SERVER-68281 Improve ValueGuard performance

Crescentek · Aug 10, 2022 · 3f2f1e8 · 3f2f1e8
1 parent 1a94ea9
commit 3f2f1e8
Show file tree

Hide file tree

Showing 2 changed files with 31 additions and 55 deletions.
diff --git a/src/mongo/db/exec/sbe/values/value.cpp b/src/mongo/db/exec/sbe/values/value.cpp
@@ -239,7 +239,7 @@ std::pair<TypeTags, Value> makeCopyIndexBounds(const IndexBounds& bounds) {
 }
 
 
-void releaseValue(TypeTags tag, Value val) noexcept {
+void releaseValueDeep(TypeTags tag, Value val) noexcept {
     switch (tag) {
         case TypeTags::RecordId:
             delete getRecordIdView(val);
@@ -393,45 +393,6 @@ BSONType tagToType(TypeTags tag) noexcept {
     }
 }
 
-bool isShallowType(TypeTags tag) noexcept {
-    switch (tag) {
-        case TypeTags::Nothing:
-        case TypeTags::Null:
-        case TypeTags::NumberInt32:
-        case TypeTags::NumberInt64:
-        case TypeTags::NumberDouble:
-        case TypeTags::Date:
-        case TypeTags::Timestamp:
-        case TypeTags::Boolean:
-        case TypeTags::StringSmall:
-        case TypeTags::MinKey:
-        case TypeTags::MaxKey:
-        case TypeTags::bsonUndefined:
-        case TypeTags::LocalLambda:
-            return true;
-        case TypeTags::RecordId:
-        case TypeTags::NumberDecimal:
-        case TypeTags::StringBig:
-        case TypeTags::bsonString:
-        case TypeTags::bsonSymbol:
-        case TypeTags::Array:
-        case TypeTags::ArraySet:
-        case TypeTags::Object:
-        case TypeTags::ObjectId:
-        case TypeTags::bsonObjectId:
-        case TypeTags::bsonObject:
-        case TypeTags::bsonArray:
-        case TypeTags::bsonBinData:
-        case TypeTags::ksValue:
-        case TypeTags::bsonRegex:
-        case TypeTags::bsonJavascript:
-        case TypeTags::bsonDBPointer:
-            return false;
-        default:
-            MONGO_UNREACHABLE;
-    }
-}
-
 inline std::size_t hashObjectId(const uint8_t* objId) noexcept {
     auto dataView = ConstDataView(reinterpret_cast<const char*>(objId));
     return abslHash(dataView.read<LittleEndian<uint64_t>>()) ^

diff --git a/src/mongo/db/exec/sbe/values/value.h b/src/mongo/db/exec/sbe/values/value.h
@@ -90,7 +90,6 @@ enum class TypeTags : uint8_t {
     NumberInt32,
     NumberInt64,
     NumberDouble,
-    NumberDecimal,
 
     // Date data types.
     Date,
@@ -99,6 +98,15 @@ enum class TypeTags : uint8_t {
     Boolean,
     Null,
     StringSmall,
+
+    MinKey,
+    MaxKey,
+
+    // Special marker
+    EndOfShallowValues = MaxKey,
+
+    // Heap values
+    NumberDecimal,
     StringBig,
     Array,
     ArraySet,
@@ -107,9 +115,6 @@ enum class TypeTags : uint8_t {
     ObjectId,
     RecordId,
 
-    MinKey,
-    MaxKey,
-
     // Raw bson values.
     bsonObject,
     bsonArray,
@@ -205,8 +210,11 @@ inline constexpr bool isCollatableType(TypeTags tag) noexcept {
     return isString(tag) || isArray(tag) || isObject(tag);
 }
 
+inline constexpr bool isShallowType(TypeTags tag) noexcept {
+    return tag <= TypeTags::EndOfShallowValues;
+}
+
 BSONType tagToType(TypeTags tag) noexcept;
-bool isShallowType(TypeTags tag) noexcept;
 
 /**
  * This function takes an SBE TypeTag, looks up the corresponding BSONType t, and then returns a
@@ -232,12 +240,28 @@ enum class SortDirection : uint8_t { Descending, Ascending };
 /**
  * Forward declarations.
  */
-void releaseValue(TypeTags tag, Value val) noexcept;
+
+/**
+ * Releases memory allocated for the value. If the value does not have any memory allocated for it,
+ * does nothing.
+ *
+ * NOTE: This function is intentionally marked as 'noexcept' and must not throw. It is used in the
+ *       destructors of several classes to implement RAII concept for values.
+ */
+void releaseValueDeep(TypeTags tag, Value val) noexcept;
 std::pair<TypeTags, Value> copyValue(TypeTags tag, Value val);
 std::size_t hashValue(TypeTags tag,
                       Value val,
                       const CollatorInterface* collator = nullptr) noexcept;
 
+inline void releaseValue(TypeTags tag, Value val) noexcept {
+    if (!isShallowType(tag)) {
+        releaseValueDeep(tag, val);
+    } else {
+        // No action is needed to release "shallow" values.
+    }
+}
+
 /**
  * Overloads for writing values and tags to stream.
  */
@@ -1316,15 +1340,6 @@ std::pair<TypeTags, Value> makeCopyCollator(const CollatorInterface& collator);
 
 std::pair<TypeTags, Value> makeCopyIndexBounds(const IndexBounds& collator);
 
-/**
- * Releases memory allocated for the value. If the value does not have any memory allocated for it,
- * does nothing.
- *
- * NOTE: This function is intentionally marked as 'noexcept' and must not throw. It is used in the
- *       destructors of several classes to implement RAII concept for values.
- */
-void releaseValue(TypeTags tag, Value val) noexcept;
-
 inline std::pair<TypeTags, Value> copyValue(TypeTags tag, Value val) {
     switch (tag) {
         case TypeTags::RecordId: