Bug 1073: Implemented Transaction chain on InMemoryDOMDataStore level. 07/7407/4
authorTony Tkacik <ttkacik@cisco.com>
Mon, 26 May 2014 20:38:26 +0000 (22:38 +0200)
committerTony Tkacik <ttkacik@cisco.com>
Mon, 2 Jun 2014 15:58:43 +0000 (17:58 +0200)
- Extracted Transactions implementations from InMemoryDOMDataStore
to separate classes
- implemented initial DOMStoreTransactionChain inside InMemoryDOMDataStore

Change-Id: I3033f26d2a4c141a32aaac6bc3a20e8c7ba1c28c
Signed-off-by: Tony Tkacik <ttkacik@cisco.com>
opendaylight/md-sal/sal-dom-broker/src/main/java/org/opendaylight/controller/md/sal/dom/store/impl/AbstractDOMStoreTransaction.java [new file with mode: 0644]
opendaylight/md-sal/sal-dom-broker/src/main/java/org/opendaylight/controller/md/sal/dom/store/impl/InMemoryDOMDataStore.java
opendaylight/md-sal/sal-dom-broker/src/main/java/org/opendaylight/controller/md/sal/dom/store/impl/SnapshotBackedReadTransaction.java [new file with mode: 0644]
opendaylight/md-sal/sal-dom-broker/src/main/java/org/opendaylight/controller/md/sal/dom/store/impl/SnapshotBackedReadWriteTransaction.java [new file with mode: 0644]
opendaylight/md-sal/sal-dom-broker/src/main/java/org/opendaylight/controller/md/sal/dom/store/impl/SnapshotBackedWriteTransaction.java [new file with mode: 0644]

diff --git a/opendaylight/md-sal/sal-dom-broker/src/main/java/org/opendaylight/controller/md/sal/dom/store/impl/AbstractDOMStoreTransaction.java b/opendaylight/md-sal/sal-dom-broker/src/main/java/org/opendaylight/controller/md/sal/dom/store/impl/AbstractDOMStoreTransaction.java
new file mode 100644 (file)
index 0000000..8a190c1
--- /dev/null
@@ -0,0 +1,51 @@
+/*
+ * Copyright (c) 2014 Cisco Systems, Inc. and others.  All rights reserved.
+ *
+ * This program and the accompanying materials are made available under the
+ * terms of the Eclipse Public License v1.0 which accompanies this distribution,
+ * and is available at http://www.eclipse.org/legal/epl-v10.html
+ */
+package org.opendaylight.controller.md.sal.dom.store.impl;
+
+import org.opendaylight.controller.sal.core.spi.data.DOMStoreTransaction;
+
+import com.google.common.base.Objects;
+import com.google.common.base.Objects.ToStringHelper;
+import com.google.common.base.Preconditions;
+
+/**
+ * Abstract DOM Store Transaction
+ *
+ * Convenience super implementation of DOM Store transaction which provides
+ * common implementation of {@link #toString()} and {@link #getIdentifier()}.
+ *
+ *
+ */
+abstract class AbstractDOMStoreTransaction implements DOMStoreTransaction {
+    private final Object identifier;
+
+    protected AbstractDOMStoreTransaction(final Object identifier) {
+        this.identifier = Preconditions.checkNotNull(identifier,"Identifier must not be null.");
+    }
+
+    @Override
+    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);
+    }
+}
\ No newline at end of file
index 87c68596efa60a668a7afe005d482eefac1f6ad7..2495146aa64d290460ab83c1c681a781e760f720 100644 (file)
@@ -7,7 +7,6 @@
  */
 package org.opendaylight.controller.md.sal.dom.store.impl;
 
