// parallelRead - reads chunks in parallel from the disks specified in []readDisks.
func parallelRead(volume, path string, readDisks []StorageAPI, orderedDisks []StorageAPI, enBlocks [][]byte, blockOffset int64, curChunkSize int64, bitRotVerify func(diskIndex int) bool, pool *bpool.BytePool) {
// WaitGroup to synchronise the read go-routines.
wg := &sync.WaitGroup{}
// Read disks in parallel.
for index := range readDisks {
if readDisks[index] == nil {
continue
}
wg.Add(1)
// Reads chunk from readDisk[index] in routine.
go func(index int) {
defer wg.Done()
// Verify bit rot for the file on this disk.
if !bitRotVerify(index) {
// So that we don't read from this disk for the next block.
orderedDisks[index] = nil
return
}
buf, err := pool.Get()
if err != nil {
errorIf(err, "unable to get buffer from byte pool")
orderedDisks[index] = nil
return
}
buf = buf[:curChunkSize]
_, err = readDisks[index].ReadFile(volume, path, blockOffset, buf)
if err != nil {
orderedDisks[index] = nil
return
}
enBlocks[index] = buf
}(index)
}
// Waiting for first routines to finish.
wg.Wait()
}
