restconf/restconf-nb-bierman02/src/main/java/org/opendaylight/netconf/sal/restconf/impl/BatchedExistenceCheck.java

   1 /*
   2  * Copyright (c) 2017 Pantheon Technologies, s.r.o. 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.netconf.sal.restconf.impl;
   9
  10 import com.google.common.util.concurrent.FutureCallback;
  11 import com.google.common.util.concurrent.Futures;
  12 import com.google.common.util.concurrent.ListenableFuture;
  13 import com.google.common.util.concurrent.MoreExecutors;
  14 import com.google.common.util.concurrent.SettableFuture;
  15 import java.util.AbstractMap.SimpleImmutableEntry;
  16 import java.util.Collection;
  17 import java.util.Map.Entry;
  18 import java.util.concurrent.ExecutionException;
  19 import java.util.concurrent.atomic.AtomicIntegerFieldUpdater;
  20 import org.opendaylight.controller.md.sal.common.api.data.LogicalDatastoreType;
  21 import org.opendaylight.controller.md.sal.common.api.data.ReadFailedException;
  22 import org.opendaylight.controller.md.sal.dom.api.DOMDataReadTransaction;
  23 import org.opendaylight.yangtools.yang.data.api.YangInstanceIdentifier;
  24 import org.opendaylight.yangtools.yang.data.api.schema.NormalizedNode;
  25
  26 final class BatchedExistenceCheck {
  27     private static final AtomicIntegerFieldUpdater<BatchedExistenceCheck> UPDATER =
  28             AtomicIntegerFieldUpdater.newUpdater(BatchedExistenceCheck.class, "outstanding");
  29
  30     private final SettableFuture<Entry<YangInstanceIdentifier, ReadFailedException>> future = SettableFuture.create();
  31
  32     @SuppressWarnings("unused")
  33     private volatile int outstanding;
  34
  35     private BatchedExistenceCheck(final int total) {
  36         this.outstanding = total;
  37     }
  38
  39     static BatchedExistenceCheck start(final DOMDataReadTransaction readTx,
  40             final LogicalDatastoreType datastore, final YangInstanceIdentifier parentPath,
  41             final Collection<? extends NormalizedNode<?, ?>> children) {
  42         final BatchedExistenceCheck ret = new BatchedExistenceCheck(children.size());
  43         for (NormalizedNode<?, ?> child : children) {
  44             final YangInstanceIdentifier path = parentPath.node(child.getIdentifier());
  45             final ListenableFuture<Boolean> f = readTx.exists(datastore, path);
  46             Futures.addCallback(f, new FutureCallback<Boolean>() {
  47                 @Override
  48                 public void onSuccess(final Boolean result) {
  49                     ret.complete(path, result.booleanValue());
  50                 }
  51
  52                 @Override
  53                 public void onFailure(final Throwable throwable) {
  54                     final Exception e;
  55                     if (throwable instanceof Exception) {
  56                         e = (Exception) throwable;
  57                     } else {
  58                         e = new ExecutionException(throwable);
  59                     }
  60
  61                     ret.complete(path, ReadFailedException.MAPPER.apply(e));
  62                 }
  63             }, MoreExecutors.directExecutor());
  64         }
  65
  66         return ret;
  67     }
  68
  69     Entry<YangInstanceIdentifier, ReadFailedException> getFailure() throws InterruptedException {
  70         try {
  71             return future.get();
  72         } catch (ExecutionException e) {
  73             // This should never happen
  74             throw new IllegalStateException(e);
  75         }
  76     }
  77
  78     private void complete(final YangInstanceIdentifier childPath, final boolean present) {
  79         final int count = UPDATER.decrementAndGet(this);
  80         if (present) {
  81             future.set(new SimpleImmutableEntry<>(childPath, null));
  82         } else if (count == 0) {
  83             future.set(null);
  84         }
  85     }
  86
  87     private void complete(final YangInstanceIdentifier childPath, final ReadFailedException cause) {
  88         UPDATER.decrementAndGet(this);
  89         future.set(new SimpleImmutableEntry<>(childPath, cause));
  90     }
  91 }