review fix and reuse duplicate code

Author: easyice

lucene/core/src/java/org/apache/lucene/codecs/lucene90/blocktree/Lucene90BlockTreeTermsReader.java

@@ -86,11 +86,8 @@ public final class Lucene90BlockTreeTermsReader extends FieldsProducer {
    */
   public static final int VERSION_MSB_VLONG_OUTPUT = 1;
 
-  /** Version that store continuous arcs label as range in FST. */
-  public static final int VERSION_ARCS_CONTINUOUS = 2;
-
   /** Current terms format. */
-  public static final int VERSION_CURRENT = VERSION_ARCS_CONTINUOUS;
+  public static final int VERSION_CURRENT = VERSION_MSB_VLONG_OUTPUT;
 
   /** Extension of terms index file */
   static final String TERMS_INDEX_EXTENSION = "tip";

lucene/core/src/java/org/apache/lucene/util/fst/FST.java

@@ -96,6 +96,11 @@ public enum INPUT_TYPE {
    */
   static final byte ARCS_FOR_DIRECT_ADDRESSING = 1 << 6;
 
+  /**
+   * Value of the arc flags to declare a node with continuous arcs designed for pos the arc directly
+   * with labelToPos - firstLabel. like {@link #ARCS_FOR_BINARY_SEARCH} we use flag combinations
+   * that will not occur at the same time.
+   */
   static final byte ARCS_FOR_CONTINUOUS = ARCS_FOR_DIRECT_ADDRESSING + ARCS_FOR_BINARY_SEARCH;
 
   // Increment version to change it
@@ -916,6 +921,7 @@ public Arc<T> readLastArcByDirectAddressing(Arc<T> arc, final BytesReader in) th
     return readArcByDirectAddressing(arc, in, arc.numArcs() - 1, presenceIndex);
   }
 
+  /** Reads the last arc of a continuous node. */
   public Arc<T> readLastArcByContinuous(Arc<T> arc, final BytesReader in) throws IOException {
     return readArcByContinuous(arc, in, arc.numArcs() - 1);
   }

lucene/core/src/java/org/apache/lucene/util/fst/FSTCompiler.java

@@ -446,8 +446,8 @@ long addNode(FSTCompiler.UnCompiledNode<T> nodeIn) throws IOException {
 
       int labelRange = nodeIn.arcs[nodeIn.numArcs - 1].label - nodeIn.arcs[0].label + 1;
       assert labelRange > 0;
-      boolean continuousLable = labelRange == nodeIn.numArcs;
-      if (continuousLable) {
+      boolean continuousLabel = labelRange == nodeIn.numArcs;
+      if (continuousLabel) {
         writeNodeForDirectAddressingOrContinuous(
             nodeIn, startAddress, maxBytesPerArcWithoutLabel, labelRange, true);
         continuousNodeCount++;

lucene/core/src/java/org/apache/lucene/util/fst/FSTEnum.java

@@ -165,24 +165,8 @@ private FST.Arc<T> doSeekCeilArrayContinuous(
       final FST.Arc<T> arc, final int targetLabel, final FST.BytesReader in) throws IOException {
     int targetIndex = targetLabel - arc.firstLabel();
     if (targetIndex >= arc.numArcs()) {
-      // Target is beyond the last arc, out of label range.
-      // Dead end (target is after the last arc);
-      // rollback to last fork then push
-      upto--;
-      while (true) {
-        if (upto == 0) {
-          return null;
-        }
-        final FST.Arc<T> prevArc = getArc(upto);
-        // System.out.println("  rollback upto=" + upto + " arc.label=" + prevArc.label + "
-        // isLast?=" + prevArc.isLast());
-        if (!prevArc.isLast()) {
-          fst.readNextArc(prevArc, fstReader);
-          pushFirst();
-          return null;
-        }
-        upto--;
-      }
+      rollbackToLastForkThenPush();
+      return null;
     } else {
       if (targetIndex < 0) {
         fst.readArcByContinuous(arc, in, 0);
@@ -211,24 +195,8 @@ private FST.Arc<T> doSeekCeilArrayDirectAddressing(
 
     int targetIndex = targetLabel - arc.firstLabel();
     if (targetIndex >= arc.numArcs()) {
-      // Target is beyond the last arc, out of label range.
-      // Dead end (target is after the last arc);
-      // rollback to last fork then push
-      upto--;
-      while (true) {
-        if (upto == 0) {
-          return null;
-        }
-        final FST.Arc<T> prevArc = getArc(upto);
-        // System.out.println("  rollback upto=" + upto + " arc.label=" + prevArc.label + "
-        // isLast?=" + prevArc.isLast());
-        if (!prevArc.isLast()) {
-          fst.readNextArc(prevArc, fstReader);
-          pushFirst();
-          return null;
-        }
-        upto--;
-      }
+      rollbackToLastForkThenPush();
+      return null;
     } else {
       if (targetIndex < 0) {
         targetIndex = -1;
@@ -458,6 +426,28 @@ private FST.Arc<T> doSeekFloorArrayDirectAddressing(
     }
   }
 
+  /**
+   * Target is beyond the last arc, out of label range. Dead end (target is after the last arc);
+   * rollback to last fork then push
+   */
+  private void rollbackToLastForkThenPush() throws IOException {
+    upto--;
+    while (true) {
+      if (upto == 0) {
+        return;
+      }
+      final FST.Arc<T> prevArc = getArc(upto);
+      // System.out.println("  rollback upto=" + upto + " arc.label=" + prevArc.label + "
+      // isLast?=" + prevArc.isLast());
+      if (!prevArc.isLast()) {
+        fst.readNextArc(prevArc, fstReader);
+        pushFirst();
+        return;
+      }
+      upto--;
+    }
+  }
+
   /**
    * Backtracks until it finds a node which first arc is before our target label.` Then on the node,
    * finds the arc just before the targetLabel.