Using https://github.com/klauspost/reedsolomon, erasure coding a large file into smaller chunks, I want to use io.Pipe()
to create a stream of pipes which connects each other. For example: one pipe which helps in Chunking the file and other which calls func Upload for uploading the file
func (rd *ReedSolomon) Chunking() {
fname := rd.File
// Create encoding matrix.
enc, err := reedsolomon.NewStream(rd.data, rd.Par)
checkErr(err)
fmt.Println("Opening", fname)
f, err := os.Open(fname)
checkErr(err)
instat, err := f.Stat()
checkErr(err)
shards := rd.Data + rd.Par
out := make([]*os.File, shards)
// Create the resulting files.
dir, file := filepath.Split(fname)
if fi.OutDir != "" {
dir = fi.OutDir
}
for i := range out {
outfn := fmt.Sprintf("%s.%d", file, i)
out[i], err = os.Create(filepath.Join(dir, outfn))
checkErr(err)
}
// Split into files.
data := make([]io.Writer, rd.Data)
for i := range data {
data[i] = out[i]
}
// Do the split
err = enc.Split(f, data, instat.Size())
checkErr(err)
// Close and re-open the files.
input := make([]io.Reader, rd.Data)
target_url := "http://localhost:8080"
for i := range data {
out[i].Close()
f, err := os.Open(out[i].Name())
checkErr(err)
input[i] = f
defer f.Close()
}
// Create parity output writers
parity := make([]io.Writer, rd.Par)
for i := range parity {
parity[i] = out[rd.Data+i]
defer out[rd.Data+i].Close()
}
err = enc.Encode(input, parity)
checkErr(err)
for _, sd := range out {
postFile(sd.Name(), target_url)
}
}
I am pretty new to the use of the io.Pipe()