-import static com.google.common.base.Preconditions.checkNotNull;
 import static com.google.common.base.Preconditions.checkState;
 
 import java.util.Collections;
@@ -16,6 +15,7 @@ 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.SnapshotBackedWriteTransaction.TransactionReadyPrototype;
 import org.opendaylight.controller.md.sal.dom.store.impl.tree.DataPreconditionFailedException;
 import org.opendaylight.controller.md.sal.dom.store.impl.tree.DataTree;
 import org.opendaylight.controller.md.sal.dom.store.impl.tree.DataTreeCandidate;
@@ -27,7 +27,6 @@ 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.DOMStoreTransactionChain;
 import org.opendaylight.controller.sal.core.spi.data.DOMStoreWriteTransaction;
 import org.opendaylight.yangtools.concepts.AbstractListenerRegistration;
@@ -40,15 +39,22 @@ 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.util.concurrent.Futures;
 import com.google.common.util.concurrent.ListenableFuture;
 import com.google.common.util.concurrent.ListeningExecutorService;
 
-public class InMemoryDOMDataStore implements DOMStore, Identifiable<String>, SchemaContextListener {
+/**
+ * In-memory DOM Data Store
+ *
+ * Implementation of {@link DOMStore} which uses {@link DataTree}
+ * and other classes such as {@link SnapshotBackedWriteTransaction}.
+ * {@link SnapshotBackedReadTransaction} and {@link ResolveDataChangeEventsTask}
+ * to implement {@link DOMStore} contract.
+ *
+ */
+public class InMemoryDOMDataStore implements DOMStore, Identifiable<String>, SchemaContextListener, TransactionReadyPrototype {
     private static final Logger LOG = LoggerFactory.getLogger(InMemoryDOMDataStore.class);
     private final DataTree dataTree = InMemoryDataTreeFactory.getInstance().create();
     private final ListenerTree listenerTree = ListenerTree.create();
@@ -83,7 +89,7 @@ public class InMemoryDOMDataStore implements DOMStore, Identifiable<String>, Sch
 
     @Override
     public DOMStoreTransactionChain createTransactionChain() {
-        throw new UnsupportedOperationException("Not implemented yet.");
+        return new DOMStoreTransactionChainImpl();
     }
 
     @Override
@@ -130,7 +136,8 @@ public class InMemoryDOMDataStore implements DOMStore, Identifiable<String>, Sch
         };
     }
 
-    private synchronized DOMStoreThreePhaseCommitCohort submit(final SnapshotBackedWriteTransaction writeTx) {
+    @Override
+    public synchronized DOMStoreThreePhaseCommitCohort ready(final SnapshotBackedWriteTransaction writeTx) {
         LOG.debug("Tx: {} is submitted. Modifications: {}", writeTx.getIdentifier(), writeTx.getMutatedView());
         return new ThreePhaseCommitImpl(writeTx);
     }
@@ -139,162 +146,61 @@ public class InMemoryDOMDataStore implements DOMStore, Identifiable<String>, Sch
         return name + "-" + txCounter.getAndIncrement();
     }
 
-    private static abstract class AbstractDOMStoreTransaction implements DOMStoreTransaction {
-        private final Object identifier;
-
-        protected AbstractDOMStoreTransaction(final Object identifier) {
-            this.identifier = identifier;
-        }
-
-        @Override
-        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 DataTreeSnapshot stableSnapshot;
+    private class DOMStoreTransactionChainImpl implements DOMStoreTransactionChain, TransactionReadyPrototype {
 
-        public SnapshotBackedReadTransaction(final Object identifier, final DataTreeSnapshot 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;
-        }
+        private SnapshotBackedWriteTransaction previousOutstandingTx;
 
