WIP: Revamped transaction API. Introduces a transaction context for running blocks of code that can be committed
atomically.
Change-Id: I6ba21050a2644a42f3c073fa04ff776ef2c5ff4c
diff --git a/core/store/dist/src/main/java/org/onosproject/store/consistent/impl/DefaultTransactionalMap.java b/core/store/dist/src/main/java/org/onosproject/store/consistent/impl/DefaultTransactionalMap.java
new file mode 100644
index 0000000..c98c336
--- /dev/null
+++ b/core/store/dist/src/main/java/org/onosproject/store/consistent/impl/DefaultTransactionalMap.java
@@ -0,0 +1,243 @@
+/*
+ * Copyright 2015 Open Networking Laboratory
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.onosproject.store.consistent.impl;
+
+import java.util.Collection;
+import java.util.List;
+import java.util.Map;
+import java.util.Map.Entry;
+import java.util.stream.Collectors;
+import java.util.Set;
+
+import org.onlab.util.HexString;
+import org.onosproject.store.service.ConsistentMap;
+import org.onosproject.store.service.Serializer;
+import org.onosproject.store.service.TransactionContext;
+import org.onosproject.store.service.TransactionalMap;
+import org.onosproject.store.service.UpdateOperation;
+import org.onosproject.store.service.Versioned;
+
+import static com.google.common.base.Preconditions.*;
+
+import com.google.common.collect.Lists;
+import com.google.common.collect.Maps;
+import com.google.common.collect.Sets;
+
+/**
+ * Default Transactional Map implementation that provides a repeatable reads
+ * transaction isolation level.
+ *
+ * @param <K> key type
+ * @param <V> value type.
+ */
+public class DefaultTransactionalMap<K, V> implements TransactionalMap<K, V> {
+
+ private final TransactionContext txContext;
+ private static final String TX_CLOSED_ERROR = "Transaction is closed";
+ private final ConsistentMap<K, V> backingMap;
+ private final String name;
+ private final Serializer serializer;
+ private final Map<K, Versioned<V>> readCache = Maps.newConcurrentMap();
+ private final Map<K, V> writeCache = Maps.newConcurrentMap();
+ private final Set<K> deleteSet = Sets.newConcurrentHashSet();
+
+ public DefaultTransactionalMap(
+ String name,
+ ConsistentMap<K, V> backingMap,
+ TransactionContext txContext,
+ Serializer serializer) {
+ this.name = name;
+ this.backingMap = backingMap;
+ this.txContext = txContext;
+ this.serializer = serializer;
+ }
+
+ @Override
+ public V get(K key) {
+ checkState(txContext.isOpen(), TX_CLOSED_ERROR);
+ if (deleteSet.contains(key)) {
+ return null;
+ } else if (writeCache.containsKey(key)) {
+ return writeCache.get(key);
+ } else {
+ if (!readCache.containsKey(key)) {
+ readCache.put(key, backingMap.get(key));
+ }
+ Versioned<V> v = readCache.get(key);
+ return v != null ? v.value() : null;
+ }
+ }
+
+ @Override
+ public V put(K key, V value) {
+ checkState(txContext.isOpen(), TX_CLOSED_ERROR);
+ Versioned<V> original = readCache.get(key);
+ V recentUpdate = writeCache.put(key, value);
+ deleteSet.remove(key);
+ return recentUpdate == null ? (original != null ? original.value() : null) : recentUpdate;
+ }
+
+ @Override
+ public V remove(K key) {
+ checkState(txContext.isOpen(), TX_CLOSED_ERROR);
+ Versioned<V> original = readCache.get(key);
+ V recentUpdate = writeCache.remove(key);
+ deleteSet.add(key);
+ return recentUpdate == null ? (original != null ? original.value() : null) : recentUpdate;
