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.tree.DataTree;
  18 import org.opendaylight.yangtools.yang.data.api.schema.tree.DataTreeCandidate;
  19 import org.opendaylight.yangtools.yang.data.api.schema.tree.DataTreeModification;
  20 import org.opendaylight.yangtools.yang.data.api.schema.tree.DataValidationFailedException;
  21 import org.opendaylight.yangtools.yang.data.api.schema.tree.ModificationType;
  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.info("Attempting to install schema contexts");
  57         LOG.debug("Following schema contexts will be attempted {}", newSchemaContext);
  58
  59         final SchemaAwareApplyOperation operation = SchemaAwareApplyOperation.from(newSchemaContext);
  60
  61         DataTreeState currentState, newState;
  62         do {
  63             currentState = state;
  64             newState = currentState.withSchemaContext(newSchemaContext, operation);
  65         } while (!STATE_UPDATER.compareAndSet(this, currentState, newState));
  66     }
  67
  68     @Override
  69     public InMemoryDataTreeSnapshot takeSnapshot() {
  70         return state.newSnapshot();
  71     }
  72
  73     @Override
  74     public void validate(final DataTreeModification modification) throws DataValidationFailedException {
  75         Preconditions.checkArgument(modification instanceof InMemoryDataTreeModification, "Invalid modification class %s", modification.getClass());
  76         final InMemoryDataTreeModification m = (InMemoryDataTreeModification)modification;
  77
  78         m.getStrategy().checkApplicable(PUBLIC_ROOT_PATH, m.getRootModification(), Optional.<TreeNode>of(state.getRoot()));
  79     }
  80
  81     @Override
  82     public DataTreeCandidate prepare(final DataTreeModification modification) {
  83         Preconditions.checkArgument(modification instanceof InMemoryDataTreeModification, "Invalid modification class %s", modification.getClass());
  84
  85         final InMemoryDataTreeModification m = (InMemoryDataTreeModification)modification;
  86         final ModifiedNode root = m.getRootModification();
  87
  88         if (root.getType() == ModificationType.UNMODIFIED) {
  89             return new NoopDataTreeCandidate(PUBLIC_ROOT_PATH, root);
  90         }
  91
  92         final TreeNode currentRoot = state.getRoot();
  93         final Optional<TreeNode> newRoot = m.getStrategy().apply(m.getRootModification(),
  94             Optional.<TreeNode>of(currentRoot), m.getVersion());
  95         Preconditions.checkState(newRoot.isPresent(), "Apply strategy failed to produce root node");
  96         return new InMemoryDataTreeCandidate(PUBLIC_ROOT_PATH, root, currentRoot, newRoot.get());
  97     }
  98
  99     @Override
 100     public void commit(final DataTreeCandidate candidate) {
 101         if (candidate instanceof NoopDataTreeCandidate) {
 102             return;
 103         }
 104
 105         Preconditions.checkArgument(candidate instanceof InMemoryDataTreeCandidate, "Invalid candidate class %s", candidate.getClass());
 106         final InMemoryDataTreeCandidate c = (InMemoryDataTreeCandidate)candidate;
 107
 108         if (LOG.isTraceEnabled()) {
 109             LOG.trace("Data Tree is {}", StoreUtils.toStringTree(c.getAfterRoot().getData()));
 110         }
 111
 112         final TreeNode newRoot = c.getAfterRoot();
 113         DataTreeState currentState, newState;
 114         do {
 115             currentState = state;
 116             final TreeNode currentRoot = currentState.getRoot();
 117             LOG.debug("Updating datastore from {} to {}", currentRoot, newRoot);
 118
 119             final TreeNode oldRoot = c.getBeforeRoot();
 120             Preconditions.checkState(oldRoot == currentRoot, "Store tree %s and candidate base %s differ.", currentRoot, oldRoot);
 121
 122             newState = currentState.withRoot(newRoot);
 123             LOG.trace("Updated state from {} to {}", currentState, newState);
 124         } while (!STATE_UPDATER.compareAndSet(this, currentState, newState));
 125     }
 126
 127     @Override
 128     public String toString() {
 129         return Objects.toStringHelper(this).add("object", super.toString()).add("state", state).toString();
 130     }
 131 }