         @Override
-        public ListenableFuture<Optional<NormalizedNode<?, ?>>> read(final InstanceIdentifier path) {
-            checkNotNull(path, "Path must not be null.");
-            checkState(stableSnapshot != null, "Transaction is closed");
-            return Futures.immediateFuture(stableSnapshot.readNode(path));
-        }
-    }
-
-    private static class SnapshotBackedWriteTransaction extends AbstractDOMStoreTransaction implements
-    DOMStoreWriteTransaction {
-        private DataTreeModification mutableTree;
-        private InMemoryDOMDataStore store;
-        private boolean ready = false;
-
-        public SnapshotBackedWriteTransaction(final Object identifier, final DataTreeSnapshot snapshot,
-                final InMemoryDOMDataStore store) {
-            super(identifier);
-            mutableTree = snapshot.newModification();
-            this.store = store;
-            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;
-        }
-
-        @Override
-        public void write(final InstanceIdentifier path, final NormalizedNode<?, ?> data) {
-            checkNotReady();
-            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);
+        public synchronized DOMStoreReadTransaction newReadOnlyTransaction() {
+            final DataTreeSnapshot snapshot;
+            if(previousOutstandingTx != null) {
+                checkState(previousOutstandingTx.isReady(), "Previous transaction in chain must be ready.");
+                snapshot = previousOutstandingTx.getMutatedView();
+            } else {
+                snapshot = dataTree.takeSnapshot();
             }
+            return new SnapshotBackedReadTransaction(nextIdentifier(), snapshot);
         }
 
         @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);
+        public synchronized DOMStoreReadWriteTransaction newReadWriteTransaction() {
+            final DataTreeSnapshot snapshot;
+            if(previousOutstandingTx != null) {
+                checkState(previousOutstandingTx.isReady(), "Previous transaction in chain must be ready.");
+                snapshot = previousOutstandingTx.getMutatedView();
+            } else {
+                snapshot = dataTree.takeSnapshot().newModification();
             }
+            SnapshotBackedReadWriteTransaction ret = new SnapshotBackedReadWriteTransaction(nextIdentifier(), snapshot,this);
+            return ret;
         }
 
         @Override
-        public void delete(final InstanceIdentifier path) {
-            checkNotReady();
-            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);
+        public synchronized DOMStoreWriteTransaction newWriteOnlyTransaction() {
+            final DataTreeSnapshot snapshot;
+            if(previousOutstandingTx != null) {
+                checkState(previousOutstandingTx.isReady(), "Previous transaction in chain must be ready.");
+                snapshot = previousOutstandingTx.getMutatedView();
+            } else {
+                snapshot = dataTree.takeSnapshot().newModification();
             }
-        }
-
-        protected final boolean isReady() {
-            return ready;
-        }
-
-        protected final void checkNotReady() {
-            checkState(!ready, "Transaction %s is ready. No further modifications allowed.", getIdentifier());
+            SnapshotBackedWriteTransaction ret =new SnapshotBackedWriteTransaction(nextIdentifier(), snapshot,this);
+            return ret;
         }
 
         @Override
-        public synchronized DOMStoreThreePhaseCommitCohort ready() {
-            checkState(!ready, "Transaction %s is already ready.", getIdentifier());
-            ready = true;
-
-            LOG.debug("Store transaction: {} : Ready", getIdentifier());
-            mutableTree.ready();
-            return store.submit(this);
-        }
-
-        protected DataTreeModification getMutatedView() {
-            return mutableTree;
+        public DOMStoreThreePhaseCommitCohort ready(final SnapshotBackedWriteTransaction tx) {
+            DOMStoreThreePhaseCommitCohort storeCohort = InMemoryDOMDataStore.this.ready(tx);
+            // FIXME: We probably want to add Transaction Chain cohort
+            return storeCohort;
         }
 
         @Override
-        protected ToStringHelper addToStringAttributes(final ToStringHelper toStringHelper) {
-            return toStringHelper.add("ready", isReady());
-        }
-    }
-
-    private static class SnapshotBackedReadWriteTransaction extends SnapshotBackedWriteTransaction implements
-    DOMStoreReadWriteTransaction {
+        public void close() {
+            // TODO Auto-generated method stub
 
