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.Objects;
  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.ModificationType;
  23 import org.opendaylight.yangtools.yang.data.api.schema.tree.spi.TreeNode;
  24 import org.opendaylight.yangtools.yang.model.api.SchemaContext;
  25 import org.slf4j.Logger;
  26 import org.slf4j.LoggerFactory;
  27
  28 /**
  29  * Read-only snapshot of the data tree.
  30  */
  31 final class InMemoryDataTree implements DataTree {
  32     private static final YangInstanceIdentifier PUBLIC_ROOT_PATH = YangInstanceIdentifier.create(Collections.<PathArgument>emptyList());
  33     private static final AtomicReferenceFieldUpdater<InMemoryDataTree, DataTreeState> STATE_UPDATER =
  34             AtomicReferenceFieldUpdater.newUpdater(InMemoryDataTree.class, DataTreeState.class, "state");
  35     private static final Logger LOG = LoggerFactory.getLogger(InMemoryDataTree.class);
  36
  37     /**
  38      * Current data store state generation.
  39      */
  40     private volatile DataTreeState state;
  41
  42     public InMemoryDataTree(final TreeNode rootNode, final SchemaContext schemaContext) {
  43         state = DataTreeState.createInitial(rootNode);
  44         if (schemaContext != null) {
  45             setSchemaContext(schemaContext);
  46         }
  47     }
  48
  49     /*
  50      * This method is synchronized to guard against user attempting to install
  51      * multiple contexts. Otherwise it runs in a lock-free manner.
  52      */
  53     @Override
  54     public synchronized void setSchemaContext(final SchemaContext newSchemaContext) {
  55         Preconditions.checkNotNull(newSchemaContext);
  56
  57         LOG.info("Attempting to install schema contexts");
  58         LOG.debug("Following schema contexts will be attempted {}", newSchemaContext);
  59
  60         final SchemaAwareApplyOperation operation = SchemaAwareApplyOperation.from(newSchemaContext);
  61
  62         DataTreeState currentState, newState;
  63         do {
  64             currentState = state;
  65             newState = currentState.withSchemaContext(newSchemaContext, operation);
  66         } while (!STATE_UPDATER.compareAndSet(this, currentState, newState));
  67     }
  68
  69     @Override
  70     public InMemoryDataTreeSnapshot takeSnapshot() {
  71         return state.newSnapshot();
  72     }
  73
  74     @Override
  75     public void validate(final DataTreeModification modification) throws DataValidationFailedException {
  76         Preconditions.checkArgument(modification instanceof InMemoryDataTreeModification, "Invalid modification class %s", modification.getClass());
  77         final InMemoryDataTreeModification m = (InMemoryDataTreeModification)modification;
  78
  79         m.getStrategy().checkApplicable(PUBLIC_ROOT_PATH, m.getRootModification(), Optional.<TreeNode>of(state.getRoot()));
  80     }
  81
  82     @Override
  83     public DataTreeCandidate prepare(final DataTreeModification modification) {
  84         Preconditions.checkArgument(modification instanceof InMemoryDataTreeModification, "Invalid modification class %s", modification.getClass());
  85
  86         final InMemoryDataTreeModification m = (InMemoryDataTreeModification)modification;
  87         final ModifiedNode root = m.getRootModification();
  88
  89         if (root.getType() == ModificationType.UNMODIFIED) {
  90             return new NoopDataTreeCandidate(PUBLIC_ROOT_PATH, root);
  91         }
  92
  93         final TreeNode currentRoot = state.getRoot();
  94         final Optional<TreeNode> newRoot = m.getStrategy().apply(m.getRootModification(),
  95             Optional.<TreeNode>of(currentRoot), m.getVersion());
  96         Preconditions.checkState(newRoot.isPresent(), "Apply strategy failed to produce root node");
  97         return new InMemoryDataTreeCandidate(PUBLIC_ROOT_PATH, root, currentRoot, newRoot.get());
  98     }
  99
 100     @Override
 101     public void commit(final DataTreeCandidate candidate) {
 102         if (candidate instanceof NoopDataTreeCandidate) {
 103             return;
 104         }
 105
 106         Preconditions.checkArgument(candidate instanceof InMemoryDataTreeCandidate, "Invalid candidate class %s", candidate.getClass());
 107         final InMemoryDataTreeCandidate c = (InMemoryDataTreeCandidate)candidate;
 108
 109         if (LOG.isTraceEnabled()) {
 110             LOG.trace("Data Tree is {}", NormalizedNodes.toStringTree(c.getAfterRoot().getData()));
 111         }
 112
 113         final TreeNode newRoot = c.getAfterRoot();
 114         DataTreeState currentState, newState;
 115         do {
 116             currentState = state;
 117             final TreeNode currentRoot = currentState.getRoot();
 118             LOG.debug("Updating datastore from {} to {}", currentRoot, newRoot);
 119
 120             final TreeNode oldRoot = c.getBeforeRoot();
 121             Preconditions.checkState(oldRoot == currentRoot, "Store tree %s and candidate base %s differ.", currentRoot, oldRoot);
 122
 123             newState = currentState.withRoot(newRoot);
 124             LOG.trace("Updated state from {} to {}", currentState, newState);
 125         } while (!STATE_UPDATER.compareAndSet(this, currentState, newState));
 126     }
 127
 128     @Override
 129     public String toString() {
 130         return Objects.toStringHelper(this).add("object", super.toString()).add("state", state).toString();
 131     }
 132 }