Perf[BMQ]: do not create tmp functors in PutEventBuilder (#478)

Signed-off-by: Evgeny Malygin <[email protected]>

.gitignore

@@ -27,6 +27,9 @@ settings.json
 .cache/
 .venv/
 
+# fuzz-test output folder
+**/boofuzz-results
+
 # Symlink from 'src/applications/bmqbrkr/run'
 src/applications/bmqbrkr/etc/etc
 

src/groups/bmq/bmqp/bmqp_puteventbuilder.cpp

@@ -49,16 +49,31 @@ bool isWordAligned(const bdlbb::Blob& blob)
 #endif
 }  // close unnamed namespace
 
+// ---------------------------------
+// class PutEventBuilder::ResetGuard
+// ---------------------------------
+
+inline PutEventBuilder::ResetGuard::ResetGuard(
+    PutEventBuilder& putEventBuilder)
+: d_putEventBuilder(putEventBuilder)
+{
+    // NOTHING
+}
+
+inline PutEventBuilder::ResetGuard::~ResetGuard()
+{
+    d_putEventBuilder.resetFields();
+}
+
 // ---------------------
 // class PutEventBuilder
 // ---------------------
 
-void PutEventBuilder::resetFields(void* ptr)
+void PutEventBuilder::resetFields()
 {
-    PutEventBuilder* builder = static_cast<PutEventBuilder*>(ptr);
-    builder->d_flags         = 0;
-    builder->d_messageGUID   = bmqt::MessageGUID();
-    builder->d_crc32c        = 0;
+    d_flags       = 0;
+    d_messageGUID = bmqt::MessageGUID();
+    d_crc32c      = 0;
 }
 
 bmqt::EventBuilderResult::Enum
@@ -219,9 +234,7 @@ PutEventBuilder::packMessageInOldStyle(int queueId)
 
     // Guid and flags need to be reset after this method (irrespective of its
     // success or failure).  Create a proctor to auto reset them.
-    const bsl::function<void()> f =
-        bdlf::BindUtil::bind(&PutEventBuilder::resetFields, this);
-    bdlb::ScopeExitAny resetter(f);
+    const ResetGuard guard(*this);
 
     // Calculate length of entire application data (includes payload, message
     // properties and padding, if any).
@@ -304,12 +317,9 @@ bmqt::EventBuilderResult::Enum PutEventBuilder::packMessage(int queueId)
 
     typedef bmqt::EventBuilderResult Result;
 
-    // CorrelationId, guid and flags need to be reset after this method
-    // (irrespective of its success or failure).  Create a proctor to auto
-    // reset them.
-    const bsl::function<void()> f =
-        bdlf::BindUtil::bind(&PutEventBuilder::resetFields, this);
-    bdlb::ScopeExitAny resetter(f);
+    // Guid and flags need to be reset after this method (irrespective of its
+    // success or failure).  Create a proctor to auto reset them.
+    const ResetGuard guard(*this);
 
     // Calculate length of entire application data (includes payload, message
     // properties and padding, if any).
@@ -398,9 +408,7 @@ bmqt::EventBuilderResult::Enum PutEventBuilder::packMessageRaw(int queueId)
 
     // Guid and flags need to be reset after this method (irrespective of its
     // success or failure).  Create a proctor to auto reset them.
-    const bsl::function<void()> f =
-        bdlf::BindUtil::bind(&PutEventBuilder::resetFields, this);
-    bdlb::ScopeExitAny resetter(f);
+    const ResetGuard guard(*this);
 
     // Note that the 'd_blobPayload_p' has the entire application data.
     return packMessageInternal(*d_blobPayload_p, queueId);

src/groups/bmq/bmqp/bmqp_puteventbuilder.h

@@ -61,7 +61,6 @@
 //
 
 // BMQ
-
 #include <bmqp_messageproperties.h>
 #include <bmqp_protocol.h>
 #include <bmqt_compressionalgorithmtype.h>
@@ -92,6 +91,18 @@ class PutEventBuilder {
     typedef bdlb::NullableValue<bmqp::Protocol::MsgGroupId> NullableMsgGroupId;
 
   private:
+    // TYPES
+    /// Mechanism to automatically reset PutEventBuilder on a built message
+    struct ResetGuard {
+        // DATA
+        PutEventBuilder& d_putEventBuilder;
+
+        // CREATORS
+        explicit ResetGuard(PutEventBuilder& putEventBuilder);
+
+        ~ResetGuard();
+    };
+
     // DATA
     bdlbb::BlobBufferFactory* d_bufferFactory_p;
 
@@ -169,13 +180,10 @@ class PutEventBuilder {
     PutEventBuilder& operator=(const PutEventBuilder&) BSLS_CPP11_DELETED;
 
   private:
-    // CLASS LEVEL METHODS
-
-    /// Reset flags and message guid of PutEventBuilder instance pointed by
-    /// the specified `ptr`.
-    static void resetFields(void* ptr);
-
     // PRIVATE MANIPULATORS
+    /// Reset flags and message guid of this object.
+    void resetFields();
+
     bmqt::EventBuilderResult::Enum
     packMessageInternal(const bdlbb::Blob& appData, int queueId);