controlloop/common/guard/src/main/java/org/onap/policy/guard/PolicyGuard.java

   1 /*-
   2  * ============LICENSE_START=======================================================
   3  * guard
   4  * ================================================================================
   5  * Copyright (C) 2017 AT&T Intellectual Property. All rights reserved.
   6  * ================================================================================
   7  * Licensed under the Apache License, Version 2.0 (the "License");
   8  * you may not use this file except in compliance with the License.
   9  * You may obtain a copy of the License at
  10  *
  11  *      http://www.apache.org/licenses/LICENSE-2.0
  12  *
  13  * Unless required by applicable law or agreed to in writing, software
  14  * distributed under the License is distributed on an "AS IS" BASIS,
  15  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  16  * See the License for the specific language governing permissions and
  17  * limitations under the License.
  18  * ============LICENSE_END=========================================================
  19  */
  20 package org.onap.policy.guard;
  21
  22 import java.util.HashMap;
  23 import java.util.Map;
  24 import java.util.UUID;
  25
  26 import org.onap.policy.controlloop.policy.TargetType;
  27 import org.onap.policy.guard.impl.PNFTargetLock;
  28 import org.onap.policy.guard.impl.VMTargetLock;
  29
  30 public class PolicyGuard {
  31
  32         private static Map<String, TargetLock> activeLocks = new HashMap<String, TargetLock>();
  33
  34         public static class LockResult<A, B> {
  35                 private A a;
  36                 private B b;
  37
  38                 public static <A, B> LockResult<A, B> createLockResult(A a, B b) {
  39                         return new LockResult<A, B>(a, b);
  40                 }
  41
  42                 public LockResult(A a, B b) {
  43                         this.a = a;
  44                         this.b = b;
  45                 }
  46
  47                 public A getA() {
  48                         return a;
  49                 }
  50
  51                 public B getB() {
  52                         return b;
  53                 }
  54         }
  55
  56         public static LockResult<GuardResult, TargetLock> lockTarget(TargetType targetType, String targetInstance, UUID requestID, LockCallback callback) {
  57
  58                 synchronized(activeLocks) {
  59                         //
  60                         // Is there a lock on this instance already?
  61                         //
  62                         if (activeLocks.containsKey(targetInstance)) {
  63                                 return LockResult.createLockResult(GuardResult.LOCK_DENIED, null);
  64                         }
  65                         TargetLock lock = null;
  66                         switch (targetType) {
  67                         case PNF:
  68                                 //
  69                                 // Create the Lock object
  70                                 //
  71                                 lock = new PNFTargetLock(targetType, targetInstance, requestID, callback);
  72                                 break;
  73                         case VM:
  74                                 //
  75                                 // Create the Lock object
  76                                 //
  77                                 lock = new VMTargetLock(targetType, targetInstance, requestID, callback);
  78                                 break;
  79                         default:
  80                                 return LockResult.createLockResult(GuardResult.LOCK_EXCEPTION, null);
  81                         }
  82                         //
  83                         // Keep track of it
  84                         //
  85                         activeLocks.put(targetInstance, lock);
  86                         //
  87                         // Return result
  88                         //
  89                         System.out.println("Locking " + lock);
  90                         return LockResult.createLockResult(GuardResult.LOCK_ACQUIRED, lock);
  91                 }
  92         }
  93
  94         public static boolean   unlockTarget(TargetLock lock) {
  95                 synchronized(activeLocks) {
  96                         if (activeLocks.containsKey(lock.getTargetInstance())) {
  97                                 System.out.println("Unlocking " + lock);
  98                                 return (activeLocks.remove(lock.getTargetInstance()) != null);
  99                         }
 100                         return false;
 101                 }
 102         }
 103
 104         public static boolean   isLocked(TargetType targetType, String targetInstance, UUID requestID) {
 105                 synchronized(activeLocks) {
 106                         if (activeLocks.containsKey(targetInstance)) {
 107                                 TargetLock lock = activeLocks.get(targetInstance);
 108                                 return (lock.getTargetType().equals(targetType) && lock.getRequestID().equals(requestID));
 109                         }
 110                         return false;
 111                 }
 112         }
 113
 114 }