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