+ }
+
+ @Override
+ public boolean remove(K key, V value) {
+ V currentValue = get(key);
+ if (value.equals(currentValue)) {
+ remove(key);
+ return true;
+ }
+ return false;
+ }
+
+ @Override
+ public boolean replace(K key, V oldValue, V newValue) {
+ V currentValue = get(key);
+ if (oldValue.equals(currentValue)) {
+ put(key, newValue);
+ return true;
+ }
+ return false;
+ }
+
+ @Override
+ public int size() {
+ // TODO
+ throw new UnsupportedOperationException();
+ }
+
+ @Override
+ public boolean isEmpty() {
+ return size() == 0;
+ }
+
+ @Override
+ public boolean containsKey(K key) {
+ return get(key) != null;
+ }
+
+ @Override
+ public boolean containsValue(V value) {
+ // TODO
+ throw new UnsupportedOperationException();
+ }
+
+ @Override
+ public void clear() {
+ // TODO
+ throw new UnsupportedOperationException();
+ }
+
+ @Override
+ public Set<K> keySet() {
+ // TODO
+ throw new UnsupportedOperationException();
+ }
+
+ @Override
+ public Collection<V> values() {
+ // TODO
+ throw new UnsupportedOperationException();
+ }
+
+ @Override
+ public Set<Entry<K, V>> entrySet() {
+ // TODO
+ throw new UnsupportedOperationException();
+ }
+
+ @Override
+ public V putIfAbsent(K key, V value) {
+ V currentValue = get(key);
+ if (currentValue == null) {
+ put(key, value);
+ return null;
+ }
+ return currentValue;
+ }
+
+ protected List<UpdateOperation<String, byte[]>> prepareDatabaseUpdates() {
+ List<UpdateOperation<K, V>> updates = Lists.newLinkedList();
+ deleteSet.forEach(key -> {
+ Versioned<V> original = readCache.get(key);
+ if (original != null) {
+ updates.add(UpdateOperation.<K, V>newBuilder()
+ .withTableName(name)
+ .withType(UpdateOperation.Type.REMOVE_IF_VERSION_MATCH)
+ .withKey(key)
+ .withCurrentVersion(original.version())
+ .build());
+ }
+ });
+ writeCache.forEach((key, value) -> {
+ Versioned<V> original = readCache.get(key);
+ if (original == null) {
+ updates.add(UpdateOperation.<K, V>newBuilder()
+ .withTableName(name)
+ .withType(UpdateOperation.Type.PUT_IF_ABSENT)
+ .withKey(key)
+ .withValue(value)
+ .build());
+ } else {
+ updates.add(UpdateOperation.<K, V>newBuilder()
+ .withTableName(name)
+ .withType(UpdateOperation.Type.PUT_IF_VERSION_MATCH)
+ .withKey(key)
+ .withCurrentVersion(original.version())
+ .withValue(value)
+ .build());
+ }
+ });
+ return updates.stream().map(this::toRawUpdateOperation).collect(Collectors.toList());
+ }
+
+ private UpdateOperation<String, byte[]> toRawUpdateOperation(UpdateOperation<K, V> update) {
+
+ UpdateOperation.Builder<String, byte[]> rawUpdate = UpdateOperation.<String, byte[]>newBuilder();
+
+ rawUpdate = rawUpdate.withKey(HexString.toHexString(serializer.encode(update.key())))
+ .withCurrentVersion(update.currentVersion())
+ .withType(update.type());
+
+ rawUpdate = rawUpdate.withTableName(update.tableName());
+
+ if (update.value() != null) {
+ rawUpdate = rawUpdate.withValue(serializer.encode(update.value()));
+ }
+
+ if (update.currentValue() != null) {
+ rawUpdate = rawUpdate.withCurrentValue(serializer.encode(update.currentValue()));
+ }
+
+ return rawUpdate.build();
+ }
+
+ /**
+ * Discards all changes made to this transactional map.
+ */
+ protected void rollback() {
+ readCache.clear();
+ writeCache.clear();
+ deleteSet.clear();
+ }
+}
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