-        protected SnapshotBackedReadWriteTransaction(final Object identifier, final DataTreeSnapshot snapshot,
-                final InMemoryDOMDataStore store) {
-            super(identifier, snapshot, store);
         }
 
-        @Override
-        public ListenableFuture<Optional<NormalizedNode<?, ?>>> read(final InstanceIdentifier path) {
-            LOG.trace("Tx: {} Read: {}", getIdentifier(), path);
-            try {
-                return Futures.immediateFuture(getMutatedView().readNode(path));
-            } catch (Exception e) {
-                LOG.error("Tx: {} Failed Read of {}", getIdentifier(), path, e);
-                throw e;
-            }
-        }
     }
 
     private class ThreePhaseCommitImpl implements DOMStoreThreePhaseCommitCohort {
diff --git a/opendaylight/md-sal/sal-dom-broker/src/main/java/org/opendaylight/controller/md/sal/dom/store/impl/SnapshotBackedReadTransaction.java b/opendaylight/md-sal/sal-dom-broker/src/main/java/org/opendaylight/controller/md/sal/dom/store/impl/SnapshotBackedReadTransaction.java
new file mode 100644 (file)
index 0000000..315293f
--- /dev/null
@@ -0,0 +1,56 @@
+/*
+ * Copyright (c) 2014 Cisco Systems, Inc. and others.  All rights reserved.
+ *
+ * This program and the accompanying materials are made available under the
+ * terms of the Eclipse Public License v1.0 which accompanies this distribution,
+ * and is available at http://www.eclipse.org/legal/epl-v10.html
+ */
+package org.opendaylight.controller.md.sal.dom.store.impl;
+
+import static com.google.common.base.Preconditions.checkNotNull;
+import static com.google.common.base.Preconditions.checkState;
+
+import org.opendaylight.controller.md.sal.dom.store.impl.tree.DataTreeSnapshot;
+import org.opendaylight.controller.sal.core.spi.data.DOMStoreReadTransaction;
+import org.opendaylight.yangtools.yang.data.api.InstanceIdentifier;
+import org.opendaylight.yangtools.yang.data.api.schema.NormalizedNode;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import com.google.common.base.Optional;
+import com.google.common.base.Preconditions;
+import com.google.common.util.concurrent.Futures;
+import com.google.common.util.concurrent.ListenableFuture;
+
+/**
+ *
+ * Implementation of read-only transaction backed by {@link DataTreeSnapshot}
+ *
+ * Implementation of read-only transaction backed by {@link DataTreeSnapshot}
+ * which delegates most of its calls to similar methods provided by underlying snapshot.
+ *
+ */
+final class SnapshotBackedReadTransaction extends AbstractDOMStoreTransaction implements
+DOMStoreReadTransaction {
+    private static final Logger LOG = LoggerFactory.getLogger(SnapshotBackedReadTransaction.class);
+    private DataTreeSnapshot stableSnapshot;
+
+    public SnapshotBackedReadTransaction(final Object identifier, final DataTreeSnapshot 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;
+    }
+
+    @Override
+    public ListenableFuture<Optional<NormalizedNode<?, ?>>> read(final InstanceIdentifier path) {
+        checkNotNull(path, "Path must not be null.");
+        checkState(stableSnapshot != null, "Transaction is closed");
+        return Futures.immediateFuture(stableSnapshot.readNode(path));
+    }
+}
\ No newline at end of file
diff --git a/opendaylight/md-sal/sal-dom-broker/src/main/java/org/opendaylight/controller/md/sal/dom/store/impl/SnapshotBackedReadWriteTransaction.java b/opendaylight/md-sal/sal-dom-broker/src/main/java/org/opendaylight/controller/md/sal/dom/store/impl/SnapshotBackedReadWriteTransaction.java
new file mode 100644 (file)
index 0000000..4abc802
--- /dev/null
@@ -0,0 +1,53 @@
+/*
+ * Copyright (c) 2014 Cisco Systems, Inc. and others.  All rights reserved.
+ *
+ * This program and the accompanying materials are made available under the
+ * terms of the Eclipse Public License v1.0 which accompanies this distribution,
