Function how_to_open_connection

src/proxy/http/HttpTransact.cc:798–843

}

inline static HttpTransact::StateMachineAction_t
how_to_open_connection(HttpTransact::State *s)
{
  ink_assert((s->pending_work == nullptr) || (s->current.request_to == ResolveInfo::PARENT_PROXY));

  // Originally we returned which type of server to open
  // Now, however, we may want to issue a cache
  // operation first in order to lock the cache
  // entry to prevent multiple origin server requests
  // for the same document.
  // The cache operation that we actually issue, of
  // course, depends on the specified "cache_action".
  // If there is no cache-action to be issued, just
  // connect to the server.
  switch (s->cache_info.action) {
  case HttpTransact::CACHE_PREPARE_TO_DELETE:
  case HttpTransact::CACHE_PREPARE_TO_UPDATE:
  case HttpTransact::CACHE_PREPARE_TO_WRITE:
    s->transact_return_point = HttpTransact::handle_cache_write_lock;
    return HttpTransact::SM_ACTION_CACHE_ISSUE_WRITE;
  default:
    // This covers:
    // CACHE_DO_UNDEFINED, CACHE_DO_NO_ACTION, CACHE_DO_DELETE,
    // CACHE_DO_LOOKUP, CACHE_DO_REPLACE, CACHE_DO_SERVE,
    // CACHE_DO_SERVE_AND_DELETE, CACHE_DO_SERVE_AND_UPDATE,
    // CACHE_DO_UPDATE, CACHE_DO_WRITE, TOTAL_CACHE_ACTION_TYPES
    break;
  }

  HttpTransact::StateMachineAction_t connect_next_action = HttpTransact::SM_ACTION_ORIGIN_SERVER_OPEN;

  // Setting up a direct CONNECT tunnel enters OriginServerRawOpen. We always do that if we
  // are not forwarding CONNECT and are not going to a parent proxy.
  if (s->method == HTTP_WKSIDX_CONNECT) {
    if (s->txn_conf->forward_connect_method != 1 && s->parent_result.result != PARENT_SPECIFIED) {
      connect_next_action = HttpTransact::SM_ACTION_ORIGIN_SERVER_RAW_OPEN;
    }
  }

  if (!s->already_downgraded) { // false unless downgraded previously (possibly due to HTTP 505)
    (&s->hdr_info.server_request)->version_set(HTTP_1_1);
    HttpTransactHeaders::convert_request(s->current.server->http_version, &s->hdr_info.server_request);
  }

  return connect_next_action;
}

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