Upgrade to lucene-7.0.0-snapshot-ad2cb77. (#25349)

Most notable changes:
 - better update concurrency: LUCENE-7868
 - TopDocs.totalHits is now a long: LUCENE-7872
 - QueryBuilder does not remove the boolean query around multi-term synonyms:
   LUCENE-7878
 - removal of Fields: LUCENE-7500

For the `TopDocs.totalHits` change, this PR relies on the fact that the encoding
of vInts and vLongs are compatible: you can write and read with any of them as
long as the value can be represented by a positive int.

7 files changed, 17 insertions, 20 deletions

diff --git a/core/src/main/java/org/elasticsearch/common/lucene/Lucene.java b/core/src/main/java/org/elasticsearch/common/lucene/Lucene.java
index 52550f1ba6..10adf530b1 100644
--- a/core/src/main/java/org/elasticsearch/common/lucene/Lucene.java
+++ b/core/src/main/java/org/elasticsearch/common/lucene/Lucene.java
@@ -272,7 +272,7 @@ public class Lucene {
     public static TopDocs readTopDocs(StreamInput in) throws IOException {
         byte type = in.readByte();
         if (type == 0) {
-            int totalHits = in.readVInt();
+            long totalHits = in.readVLong();
             float maxScore = in.readFloat();
 
             ScoreDoc[] scoreDocs = new ScoreDoc[in.readVInt()];
@@ -281,7 +281,7 @@ public class Lucene {
             }
             return new TopDocs(totalHits, scoreDocs, maxScore);
         } else if (type == 1) {
-            int totalHits = in.readVInt();
+            long totalHits = in.readVLong();
             float maxScore = in.readFloat();
 
             SortField[] fields = new SortField[in.readVInt()];
@@ -385,7 +385,7 @@ public class Lucene {
             out.writeByte((byte) 2);
             CollapseTopFieldDocs collapseDocs = (CollapseTopFieldDocs) topDocs;
 
-            out.writeVInt(topDocs.totalHits);
+            out.writeVLong(topDocs.totalHits);
             out.writeFloat(topDocs.getMaxScore());
 
             out.writeString(collapseDocs.field);
@@ -405,7 +405,7 @@ public class Lucene {
             out.writeByte((byte) 1);
             TopFieldDocs topFieldDocs = (TopFieldDocs) topDocs;
 
-            out.writeVInt(topDocs.totalHits);
+            out.writeVLong(topDocs.totalHits);
             out.writeFloat(topDocs.getMaxScore());
 
             out.writeVInt(topFieldDocs.fields.length);
@@ -419,7 +419,7 @@ public class Lucene {
             }
         } else {
             out.writeByte((byte) 0);
-            out.writeVInt(topDocs.totalHits);
+            out.writeVLong(topDocs.totalHits);
             out.writeFloat(topDocs.getMaxScore());
 
             out.writeVInt(topDocs.scoreDocs.length);
diff --git a/core/src/main/java/org/elasticsearch/common/lucene/uid/PerThreadIDVersionAndSeqNoLookup.java b/core/src/main/java/org/elasticsearch/common/lucene/uid/PerThreadIDVersionAndSeqNoLookup.java
index ae3d978928..2b37c338c9 100644
--- a/core/src/main/java/org/elasticsearch/common/lucene/uid/PerThreadIDVersionAndSeqNoLookup.java
+++ b/core/src/main/java/org/elasticsearch/common/lucene/uid/PerThreadIDVersionAndSeqNoLookup.java
@@ -19,7 +19,6 @@ package org.elasticsearch.common.lucene.uid;
  * under the License.
  */
 
-import org.apache.lucene.index.Fields;
 import org.apache.lucene.index.LeafReader;
 import org.apache.lucene.index.LeafReaderContext;
 import org.apache.lucene.index.NumericDocValues;
@@ -67,8 +66,7 @@ final class PerThreadIDVersionAndSeqNoLookup {
      */
     PerThreadIDVersionAndSeqNoLookup(LeafReader reader, String uidField) throws IOException {
         this.uidField = uidField;
-        Fields fields = reader.fields();
-        Terms terms = fields.terms(uidField);
+        Terms terms = reader.terms(uidField);
         if (terms == null) {
             throw new IllegalArgumentException("reader misses the [" + uidField + "] field");
         }
diff --git a/core/src/main/java/org/elasticsearch/index/fielddata/plain/PagedBytesIndexFieldData.java b/core/src/main/java/org/elasticsearch/index/fielddata/plain/PagedBytesIndexFieldData.java
index eab98040bb..fa126d6813 100644
--- a/core/src/main/java/org/elasticsearch/index/fielddata/plain/PagedBytesIndexFieldData.java
+++ b/core/src/main/java/org/elasticsearch/index/fielddata/plain/PagedBytesIndexFieldData.java
@@ -180,8 +180,7 @@ public class PagedBytesIndexFieldData extends AbstractIndexOrdinalsFieldData {
                 LeafReader reader = context.reader();
                 Terms terms = reader.terms(getFieldName());
 
