Method backlog

src/proxy/http/HttpTunnel.cc:491–533

HttpTunnelProducer::HttpTunnelProducer() : consumer_list() {}

uint64_t
HttpTunnelProducer::backlog(uint64_t limit)
{
  uint64_t zret = 0;
  // Calculate the total backlog, the # of bytes inside ATS for this producer.
  // We go all the way through each chain to the ending sink and take the maximum
  // over those paths. Do need to be careful about loops which can occur.
  for (HttpTunnelConsumer *c = consumer_list.head; c; c = c->link.next) {
    if (c->alive && c->write_vio) {
      uint64_t n = 0;
      if (HT_TRANSFORM == c->vc_type) {
        n += static_cast<TransformVCChain *>(c->vc)->backlog(limit);
      } else {
        IOBufferReader *r = c->write_vio->get_reader();
        if (r) {
          n += static_cast<uint64_t>(r->read_avail());
        }
      }
      if (n >= limit) {
        return n;
      }

      if (!c->is_sink()) {
        HttpTunnelProducer *dsp = c->self_producer;
        if (dsp) {
          n += dsp->backlog();
        }
      }
      if (n >= limit) {
        return n;
      }
      if (n > zret) {
        zret = n;
      }
    }
  }

  if (chunked_handler.chunked_reader) {
    zret += static_cast<uint64_t>(chunked_handler.chunked_reader->read_avail());
  }

  return zret;
}

/*  We set the producers in a flow chain specifically rather than
    using a tunnel level variable in order to handle bi-directional