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.Optional;
  12 import com.google.common.base.Preconditions;
  13 import java.util.concurrent.atomic.AtomicReferenceFieldUpdater;
  14 import org.opendaylight.yangtools.yang.data.api.YangInstanceIdentifier;
  15 import org.opendaylight.yangtools.yang.data.api.schema.NormalizedNodes;
  16 import org.opendaylight.yangtools.yang.data.api.schema.tree.DataTreeCandidate;
  17 import org.opendaylight.yangtools.yang.data.api.schema.tree.StoreTreeNodes;
  18 import org.opendaylight.yangtools.yang.data.api.schema.tree.TipProducingDataTree;
  19 import org.opendaylight.yangtools.yang.data.api.schema.tree.TreeType;
  20 import org.opendaylight.yangtools.yang.data.api.schema.tree.spi.TreeNode;
  21 import org.opendaylight.yangtools.yang.model.api.SchemaContext;
  22 import org.slf4j.Logger;
  23 import org.slf4j.LoggerFactory;
  24
  25 /**
  26  * Read-only snapshot of the data tree.
  27  */
  28 final class InMemoryDataTree extends AbstractDataTreeTip implements TipProducingDataTree {
  29     private static final AtomicReferenceFieldUpdater<InMemoryDataTree, DataTreeState> STATE_UPDATER =
  30             AtomicReferenceFieldUpdater.newUpdater(InMemoryDataTree.class, DataTreeState.class, "state");
  31     private static final Logger LOG = LoggerFactory.getLogger(InMemoryDataTree.class);
  32
  33     private final YangInstanceIdentifier rootPath;
  34     private final TreeType treeType;
  35
  36     /**
  37      * Current data store state generation.
  38      */
  39     private volatile DataTreeState state;
  40
  41     public InMemoryDataTree(final TreeNode rootNode, final TreeType treeType, final YangInstanceIdentifier rootPath, final SchemaContext schemaContext) {
  42         this.treeType = Preconditions.checkNotNull(treeType, "treeType");
  43         this.rootPath = Preconditions.checkNotNull(rootPath, "rootPath");
  44         state = DataTreeState.createInitial(rootNode);
  45         if (schemaContext != null) {
  46             setSchemaContext(schemaContext);
  47         }
  48     }
  49
  50     /*
  51      * This method is synchronized to guard against user attempting to install
  52      * multiple contexts. Otherwise it runs in a lock-free manner.
  53      */
  54     @Override
  55     public synchronized void setSchemaContext(final SchemaContext newSchemaContext) {
  56         Preconditions.checkNotNull(newSchemaContext);
  57
  58         LOG.debug("Following schema contexts will be attempted {}", newSchemaContext);
  59
  60         final ModificationApplyOperation op = SchemaAwareApplyOperation.from(newSchemaContext, treeType);
  61         final Optional<ModificationApplyOperation> maybeRootNode = StoreTreeNodes.findNode(op, rootPath);
  62         if (!maybeRootNode.isPresent()) {
  63             LOG.debug("Could not find root {} in new schema context, not upgrading", rootPath);
  64             return;
  65         }
  66
  67         final ModificationApplyOperation rootNode = maybeRootNode.get();
  68         if (!(rootNode instanceof AbstractNodeContainerModificationStrategy)) {
  69             LOG.warn("Root {} resolves to non-container type {}, not upgrading", rootPath, rootNode);
  70             return;
  71         }
  72
  73         DataTreeState currentState, newState;
  74         do {
  75             currentState = state;
  76             newState = currentState.withSchemaContext(newSchemaContext, (SchemaAwareApplyOperation) rootNode);
  77         } while (!STATE_UPDATER.compareAndSet(this, currentState, newState));
  78     }
  79
  80     @Override
  81     public InMemoryDataTreeSnapshot takeSnapshot() {
  82         return state.newSnapshot();
  83     }
  84
  85     @Override
  86     public void commit(final DataTreeCandidate candidate) {
  87         if (candidate instanceof NoopDataTreeCandidate) {
  88             return;
  89         }
  90         Preconditions.checkArgument(candidate instanceof InMemoryDataTreeCandidate, "Invalid candidate class %s", candidate.getClass());
  91         final InMemoryDataTreeCandidate c = (InMemoryDataTreeCandidate)candidate;
  92
  93         if (LOG.isTraceEnabled()) {
  94             LOG.trace("Data Tree is {}", NormalizedNodes.toStringTree(c.getTipRoot().getData()));
  95         }
  96
  97         final TreeNode newRoot = c.getTipRoot();
  98         DataTreeState currentState, newState;
  99         do {
 100             currentState = state;
 101             final TreeNode currentRoot = currentState.getRoot();
 102             LOG.debug("Updating datastore from {} to {}", currentRoot, newRoot);
 103
 104             final TreeNode oldRoot = c.getBeforeRoot();
 105             Preconditions.checkState(oldRoot == currentRoot, "Store tree %s and candidate base %s differ.", currentRoot, oldRoot);
 106
 107             newState = currentState.withRoot(newRoot);
 108             LOG.trace("Updated state from {} to {}", currentState, newState);
 109         } while (!STATE_UPDATER.compareAndSet(this, currentState, newState));
 110     }
 111
 112     @Override
 113     public YangInstanceIdentifier getRootPath() {
 114         return rootPath;
 115     }
 116
 117     @Override
 118     public String toString() {
 119         return MoreObjects.toStringHelper(this).
 120                 add("object", super.toString()).
 121                 add("rootPath", rootPath).
 122                 add("state", state).
 123                 toString();
 124     }
 125
 126     @Override
 127     protected TreeNode getTipRoot() {
 128         return state.getRoot();
 129     }
 130 }