-                Fields fields = reader.fields();
-                final Terms fieldTerms = fields.terms(getFieldName());
+                final Terms fieldTerms = reader.terms(getFieldName());
 
                 if (fieldTerms instanceof FieldReader) {
                     final Stats stats = ((FieldReader) fieldTerms).getStats();
diff --git a/core/src/main/java/org/elasticsearch/search/aggregations/metrics/tophits/InternalTopHits.java b/core/src/main/java/org/elasticsearch/search/aggregations/metrics/tophits/InternalTopHits.java
index d1986f2dd2..e2cb84f03a 100644
--- a/core/src/main/java/org/elasticsearch/search/aggregations/metrics/tophits/InternalTopHits.java
+++ b/core/src/main/java/org/elasticsearch/search/aggregations/metrics/tophits/InternalTopHits.java
@@ -191,7 +191,7 @@ public class InternalTopHits extends InternalAggregation implements TopHits {
     protected int doHashCode() {
         int hashCode = from;
         hashCode = 31 * hashCode + size;
-        hashCode = 31 * hashCode + topDocs.totalHits;
+        hashCode = 31 * hashCode + Long.hashCode(topDocs.totalHits);
         for (int d = 0; d < topDocs.scoreDocs.length; d++) {
             ScoreDoc doc = topDocs.scoreDocs[d];
             hashCode = 31 * hashCode + doc.doc;
diff --git a/core/src/main/java/org/elasticsearch/search/internal/ScrollContext.java b/core/src/main/java/org/elasticsearch/search/internal/ScrollContext.java
index 163dbcc73d..75d48d5d63 100644
--- a/core/src/main/java/org/elasticsearch/search/internal/ScrollContext.java
+++ b/core/src/main/java/org/elasticsearch/search/internal/ScrollContext.java
@@ -30,7 +30,7 @@ public final class ScrollContext {
 
     private Map<String, Object> context = null;
 
-    public int totalHits = -1;
+    public long totalHits = -1;
     public float maxScore;
     public ScoreDoc lastEmittedDoc;
     public Scroll scroll;
diff --git a/core/src/main/java/org/elasticsearch/search/query/QuerySearchResult.java b/core/src/main/java/org/elasticsearch/search/query/QuerySearchResult.java
index f071c62f12..8549f42040 100644
--- a/core/src/main/java/org/elasticsearch/search/query/QuerySearchResult.java
+++ b/core/src/main/java/org/elasticsearch/search/query/QuerySearchResult.java
@@ -56,7 +56,7 @@ public final class QuerySearchResult extends SearchPhaseResult {
     private ProfileShardResult profileShardResults;
     private boolean hasProfileResults;
     private boolean hasScoreDocs;
-    private int totalHits;
+    private long totalHits;
     private float maxScore;
 
     public QuerySearchResult() {
@@ -317,7 +317,7 @@ public final class QuerySearchResult extends SearchPhaseResult {
         out.writeOptionalWriteable(profileShardResults);
     }
 
-    public int getTotalHits() {
+    public long getTotalHits() {
         return totalHits;
     }
 
diff --git a/core/src/main/java/org/elasticsearch/search/suggest/completion/CompletionFieldStats.java b/core/src/main/java/org/elasticsearch/search/suggest/completion/CompletionFieldStats.java
index 8b5761a7e9..c9b8356362 100644
--- a/core/src/main/java/org/elasticsearch/search/suggest/completion/CompletionFieldStats.java
+++ b/core/src/main/java/org/elasticsearch/search/suggest/completion/CompletionFieldStats.java
@@ -20,7 +20,8 @@
 package org.elasticsearch.search.suggest.completion;
 
 import com.carrotsearch.hppc.ObjectLongHashMap;
-import org.apache.lucene.index.Fields;
+
+import org.apache.lucene.index.FieldInfo;
 import org.apache.lucene.index.IndexReader;
 import org.apache.lucene.index.LeafReader;
 import org.apache.lucene.index.LeafReaderContext;
@@ -49,14 +50,13 @@ public class CompletionFieldStats {
         for (LeafReaderContext atomicReaderContext : indexReader.leaves()) {
             LeafReader atomicReader = atomicReaderContext.reader();
             try {
-                Fields fields = atomicReader.fields();
-                for (String fieldName : fields) {
-                    Terms terms = fields.terms(fieldName);
+                for (FieldInfo info : atomicReader.getFieldInfos()) {
+                    Terms terms = atomicReader.terms(info.name);
                     if (terms instanceof CompletionTerms) {
                         // TODO: currently we load up the suggester for reporting its size
                         long fstSize = ((CompletionTerms) terms).suggester().ramBytesUsed();
-                        if (fieldNamePatterns != null && fieldNamePatterns.length > 0 && Regex.simpleMatch(fieldNamePatterns, fieldName)) {
-                            completionFields.addTo(fieldName, fstSize);
+                        if (fieldNamePatterns != null && fieldNamePatterns.length > 0 && Regex.simpleMatch(fieldNamePatterns, info.name)) {
+                            completionFields.addTo(info.name, fstSize);
                         }
                         sizeInBytes += fstSize;
                     }