+ * and is available at http://www.eclipse.org/legal/epl-v10.html
+ */
+package org.opendaylight.controller.md.sal.dom.store.impl;
+
+import org.opendaylight.controller.md.sal.dom.store.impl.tree.DataTreeSnapshot;
+import org.opendaylight.controller.sal.core.spi.data.DOMStoreReadWriteTransaction;
+import org.opendaylight.yangtools.yang.data.api.InstanceIdentifier;
+import org.opendaylight.yangtools.yang.data.api.schema.NormalizedNode;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import com.google.common.base.Optional;
+import com.google.common.util.concurrent.Futures;
+import com.google.common.util.concurrent.ListenableFuture;
+
+/**
+ * Implementation of Read-Write transaction which is backed by {@link DataTreeSnapshot}
+ * and executed according to {@link TransactionReadyPrototype}.
+ *
+ */
+class SnapshotBackedReadWriteTransaction extends SnapshotBackedWriteTransaction implements
+DOMStoreReadWriteTransaction {
+
+    private static final Logger LOG = LoggerFactory.getLogger(SnapshotBackedReadWriteTransaction.class);
+
+    /**
+     * Creates new read-write transaction.
+     *
+     * @param identifier transaction Identifier
+     * @param snapshot Snapshot which will be modified.
+     * @param readyImpl Implementation of ready method.
+     */
+    protected SnapshotBackedReadWriteTransaction(final Object identifier, final DataTreeSnapshot snapshot,
+            final TransactionReadyPrototype store) {
+        super(identifier, snapshot, store);
+    }
+
+    @Override
+    public ListenableFuture<Optional<NormalizedNode<?, ?>>> read(final InstanceIdentifier path) {
+        LOG.debug("Tx: {} Read: {}", getIdentifier(), path);
+        try {
+            return Futures.immediateFuture(getMutatedView().readNode(path));
+        } catch (Exception e) {
+            LOG.error("Tx: {} Failed Read of {}", getIdentifier(), path, e);
+            throw e;
+        }
+    }
+}
\ No newline at end of file
diff --git a/opendaylight/md-sal/sal-dom-broker/src/main/java/org/opendaylight/controller/md/sal/dom/store/impl/SnapshotBackedWriteTransaction.java b/opendaylight/md-sal/sal-dom-broker/src/main/java/org/opendaylight/controller/md/sal/dom/store/impl/SnapshotBackedWriteTransaction.java
new file mode 100644 (file)
index 0000000..717fb11
--- /dev/null
@@ -0,0 +1,162 @@
+/*
+ * Copyright (c) 2014 Cisco Systems, Inc. and others.  All rights reserved.
+ *
+ * This program and the accompanying materials are made available under the
+ * terms of the Eclipse Public License v1.0 which accompanies this distribution,
+ * and is available at http://www.eclipse.org/legal/epl-v10.html
+ */
+package org.opendaylight.controller.md.sal.dom.store.impl;
+
+import static com.google.common.base.Preconditions.checkState;
+
+import org.opendaylight.controller.md.sal.dom.store.impl.tree.DataTreeModification;
+import org.opendaylight.controller.md.sal.dom.store.impl.tree.DataTreeSnapshot;
+import org.opendaylight.controller.sal.core.spi.data.DOMStoreThreePhaseCommitCohort;
+import org.opendaylight.controller.sal.core.spi.data.DOMStoreWriteTransaction;
+import org.opendaylight.yangtools.yang.data.api.InstanceIdentifier;
+import org.opendaylight.yangtools.yang.data.api.schema.NormalizedNode;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import com.google.common.base.Objects.ToStringHelper;
+import com.google.common.base.Preconditions;
+import com.google.common.base.Throwables;
+
+/**
+ * Implementation of Write transaction which is backed by
+ * {@link DataTreeSnapshot} and executed according to
+ * {@link TransactionReadyPrototype}.
+ * 
+ */
+class SnapshotBackedWriteTransaction extends AbstractDOMStoreTransaction implements DOMStoreWriteTransaction {
+
+    private static final Logger LOG = LoggerFactory.getLogger(SnapshotBackedWriteTransaction.class);
+    private DataTreeModification mutableTree;
+    private boolean ready = false;
