private void loadQueue()

in hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-resourcemanager/src/main/java/org/apache/hadoop/yarn/server/resourcemanager/scheduler/fair/allocation/AllocationFileQueueParser.java [106:256]
139 lines of code
36 McCabe index (conditional complexity)

  private void loadQueue(String parentName, Element element,
      QueueProperties.Builder builder) throws AllocationConfigurationException {
    String queueName =
        FairSchedulerUtilities.trimQueueName(element.getAttribute("name"));

    if (queueName.contains(".")) {
      throw new AllocationConfigurationException("Bad fair scheduler config "
          + "file: queue name (" + queueName + ") shouldn't contain period.");
    }

    if (queueName.isEmpty()) {
      throw new AllocationConfigurationException("Bad fair scheduler config "
          + "file: queue name shouldn't be empty or "
          + "consist only of whitespace.");
    }

    if (parentName != null) {
      queueName = parentName + "." + queueName;
    }

    NodeList fields = element.getChildNodes();
    boolean isLeaf = true;
    boolean isReservable = false;
    boolean isMaxAMShareSet = false;

    for (int j = 0; j < fields.getLength(); j++) {
      Node fieldNode = fields.item(j);
      if (!(fieldNode instanceof Element)) {
        continue;
      }
      Element field = (Element) fieldNode;
      if (MIN_RESOURCES.equals(field.getTagName())) {
        String text = getTrimmedTextData(field);
        ConfigurableResource val =
            FairSchedulerConfiguration.parseResourceConfigValue(text, 0L);
        builder.minQueueResources(queueName, val.getResource());
      } else if (MAX_RESOURCES.equals(field.getTagName())) {
        String text = getTrimmedTextData(field);
        ConfigurableResource val =
            FairSchedulerConfiguration.parseResourceConfigValue(text);
        builder.maxQueueResources(queueName, val);
      } else if (MAX_CHILD_RESOURCES.equals(field.getTagName())) {
        String text = getTrimmedTextData(field);
        ConfigurableResource val =
            FairSchedulerConfiguration.parseResourceConfigValue(text);
        builder.maxChildQueueResources(queueName, val);
      } else if (MAX_RUNNING_APPS.equals(field.getTagName())) {
        String text = getTrimmedTextData(field);
        int val = Integer.parseInt(text);
        builder.queueMaxApps(queueName, val);
      } else if (MAX_AMSHARE.equals(field.getTagName())) {
        String text = getTrimmedTextData(field);
        float val = Float.parseFloat(text);
        val = Math.min(val, 1.0f);
        builder.queueMaxAMShares(queueName, val);
        isMaxAMShareSet = true;
      } else if (MAX_CONTAINER_ALLOCATION.equals(field.getTagName())) {
        String text = getTrimmedTextData(field);
        ConfigurableResource val =
            FairSchedulerConfiguration.parseResourceConfigValue(text);
        builder.queueMaxContainerAllocation(queueName, val.getResource());
      } else if (WEIGHT.equals(field.getTagName())) {
        String text = getTrimmedTextData(field);
        double val = Double.parseDouble(text);
        builder.queueWeights(queueName, (float) val);
      } else if (MIN_SHARE_PREEMPTION_TIMEOUT.equals(field.getTagName())) {
        String text = getTrimmedTextData(field);
        long val = Long.parseLong(text) * 1000L;
        builder.minSharePreemptionTimeouts(queueName, val);
      } else if (FAIR_SHARE_PREEMPTION_TIMEOUT.equals(field.getTagName())) {
        String text = getTrimmedTextData(field);
        long val = Long.parseLong(text) * 1000L;
        builder.fairSharePreemptionTimeouts(queueName, val);
      } else if (FAIR_SHARE_PREEMPTION_THRESHOLD.equals(field.getTagName())) {
        String text = getTrimmedTextData(field);
        float val = Float.parseFloat(text);
        val = Math.max(Math.min(val, 1.0f), 0.0f);
        builder.fairSharePreemptionThresholds(queueName, val);
      } else if (SCHEDULING_POLICY.equals(field.getTagName())
          || SCHEDULING_MODE.equals(field.getTagName())) {
        String text = getTrimmedTextData(field);
        SchedulingPolicy policy = SchedulingPolicy.parse(text);
        builder.queuePolicies(queueName, policy);
      } else if (ACL_SUBMIT_APPS.equals(field.getTagName())) {
        String text = ((Text) field.getFirstChild()).getData();
        builder.queueAcls(queueName, AccessType.SUBMIT_APP,
            new AccessControlList(text));
      } else if (ACL_ADMINISTER_APPS.equals(field.getTagName())) {
        String text = ((Text) field.getFirstChild()).getData();
        builder.queueAcls(queueName, AccessType.ADMINISTER_QUEUE,
            new AccessControlList(text));
      } else if (ACL_ADMINISTER_RESERVATIONS.equals(field.getTagName())) {
        String text = ((Text) field.getFirstChild()).getData();
        builder.reservationAcls(queueName,
            ReservationACL.ADMINISTER_RESERVATIONS,
            new AccessControlList(text));
      } else if (ACL_LIST_RESERVATIONS.equals(field.getTagName())) {
        String text = ((Text) field.getFirstChild()).getData();
        builder.reservationAcls(queueName, ReservationACL.LIST_RESERVATIONS,
            new AccessControlList(text));
      } else if (ACL_SUBMIT_RESERVATIONS.equals(field.getTagName())) {
        String text = ((Text) field.getFirstChild()).getData();
        builder.reservationAcls(queueName, ReservationACL.SUBMIT_RESERVATIONS,
            new AccessControlList(text));
      } else if (RESERVATION.equals(field.getTagName())) {
        isReservable = true;
        builder.reservableQueues(queueName);
        builder.configuredQueues(FSQueueType.PARENT, queueName);
      } else if (ALLOW_PREEMPTION_FROM.equals(field.getTagName())) {
        String text = getTrimmedTextData(field);
        if (!Boolean.parseBoolean(text)) {
          builder.nonPreemptableQueues(queueName);
        }
      } else if (QUEUE.endsWith(field.getTagName())
          || POOL.equals(field.getTagName())) {
        loadQueue(queueName, field, builder);
        isLeaf = false;
      }
    }
    // if a leaf in the alloc file is marked as type='parent'
    // then store it as a parent queue
    if (isLeaf && !"parent".equals(element.getAttribute("type"))) {
      // reservable queue has been already configured as parent
      if (!isReservable) {
        builder.configuredQueues(FSQueueType.LEAF, queueName);
      }
    } else {
      if (isReservable) {
        throw new AllocationConfigurationException(
            getErrorString(queueName, RESERVATION));
      } else if (isMaxAMShareSet) {
        throw new AllocationConfigurationException(
            getErrorString(queueName, MAX_AMSHARE));
      }
      builder.configuredQueues(FSQueueType.PARENT, queueName);
    }

    // Set default acls if not defined
    // The root queue defaults to all access
    for (QueueACL acl : QueueACL.values()) {
      AccessType accessType = SchedulerUtils.toAccessType(acl);
      if (!builder.isAclDefinedForAccessType(queueName, accessType)) {
        AccessControlList defaultAcl =
            queueName.equals(ROOT) ? EVERYBODY_ACL : NOBODY_ACL;
        builder.queueAcls(queueName, accessType, defaultAcl);
      }
    }

    checkMinAndMaxResource(builder.getMinQueueResources(),
        builder.getMaxQueueResources(), queueName);
  }