func comp(block *Block, out chan *Block, block_size int, wg *sync.WaitGroup) {
defer wg.Done()
comp_len := snappy.MaxEncodedLen(block_size)
comp_block := &Block{make([]byte, comp_len), 0, 0}
if block.NBytes == block_size {
comp_block.Buf, comp_block.NBytes = snappy.Encode(comp_block.Buf, block.Buf)
comp_block.BlockID = block.BlockID
} else {
comp_block.NBytes = block.NBytes
comp_block.BlockID = block.BlockID
copy(comp_block.Buf[:comp_block.NBytes], block.Buf)
}
out <- comp_block
}
func block_decomp(in DuplexPipe, block_size, conc_level int) DuplexPipe {
// This is the output of the generator
out := DuplexPipe{make(chan *Block, conc_level), make(chan *Block, conc_level)}
comp_len := snappy.MaxEncodedLen(block_size)
for i := 0; i < conc_level; i++ {
out.Upstream <- &Block{make([]byte, comp_len), 0, 0}
}
var wg sync.WaitGroup
go func() {
for block := range in.Downstream {
wg.Add(1)
go comp(<-out.Upstream, block, in, out, block_size, &wg)
}
wg.Wait()
close(out.Downstream)
}()
return out
}