+    private TransactionReadyPrototype readyImpl;
+
+    /**
+     * Creates new write-only transaction.
+     * 
+     * @param identifier
+     *            transaction Identifier
+     * @param snapshot
+     *            Snapshot which will be modified.
+     * @param readyImpl
+     *            Implementation of ready method.
+     */
+    public SnapshotBackedWriteTransaction(final Object identifier, final DataTreeSnapshot snapshot,
+            final TransactionReadyPrototype readyImpl) {
+        super(identifier);
+        mutableTree = snapshot.newModification();
+        this.readyImpl = Preconditions.checkNotNull(readyImpl, "readyImpl must not be null.");
+        LOG.debug("Write Tx: {} allocated with snapshot {}", identifier, snapshot);
+    }
+
+    @Override
+    public void close() {
+        LOG.debug("Store transaction: {} : Closed", getIdentifier());
+        this.mutableTree = null;
+        this.readyImpl = null;
+    }
+
+    @Override
+    public void write(final InstanceIdentifier path, final NormalizedNode<?, ?> data) {
+        checkNotReady();
+        try {
+            LOG.debug("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);
+            // Rethrow original ones if they are subclasses of RuntimeException
+            // or Error
+            Throwables.propagateIfPossible(e);
+            // FIXME: Introduce proper checked exception
+            throw new IllegalArgumentException("Illegal input data.", e);
+        }
+    }
+
+    @Override
+    public void merge(final InstanceIdentifier path, final NormalizedNode<?, ?> data) {
+        checkNotReady();
+        try {
+            LOG.debug("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);
+            // Rethrow original ones if they are subclasses of RuntimeException
+            // or Error
+            Throwables.propagateIfPossible(e);
+            // FIXME: Introduce proper checked exception
+            throw new IllegalArgumentException("Illegal input data.", e);
+        }
+    }
+
+    @Override
+    public void delete(final InstanceIdentifier path) {
+        checkNotReady();
+        try {
+            LOG.debug("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);
+            // Rethrow original ones if they are subclasses of RuntimeException
+            // or Error
+            Throwables.propagateIfPossible(e);
+            // FIXME: Introduce proper checked exception
+            throw new IllegalArgumentException("Illegal path to delete.", e);
+        }
+    }
+
+    protected final boolean isReady() {
+        return ready;
+    }
+
+    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.ready();
+        return readyImpl.ready(this);
+    }
+
+    protected DataTreeModification getMutatedView() {
+        return mutableTree;
+    }
+
+    @Override
+    protected ToStringHelper addToStringAttributes(final ToStringHelper toStringHelper) {
+        return toStringHelper.add("ready", isReady());
+    }
+
+    /**
+     * Prototype implementation of
+     * {@link #ready(SnapshotBackedWriteTransaction)}
+     * 
+     * This class is intended to be implemented by Transaction factories
+     * responsible for allocation of {@link SnapshotBackedWriteTransaction} and
+     * providing underlying logic for applying implementation.
+     * 
+     */
+    public static interface TransactionReadyPrototype {
+
+        /**
+         * Returns a commit coordinator associated with supplied transactions.
+         * 
+         * This call must not fail.
+         * 
+         * @param tx
+         *            Transaction on which ready was invoked.
+         * @return DOMStoreThreePhaseCommitCohort associated with transaction
+         */
+        DOMStoreThreePhaseCommitCohort ready(SnapshotBackedWriteTransaction tx);
+    }
+}
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