[performance] update go-structr and go-mutexes with memory usage improvements (#2909)

* update go-structr and go-mutexes with memory usage improvements

* bump to go-structr v0.8.4

vendor/codeberg.org/gruf/go-mempool/pool.go

@@ -0,0 +1,99 @@
+package mempool
+
+import (
+	"unsafe"
+)
+
+const DefaultDirtyFactor = 128
+
+// Pool provides a type-safe form
+// of UnsafePool using generics.
+//
+// Note it is NOT safe for concurrent
+// use, you must protect it yourself!
+type Pool[T any] struct {
+
+	// New is an optionally provided
+	// allocator used when no value
+	// is available for use in pool.
+	New func() T
+
+	// Reset is an optionally provided
+	// value resetting function called
+	// on passed value to Put().
+	Reset func(T)
+
+	UnsafePool
+}
+
+func (p *Pool[T]) Get() T {
+	if ptr := p.UnsafePool.Get(); ptr != nil {
+		return *(*T)(ptr)
+	} else if p.New != nil {
+		return p.New()
+	}
+	var z T
+	return z
+}
+
+func (p *Pool[T]) Put(t T) {
+	if p.Reset != nil {
+		p.Reset(t)
+	}
+	ptr := unsafe.Pointer(&t)
+	p.UnsafePool.Put(ptr)
+}
+
+// UnsafePool provides an incredibly
+// simple memory pool implementation
+// that stores ptrs to memory values,
+// and regularly flushes internal pool
+// structures according to DirtyFactor.
+//
+// Note it is NOT safe for concurrent
+// use, you must protect it yourself!
+type UnsafePool struct {
+
+	// DirtyFactor determines the max
+	// number of $dirty count before
+	// pool is garbage collected. Where:
+	// $dirty = len(current) - len(victim)
+	DirtyFactor int
+
+	current []unsafe.Pointer
+	victim  []unsafe.Pointer
+}
+
+func (p *UnsafePool) Get() unsafe.Pointer {
+	// First try current list.
+	if len(p.current) > 0 {
+		ptr := p.current[len(p.current)-1]
+		p.current = p.current[:len(p.current)-1]
+		return ptr
+	}
+
+	// Fallback to victim.
+	if len(p.victim) > 0 {
+		ptr := p.victim[len(p.victim)-1]
+		p.victim = p.victim[:len(p.victim)-1]
+		return ptr
+	}
+
+	return nil
+}
+
+func (p *UnsafePool) Put(ptr unsafe.Pointer) {
+	p.current = append(p.current, ptr)
+
+	// Get dirty factor.
+	df := p.DirtyFactor
+	if df == 0 {
+		df = DefaultDirtyFactor
+	}
+
+	if len(p.current)-len(p.victim) > df {
+		// Garbage collection!
+		p.victim = p.current
+		p.current = nil
+	}
+}