readTriggerCh <- true
				return
			}
			bufIdx := p.readerToBuf[i]
			if p.buf[bufIdx] == nil {
				// Reading first time on this disk, hence the buffer needs to be allocated.
				// Subsequent reads will reuse this buffer.
				p.buf[bufIdx] = make([]byte, p.shardSize)
			}
			// For the last shard, the shardsize might be less than previous shard sizes.