BUG-509: reorganize data tree abstractions.
[controller.git] / opendaylight / md-sal / sal-dom-broker / src / main / java / org / opendaylight / controller / md / sal / dom / store / impl / InMemoryDOMDataStore.java
index 0944c2efaebdbf4d328ec94e7a4b3996a1c66239..7d2ff30b1fe64f96d89619894e83d26880f8bd73 100644 (file)
@@ -11,33 +11,37 @@ import static com.google.common.base.Preconditions.checkNotNull;
 import static com.google.common.base.Preconditions.checkState;
 import static org.opendaylight.controller.md.sal.dom.store.impl.StoreUtils.increase;
 
+import java.util.Collections;
 import java.util.concurrent.Callable;
 import java.util.concurrent.atomic.AtomicLong;
 
 import org.opendaylight.controller.md.sal.common.api.data.AsyncDataBroker.DataChangeScope;
 import org.opendaylight.controller.md.sal.common.api.data.AsyncDataChangeListener;
-import org.opendaylight.controller.md.sal.dom.store.impl.tree.ListenerRegistrationNode;
+import org.opendaylight.controller.md.sal.dom.store.impl.tree.ListenerTree;
 import org.opendaylight.controller.md.sal.dom.store.impl.tree.ModificationType;
 import org.opendaylight.controller.md.sal.dom.store.impl.tree.NodeModification;
 import org.opendaylight.controller.md.sal.dom.store.impl.tree.StoreMetadataNode;
-import org.opendaylight.controller.md.sal.dom.store.impl.tree.TreeNodeUtils;
 import org.opendaylight.controller.sal.core.spi.data.DOMStore;
 import org.opendaylight.controller.sal.core.spi.data.DOMStoreReadTransaction;
 import org.opendaylight.controller.sal.core.spi.data.DOMStoreReadWriteTransaction;
 import org.opendaylight.controller.sal.core.spi.data.DOMStoreThreePhaseCommitCohort;
+import org.opendaylight.controller.sal.core.spi.data.DOMStoreTransaction;
 import org.opendaylight.controller.sal.core.spi.data.DOMStoreWriteTransaction;
+import org.opendaylight.yangtools.concepts.AbstractListenerRegistration;
 import org.opendaylight.yangtools.concepts.Identifiable;
 import org.opendaylight.yangtools.concepts.ListenerRegistration;
 import org.opendaylight.yangtools.yang.data.api.InstanceIdentifier;
 import org.opendaylight.yangtools.yang.data.api.InstanceIdentifier.PathArgument;
 import org.opendaylight.yangtools.yang.data.api.schema.NormalizedNode;
-import org.opendaylight.yangtools.yang.data.impl.schema.NormalizedNodeUtils;
 import org.opendaylight.yangtools.yang.model.api.SchemaContext;
 import org.opendaylight.yangtools.yang.model.api.SchemaContextListener;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
+import com.google.common.base.Objects;
+import com.google.common.base.Objects.ToStringHelper;
 import com.google.common.base.Optional;
+import com.google.common.base.Preconditions;
 import com.google.common.primitives.UnsignedLong;
 import com.google.common.util.concurrent.Futures;
 import com.google.common.util.concurrent.ListenableFuture;
@@ -48,86 +52,92 @@ public class InMemoryDOMDataStore implements DOMStore, Identifiable<String>, Sch
     private static final Logger LOG = LoggerFactory.getLogger(InMemoryDOMDataStore.class);
     private static final InstanceIdentifier PUBLIC_ROOT_PATH = InstanceIdentifier.builder().build();
 
-
     private final ListeningExecutorService executor;
     private final String name;
     private final AtomicLong txCounter = new AtomicLong(0);
-
-    private DataAndMetadataSnapshot snapshot;
-    private ModificationApplyOperation operationTree;
-    private final ListenerRegistrationNode listenerTree;
-
-
-
-    private SchemaContext schemaContext;
+    private final ListenerTree listenerTree = ListenerTree.create();
+    private final DataTree dataTree = DataTree.create(null);
+    private ModificationApplyOperation operationTree = new AlwaysFailOperation();
 
     public InMemoryDOMDataStore(final String name, final ListeningExecutorService executor) {
-        this.executor = executor;
-        this.name = name;
-        this.operationTree = new AllwaysFailOperation();
-        this.snapshot = DataAndMetadataSnapshot.createEmpty();
-        this.listenerTree = ListenerRegistrationNode.createRoot();
+        this.name = Preconditions.checkNotNull(name);
+        this.executor = Preconditions.checkNotNull(executor);
     }
 
