Some minor cleanup in o.e.i.fielddata.ordinals

Some minor random finds from researching other things. Saving a field
access during iteration is a bit of a win though.

Author: original-brownbear

server/src/main/java/org/elasticsearch/index/fielddata/ordinals/MultiOrdinals.java

@@ -19,7 +19,6 @@
 import org.elasticsearch.index.fielddata.AbstractSortedDocValues;
 import org.elasticsearch.index.fielddata.AbstractSortedSetDocValues;
 
-import java.io.IOException;
 import java.util.Collection;
 import java.util.List;
 
@@ -107,7 +106,6 @@ private static class SingleDocs extends AbstractSortedDocValues {
 
         private int currentDoc = -1;
         private long currentStartOffset;
-        private long currentEndOffset;
 
         SingleDocs(MultiOrdinals ordinals, ValuesHolder values) {
             this.valueCount = (int) ordinals.valueCount;
@@ -122,11 +120,10 @@ public int ordValue() {
         }
 
         @Override
-        public boolean advanceExact(int docId) throws IOException {
+        public boolean advanceExact(int docId) {
             currentDoc = docId;
             currentStartOffset = docId != 0 ? endOffsets.get(docId - 1) : 0;
-            currentEndOffset = endOffsets.get(docId);
-            return currentStartOffset != currentEndOffset;
+            return currentStartOffset != endOffsets.get(docId);
         }
 
         @Override
@@ -169,14 +166,14 @@ public long getValueCount() {
         }
 
         @Override
-        public boolean advanceExact(int docId) throws IOException {
+        public boolean advanceExact(int docId) {
             currentOffset = docId != 0 ? endOffsets.get(docId - 1) : 0;
             currentEndOffset = endOffsets.get(docId);
             return currentOffset != currentEndOffset;
         }
 
         @Override
-        public long nextOrd() throws IOException {
+        public long nextOrd() {
             if (currentOffset == currentEndOffset) {
                 return SortedSetDocValues.NO_MORE_ORDS;
             } else {

server/src/main/java/org/elasticsearch/index/fielddata/ordinals/OrdinalsBuilder.java

@@ -119,7 +119,7 @@ private static int numOrdinals(int level, long offset) {
         }
 
         // Current position
-        private PagedGrowableWriter positions;
+        private final PagedGrowableWriter positions;
         // First level (0) of ordinals and pointers to the next level
         private final GrowableWriter firstOrdinals;
         private PagedGrowableWriter firstNextLevelSlices;

server/src/main/java/org/elasticsearch/index/fielddata/ordinals/SinglePackedOrdinals.java

@@ -17,7 +17,6 @@
 import org.apache.lucene.util.packed.PackedInts;
 import org.elasticsearch.index.fielddata.AbstractSortedDocValues;
 
-import java.io.IOException;
 import java.util.Collection;
 import java.util.Collections;
 
@@ -86,7 +85,7 @@ public int ordValue() {
         }
 
         @Override
-        public boolean advanceExact(int docID) throws IOException {
+        public boolean advanceExact(int docID) {
             currentDoc = docID;
             currentOrd = (int) (reader.get(docID) - 1);
             return currentOrd != -1;