Revert "Add ResolvedExpression wrapper (elastic#114592)" (elastic#115317

) (elastic#115376)

This reverts commit 4c15cc0.
This commit introduced an orders of magnitude regression when searching many shards.

(cherry picked from commit d9baf6f)

Co-authored-by: Armin Braun <me@obrown.io>

docs/changelog/115317.yaml

@@ -0,0 +1,5 @@
+pr: 115317
+summary: Revert "Add `ResolvedExpression` wrapper"
+area: Indices APIs
+type: bug
+issues: []

server/src/main/java/org/elasticsearch/action/admin/cluster/shards/TransportClusterSearchShardsAction.java

@@ -17,7 +17,6 @@
 import org.elasticsearch.cluster.block.ClusterBlockException;
 import org.elasticsearch.cluster.block.ClusterBlockLevel;
 import org.elasticsearch.cluster.metadata.IndexNameExpressionResolver;
-import org.elasticsearch.cluster.metadata.IndexNameExpressionResolver.ResolvedExpression;
 import org.elasticsearch.cluster.node.DiscoveryNode;
 import org.elasticsearch.cluster.routing.GroupShardsIterator;
 import org.elasticsearch.cluster.routing.ShardIterator;
@@ -85,7 +84,7 @@ protected void masterOperation(
         String[] concreteIndices = indexNameExpressionResolver.concreteIndexNames(clusterState, request);
         Map<String, Set<String>> routingMap = indexNameExpressionResolver.resolveSearchRouting(state, request.routing(), request.indices());
         Map<String, AliasFilter> indicesAndFilters = new HashMap<>();
-        Set<ResolvedExpression> indicesAndAliases = indexNameExpressionResolver.resolveExpressions(clusterState, request.indices());
+        Set<String> indicesAndAliases = indexNameExpressionResolver.resolveExpressions(clusterState, request.indices());
         for (String index : concreteIndices) {
             final AliasFilter aliasFilter = indicesService.buildAliasFilter(clusterState, index, indicesAndAliases);
             final String[] aliases = indexNameExpressionResolver.indexAliases(

server/src/main/java/org/elasticsearch/action/admin/indices/resolve/ResolveIndexAction.java

@@ -25,7 +25,6 @@
 import org.elasticsearch.cluster.metadata.IndexAbstraction;
 import org.elasticsearch.cluster.metadata.IndexMetadata;
 import org.elasticsearch.cluster.metadata.IndexNameExpressionResolver;
-import org.elasticsearch.cluster.metadata.IndexNameExpressionResolver.ResolvedExpression;
 import org.elasticsearch.cluster.metadata.Metadata;
 import org.elasticsearch.cluster.service.ClusterService;
 import org.elasticsearch.common.Strings;
@@ -566,8 +565,8 @@ static void resolveIndices(
             if (names.length == 1 && (Metadata.ALL.equals(names[0]) || Regex.isMatchAllPattern(names[0]))) {
                 names = new String[] { "**" };
             }
-            Set<ResolvedExpression> resolvedIndexAbstractions = resolver.resolveExpressions(clusterState, indicesOptions, true, names);
-            for (ResolvedExpression s : resolvedIndexAbstractions) {
+            Set<String> resolvedIndexAbstractions = resolver.resolveExpressions(clusterState, indicesOptions, true, names);
+            for (String s : resolvedIndexAbstractions) {
                 enrichIndexAbstraction(clusterState, s, indices, aliases, dataStreams);
             }
             indices.sort(Comparator.comparing(ResolvedIndexAbstraction::getName));
@@ -598,12 +597,12 @@ private static void mergeResults(
 
         private static void enrichIndexAbstraction(
             ClusterState clusterState,
-            ResolvedExpression indexAbstraction,
+            String indexAbstraction,
             List<ResolvedIndex> indices,
             List<ResolvedAlias> aliases,
             List<ResolvedDataStream> dataStreams
         ) {
-            IndexAbstraction ia = clusterState.metadata().getIndicesLookup().get(indexAbstraction.resource());
+            IndexAbstraction ia = clusterState.metadata().getIndicesLookup().get(indexAbstraction);
             if (ia != null) {
                 switch (ia.getType()) {
                     case CONCRETE_INDEX -> {

server/src/main/java/org/elasticsearch/action/admin/indices/validate/query/TransportValidateQueryAction.java

