Refactor DocValuesSkipper stat methods to accept IndexReader instead of IndexSearcher (#15514)

Author: bugmakerrrrrr

lucene/CHANGES.txt

@@ -180,6 +180,8 @@ API Changes
 
 * GITHUB#15501: Introduce optional access to backing vector values from the scorer  (Chris Hegarty)
 
+* GITHUB#15514: Refactor DocValuesSkipper stat methods to accept IndexReader instead of IndexSearcher (Pan Guixin)
+
 New Features
 ---------------------
 * GITHUB#15328: VectorSimilarityFunction.getValues() now implements doubleVal allowing its

lucene/core/src/java/org/apache/lucene/document/SortedNumericDocValuesRangeQuery.java

@@ -93,14 +93,14 @@ public Query rewrite(IndexSearcher indexSearcher) throws IOException {
     if (lowerValue > upperValue) {
       return MatchNoDocsQuery.INSTANCE;
     }
-    long globalMin = DocValuesSkipper.globalMinValue(indexSearcher, field);
-    long globalMax = DocValuesSkipper.globalMaxValue(indexSearcher, field);
+    long globalMin = DocValuesSkipper.globalMinValue(indexSearcher.getIndexReader(), field);
+    long globalMax = DocValuesSkipper.globalMaxValue(indexSearcher.getIndexReader(), field);
     if (lowerValue > globalMax || upperValue < globalMin) {
       return MatchNoDocsQuery.INSTANCE;
     }
     if (lowerValue <= globalMin
         && upperValue >= globalMax
-        && DocValuesSkipper.globalDocCount(indexSearcher, field)
+        && DocValuesSkipper.globalDocCount(indexSearcher.getIndexReader(), field)
             == indexSearcher.getIndexReader().maxDoc()) {
       return MatchAllDocsQuery.INSTANCE;
     }

lucene/core/src/java/org/apache/lucene/index/DocValuesSkipper.java

@@ -18,7 +18,6 @@
 
 import java.io.IOException;
 import org.apache.lucene.search.DocIdSetIterator;
-import org.apache.lucene.search.IndexSearcher;
 
 /**
  * Skipper for {@link DocValues}.
@@ -128,12 +127,12 @@ public final void advance(long minValue, long maxValue) throws IOException {
    * Returns the minimum value for a field across all segments, or {@link Long#MIN_VALUE} if not
    * available
    *
-   * @param searcher a searcher over the index
+   * @param reader the index reader to be queried
    * @param field the field to retrieve values for
    */
-  public static long globalMinValue(IndexSearcher searcher, String field) throws IOException {
+  public static long globalMinValue(IndexReader reader, String field) throws IOException {
     long minValue = Long.MAX_VALUE;
-    for (LeafReaderContext ctx : searcher.getLeafContexts()) {
+    for (LeafReaderContext ctx : reader.leaves()) {
       if (ctx.reader().getFieldInfos().fieldInfo(field) == null) {
         continue; // no field values in this segment, so we can ignore it
       }
@@ -152,12 +151,12 @@ public static long globalMinValue(IndexSearcher searcher, String field) throws I
    * Returns the maximum value for a field across all segments, or {@link Long#MIN_VALUE} if not
    * available
    *
-   * @param searcher a searcher over the index
+   * @param reader the index reader to be queried
    * @param field the field to retrieve values for
    */
-  public static long globalMaxValue(IndexSearcher searcher, String field) throws IOException {
+  public static long globalMaxValue(IndexReader reader, String field) throws IOException {
     long maxValue = Long.MIN_VALUE;
-    for (LeafReaderContext ctx : searcher.getLeafContexts()) {
+    for (LeafReaderContext ctx : reader.leaves()) {
       if (ctx.reader().getFieldInfos().fieldInfo(field) == null) {
         continue; // no field values in this segment, so we can ignore it
       }
@@ -175,12 +174,12 @@ public static long globalMaxValue(IndexSearcher searcher, String field) throws I
   /**
    * Returns the total skipper document count for a field across all segments
    *
-   * @param searcher a searcher over the index
+   * @param reader the index reader to be queried
    * @param field the field to retrieve values for
    */
-  public static int globalDocCount(IndexSearcher searcher, String field) throws IOException {
+  public static int globalDocCount(IndexReader reader, String field) throws IOException {
     int docCount = 0;
-    for (LeafReaderContext ctx : searcher.getLeafContexts()) {
+    for (LeafReaderContext ctx : reader.leaves()) {
       DocValuesSkipper skipper = ctx.reader().getDocValuesSkipper(field);
       if (skipper != null) {
         docCount += skipper.docCount();