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.MoreObjects;
  11 import com.google.common.base.Preconditions;
  12 import java.util.concurrent.atomic.AtomicReferenceFieldUpdater;
  13 import org.opendaylight.yangtools.yang.data.api.schema.NormalizedNodes;
  14 import org.opendaylight.yangtools.yang.data.api.schema.tree.DataTreeCandidate;
  15 import org.opendaylight.yangtools.yang.data.api.schema.tree.TipProducingDataTree;
  16 import org.opendaylight.yangtools.yang.data.api.schema.tree.TreeType;
  17 import org.opendaylight.yangtools.yang.data.api.schema.tree.spi.TreeNode;
  18 import org.opendaylight.yangtools.yang.model.api.SchemaContext;
  19 import org.slf4j.Logger;
  20 import org.slf4j.LoggerFactory;
  21
  22 /**
  23  * Read-only snapshot of the data tree.
  24  */
  25 final class InMemoryDataTree extends AbstractDataTreeTip implements TipProducingDataTree {
  26     private static final AtomicReferenceFieldUpdater<InMemoryDataTree, DataTreeState> STATE_UPDATER =
  27             AtomicReferenceFieldUpdater.newUpdater(InMemoryDataTree.class, DataTreeState.class, "state");
  28     private static final Logger LOG = LoggerFactory.getLogger(InMemoryDataTree.class);
  29
  30     /**
  31      * Current data store state generation.
  32      */
  33     private volatile DataTreeState state;
  34     private final TreeType treeType;
  35
  36     public InMemoryDataTree(final TreeNode rootNode, final TreeType treeType, final SchemaContext schemaContext) {
  37         this.treeType = Preconditions.checkNotNull(treeType,treeType);
  38         state = DataTreeState.createInitial(rootNode);
  39         if (schemaContext != null) {
  40             setSchemaContext(schemaContext);
  41         }
  42     }
  43
  44     /*
  45      * This method is synchronized to guard against user attempting to install
  46      * multiple contexts. Otherwise it runs in a lock-free manner.
  47      */
  48     @Override
  49     public synchronized void setSchemaContext(final SchemaContext newSchemaContext) {
  50         Preconditions.checkNotNull(newSchemaContext);
  51
  52         LOG.debug("Following schema contexts will be attempted {}", newSchemaContext);
  53
  54         final SchemaAwareApplyOperation operation = SchemaAwareApplyOperation.from(newSchemaContext,treeType);
  55
  56         DataTreeState currentState, newState;
  57         do {
  58             currentState = state;
  59             newState = currentState.withSchemaContext(newSchemaContext, operation);
  60         } while (!STATE_UPDATER.compareAndSet(this, currentState, newState));
  61     }
  62
  63     @Override
  64     public InMemoryDataTreeSnapshot takeSnapshot() {
  65         return state.newSnapshot();
  66     }
  67
  68     @Override
  69     public void commit(final DataTreeCandidate candidate) {
  70         if (candidate instanceof NoopDataTreeCandidate) {
  71             return;
  72         }
  73         Preconditions.checkArgument(candidate instanceof InMemoryDataTreeCandidate, "Invalid candidate class %s", candidate.getClass());
  74         final InMemoryDataTreeCandidate c = (InMemoryDataTreeCandidate)candidate;
  75
  76         if (LOG.isTraceEnabled()) {
  77             LOG.trace("Data Tree is {}", NormalizedNodes.toStringTree(c.getTipRoot().getData()));
  78         }
  79
  80         final TreeNode newRoot = c.getTipRoot();
  81         DataTreeState currentState, newState;
  82         do {
  83             currentState = state;
  84             final TreeNode currentRoot = currentState.getRoot();
  85             LOG.debug("Updating datastore from {} to {}", currentRoot, newRoot);
  86
  87             final TreeNode oldRoot = c.getBeforeRoot();
  88             Preconditions.checkState(oldRoot == currentRoot, "Store tree %s and candidate base %s differ.", currentRoot, oldRoot);
  89
  90             newState = currentState.withRoot(newRoot);
  91             LOG.trace("Updated state from {} to {}", currentState, newState);
  92         } while (!STATE_UPDATER.compareAndSet(this, currentState, newState));
  93     }
  94
  95     @Override
  96     public String toString() {
  97         return MoreObjects.toStringHelper(this).add("object", super.toString()).add("state", state).toString();
  98     }
  99
 100     @Override
 101     protected TreeNode getTipRoot() {
 102         return state.getRoot();
 103     }
 104 }