Added distributed transaction support through a two phase commit protocol
Change-Id: I85d64234a24823fee8b3c2ea830abbb6867dad38
diff --git a/core/api/src/main/java/org/onosproject/store/service/DatabaseUpdate.java b/core/api/src/main/java/org/onosproject/store/service/DatabaseUpdate.java
new file mode 100644
index 0000000..fd4373e
--- /dev/null
+++ b/core/api/src/main/java/org/onosproject/store/service/DatabaseUpdate.java
@@ -0,0 +1,220 @@
+/*
+ * 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.service;
+
+import static com.google.common.base.Preconditions.checkArgument;
+import static com.google.common.base.Preconditions.checkNotNull;
+import static com.google.common.base.Preconditions.checkState;
+
+import com.google.common.base.MoreObjects;
+
+/**
+ * Database update operation.
+ *
+ */
+public final class DatabaseUpdate {
+
+ /**
+ * Type of database update operation.
+ */
+ public static enum Type {
+ /**
+ * Insert/Update entry without any checks.
+ */
+ PUT,
+ /**
+ * Insert an entry iff there is no existing entry for that key.
+ */
+ PUT_IF_ABSENT,
+
+ /**
+ * Update entry if the current version matches specified version.
+ */
+ PUT_IF_VERSION_MATCH,
+
+ /**
+ * Update entry if the current value matches specified value.
+ */
+ PUT_IF_VALUE_MATCH,
+
+ /**
+ * Remove entry without any checks.
+ */
+ REMOVE,
+
+ /**
+ * Remove entry if the current version matches specified version.
+ */
+ REMOVE_IF_VERSION_MATCH,
+
+ /**
+ * Remove entry if the current value matches specified value.
+ */
+ REMOVE_IF_VALUE_MATCH,
+ }
+
+ private Type type;
+ private String tableName;
+ private String key;
+ private byte[] value;
+ private byte[] currentValue;
+ private long currentVersion = -1;
+
+ /**
+ * Returns the type of update operation.
+ * @return type of update.
+ */
+ public Type type() {
+ return type;
+ }
+
+ /**
+ * Returns the tableName being updated.
+ * @return table name.
+ */
+ public String tableName() {
+ return tableName;
+ }
+
+ /**
+ * Returns the item key being updated.
+ * @return item key
+ */
+ public String key() {
+ return key;
+ }
+
+ /**
+ * Returns the new value.
+ * @return item's target value.
+ */
+ public byte[] value() {
+ return value;
+ }
+
+ /**
+ * Returns the expected current value in the database value for the key.
+ * @return current value in database.
+ */
+ public byte[] currentValue() {
+ return currentValue;
+ }
+
+ /**
+ * Returns the expected current version in the database for the key.
+ * @return expected version.
+ */
+ public long currentVersion() {
+ return currentVersion;
+ }
+
+ @Override
+ public String toString() {
+ return MoreObjects.toStringHelper(this)
+ .add("type", type)
+ .add("tableName", tableName)
+ .add("key", key)
+ .add("value", value)
+ .add("currentValue", currentValue)
+ .add("currentVersion", currentVersion)
+ .toString();
+ }
+
+ /**
+ * Creates a new builder instance.
+ *
+ * @return builder.
+ */
+ public static Builder newBuilder() {
+ return new Builder();
+ }
+
+ /**
+ * DatabaseUpdate builder.
+ *
+ */
+ public static final class Builder {
+
+ private DatabaseUpdate update = new DatabaseUpdate();
+
+ public DatabaseUpdate build() {
+ validateInputs();
+ return update;
+ }
+
+ public Builder withType(Type type) {
+ update.type = checkNotNull(type, "type cannot be null");
+ return this;
+ }
+
+ public Builder withTableName(String tableName) {
+ update.tableName = checkNotNull(tableName, "tableName cannot be null");
+ return this;
+ }
+
+ public Builder withKey(String key) {
+ update.key = checkNotNull(key, "key cannot be null");
+ return this;
+ }
+
+ public Builder withCurrentValue(byte[] value) {
+ update.currentValue = checkNotNull(value, "currentValue cannot be null");
+ return this;
+ }
+
+ public Builder withValue(byte[] value) {
+ update.value = checkNotNull(value, "value cannot be null");
+ return this;
+ }
+
+ public Builder withCurrentVersion(long version) {
+ checkArgument(version >= 0, "version cannot be negative");
+ update.currentVersion = version;
+ return this;
+ }
+
+ private void validateInputs() {
+ checkNotNull(update.type, "type must be specified");
+ checkNotNull(update.tableName, "table name must be specified");
+ checkNotNull(update.key, "key must be specified");
+ switch (update.type) {
+ case PUT:
+ case PUT_IF_ABSENT:
+ checkNotNull(update.value, "value must be specified.");
+ break;
+ case PUT_IF_VERSION_MATCH:
+ checkNotNull(update.value, "value must be specified.");
+ checkState(update.currentVersion >= 0, "current version must be specified");
+ break;
+ case PUT_IF_VALUE_MATCH:
+ checkNotNull(update.value, "value must be specified.");
+ checkNotNull(update.currentValue, "currentValue must be specified.");
+ break;
+ case REMOVE:
+ break;
+ case REMOVE_IF_VERSION_MATCH:
+ checkState(update.currentVersion >= 0, "current version must be specified");
+ break;
+ case REMOVE_IF_VALUE_MATCH:
+ checkNotNull(update.currentValue, "currentValue must be specified.");
+ break;
+ default:
+ throw new IllegalStateException("Unknown operation type");
+ }
+ }
+ }
+}