From 25892271e83e9d510c22d5d6cdca0115677eceb1 Mon Sep 17 00:00:00 2001
From: David Smiley <dsmiley@salesforce.com>
Date: Thu, 13 Feb 2020 18:54:32 -0800
Subject: [PATCH] SOLR-14258: DocList should not extend DocSet

---
 solr/CHANGES.txt                              |  2 +
 .../java/org/apache/solr/search/DocList.java  | 56 +------------------
 .../java/org/apache/solr/search/DocSlice.java | 44 +--------------
 .../org/apache/solr/search/TestDocSet.java    |  6 +-
 .../apache/solr/search/TestRangeQuery.java    | 21 ++++---
 5 files changed, 20 insertions(+), 109 deletions(-)

diff --git a/solr/CHANGES.txt b/solr/CHANGES.txt
index f4f55e50f51..7db27286461 100644
--- a/solr/CHANGES.txt
+++ b/solr/CHANGES.txt
@@ -35,6 +35,8 @@ Other Changes
 * SOLR-14272: Remove autoReplicaFailoverBadNodeExpiration and autoReplicaFailoverWorkLoopDelay for 9.0 as it was
   deprecated in 7.1 (Anshum Gupta)
 
+* SOLR-14258: DocList no longer extends DocSet. (David Smiley)
+
 ==================  8.5.0 ==================
 
 Consult the LUCENE_CHANGES.txt file for additional, low level, changes in this release.
diff --git a/solr/core/src/java/org/apache/solr/search/DocList.java b/solr/core/src/java/org/apache/solr/search/DocList.java
index fee2c138b73..b136d280a93 100644
--- a/solr/core/src/java/org/apache/solr/search/DocList.java
+++ b/solr/core/src/java/org/apache/solr/search/DocList.java
@@ -25,7 +25,7 @@ package org.apache.solr.search;
  *
  * @since solr 0.9
  */
-public interface DocList extends DocSet {
+public interface DocList {
 
   /**
    * Returns the zero based offset of this list within the total ordered list of matches to the query.
@@ -35,7 +35,6 @@ public interface DocList extends DocSet {
   /**
    * Returns the number of ids in this list.
    */
-  @Override
   public int size();
 
   /**
@@ -76,7 +75,6 @@ public interface DocList extends DocSet {
    * </p>
    * @see #hasScores
    */
-  @Override
   public DocIterator iterator();
     
   /** True if scores were retained */
@@ -87,55 +85,3 @@ public interface DocList extends DocSet {
    */
   public float maxScore();
 }
-
-
-/****  Maybe do this at a higher level (more efficient)
-
-class SmartDocSet implements DocSet {
-  static int INITIAL_SIZE=10;
-  static int TRANSITION_SIZE=10;
-
-  protected BitSet bits;
-  int size;
-
-  protected int[] arr;     // keep small set as an array, or as a hash?
-  protected int arrsize;
-
-  public SmartDocSet() {
-    if (INITIAL_SIZE>0) {
-      arr=new int[INITIAL_SIZE];
-    } else {
-      bits=new BitSet();
-    }
-  }
-
-
-  public void addUnique(int doc) {
-    size++;
-    if (bits != null) {
-      bits.set(doc);
-    }
-    else {
-      if (arrsize<10) {
-        arr[arrsize++]=doc;
-      } else  {
-        // TODO: transition to bit set
-      }
-    }
-  };
-
-  public int size() {
-    return size;
-  }
-  public boolean exists(int docid) {
-    return false;
-  }
-  public DocSet intersection(DocSet other) {
-    return null;
-
-  }
-  public DocSet union(DocSet other) {
-    return null;
-  }
-}
-***/
diff --git a/solr/core/src/java/org/apache/solr/search/DocSlice.java b/solr/core/src/java/org/apache/solr/search/DocSlice.java
index abd438844e4..b12ef1a916d 100644
--- a/solr/core/src/java/org/apache/solr/search/DocSlice.java
+++ b/solr/core/src/java/org/apache/solr/search/DocSlice.java
@@ -28,7 +28,7 @@ import org.apache.lucene.util.RamUsageEstimator;
  *
  * @since solr 0.9
  */
-public class DocSlice extends DocSetBase implements DocList {
+public class DocSlice implements DocList, Accountable {
   private static final long BASE_RAM_BYTES_USED = RamUsageEstimator.shallowSizeOfInstance(DocSlice.class) + RamUsageEstimator.NUM_BYTES_ARRAY_HEADER;
 
   final int offset;    // starting position of the docs (zero based)
@@ -92,15 +92,6 @@ public class DocSlice extends DocSetBase implements DocList {
   public long matches() { return matches; }
 
