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.Collections;
  14 import java.util.concurrent.atomic.AtomicReferenceFieldUpdater;
  15 import org.opendaylight.yangtools.yang.data.api.YangInstanceIdentifier;
  16 import org.opendaylight.yangtools.yang.data.api.YangInstanceIdentifier.PathArgument;
  17 import org.opendaylight.yangtools.yang.data.api.schema.NormalizedNodes;
  18 import org.opendaylight.yangtools.yang.data.api.schema.tree.DataTree;
  19 import org.opendaylight.yangtools.yang.data.api.schema.tree.DataTreeCandidate;
  20 import org.opendaylight.yangtools.yang.data.api.schema.tree.DataTreeModification;
  21 import org.opendaylight.yangtools.yang.data.api.schema.tree.DataValidationFailedException;
  22 import org.opendaylight.yangtools.yang.data.api.schema.tree.spi.TreeNode;
  23 import org.opendaylight.yangtools.yang.model.api.SchemaContext;
  24 import org.slf4j.Logger;
  25 import org.slf4j.LoggerFactory;
  26
  27 /**
  28  * Read-only snapshot of the data tree.
  29  */
  30 final class InMemoryDataTree implements DataTree {
  31     private static final YangInstanceIdentifier PUBLIC_ROOT_PATH = YangInstanceIdentifier.create(Collections.<PathArgument>emptyList());
  32     private static final AtomicReferenceFieldUpdater<InMemoryDataTree, DataTreeState> STATE_UPDATER =
  33             AtomicReferenceFieldUpdater.newUpdater(InMemoryDataTree.class, DataTreeState.class, "state");
  34     private static final Logger LOG = LoggerFactory.getLogger(InMemoryDataTree.class);
  35
  36     /**
  37      * Current data store state generation.
  38      */
  39     private volatile DataTreeState state;
  40
  41     public InMemoryDataTree(final TreeNode rootNode, final SchemaContext schemaContext) {
  42         state = DataTreeState.createInitial(rootNode);
  43         if (schemaContext != null) {
  44             setSchemaContext(schemaContext);
  45         }
  46     }
  47
  48     /*
  49      * This method is synchronized to guard against user attempting to install
  50      * multiple contexts. Otherwise it runs in a lock-free manner.
  51      */
  52     @Override
  53     public synchronized void setSchemaContext(final SchemaContext newSchemaContext) {
  54         Preconditions.checkNotNull(newSchemaContext);
  55
  56         LOG.debug("Following schema contexts will be attempted {}", newSchemaContext);
  57
  58         final SchemaAwareApplyOperation operation = SchemaAwareApplyOperation.from(newSchemaContext);
  59
  60         DataTreeState currentState, newState;
  61         do {
  62             currentState = state;
  63             newState = currentState.withSchemaContext(newSchemaContext, operation);
  64         } while (!STATE_UPDATER.compareAndSet(this, currentState, newState));
  65     }
  66
  67     @Override
  68     public InMemoryDataTreeSnapshot takeSnapshot() {
  69         return state.newSnapshot();
  70     }
  71
  72     @Override
  73     public void validate(final DataTreeModification modification) throws DataValidationFailedException {
  74         Preconditions.checkArgument(modification instanceof InMemoryDataTreeModification, "Invalid modification class %s", modification.getClass());
  75         final InMemoryDataTreeModification m = (InMemoryDataTreeModification)modification;
  76
  77         m.getStrategy().checkApplicable(PUBLIC_ROOT_PATH, m.getRootModification(), Optional.<TreeNode>of(state.getRoot()));
  78     }
  79
  80     @Override
  81     public DataTreeCandidate prepare(final DataTreeModification modification) {
  82         Preconditions.checkArgument(modification instanceof InMemoryDataTreeModification, "Invalid modification class %s", modification.getClass());
  83
  84         final InMemoryDataTreeModification m = (InMemoryDataTreeModification)modification;
  85         final ModifiedNode root = m.getRootModification();
  86
  87         if (root.getOperation() == LogicalOperation.NONE) {
  88             return new NoopDataTreeCandidate(PUBLIC_ROOT_PATH, root);
  89         }
  90
  91         final TreeNode currentRoot = state.getRoot();
  92         final Optional<TreeNode> newRoot = m.getStrategy().apply(m.getRootModification(),
  93             Optional.<TreeNode>of(currentRoot), m.getVersion());
  94         Preconditions.checkState(newRoot.isPresent(), "Apply strategy failed to produce root node");
  95         return new InMemoryDataTreeCandidate(PUBLIC_ROOT_PATH, root, currentRoot, newRoot.get());
  96     }
  97
  98     @Override
  99     public void commit(final DataTreeCandidate candidate) {
 100         if (candidate instanceof NoopDataTreeCandidate) {
 101             return;
 102         }
 103
 104         Preconditions.checkArgument(candidate instanceof InMemoryDataTreeCandidate, "Invalid candidate class %s", candidate.getClass());
 105         final InMemoryDataTreeCandidate c = (InMemoryDataTreeCandidate)candidate;
 106
 107         if (LOG.isTraceEnabled()) {
 108             LOG.trace("Data Tree is {}", NormalizedNodes.toStringTree(c.getAfterRoot().getData()));
 109         }
 110
 111         final TreeNode newRoot = c.getAfterRoot();
 112         DataTreeState currentState, newState;
 113         do {
 114             currentState = state;
 115             final TreeNode currentRoot = currentState.getRoot();
 116             LOG.debug("Updating datastore from {} to {}", currentRoot, newRoot);
 117
 118             final TreeNode oldRoot = c.getBeforeRoot();
 119             Preconditions.checkState(oldRoot == currentRoot, "Store tree %s and candidate base %s differ.", currentRoot, oldRoot);
 120
 121             newState = currentState.withRoot(newRoot);
 122             LOG.trace("Updated state from {} to {}", currentState, newState);
 123         } while (!STATE_UPDATER.compareAndSet(this, currentState, newState));
 124     }
 125
 126     @Override
 127     public String toString() {
 128         return MoreObjects.toStringHelper(this).add("object", super.toString()).add("state", state).toString();
 129     }
 130 }