     @Override
-    public String getIdentifier() {
+    public final String getIdentifier() {
         return name;
     }
 
     @Override
     public DOMStoreReadTransaction newReadOnlyTransaction() {
-        return new SnapshotBackedReadTransaction(nextIdentifier(), snapshot);
+        return new SnapshotBackedReadTransaction(nextIdentifier(), dataTree.takeSnapshot());
     }
 
     @Override
     public DOMStoreReadWriteTransaction newReadWriteTransaction() {
-        return new SnapshotBackedReadWriteTransaction(nextIdentifier(), snapshot, this, operationTree);
+        return new SnapshotBackedReadWriteTransaction(nextIdentifier(), dataTree.takeSnapshot(), this, operationTree);
     }
 
     @Override
     public DOMStoreWriteTransaction newWriteOnlyTransaction() {
-        return new SnaphostBackedWriteTransaction(nextIdentifier(), snapshot, this, operationTree);
+        return new SnapshotBackedWriteTransaction(nextIdentifier(), dataTree.takeSnapshot(), this, operationTree);
     }
 
     @Override
     public synchronized void onGlobalContextUpdated(final SchemaContext ctx) {
-        operationTree = SchemaAwareApplyOperationRoot.from(ctx);
-        schemaContext = ctx;
+        /*
+         * Order of operations is important: dataTree may reject the context
+         * and creation of ModificationApplyOperation may fail. So pre-construct
+         * the operation, then update the data tree and then move the operation
+         * into view.
+         */
+        final ModificationApplyOperation newOperationTree = SchemaAwareApplyOperationRoot.from(ctx);
+        dataTree.setSchemaContext(ctx);
+        operationTree = newOperationTree;
     }
 
     @Override
     public <L extends AsyncDataChangeListener<InstanceIdentifier, NormalizedNode<?, ?>>> ListenerRegistration<L> registerChangeListener(
             final InstanceIdentifier path, final L listener, final DataChangeScope scope) {
 
-        Optional<ListenerRegistrationNode> listenerNode = TreeNodeUtils.findNode(listenerTree, path);
-        checkState(listenerNode.isPresent());
-        synchronized (listener) {
-            notifyInitialState(path, listener);
-        }
-        return listenerNode.get().registerDataChangeListener(listener, scope);
-    }
+        /*
+         * Make sure commit is not occurring right now. Listener has to be
+         * registered and its state capture enqueued at a consistent point.
+         *
+         * FIXME: improve this to read-write lock, such that multiple listener
+         * registrations can occur simultaneously
+         */
+        final DataChangeListenerRegistration<L> reg;
+        synchronized (this) {
+            LOG.debug("{}: Registering data change listener {} for {}", name, listener, path);
 
-    private void notifyInitialState(final InstanceIdentifier path,
-            final AsyncDataChangeListener<InstanceIdentifier, NormalizedNode<?, ?>> listener) {
-        Optional<StoreMetadataNode> currentState = snapshot.read(path);
-        try {
+            reg = listenerTree.registerDataChangeListener(path, listener, scope);
+
+            Optional<NormalizedNode<?, ?>> currentState = dataTree.takeSnapshot().readNode(path);
             if (currentState.isPresent()) {
-                NormalizedNode<?, ?> data = currentState.get().getData();
-                listener.onDataChanged(DOMImmutableDataChangeEvent.builder() //
+                final NormalizedNode<?, ?> data = currentState.get();
+
+                final DOMImmutableDataChangeEvent event = DOMImmutableDataChangeEvent.builder(DataChangeScope.BASE) //
                         .setAfter(data) //
                         .addCreated(path, data) //
-                        .build() //
-                );
+                        .build();
+                executor.submit(new ChangeListenerNotifyTask(Collections.singletonList(reg), event));
             }
-        } catch (Exception e) {
-            LOG.error("Unhandled exception encountered when invoking listener {}", listener, e);
         }
 
