[][refactoring] Reduce copy-paste by introducing BuildJoinRenameLambda

3 files changed, 44 insertions, 34 deletions

diff --git a/ydb/core/kqp/provider/yql_kikimr_opt_join.cpp b/ydb/core/kqp/provider/yql_kikimr_opt_join.cpp
index 662082c5432..15c78510d88 100644
--- a/ydb/core/kqp/provider/yql_kikimr_opt_join.cpp
+++ b/ydb/core/kqp/provider/yql_kikimr_opt_join.cpp
@@ -924,43 +924,11 @@ TExprNode::TPtr KiRewriteEquiJoin(TExprBase node, const TKikimrTablesData& table
     TExprBase joinExpr = rewrittenJoin.Cast();
     auto resultType = node.Ptr()->GetTypeAnn()->Cast<TListExprType>()->GetItemType()->Cast<TStructExprType>();
     auto renameMap = LoadJoinRenameMap(*joinOptions.Ptr());
-
-    THashMap<TStringBuf, TStringBuf> reverseRenameMap;
-    for (auto& pair : renameMap) {
-        for (TStringBuf newName : pair.second) {
-            reverseRenameMap[newName] = pair.first;
-        }
-    }
-
-    TCoArgument rowArg = Build<TCoArgument>(ctx, joinExpr.Pos())
-        .Name("row")
-        .Done();
-
-    TVector<TExprBase> renameTuples;
-    for (auto& item : resultType->GetItems()) {
-        TStringBuf newName = item->GetName();
-        auto renamedFrom = reverseRenameMap.FindPtr(newName);
-        TStringBuf oldName = renamedFrom ? *renamedFrom : newName;
-
-        auto tuple = Build<TCoNameValueTuple>(ctx, joinExpr.Pos())
-            .Name().Build(newName)
-            .Value<TCoMember>()
-                .Struct(rowArg)
-                .Name().Build(oldName)
-                .Build()
-            .Done();
-
-        renameTuples.push_back(tuple);
-    }
+    TCoLambda renamingLambda = BuildJoinRenameLambda(joinExpr.Pos(), renameMap, *resultType, ctx);
 
     return Build<TCoMap>(ctx, joinExpr.Pos())
         .Input(joinExpr)
-        .Lambda()
-            .Args({rowArg})
-            .Body<TCoAsStruct>()
-                .Add(renameTuples)
-                .Build()
-            .Build()
+        .Lambda(renamingLambda)
         .Done()
         .Ptr();
 }
diff --git a/ydb/library/yql/core/yql_join.cpp b/ydb/library/yql/core/yql_join.cpp
index b6e1861badc..b10fbd20276 100644
--- a/ydb/library/yql/core/yql_join.cpp
+++ b/ydb/library/yql/core/yql_join.cpp
@@ -895,6 +895,46 @@ TMap<TStringBuf, TVector<TStringBuf>> LoadJoinRenameMap(const TExprNode& setting
     return res;
 }
 
+TCoLambda BuildJoinRenameLambda(TPositionHandle pos, const TMap<TStringBuf, TVector<TStringBuf>>& renameMap,
+    const TStructExprType& joinResultType, TExprContext& ctx)
+{
+    THashMap<TStringBuf, TStringBuf> reverseRenameMap;
+    for (const auto& [oldName , targets] : renameMap) {
+        for (TStringBuf newName : targets) {
+            reverseRenameMap[newName] = oldName;
+        }
+    }
+
+    TCoArgument rowArg = Build<TCoArgument>(ctx, pos)
+        .Name("row")
+        .Done();
+
+    TVector<TExprBase> renameTuples;
+    for (auto& item : joinResultType.GetItems()) {
+        TStringBuf newName = item->GetName();
+        auto renamedFrom = reverseRenameMap.FindPtr(newName);
+        TStringBuf oldName = renamedFrom ? *renamedFrom : newName;
+
+        auto tuple = Build<TCoNameValueTuple>(ctx, pos)
+            .Name().Build(newName)
+            .Value<TCoMember>()
+                .Struct(rowArg)
+                .Name().Build(oldName)
+            .Build()
+            .Done();
+
+        renameTuples.push_back(tuple);
+    }
+
+    return Build<TCoLambda>(ctx, pos)
+        .Args({rowArg})
+        .Body<TCoAsStruct>()
+            .Add(renameTuples)
+        .Build()
+        .Done();
+}
+
+
 TSet<TVector<TStringBuf>> LoadJoinSortSets(const TExprNode& settings) {
     TSet<TVector<TStringBuf>> res;
     for (const auto& child : settings.Children()) {
diff --git a/ydb/library/yql/core/yql_join.h b/ydb/library/yql/core/yql_join.h
index 672645bf120..a37b517bbb3 100644
--- a/ydb/library/yql/core/yql_join.h
+++ b/ydb/library/yql/core/yql_join.h
@@ -84,6 +84,8 @@ TExprNode::TPtr FilterOutNullJoinColumns(TPositionHandle pos, const TExprNode::T
     const TJoinLabel& label, const TSet<TString>& optionalKeyColumns, TExprContext& ctx);
 
 TMap<TStringBuf, TVector<TStringBuf>> LoadJoinRenameMap(const TExprNode& settings);
+NNodes::TCoLambda BuildJoinRenameLambda(TPositionHandle pos, const TMap<TStringBuf, TVector<TStringBuf>>& renameMap,
+    const TStructExprType& joinResultType, TExprContext& ctx);
 TSet<TVector<TStringBuf>> LoadJoinSortSets(const TExprNode& settings);
 
 THashMap<TString, const TTypeAnnotationNode*> GetJoinColumnTypes(const TExprNode& joins,