SERVER-56877 rename IndexCatalogEntryImpl::_indexMultikeyPaths to _indexMultikeyPathsForRead

(cherry picked from commit 262036ae4b0219c229ff38c644a1e10487e7a586)

2 files changed, 14 insertions, 13 deletions

diff --git a/src/mongo/db/catalog/index_catalog_entry_impl.cpp b/src/mongo/db/catalog/index_catalog_entry_impl.cpp
index f1dc1c1c8ef..d2d570c456b 100644
--- a/src/mongo/db/catalog/index_catalog_entry_impl.cpp
+++ b/src/mongo/db/catalog/index_catalog_entry_impl.cpp
@@ -81,10 +81,10 @@ IndexCatalogEntryImpl::IndexCatalogEntryImpl(OperationContext* const opCtx,
 
     {
         stdx::lock_guard<Latch> lk(_indexMultikeyPathsMutex);
-        const bool isMultikey = _catalogIsMultikey(opCtx, &_indexMultikeyPaths);
+        const bool isMultikey = _catalogIsMultikey(opCtx, &_indexMultikeyPathsForRead);
         _isMultikeyForRead.store(isMultikey);
         _isMultikeyForWrite.store(isMultikey);
-        _indexTracksMultikeyPathsInCatalog = !_indexMultikeyPaths.empty();
+        _indexTracksMultikeyPathsInCatalog = !_indexMultikeyPathsForRead.empty();
     }
 
     const BSONObj& collation = _descriptor->collation();
@@ -166,7 +166,7 @@ bool IndexCatalogEntryImpl::isMultikey() const {
 
 MultikeyPaths IndexCatalogEntryImpl::getMultikeyPaths(OperationContext* opCtx) const {
     stdx::lock_guard<Latch> lk(_indexMultikeyPathsMutex);
-    return _indexMultikeyPaths;
+    return _indexMultikeyPathsForRead;
 }
 
 // ---
@@ -196,12 +196,12 @@ void IndexCatalogEntryImpl::setMultikey(OperationContext* opCtx,
 
     if (_indexTracksMultikeyPathsInCatalog) {
         stdx::lock_guard<Latch> lk(_indexMultikeyPathsMutex);
-        invariant(multikeyPaths.size() == _indexMultikeyPaths.size());
+        invariant(multikeyPaths.size() == _indexMultikeyPathsForRead.size());
 
         bool newPathIsMultikey = false;
         for (size_t i = 0; i < multikeyPaths.size(); ++i) {
-            if (!std::includes(_indexMultikeyPaths[i].begin(),
-                               _indexMultikeyPaths[i].end(),
+            if (!std::includes(_indexMultikeyPathsForRead[i].begin(),
+                               _indexMultikeyPathsForRead[i].end(),
                                multikeyPaths[i].begin(),
                                multikeyPaths[i].end())) {
                 // If 'multikeyPaths' contains a new path component that causes this index to be
@@ -361,7 +361,7 @@ void IndexCatalogEntryImpl::_catalogSetMultikey(OperationContext* opCtx,
                                                        _descriptor->indexName(),
                                                        multikeyPaths);
 
-    // In the absense of using the storage engine to read from the catalog, we must set multikey
+    // In the absence of using the storage engine to read from the catalog, we must set multikey
     // prior to the storage engine transaction committing.
     //
     // Moreover, there must not be an `onRollback` handler to reset this back to false. Given a long
@@ -372,7 +372,7 @@ void IndexCatalogEntryImpl::_catalogSetMultikey(OperationContext* opCtx,
     if (_indexTracksMultikeyPathsInCatalog) {
         stdx::lock_guard<Latch> lk(_indexMultikeyPathsMutex);
         for (size_t i = 0; i < multikeyPaths.size(); ++i) {
-            _indexMultikeyPaths[i].insert(multikeyPaths[i].begin(), multikeyPaths[i].end());
+            _indexMultikeyPathsForRead[i].insert(multikeyPaths[i].begin(), multikeyPaths[i].end());
         }
     }
     if (indexMetadataHasChanged && _queryInfo) {
diff --git a/src/mongo/db/catalog/index_catalog_entry_impl.h b/src/mongo/db/catalog/index_catalog_entry_impl.h
index 8d6077423e5..48acd848b45 100644
--- a/src/mongo/db/catalog/index_catalog_entry_impl.h
+++ b/src/mongo/db/catalog/index_catalog_entry_impl.h
@@ -248,19 +248,20 @@ private:
     // this point, future writers do not need to update the catalog.
     AtomicWord<bool> _isMultikeyForWrite;
 
-    // Controls concurrent access to '_indexMultikeyPaths'. We acquire this mutex rather than the
-    // RESOURCE_METADATA lock as a performance optimization so that it is cheaper to detect whether
-    // there is actually any path-level multikey information to update or not.
+    // Controls concurrent access to '_indexMultikeyPathsForRead'.
+    // We acquire this mutex rather than the RESOURCE_METADATA lock as a performance optimization
+    // so that it is cheaper to detect whether there is actually any path-level multikey
+    // information to update or not.
     mutable Mutex _indexMultikeyPathsMutex =
         MONGO_MAKE_LATCH("IndexCatalogEntryImpl::_indexMultikeyPathsMutex");
 
     // Non-empty only if '_indexTracksPathLevelMultikeyInfo' is true.
     //
-    // If non-empty, '_indexMultikeyPaths' is a vector with size equal to the number of elements
+    // If non-empty, '_indexMultikeyPaths*' is a vector with size equal to the number of elements
     // in the index key pattern. Each element in the vector is an ordered set of positions (starting
     // at 0) into the corresponding indexed field that represent what prefixes of the indexed field
     // causes the index to be multikey.
-    MultikeyPaths _indexMultikeyPaths;
+    MultikeyPaths _indexMultikeyPathsForRead;  // May include paths not committed to catalog.
 
     // KVPrefix used to differentiate between index entries in different logical indexes sharing the
     // same underlying sorted data interface.