switched to raw slice

README.md

@@ -10,10 +10,10 @@ goos: darwin
 goarch: amd64
 pkg: github.com/vtopc/go-airmat
 cpu: Intel(R) Core(TM) i7-9750H CPU @ 2.60GHz
-BenchmarkMakeSlices/8-4         	 1677363	       731.3 ns/op	    4080 B/op	       8 allocs/op
-BenchmarkMakeSlices/16-4         	   10000	    105324 ns/op	 1048563 B/op	      16 allocs/op
-BenchmarkMakeSlices/24-4         	     100	  15483531 ns/op	268435443 B/op	      24 allocs/op
-BenchmarkPool/8-4                	 4156912	       288.8 ns/op	       0 B/op	       0 allocs/op
-BenchmarkPool/16-4               	   56299	     19531 ns/op	       9 B/op	       0 allocs/op
-BenchmarkPool/24-4               	     133	   8669618 ns/op	      13 B/op	       0 allocs/op
+BenchmarkMakeSlices/8-4 	 1573507	       719.0 ns/op	    4080 B/op	       8 allocs/op
+BenchmarkMakeSlices/16-4         	   10000	    125151 ns/op	 1048562 B/op	      16 allocs/op
+BenchmarkMakeSlices/24-4         	     100	  18851436 ns/op	268435446 B/op	      24 allocs/op
+BenchmarkPool/8-4                	 3459918	       289.3 ns/op	       0 B/op	       0 allocs/op
+BenchmarkPool/16-4               	   54115	     20723 ns/op	       9 B/op	       0 allocs/op
+BenchmarkPool/24-4               	     110	  11347946 ns/op	      15 B/op	       0 allocs/op
 ```

mattress.go

@@ -1,26 +1,22 @@
 package airmat
 
-// Mattress is a container for a Slice.
-// Slice should be updated by the index, not with append(...) func.
-type Mattress[T any] struct {
-	Slice []T
-}
+// Mattress is a sync.Pool compatible slice,
+// should be updated by the index, not with append(...) func.
+type Mattress[T any] []T
 
-func NewMattress[T any](size int) *Mattress[T] {
-	return &Mattress[T]{
-		Slice: make([]T, size),
-	}
+func NewMattress[T any](size int) Mattress[T] {
+	return make([]T, size)
 }
 
 // SetSize extends or shrinks length of underlying Slice.
 func (m *Mattress[T]) SetSize(size int) {
-	if m.Slice == nil {
-		m.Slice = make([]T, size)
+	if m == nil || *m == nil {
+		*m = make([]T, size)
 
 		return
 	}
 
-	l := len(m.Slice)
+	l := len(*m)
 
 	switch {
 	case l == size:
@@ -33,19 +29,11 @@ func (m *Mattress[T]) SetSize(size int) {
 }
 
 func (m *Mattress[T]) extend(l int) {
-	diff := l - len(m.Slice)
+	diff := l - len(*m)
 
-	// if diff < 0 {
-	// 	return
-	// }
-
-	m.Slice = append(m.Slice, make([]T, diff)...)
+	*m = append(*m, make([]T, diff)...)
 }
 
 func (m *Mattress[T]) shrink(l int) {
-	// if len(m.Slice) < len {
-	// 	return
-	// }
-
-	m.Slice = m.Slice[:l]
+	*m = (*m)[:l]
 }

mattress_test.go

@@ -15,41 +15,41 @@ func TestNewMattress(t *testing.T) {
 
 	t.Run("simple", func(t *testing.T) {
 		m := NewMattress[int](size)
-		assert.Len(t, m.Slice, size)
+		assert.Len(t, m, size)
 	})
 
 	t.Run("struct", func(t *testing.T) {
 		m := NewMattress[S](size)
-		assert.Len(t, m.Slice, size)
+		assert.Len(t, m, size)
 
-		m.Slice[1].F = 42
-		assert.Equal(t, m.Slice[1].F, 42)
+		m[1].F = 42
+		assert.Equal(t, m[1].F, 42)
 	})
 
 	t.Run("struct_ptr", func(t *testing.T) {
 		m := NewMattress[*S](size)
-		assert.Len(t, m.Slice, size)
+		assert.Len(t, m, size)
 
 		// TODO: automate?
-		if m.Slice[1] == nil {
-			m.Slice[1] = &S{}
+		if m[1] == nil {
+			m[1] = &S{}
 		}
 
-		m.Slice[1].F = 42
-		assert.Equal(t, m.Slice[1].F, 42)
+		m[1].F = 42
+		assert.Equal(t, m[1].F, 42)
 	})
 }
 
 func TestMattress_Grow(t *testing.T) {
 	tests := []struct {
 		name string
-		m    *Mattress[string]
+		m    Mattress[string]
 		len  int
 		cap  int
 	}{
 		{
 			name: "nil",
-			m:    &Mattress[string]{},
+			m:    nil,
 			len:  size,
 			cap:  size,
 		},
@@ -88,8 +88,8 @@ func TestMattress_Grow(t *testing.T) {
 	for _, tt := range tests {
 		t.Run(tt.name, func(t *testing.T) {
 			tt.m.SetSize(tt.len)
-			assert.Equal(t, tt.len, len(tt.m.Slice))
-			assert.Equal(t, tt.cap, cap(tt.m.Slice))
+			assert.Equal(t, tt.len, len(tt.m))
+			assert.Equal(t, tt.cap, cap(tt.m))
 		})
 	}
 }