+        return new AbstractListenerRegistration<L>(listener) {
+            @Override
+            protected void removeRegistration() {
+                synchronized (InMemoryDOMDataStore.this) {
+                    reg.close();
+                }
+            }
+        };
     }
 
-    private synchronized DOMStoreThreePhaseCommitCohort submit(
-            final SnaphostBackedWriteTransaction writeTx) {
-        LOG.debug("Tx: {} is submitted. Modifications: {}",writeTx.getIdentifier(),writeTx.getMutatedView());
+    private synchronized DOMStoreThreePhaseCommitCohort submit(final SnapshotBackedWriteTransaction writeTx) {
+        LOG.debug("Tx: {} is submitted. Modifications: {}", writeTx.getIdentifier(), writeTx.getMutatedView());
         return new ThreePhaseCommitImpl(writeTx);
     }
 
@@ -135,43 +145,70 @@ public class InMemoryDOMDataStore implements DOMStore, Identifiable<String>, Sch
         return name + "-" + txCounter.getAndIncrement();
     }
 
-    private synchronized void commit(final DataAndMetadataSnapshot currentSnapshot,
-            final StoreMetadataNode newDataTree, final Iterable<ChangeListenerNotifyTask> listenerTasks) {
-        LOG.debug("Updating Store snaphot version: {} with version:{}",currentSnapshot.getMetadataTree().getSubtreeVersion(),newDataTree.getSubtreeVersion());
-        if(LOG.isTraceEnabled()) {
-            LOG.trace("Data Tree is {}",StoreUtils.toStringTree(newDataTree));
-        }
-        checkState(snapshot == currentSnapshot, "Store snapshot and transaction snapshot differs");
-        snapshot = DataAndMetadataSnapshot.builder() //
-                .setMetadataTree(newDataTree) //
-                .setSchemaContext(schemaContext) //
-                .build();
-
-        for(ChangeListenerNotifyTask task : listenerTasks) {
-            executor.submit(task);
+    private void commit(final DataTree.Snapshot currentSnapshot, final StoreMetadataNode newDataTree,
+            final ResolveDataChangeEventsTask listenerResolver) {
+        LOG.debug("Updating Store snaphot version: {} with version:{}", currentSnapshot, newDataTree.getSubtreeVersion());
+
+        if (LOG.isTraceEnabled()) {
+            LOG.trace("Data Tree is {}", StoreUtils.toStringTree(newDataTree.getData()));
         }
 
-    }
+        /*
+         * The commit has to occur atomically with regard to listener
+         * registrations.
+         */
+        synchronized (this) {
+            dataTree.commitSnapshot(currentSnapshot, newDataTree);
 
-    private static class SnapshotBackedReadTransaction implements DOMStoreReadTransaction {
+            for (ChangeListenerNotifyTask task : listenerResolver.call()) {
+                LOG.trace("Scheduling invocation of listeners: {}", task);
+                executor.submit(task);
+            }
+        }
+    }
 
-        private DataAndMetadataSnapshot stableSnapshot;
+    private static abstract class AbstractDOMStoreTransaction implements DOMStoreTransaction {
         private final Object identifier;
 
-        public SnapshotBackedReadTransaction(final Object identifier, final DataAndMetadataSnapshot snapshot) {
+        protected AbstractDOMStoreTransaction(final Object identifier) {
             this.identifier = identifier;
-            this.stableSnapshot = snapshot;
-            LOG.debug("ReadOnly Tx: {} allocated with snapshot {}",identifier,snapshot.getMetadataTree().getSubtreeVersion());
-
         }
 
         @Override
-        public Object getIdentifier() {
+        public final Object getIdentifier() {
             return identifier;
         }
 
