opendaylight/md-sal/sal-dom-broker/src/main/java/org/opendaylight/controller/md/sal/dom/store/impl/tree/data/InMemoryDataTree.java

   1 /*
   2  * Copyright (c) 2014 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 package org.opendaylight.controller.md.sal.dom.store.impl.tree.data;
   9
  10 import java.util.concurrent.locks.ReadWriteLock;
  11 import java.util.concurrent.locks.ReentrantReadWriteLock;
  12
  13 import org.opendaylight.controller.md.sal.dom.store.impl.tree.DataValidationFailedException;
  14 import org.opendaylight.controller.md.sal.dom.store.impl.tree.DataTree;
  15 import org.opendaylight.controller.md.sal.dom.store.impl.tree.DataTreeCandidate;
  16 import org.opendaylight.controller.md.sal.dom.store.impl.tree.DataTreeModification;
  17 import org.opendaylight.controller.md.sal.dom.store.impl.tree.ModificationType;
  18 import org.opendaylight.controller.md.sal.dom.store.impl.tree.StoreUtils;
  19 import org.opendaylight.controller.md.sal.dom.store.impl.tree.spi.TreeNode;
  20 import org.opendaylight.yangtools.yang.data.api.InstanceIdentifier;
  21 import org.opendaylight.yangtools.yang.model.api.SchemaContext;
  22 import org.slf4j.Logger;
  23 import org.slf4j.LoggerFactory;
  24
  25 import com.google.common.base.Optional;
  26 import com.google.common.base.Preconditions;
  27
  28 /**
  29  * Read-only snapshot of the data tree.
  30  */
  31 final class InMemoryDataTree implements DataTree {
  32     private static final Logger LOG = LoggerFactory.getLogger(InMemoryDataTree.class);
  33     private static final InstanceIdentifier PUBLIC_ROOT_PATH = InstanceIdentifier.builder().build();
  34
  35     private final ReadWriteLock rwLock = new ReentrantReadWriteLock(true);
  36     private ModificationApplyOperation applyOper = new AlwaysFailOperation();
  37     private SchemaContext currentSchemaContext;
  38     private TreeNode rootNode;
  39
  40     public InMemoryDataTree(final TreeNode rootNode, final SchemaContext schemaContext) {
  41         this.rootNode = Preconditions.checkNotNull(rootNode);
  42
  43         if (schemaContext != null) {
  44             // Also sets applyOper
  45             setSchemaContext(schemaContext);
  46         }
  47     }
  48
  49     @Override
  50     public synchronized void setSchemaContext(final SchemaContext newSchemaContext) {
  51         Preconditions.checkNotNull(newSchemaContext);
  52
  53         LOG.info("Attepting to install schema context {}", newSchemaContext);
  54
  55         /*
  56          * FIXME: we should walk the schema contexts, both current and new and see
  57          *        whether they are compatible here. Reject incompatible changes.
  58          */
  59
  60         // Instantiate new apply operation, this still may fail
  61         final ModificationApplyOperation newApplyOper = SchemaAwareApplyOperation.from(newSchemaContext);
  62
  63         // Ready to change the context now, make sure no operations are running
  64         rwLock.writeLock().lock();
  65         try {
  66             this.applyOper = newApplyOper;
  67             this.currentSchemaContext = newSchemaContext;
  68         } finally {
  69             rwLock.writeLock().unlock();
  70         }
  71     }
  72
  73     @Override
  74     public InMemoryDataTreeSnapshot takeSnapshot() {
  75         rwLock.readLock().lock();
  76         try {
  77             return new InMemoryDataTreeSnapshot(currentSchemaContext, rootNode, applyOper);
  78         } finally {
  79             rwLock.readLock().unlock();
  80         }
  81     }
  82
  83     @Override
  84     public void validate(final DataTreeModification modification) throws DataValidationFailedException {
  85         Preconditions.checkArgument(modification instanceof InMemoryDataTreeModification, "Invalid modification class %s", modification.getClass());
  86
  87         final InMemoryDataTreeModification m = (InMemoryDataTreeModification)modification;
  88         m.getStrategy().checkApplicable(PUBLIC_ROOT_PATH, m.getRootModification(), Optional.<TreeNode>of(rootNode));
  89     }
  90
  91     @Override
  92     public synchronized DataTreeCandidate prepare(final DataTreeModification modification) {
  93         Preconditions.checkArgument(modification instanceof InMemoryDataTreeModification, "Invalid modification class %s", modification.getClass());
  94
  95         final InMemoryDataTreeModification m = (InMemoryDataTreeModification)modification;
  96         final ModifiedNode root = m.getRootModification();
  97
  98         if (root.getType() == ModificationType.UNMODIFIED) {
  99             return new NoopDataTreeCandidate(PUBLIC_ROOT_PATH, root);
 100         }
 101
 102         rwLock.writeLock().lock();
 103         try {
 104             final Optional<TreeNode> newRoot = m.getStrategy().apply(m.getRootModification(),
 105                     Optional.<TreeNode>of(rootNode), rootNode.getSubtreeVersion().next());
 106             Preconditions.checkState(newRoot.isPresent(), "Apply strategy failed to produce root node");
 107             return new InMemoryDataTreeCandidate(PUBLIC_ROOT_PATH, root, rootNode, newRoot.get());
 108         } finally {
 109             rwLock.writeLock().unlock();
 110         }
 111     }
 112
 113     @Override
 114     public synchronized void commit(final DataTreeCandidate candidate) {
 115         if (candidate instanceof NoopDataTreeCandidate) {
 116             return;
 117         }
 118
 119         Preconditions.checkArgument(candidate instanceof InMemoryDataTreeCandidate, "Invalid candidate class %s", candidate.getClass());
 120         final InMemoryDataTreeCandidate c = (InMemoryDataTreeCandidate)candidate;
 121
 122         LOG.debug("Updating datastore from {} to {}", rootNode, c.getAfterRoot());
 123
 124         if (LOG.isTraceEnabled()) {
 125             LOG.trace("Data Tree is {}", StoreUtils.toStringTree(c.getAfterRoot().getData()));
 126         }
 127
 128         // Ready to change the context now, make sure no operations are running
 129         rwLock.writeLock().lock();
 130         try {
 131             Preconditions.checkState(c.getBeforeRoot() == rootNode,
 132                     String.format("Store tree %s and candidate base %s differ.", rootNode, c.getBeforeRoot()));
 133             this.rootNode = c.getAfterRoot();
 134         } finally {
 135             rwLock.writeLock().unlock();
 136         }
 137     }
 138 }