idmanager/idmanager-impl/src/main/java/org/opendaylight/genius/idmanager/ReleasedIdHolder.java

   1 /*
   2  * Copyright (c) 2016 Ericsson India Global Services Pvt Ltd. 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 package org.opendaylight.genius.idmanager;
   9
  10 import java.io.Serializable;
  11 import java.util.List;
  12 import java.util.Optional;
  13 import java.util.concurrent.CopyOnWriteArrayList;
  14 import java.util.concurrent.atomic.AtomicLong;
  15 import org.eclipse.jdt.annotation.NonNull;
  16 import org.opendaylight.yang.gen.v1.urn.opendaylight.genius.idmanager.rev160406.id.pools.IdPoolBuilder;
  17
  18 public class ReleasedIdHolder implements IdHolder {
  19     private static final int INITIAL_INDEX = 0;
  20
  21     private final AtomicLong availableIdCount = new AtomicLong();
  22
  23     private final long timeDelaySec;
  24     private final IdUtils idUtils;
  25
  26     private volatile List<DelayedIdEntry> delayedEntries = new CopyOnWriteArrayList<>();
  27
  28     public ReleasedIdHolder(IdUtils idUtils, long timeDelaySec) {
  29         this.idUtils = idUtils;
  30         this.timeDelaySec = timeDelaySec;
  31         availableIdCount.set(0);
  32     }
  33
  34     public ReleasedIdHolder(IdUtils idUtils, long timeDelaySec, List<DelayedIdEntry> delayedEntries) {
  35         this(idUtils, timeDelaySec);
  36         this.delayedEntries.addAll(delayedEntries);
  37     }
  38
  39     public static class DelayedIdEntry implements Serializable {
  40
  41         private static final long serialVersionUID = 1L;
  42
  43         private final long id;
  44         private final long readyTimeSec;
  45
  46         public DelayedIdEntry(long id, long readyTimeSec) {
  47             this.id = id;
  48             this.readyTimeSec = readyTimeSec;
  49         }
  50
  51         @Override
  52         public String toString() {
  53             return "{Id: " + id + " ReadyTimeSec: " + readyTimeSec + "}";
  54         }
  55
  56         public long getId() {
  57             return id;
  58         }
  59
  60         public long getReadyTimeSec() {
  61             return readyTimeSec;
  62         }
  63     }
  64
  65     @Override
  66     public Optional<Long> allocateId() {
  67         long curTimeSec = System.currentTimeMillis() / 1000;
  68         Optional<Long> allocatedId = Optional.empty();
  69         if (isIdAvailable(curTimeSec)) {
  70             Long count = availableIdCount.decrementAndGet();
  71             if (count < 0L) {
  72                 availableIdCount.incrementAndGet();
  73                 return allocatedId;
  74             }
  75             DelayedIdEntry idEntry = delayedEntries.remove(INITIAL_INDEX);
  76             if (idEntry.getReadyTimeSec() <= curTimeSec) {
  77                 allocatedId = Optional.of(idEntry.getId());
  78             } else {
  79                 delayedEntries.add(INITIAL_INDEX, idEntry);
  80                 availableIdCount.incrementAndGet();
  81             }
  82         }
  83         return allocatedId;
  84     }
  85
  86     @Override
  87     public void addId(long id) {
  88         long curTimeSec = System.currentTimeMillis() / 1000;
  89         DelayedIdEntry entry = new DelayedIdEntry(id, curTimeSec + timeDelaySec);
  90         availableIdCount.incrementAndGet();
  91         delayedEntries.add(entry);
  92     }
  93
  94     @Override
  95     public boolean isIdAvailable(long curTimeSec) {
  96         if (availableIdCount.get() <= 0) {
  97             return false;
  98         }
  99         boolean isIdExists = false;
 100         if (!delayedEntries.isEmpty() && delayedEntries.get(INITIAL_INDEX).readyTimeSec <= curTimeSec) {
 101             isIdExists = true;
 102         }
 103         return isIdExists;
 104     }
 105
 106     @Override
 107     public long getAvailableIdCount() {
 108         long availableDelayedEntries = availableIdCount.get();
 109         int index = INITIAL_INDEX;
 110         if (delayedEntries.isEmpty()) {
 111             return index;
 112         }
 113         long curTimeSec = System.currentTimeMillis() / 1000;
 114         while (index < availableDelayedEntries && delayedEntries.get(index).readyTimeSec <= curTimeSec) {
 115             index++;
 116         }
 117         return index;
 118     }
 119
 120     public long getTimeDelaySec() {
 121         return timeDelaySec;
 122     }
 123
 124     @NonNull
 125     public List<DelayedIdEntry> getDelayedEntries() {
 126         return delayedEntries;
 127     }
 128
 129     public void replaceDelayedEntries(@NonNull List<DelayedIdEntry> newDelayedEntries) {
 130         this.delayedEntries = new CopyOnWriteArrayList<>(newDelayedEntries);
 131     }
 132
 133     public void setAvailableIdCount(long availableIdCount) {
 134         this.availableIdCount.set(availableIdCount);
 135     }
 136
 137     @Override
 138     public String toString() {
 139         return "ReleasedIdHolder [availableIdCount=" + availableIdCount
 140                 + ", timeDelaySec=" + timeDelaySec + ", delayedEntries="
 141                 + delayedEntries + "]";
 142     }
 143
 144     @Override
 145     public void refreshDataStore(IdPoolBuilder idPoolBuilder) {
 146         idUtils.syncReleaseIdHolder(this, idPoolBuilder);
 147     }
 148 }