 
-  @Override
-  public boolean exists(int doc) {
-    int end = offset+len;
-    for (int i=offset; i<end; i++) {
-      if (docs[i]==doc) return true;
-    }
-    return false;
-  }
-
   // Hmmm, maybe I could have reused the scorer interface here...
   // except that it carries Similarity baggage...
   @Override
@@ -138,39 +129,6 @@ public class DocSlice extends DocSetBase implements DocList {
     };
   }
 
-
-  @Override
-  public DocSet intersection(DocSet other) {
-    if (other instanceof SortedIntDocSet || other instanceof HashDocSet) {
-      return other.intersection(this);
-    }
-    HashDocSet h = new HashDocSet(docs,offset,len);
-    return h.intersection(other);
-  }
-
-  @Override
-  public int intersectionSize(DocSet other) {
-    if (other instanceof SortedIntDocSet || other instanceof HashDocSet) {
-      return other.intersectionSize(this);
-    }
-    HashDocSet h = new HashDocSet(docs,offset,len);
-    return h.intersectionSize(other);  
-  }
-
-  @Override
-  public boolean intersects(DocSet other) {
-    if (other instanceof SortedIntDocSet || other instanceof HashDocSet) {
-      return other.intersects(this);
-    }
-    HashDocSet h = new HashDocSet(docs,offset,len);
-    return h.intersects(other);
-  }
-
-  @Override
-  public DocSlice clone() {
-    return (DocSlice) super.clone();
-  }
-
   /** WARNING: this can over-estimate real memory use since backing arrays are shared with other DocSlice instances */
   @Override
   public long ramBytesUsed() {
diff --git a/solr/core/src/test/org/apache/solr/search/TestDocSet.java b/solr/core/src/test/org/apache/solr/search/TestDocSet.java
index 20879ea47fd..db989a99730 100644
--- a/solr/core/src/test/org/apache/solr/search/TestDocSet.java
+++ b/solr/core/src/test/org/apache/solr/search/TestDocSet.java
@@ -111,7 +111,7 @@ public class TestDocSet extends SolrTestCase {
     return new BitDocSet(bs);
   }
 
-  public DocSet getDocSlice(FixedBitSet bs) {
+  public DocSlice getDocSlice(FixedBitSet bs) {
     int len = bs.cardinality();
     int[] arr = new int[len+5];
     arr[0]=10; arr[1]=20; arr[2]=30; arr[arr.length-1]=1; arr[arr.length-2]=2;
@@ -129,7 +129,7 @@ public class TestDocSet extends SolrTestCase {
 
 
   public DocSet getDocSet(FixedBitSet bs) {
-    switch(rand.nextInt(10)) {
+    switch(rand.nextInt(9)) {
       case 0: return getHashDocSet(bs);
 
       case 1: return getBitDocSet(bs);
@@ -141,8 +141,6 @@ public class TestDocSet extends SolrTestCase {
       case 6: return getIntDocSet(bs);
       case 7: return getIntDocSet(bs);
       case 8: return getIntDocSet(bs);
-
-      case 9: return getDocSlice(bs);
     }
     return null;
   }
diff --git a/solr/core/src/test/org/apache/solr/search/TestRangeQuery.java b/solr/core/src/test/org/apache/solr/search/TestRangeQuery.java
index e5f188712f5..5eb182870b6 100644
--- a/solr/core/src/test/org/apache/solr/search/TestRangeQuery.java
+++ b/solr/core/src/test/org/apache/solr/search/TestRangeQuery.java
@@ -25,6 +25,8 @@ import java.util.HashMap;
 import java.util.List;
 import java.util.Locale;
 import java.util.Map;
+
+import com.carrotsearch.hppc.IntHashSet;
 import org.apache.lucene.util.TestUtil;
 import org.apache.solr.SolrTestCaseJ4;
 import org.apache.solr.common.SolrInputDocument;
@@ -684,14 +686,19 @@ public class TestRangeQuery extends SolrTestCaseJ4 {
     return randomInt(cardinality);
   }
 
-  static boolean sameDocs(String msg, DocSet a, DocSet b) {
-    DocIterator i = a.iterator();
-    // System.out.println("SIZES="+a.size() + "," + b.size());
+  static boolean sameDocs(String msg, DocList a, DocList b) {
     assertEquals(msg, a.size(), b.size());
-    while (i.hasNext()) {
-      int doc = i.nextDoc();
-      assertTrue(msg, b.exists(doc));
-      // System.out.println("MATCH! " + doc);
+
+    IntHashSet bIds = new IntHashSet(b.size());
+    DocIterator bIter = b.iterator();
+    while (bIter.hasNext()) {
+      bIds.add(bIter.nextDoc());
+    }
+
+    DocIterator aIter = a.iterator();
+    while (aIter.hasNext()) {
+      int doc = aIter.nextDoc();
+      assertTrue(msg, bIds.contains(doc));
     }
     return true;
   }