netconf/netconf-mapping-api/src/main/java/org/opendaylight/netconf/mapping/api/HandlingPriority.java

   1 /*
   2  * Copyright (c) 2013 Cisco Systems, Inc. and others.  All rights reserved.
   3  *
   4  * This program and the accompanying materials are made available under the
   5  * terms of the Eclipse Public License v1.0 which accompanies this distribution,
   6  * and is available at http://www.eclipse.org/legal/epl-v10.html
   7  */
   8
   9 package org.opendaylight.netconf.mapping.api;
  10
  11 import com.google.common.base.MoreObjects;
  12 import com.google.common.base.Optional;
  13 import com.google.common.base.Preconditions;
  14 import java.util.Objects;
  15
  16 public final class HandlingPriority implements Comparable<HandlingPriority> {
  17
  18     public static final HandlingPriority CANNOT_HANDLE = new HandlingPriority();
  19     public static final HandlingPriority HANDLE_WITH_DEFAULT_PRIORITY = new HandlingPriority(Integer.MIN_VALUE);
  20     public static final HandlingPriority HANDLE_WITH_MAX_PRIORITY = new HandlingPriority(Integer.MAX_VALUE);
  21
  22     private Integer priority;
  23
  24     public static HandlingPriority getHandlingPriority(int priority) {
  25         return new HandlingPriority(priority);
  26     }
  27
  28     private HandlingPriority(int priority) {
  29         this.priority = priority;
  30     }
  31
  32     private HandlingPriority() {
  33     }
  34
  35     /**
  36      * Get priority number.
  37      *
  38      * @return priority number or Optional.absent otherwise
  39      */
  40     public Optional<Integer> getPriority() {
  41         return Optional.fromNullable(priority);
  42     }
  43
  44     public HandlingPriority increasePriority(int priorityIncrease) {
  45         Preconditions.checkState(priority != null, "Unable to increase priority for %s", this);
  46         Preconditions.checkArgument(priorityIncrease > 0, "Negative increase");
  47         Preconditions.checkArgument(Long.valueOf(priority) + priorityIncrease < Integer.MAX_VALUE,
  48                 "Resulting priority cannot be higher than %s", Integer.MAX_VALUE);
  49         return getHandlingPriority(priority + priorityIncrease);
  50     }
  51
  52     public boolean isCannotHandle() {
  53         return this.equals(CANNOT_HANDLE);
  54     }
  55
  56     @Override
  57     public int compareTo(HandlingPriority priority) {
  58         if (this == priority) {
  59             return 0;
  60         }
  61         if (isCannotHandle()) {
  62             return -1;
  63         }
  64         if (priority.isCannotHandle()) {
  65             return 1;
  66         }
  67
  68         if (this.priority > priority.priority) {
  69             return 1;
  70         }
  71         if (this.priority.equals(priority.priority)) {
  72             return 0;
  73         }
  74         if (this.priority < priority.priority) {
  75             return -1;
  76         }
  77
  78         throw new IllegalStateException("Unexpected state comparing " + this + " with " + priority);
  79     }
  80
  81     @Override
  82     public boolean equals(Object obj) {
  83         if (this == obj) {
  84             return true;
  85         }
  86         if (!(obj instanceof HandlingPriority)) {
  87             return false;
  88         }
  89
  90         HandlingPriority that = (HandlingPriority) obj;
  91
  92         return Objects.equals(priority, that.priority);
  93     }
  94
  95     @Override
  96     public int hashCode() {
  97         return priority != null ? priority.hashCode() : 0;
  98     }
  99
 100     @Override
 101     public String toString() {
 102         return MoreObjects.toStringHelper(this)
 103                 .add("priority", priority)
 104                 .toString();
 105     }
 106 }