+        @Override
+        public final String toString() {
+            return addToStringAttributes(Objects.toStringHelper(this)).toString();
+        }
+
+        /**
+         * Add class-specific toString attributes.
+         *
+         * @param toStringHelper
+         *            ToStringHelper instance
+         * @return ToStringHelper instance which was passed in
+         */
+        protected ToStringHelper addToStringAttributes(final ToStringHelper toStringHelper) {
+            return toStringHelper.add("id", identifier);
+        }
+    }
+
+    private static final class SnapshotBackedReadTransaction extends AbstractDOMStoreTransaction implements
+            DOMStoreReadTransaction {
+        private DataTree.Snapshot stableSnapshot;
+
+        public SnapshotBackedReadTransaction(final Object identifier, final DataTree.Snapshot snapshot) {
+            super(identifier);
+            this.stableSnapshot = Preconditions.checkNotNull(snapshot);
+            LOG.debug("ReadOnly Tx: {} allocated with snapshot {}", identifier, snapshot);
+        }
+
         @Override
         public void close() {
+            LOG.debug("Store transaction: {} : Closed", getIdentifier());
             stableSnapshot = null;
         }
 
@@ -179,39 +216,27 @@ public class InMemoryDOMDataStore implements DOMStore, Identifiable<String>, Sch
         public ListenableFuture<Optional<NormalizedNode<?, ?>>> read(final InstanceIdentifier path) {
             checkNotNull(path, "Path must not be null.");
             checkState(stableSnapshot != null, "Transaction is closed");
-            return Futures.immediateFuture(NormalizedNodeUtils.findNode(stableSnapshot.getDataTree(), path));
-        }
-
-        @Override
-        public String toString() {
-            return "SnapshotBackedReadTransaction [id =" + identifier + "]";
+            return Futures.immediateFuture(stableSnapshot.readNode(path));
         }
-
     }
 
-    private static class SnaphostBackedWriteTransaction implements DOMStoreWriteTransaction {
-
+    private static class SnapshotBackedWriteTransaction extends AbstractDOMStoreTransaction implements
+            DOMStoreWriteTransaction {
         private MutableDataTree mutableTree;
-        private final Object identifier;
         private InMemoryDOMDataStore store;
-
         private boolean ready = false;
 
-        public SnaphostBackedWriteTransaction(final Object identifier, final DataAndMetadataSnapshot snapshot,
+        public SnapshotBackedWriteTransaction(final Object identifier, final DataTree.Snapshot snapshot,
                 final InMemoryDOMDataStore store, final ModificationApplyOperation applyOper) {
-            this.identifier = identifier;
+            super(identifier);
             mutableTree = MutableDataTree.from(snapshot, applyOper);
             this.store = store;
-            LOG.debug("Write Tx: {} allocated with snapshot {}",identifier,snapshot.getMetadataTree().getSubtreeVersion());
-        }
-
-        @Override
-        public Object getIdentifier() {
-            return identifier;
+            LOG.debug("Write Tx: {} allocated with snapshot {}", identifier, snapshot);
         }
 
         @Override
         public void close() {
+            LOG.debug("Store transaction: {} : Closed", getIdentifier());
             this.mutableTree = null;
             this.store = null;
         }
@@ -219,26 +244,52 @@ public class InMemoryDOMDataStore implements DOMStore, Identifiable<String>, Sch
         @Override
         public void write(final InstanceIdentifier path, final NormalizedNode<?, ?> data) {
             checkNotReady();
-            mutableTree.write(path, data);
+            try {
+                LOG.trace("Tx: {} Write: {}:{}", getIdentifier(), path, data);
+                mutableTree.write(path, data);
+                // FIXME: Add checked exception
+            } catch (Exception e) {
+                LOG.error("Tx: {}, failed to write {}:{} in {}", getIdentifier(), path, data, mutableTree, e);
+            }
+        }
+
+        @Override
+        public void merge(final InstanceIdentifier path, final NormalizedNode<?, ?> data) {
+            checkNotReady();
+            try {
+                LOG.trace("Tx: {} Merge: {}:{}", getIdentifier(), path, data);
+                mutableTree.merge(path, data);
+                // FIXME: Add checked exception
+            } catch (Exception e) {
+                LOG.error("Tx: {}, failed to write {}:{} in {}", getIdentifier(), path, data, mutableTree, e);
+            }
         }
 
