Introduce RealtimeTableView and Implement HoodieRealtimeTableCompactor (#73)

hoodie-common/src/main/java/com/uber/hoodie/common/model/HoodieAvroPayload.java

@@ -0,0 +1,52 @@
+/*
+ *  Copyright (c) 2016 Uber Technologies, Inc. (hoodie-dev-group@uber.com)
+ *
+ *  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 com.uber.hoodie.common.model;
+
+import com.uber.hoodie.common.util.HoodieAvroUtils;
+import org.apache.avro.Schema;
+import org.apache.avro.generic.GenericRecord;
+import org.apache.avro.generic.IndexedRecord;
+
+import java.io.IOException;
+
+/**
+ * This is a payload to wrap a existing Hoodie Avro Record.
+ * Useful to create a HoodieRecord over existing GenericRecords in a hoodie datasets (useful in compactions)
+ */
+public class HoodieAvroPayload implements HoodieRecordPayload<HoodieAvroPayload> {
+    private final GenericRecord record;
+
+    public HoodieAvroPayload(GenericRecord record) {
+        this.record = record;
+    }
+
+    @Override
+    public HoodieAvroPayload preCombine(HoodieAvroPayload another) {
+        return this;
+    }
+
+    @Override
+    public IndexedRecord combineAndGetUpdateValue(IndexedRecord currentValue, Schema schema)
+        throws IOException {
+        return getInsertValue(schema);
+    }
+
+    @Override
+    public IndexedRecord getInsertValue(Schema schema) throws IOException {
+        return HoodieAvroUtils.rewriteRecord(record, schema);
+    }
+}

hoodie-common/src/main/java/com/uber/hoodie/common/model/HoodieFileFormat.java

@@ -17,7 +17,7 @@
 package com.uber.hoodie.common.model;
 
 public enum HoodieFileFormat {
-    PARQUET(".parquet");
+    PARQUET(".parquet"), AVRO(".avro");
 
     private final String extension;
 

hoodie-common/src/main/java/com/uber/hoodie/common/model/HoodieTableType.java

@@ -31,5 +31,5 @@ package com.uber.hoodie.common.model;
  * SIMPLE_LSM    - A simple 2 level LSM tree.
  */
 public enum HoodieTableType {
-    COPY_ON_WRITE
+    COPY_ON_WRITE, MERGE_ON_READ
 }