reduce memory churn (#248)

* eliminated allocation in SetCurrentThreadName
* reduced memory allocator activity in cache RPC response building
* reduced allocations in compact binary building

4 files changed, 18 insertions, 6 deletions

diff --git a/src/zencore/compactbinarybuilder.cpp b/src/zencore/compactbinarybuilder.cpp
index 3331291ce..a60de023d 100644
--- a/src/zencore/compactbinarybuilder.cpp
+++ b/src/zencore/compactbinarybuilder.cpp
@@ -93,6 +93,7 @@ AppendCompactBinary(const CbFieldView& Value, std::vector<uint8_t>& OutData)
 
 CbWriter::CbWriter()
 {
+	States.reserve(4);
 	States.emplace_back();
 }
 
diff --git a/src/zencore/compactbinarypackage.cpp b/src/zencore/compactbinarypackage.cpp
index 0117b326e..7de161845 100644
--- a/src/zencore/compactbinarypackage.cpp
+++ b/src/zencore/compactbinarypackage.cpp
@@ -308,6 +308,11 @@ CbAttachment::AsObject() const
 
 ///////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
 
+CbPackage::CbPackage()
+{
+	Attachments.reserve(16);
+}
+
 void
 CbPackage::SetObject(CbObject InObject, const IoHash* InObjectHash, AttachmentResolver* InResolver)
 {
diff --git a/src/zencore/include/zencore/compactbinarypackage.h b/src/zencore/include/zencore/compactbinarypackage.h
index fe4a60a30..064481f83 100644
--- a/src/zencore/include/zencore/compactbinarypackage.h
+++ b/src/zencore/include/zencore/compactbinarypackage.h
@@ -172,14 +172,14 @@ public:
 	using AttachmentResolver = std::function<SharedBuffer(const IoHash& Hash)>;
 
 	/** Construct a null package. */
-	CbPackage() = default;
+	CbPackage();
 
 	/**
 	 * Construct a package from a root object without gathering attachments.
 	 *
 	 * @param InObject The root object, which will be cloned unless it is owned.
 	 */
-	inline explicit CbPackage(CbObject InObject) { SetObject(std::move(InObject)); }
+	inline explicit CbPackage(CbObject InObject) : CbPackage() { SetObject(std::move(InObject)); }
 
 	/**
 	 * Construct a package from a root object and gather attachments using the resolver.
@@ -187,7 +187,10 @@ public:
 	 * @param InObject The root object, which will be cloned unless it is owned.
 	 * @param InResolver A function that is invoked for every reference and binary reference field.
 	 */
-	inline explicit CbPackage(CbObject InObject, AttachmentResolver InResolver) { SetObject(std::move(InObject), InResolver); }
+	inline explicit CbPackage(CbObject InObject, AttachmentResolver InResolver) : CbPackage()
+	{
+		SetObject(std::move(InObject), InResolver);
+	}
 
 	/**
 	 * Construct a package from a root object without gathering attachments.
@@ -195,7 +198,7 @@ public:
 	 * @param InObject The root object, which will be cloned unless it is owned.
 	 * @param InObjectHash The hash of the object, which must match to avoid validation errors.
 	 */
-	inline explicit CbPackage(CbObject InObject, const IoHash& InObjectHash) { SetObject(std::move(InObject), InObjectHash); }
+	inline explicit CbPackage(CbObject InObject, const IoHash& InObjectHash) : CbPackage() { SetObject(std::move(InObject), InObjectHash); }
 
 	/**
 	 * Construct a package from a root object and gather attachments using the resolver.
@@ -204,7 +207,7 @@ public:
 	 * @param InObjectHash The hash of the object, which must match to avoid validation errors.
 	 * @param InResolver A function that is invoked for every reference and binary reference field.
 	 */
-	inline explicit CbPackage(CbObject InObject, const IoHash& InObjectHash, AttachmentResolver InResolver)
+	inline explicit CbPackage(CbObject InObject, const IoHash& InObjectHash, AttachmentResolver InResolver) : CbPackage()
 	{
 		SetObject(std::move(InObject), InObjectHash, InResolver);
 	}
diff --git a/src/zencore/thread.cpp b/src/zencore/thread.cpp
index 78afe924b..ab7e6857a 100644
--- a/src/zencore/thread.cpp
+++ b/src/zencore/thread.cpp
@@ -95,7 +95,10 @@ SetCurrentThreadName([[maybe_unused]] std::string_view ThreadName)
 
 	if (SetThreadDescriptionFunc)
 	{
-		SetThreadDescriptionFunc(::GetCurrentThread(), Utf8ToWide(ThreadName).c_str());
+		WideStringBuilder<256> ThreadNameW;
+		Utf8ToWide(ThreadName, ThreadNameW);
+
+		SetThreadDescriptionFunc(::GetCurrentThread(), ThreadNameW.c_str());
 	}
 
 	// The debugger needs to be around to catch the name in the exception.  If