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