShowCommandHelp(c, "decode")
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return
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}
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config, err := parseInput(c)
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if err != nil {
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log.Fatal(err)
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}
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k := config.k
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m := config.m
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// check if output file exists, fail if so
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if _, err := os.Stat(config.output); !os.IsNotExist(err) {
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log.Fatal("Output file exists")
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}
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// get list of files
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var inputFiles []string
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if _, err := os.Stat(config.input + ".length"); os.IsNotExist(err) {
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err = nil
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chunkCount := 0
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for !os.IsNotExist(err) {
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_, err = os.Stat(config.input + "." + strconv.Itoa(chunkCount) + ".length")
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chunkCount += 1
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}
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chunkCount = chunkCount - 1
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inputFiles = make([]string, chunkCount)
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for i := 0; i < chunkCount; i++ {
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inputFiles[i] = config.input + "." + strconv.Itoa(i)
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}
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} else {
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inputFiles = []string{config.input}
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}
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// open file to write
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outputFile, err := os.OpenFile(config.output, os.O_CREATE|os.O_WRONLY, 0600)
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defer outputFile.Close()
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if err != nil {
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log.Fatal(err)
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}
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for _, inputFile := range inputFiles {
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// get chunks
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chunks := make([][]byte, k+m)
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for i := 0; i < k+m; i++ {
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chunks[i], _ = ioutil.ReadFile(inputFile + "." + strconv.Itoa(i))
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}
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// get length
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lengthBytes, err := ioutil.ReadFile(inputFile + ".length")
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if err != nil {
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log.Fatal(err)
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}
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lengthString := string(lengthBytes)
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length, err := strconv.Atoi(lengthString)
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if err != nil {
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log.Fatal(err)
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}
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// set up encoder
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erasureParameters, _ := erasure.ParseEncoderParams(k, m, erasure.CAUCHY)
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// decode data
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decodedData, err := erasure.Decode(chunks, erasureParameters, length)
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if err != nil {
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log.Fatal(err)
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}
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// append decoded data
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length, err = outputFile.Write(decodedData)
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if err != nil {
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log.Fatal(err)
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}
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}
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}
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