1 files changed, 50 insertions, 0 deletions
diff --git a/infra/translate-api/src/main/java/io/fd/honeycomb/translate/write/WriteContext.java b/infra/translate-api/src/main/java/io/fd/honeycomb/translate/write/WriteContext.java
new file mode 100644
index 000000000..17aea8d8a
--- /dev/null
+++ b/infra/translate-api/src/main/java/io/fd/honeycomb/translate/write/WriteContext.java
@@ -0,0 +1,50 @@
+/*
+ * Copyright (c) 2016 Cisco and/or its affiliates.
+ *
+ * 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 io.fd.honeycomb.translate.write;
+
+import com.google.common.annotations.Beta;
+import com.google.common.base.Optional;
+import io.fd.honeycomb.translate.ModificationContext;
+import javax.annotation.Nonnull;
+import org.opendaylight.yangtools.yang.binding.DataObject;
+import org.opendaylight.yangtools.yang.binding.InstanceIdentifier;
+
+/**
+ * Context providing information about current state of DataTree to writers
+ */
+@Beta
+public interface WriteContext extends ModificationContext {
+
+    /**
+     * Read any config data object before current modification was applied
+     *
+     * @param currentId Id of an object to read
+     *
+     * @return Data before the modification was applied
+     */
+    <T extends DataObject> Optional<T> readBefore(@Nonnull final InstanceIdentifier<T> currentId);
+
+    /**
+     * Read any config data object from current modification
+     *
+     * @param currentId Id of an object to read
+     *
+     * @return Data from the modification
+     */
+    <T extends DataObject> Optional<T> readAfter(@Nonnull final InstanceIdentifier<T> currentId);
+
+}