         @Override
         public void delete(final InstanceIdentifier path) {
             checkNotReady();
-            mutableTree.delete(path);
+            try {
+                LOG.trace("Tx: {} Delete: {}", getIdentifier(), path);
+                mutableTree.delete(path);
+                // FIXME: Add checked exception
+            } catch (Exception e) {
+                LOG.error("Tx: {}, failed to delete {} in {}", getIdentifier(), path, mutableTree, e);
+            }
         }
 
-        protected boolean isReady() {
+        protected final boolean isReady() {
             return ready;
         }
 
-        protected void checkNotReady() {
-            checkState(!ready, "Transaction is ready. No further modifications allowed.");
+        protected final void checkNotReady() {
+            checkState(!ready, "Transaction %s is ready. No further modifications allowed.", getIdentifier());
         }
 
         @Override
         public synchronized DOMStoreThreePhaseCommitCohort ready() {
+            checkState(!ready, "Transaction %s is already ready.", getIdentifier());
             ready = true;
+
             LOG.debug("Store transaction: {} : Ready", getIdentifier());
             mutableTree.seal();
             return store.submit(this);
@@ -249,58 +300,64 @@ public class InMemoryDOMDataStore implements DOMStore, Identifiable<String>, Sch
         }
 
         @Override
-        public String toString() {
-            return "SnaphostBackedWriteTransaction [id=" + getIdentifier() + ", ready=" + isReady() + "]";
+        protected ToStringHelper addToStringAttributes(final ToStringHelper toStringHelper) {
+            return toStringHelper.add("ready", isReady());
         }
-
     }
 
-    private static class SnapshotBackedReadWriteTransaction extends SnaphostBackedWriteTransaction implements
+    private static class SnapshotBackedReadWriteTransaction extends SnapshotBackedWriteTransaction implements
             DOMStoreReadWriteTransaction {
 
-        protected SnapshotBackedReadWriteTransaction(final Object identifier, final DataAndMetadataSnapshot snapshot,
+        protected SnapshotBackedReadWriteTransaction(final Object identifier, final DataTree.Snapshot snapshot,
                 final InMemoryDOMDataStore store, final ModificationApplyOperation applyOper) {
             super(identifier, snapshot, store, applyOper);
         }
 
         @Override
         public ListenableFuture<Optional<NormalizedNode<?, ?>>> read(final InstanceIdentifier path) {
-            return Futures.immediateFuture(getMutatedView().read(path));
-        }
-
-        @Override
-        public String toString() {
-            return "SnapshotBackedReadWriteTransaction [id=" + getIdentifier() + ", ready=" + isReady() + "]";
+            LOG.trace("Tx: {} Read: {}", getIdentifier(), path);
+            try {
+                return Futures.immediateFuture(getMutatedView().read(path));
+            } catch (Exception e) {
+                LOG.error("Tx: {} Failed Read of {}", getIdentifier(), path, e);
+                throw e;
+            }
         }
-
     }
 
     private class ThreePhaseCommitImpl implements DOMStoreThreePhaseCommitCohort {
 
-        private final SnaphostBackedWriteTransaction transaction;
+        private final SnapshotBackedWriteTransaction transaction;
         private final NodeModification modification;
 
-        private DataAndMetadataSnapshot storeSnapshot;
+        private DataTree.Snapshot storeSnapshot;
         private Optional<StoreMetadataNode> proposedSubtree;
-        private Iterable<ChangeListenerNotifyTask> listenerTasks;
+        private ResolveDataChangeEventsTask listenerResolver;
 
-        public ThreePhaseCommitImpl(final SnaphostBackedWriteTransaction writeTransaction) {
+        public ThreePhaseCommitImpl(final SnapshotBackedWriteTransaction writeTransaction) {
             this.transaction = writeTransaction;
             this.modification = transaction.getMutatedView().getRootModification();
         }
 
