Adding another metric to HoodieWriteStat to determine if there were inserts converted to updates, added one test for this

hoodie-common/src/main/avro/HoodieCommitMetadata.avsc

@@ -61,6 +61,11 @@
                         "name":"totalUpdatedRecordsCompacted",
                         "type":["null","long"],
                         "default" : null
+                     },
+                     {
+                        "name":"numInserts",
+                        "type":["null","long"],
+                        "default" : null
                      }
                   ]
                }

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

@@ -61,6 +61,11 @@ public class HoodieWriteStat implements Serializable {
    */
   private long numUpdateWrites;
 
+  /**
+   * Total number of insert records or converted to updates (for small file handling)
+   */
+  private long numInserts;
+
   /**
    * Total size of file written
    */
@@ -160,6 +165,10 @@ public class HoodieWriteStat implements Serializable {
     this.numUpdateWrites = numUpdateWrites;
   }
 
+  public void setNumInserts(long numInserts) {
+    this.numInserts = numInserts;
+  }
+
   public long getTotalWriteBytes() {
     return totalWriteBytes;
   }
@@ -192,6 +201,10 @@ public class HoodieWriteStat implements Serializable {
     return numUpdateWrites;
   }
 
+  public long getNumInserts() {
+    return numInserts;
+  }
+
   public String getFileId() {
     return fileId;
   }