@@ -21,7 +21,6 @@
 import org.elasticsearch.cluster.block.ClusterBlockException;
 import org.elasticsearch.cluster.block.ClusterBlockLevel;
 import org.elasticsearch.cluster.metadata.IndexNameExpressionResolver;
-import org.elasticsearch.cluster.metadata.IndexNameExpressionResolver.ResolvedExpression;
 import org.elasticsearch.cluster.routing.GroupShardsIterator;
 import org.elasticsearch.cluster.routing.ShardIterator;
 import org.elasticsearch.cluster.routing.ShardRouting;
@@ -134,7 +133,7 @@ protected void doExecute(Task task, ValidateQueryRequest request, ActionListener
     @Override
     protected ShardValidateQueryRequest newShardRequest(int numShards, ShardRouting shard, ValidateQueryRequest request) {
         final ClusterState clusterState = clusterService.state();
-        final Set<ResolvedExpression> indicesAndAliases = indexNameExpressionResolver.resolveExpressions(clusterState, request.indices());
+        final Set<String> indicesAndAliases = indexNameExpressionResolver.resolveExpressions(clusterState, request.indices());
         final AliasFilter aliasFilter = searchService.buildAliasFilter(clusterState, shard.getIndexName(), indicesAndAliases);
         return new ShardValidateQueryRequest(shard.shardId(), aliasFilter, request);
     }

server/src/main/java/org/elasticsearch/action/explain/TransportExplainAction.java

@@ -18,7 +18,6 @@
 import org.elasticsearch.action.support.single.shard.TransportSingleShardAction;
 import org.elasticsearch.cluster.ClusterState;
 import org.elasticsearch.cluster.metadata.IndexNameExpressionResolver;
-import org.elasticsearch.cluster.metadata.IndexNameExpressionResolver.ResolvedExpression;
 import org.elasticsearch.cluster.routing.ShardIterator;
 import org.elasticsearch.cluster.service.ClusterService;
 import org.elasticsearch.common.io.stream.Writeable;
@@ -110,7 +109,7 @@ protected boolean resolveIndex(ExplainRequest request) {
 
     @Override
     protected void resolveRequest(ClusterState state, InternalRequest request) {
-        final Set<ResolvedExpression> indicesAndAliases = indexNameExpressionResolver.resolveExpressions(state, request.request().index());
+        final Set<String> indicesAndAliases = indexNameExpressionResolver.resolveExpressions(state, request.request().index());
         final AliasFilter aliasFilter = searchService.buildAliasFilter(state, request.concreteIndex(), indicesAndAliases);
         request.request().filteringAlias(aliasFilter);
     }

server/src/main/java/org/elasticsearch/action/search/TransportSearchAction.java

@@ -37,7 +37,6 @@
 import org.elasticsearch.cluster.metadata.IndexAbstraction;
 import org.elasticsearch.cluster.metadata.IndexMetadata;
 import org.elasticsearch.cluster.metadata.IndexNameExpressionResolver;
-import org.elasticsearch.cluster.metadata.IndexNameExpressionResolver.ResolvedExpression;
 import org.elasticsearch.cluster.node.DiscoveryNode;
 import org.elasticsearch.cluster.node.DiscoveryNodes;
 import org.elasticsearch.cluster.routing.GroupShardsIterator;
@@ -111,7 +110,6 @@
 import java.util.function.BiFunction;
 import java.util.function.Function;
 import java.util.function.LongSupplier;
-import java.util.stream.Collectors;
 
 import static org.elasticsearch.action.search.SearchType.DFS_QUERY_THEN_FETCH;
 import static org.elasticsearch.action.search.SearchType.QUERY_THEN_FETCH;
@@ -205,17 +203,14 @@ public TransportSearchAction(
 