         @Override
         public ListenableFuture<Boolean> canCommit() {
-            final DataAndMetadataSnapshot snapshotCapture = snapshot;
+            final DataTree.Snapshot snapshotCapture = dataTree.takeSnapshot();
             final ModificationApplyOperation snapshotOperation = operationTree;
 
             return executor.submit(new Callable<Boolean>() {
 
                 @Override
                 public Boolean call() throws Exception {
-                    boolean applicable = snapshotOperation.isApplicable(modification,
-                            Optional.of(snapshotCapture.getMetadataTree()));
-                    LOG.debug("Store Transcation: {} : canCommit : {}", transaction.getIdentifier(), applicable);
+                    Boolean applicable = false;
+                    try {
+                        snapshotOperation.checkApplicable(PUBLIC_ROOT_PATH, modification,
+                            Optional.of(snapshotCapture.getRootNode()));
+                        applicable = true;
+                    } catch (DataPreconditionFailedException e) {
+                        LOG.warn("Store Tx: {} Data Precondition failed for {}.",transaction.getIdentifier(),e.getPath(),e);
+                        applicable = false;
+                    }
+                    LOG.debug("Store Transaction: {} : canCommit : {}", transaction.getIdentifier(), applicable);
                     return applicable;
                 }
             });
@@ -308,29 +365,25 @@ public class InMemoryDOMDataStore implements DOMStore, Identifiable<String>, Sch
 
         @Override
         public ListenableFuture<Void> preCommit() {
-            storeSnapshot = snapshot;
-            if(modification.getModificationType() == ModificationType.UNMODIFIED) {
+            storeSnapshot = dataTree.takeSnapshot();
+            if (modification.getModificationType() == ModificationType.UNMODIFIED) {
                 return Futures.immediateFuture(null);
             }
             return executor.submit(new Callable<Void>() {
 
-
-
                 @Override
                 public Void call() throws Exception {
-                    StoreMetadataNode metadataTree = storeSnapshot.getMetadataTree();
+                    StoreMetadataNode metadataTree = storeSnapshot.getRootNode();
 
                     proposedSubtree = operationTree.apply(modification, Optional.of(metadataTree),
                             increase(metadataTree.getSubtreeVersion()));
 
-
-                    listenerTasks = DataChangeEventResolver.create() //
+                    listenerResolver = ResolveDataChangeEventsTask.create() //
                             .setRootPath(PUBLIC_ROOT_PATH) //
                             .setBeforeRoot(Optional.of(metadataTree)) //
                             .setAfterRoot(proposedSubtree) //
                             .setModificationRoot(modification) //
-                            .setListenerRoot(listenerTree) //
-                            .resolve();
+                            .setListenerRoot(listenerTree);
 
                     return null;
                 }
@@ -346,20 +399,20 @@ public class InMemoryDOMDataStore implements DOMStore, Identifiable<String>, Sch
 
         @Override
         public ListenableFuture<Void> commit() {
-            if(modification.getModificationType() == ModificationType.UNMODIFIED) {
+            if (modification.getModificationType() == ModificationType.UNMODIFIED) {
                 return Futures.immediateFuture(null);
             }
 
-            checkState(proposedSubtree != null,"Proposed subtree must be computed");
-            checkState(storeSnapshot != null,"Proposed subtree must be computed");
+            checkState(proposedSubtree != null, "Proposed subtree must be computed");
+            checkState(storeSnapshot != null, "Proposed subtree must be computed");
             // return ImmediateFuture<>;
-            InMemoryDOMDataStore.this.commit(storeSnapshot, proposedSubtree.get(),listenerTasks);
+            InMemoryDOMDataStore.this.commit(storeSnapshot, proposedSubtree.get(), listenerResolver);
             return Futures.<Void> immediateFuture(null);
         }
 
     }
 
-    private class AllwaysFailOperation implements ModificationApplyOperation {
+    private static final class AlwaysFailOperation implements ModificationApplyOperation {
 
         @Override
         public Optional<StoreMetadataNode> apply(final NodeModification modification,
@@ -368,7 +421,7 @@ public class InMemoryDOMDataStore implements DOMStore, Identifiable<String>, Sch
         }
 
         @Override
-        public boolean isApplicable(final NodeModification modification, final Optional<StoreMetadataNode> storeMetadata) {
+        public void checkApplicable(final InstanceIdentifier path,final NodeModification modification, final Optional<StoreMetadataNode> storeMetadata) {
             throw new IllegalStateException("Schema Context is not available.");
         }