     private Map<String, OriginalIndices> buildPerIndexOriginalIndices(
         ClusterState clusterState,
-        Set<ResolvedExpression> indicesAndAliases,
+        Set<String> indicesAndAliases,
         String[] indices,
         IndicesOptions indicesOptions
     ) {
         Map<String, OriginalIndices> res = Maps.newMapWithExpectedSize(indices.length);
         var blocks = clusterState.blocks();
         // optimization: mostly we do not have any blocks so there's no point in the expensive per-index checking
         boolean hasBlocks = blocks.global().isEmpty() == false || blocks.indices().isEmpty() == false;
-        // Get a distinct set of index abstraction names present from the resolved expressions to help with the reverse resolution from
-        // concrete index to the expression that produced it.
-        Set<String> indicesAndAliasesResources = indicesAndAliases.stream().map(ResolvedExpression::resource).collect(Collectors.toSet());
         for (String index : indices) {
             if (hasBlocks) {
                 blocks.indexBlockedRaiseException(ClusterBlockLevel.READ, index);
@@ -232,8 +227,8 @@ private Map<String, OriginalIndices> buildPerIndexOriginalIndices(
             String[] finalIndices = Strings.EMPTY_ARRAY;
             if (aliases == null
                 || aliases.length == 0
-                || indicesAndAliasesResources.contains(index)
-                || hasDataStreamRef(clusterState, indicesAndAliasesResources, index)) {
+                || indicesAndAliases.contains(index)
+                || hasDataStreamRef(clusterState, indicesAndAliases, index)) {
                 finalIndices = new String[] { index };
             }
             if (aliases != null) {
@@ -252,11 +247,7 @@ private static boolean hasDataStreamRef(ClusterState clusterState, Set<String> i
         return indicesAndAliases.contains(ret.getParentDataStream().getName());
     }
 
-    Map<String, AliasFilter> buildIndexAliasFilters(
-        ClusterState clusterState,
-        Set<ResolvedExpression> indicesAndAliases,
-        Index[] concreteIndices
-    ) {
+    Map<String, AliasFilter> buildIndexAliasFilters(ClusterState clusterState, Set<String> indicesAndAliases, Index[] concreteIndices) {
         final Map<String, AliasFilter> aliasFilterMap = new HashMap<>();
         for (Index index : concreteIndices) {
             clusterState.blocks().indexBlockedRaiseException(ClusterBlockLevel.READ, index.getName());
@@ -1246,10 +1237,7 @@ private void executeSearch(
         } else {
             final Index[] indices = resolvedIndices.getConcreteLocalIndices();
             concreteLocalIndices = Arrays.stream(indices).map(Index::getName).toArray(String[]::new);
-            final Set<ResolvedExpression> indicesAndAliases = indexNameExpressionResolver.resolveExpressions(
-                clusterState,
-                searchRequest.indices()
-            );
+            final Set<String> indicesAndAliases = indexNameExpressionResolver.resolveExpressions(clusterState, searchRequest.indices());
             aliasFilter = buildIndexAliasFilters(clusterState, indicesAndAliases, indices);
             aliasFilter.putAll(remoteAliasMap);
             localShardIterators = getLocalShardsIterator(
@@ -1822,7 +1810,7 @@ List<SearchShardIterator> getLocalShardsIterator(
         ClusterState clusterState,
         SearchRequest searchRequest,
         String clusterAlias,
-        Set<ResolvedExpression> indicesAndAliases,
+        Set<String> indicesAndAliases,
         String[] concreteIndices
     ) {
         var routingMap = indexNameExpressionResolver.resolveSearchRouting(clusterState, searchRequest.routing(), searchRequest.indices());

server/src/main/java/org/elasticsearch/action/search/TransportSearchShardsAction.java

@@ -17,7 +17,6 @@
 import org.elasticsearch.action.support.HandledTransportAction;
 import org.elasticsearch.cluster.ClusterState;
 import org.elasticsearch.cluster.metadata.IndexNameExpressionResolver;
-import org.elasticsearch.cluster.metadata.IndexNameExpressionResolver.ResolvedExpression;
 import org.elasticsearch.cluster.routing.GroupShardsIterator;
 import org.elasticsearch.cluster.service.ClusterService;
 import org.elasticsearch.index.Index;
@@ -128,10 +127,7 @@ public void searchShards(Task task, SearchShardsRequest searchShardsRequest, Act
             searchService.getRewriteContext(timeProvider::absoluteStartMillis, resolvedIndices, null),
             listener.delegateFailureAndWrap((delegate, searchRequest) -> {
                 Index[] concreteIndices = resolvedIndices.getConcreteLocalIndices();
-                final Set<ResolvedExpression> indicesAndAliases = indexNameExpressionResolver.resolveExpressions(
-                    clusterState,
-                    searchRequest.indices()
-                );
+                final Set<String> indicesAndAliases = indexNameExpressionResolver.resolveExpressions(clusterState, searchRequest.indices());
                 final Map<String, AliasFilter> aliasFilters = transportSearchAction.buildIndexAliasFilters(
                     clusterState,
                     indicesAndAliases,