real storage

level/rrrr.go

@@ -0,0 +1,153 @@
+package level
+
+import (
+	"errors"
+	"math"
+	"slices"
+)
+
+type RealStorageFormat struct {
+	AvailableBpes []uint8
+	BiggestDirect bool
+	Len           int32
+}
+
+var BpeNotAvailableErr = errors.New("bpe not available")
+var OutOfBoundsErr = errors.New("out of bounds")
+var AvailableBpeMustBeLenOneErr = errors.New("available bpe must be 1")
+var NoAvailableBpeErr = errors.New("no available bpe")
+
+func (r RealStorageFormat) Import(data []uint64, bpe uint8, palette []int32) (s *RealStorage, err error) {
+	if !slices.Contains(r.AvailableBpes, bpe) {
+		err = BpeNotAvailableErr
+		return
+	}
+	s = new(RealStorage)
+	s.format = r
+	s.resize(bpe)
+	s.data = data
+	s.palette = palette
+	return
+}
+
+func (r RealStorageFormat) ImportDataDirect(data []uint64) (s *RealStorage, err error) {
+	if len(r.AvailableBpes) != 1 {
+		err = AvailableBpeMustBeLenOneErr
+		return
+	}
+	return r.Import(data, r.AvailableBpes[0], nil)
+}
+
+type RealStorage struct {
+	format  RealStorageFormat
+	data    []uint64
+	bpe     uint8
+	palette []int32
+
+	elementsPerLong, maxAtCurrentBpe int32
+
+	mask uint64
+}
+
+func (r *RealStorage) doWeResizeDirect(bpe uint8) bool {
+	if !r.format.BiggestDirect || r.format.AvailableBpes == nil {
+		return false
+	}
+	return slices.Index(r.format.AvailableBpes, bpe) == len(r.format.AvailableBpes)-1
+}
+
+// only resizes upwards
+func (r *RealStorage) resize(bpe uint8) {
+	if bpe == 0 {
+		r.data = nil
+		r.bpe = 0
+		r.elementsPerLong = 0
+		r.mask = 0
+		r.maxAtCurrentBpe = 1
+		return
+	}
+	elementsPerLong := int32(64 / int(bpe))
+	numberOfLongs := int(math.Ceil(float64(r.format.Len) / float64(elementsPerLong)))
+	newData := make([]uint64, numberOfLongs)
+	mask := (uint64(1) << uint32(bpe)) - 1
+	maxAtCurrentBpe := int32(1 << bpe)
+	if r.bpe == 0 {
+		r.data = newData
+		r.bpe = bpe
+		r.elementsPerLong = elementsPerLong
+		r.mask = mask
+		r.maxAtCurrentBpe = maxAtCurrentBpe
+		return
+	}
+	resizeDirect := r.doWeResizeDirect(bpe)
+	for i := range r.format.Len {
+		var v int32
+		if resizeDirect {
+			v, _ = r.Get(i)
+		} else {
+			v = int32((r.data[i/r.elementsPerLong] >> ((i % r.elementsPerLong) * int32(r.bpe))) & r.mask)
+		}
+		newData[i/elementsPerLong] |= uint64(v) << ((i % elementsPerLong) * int32(bpe))
+	}
+	r.data = newData
+	r.bpe = bpe
+	r.elementsPerLong = elementsPerLong
+	r.mask = mask
+	r.maxAtCurrentBpe = maxAtCurrentBpe
+	return
+
+}
+
+func (r *RealStorage) Get(i int32) (s int32, err error) {
+	if i < 0 || i >= r.format.Len {
+		err = OutOfBoundsErr
+		return
+	}
+	v := int32((r.data[i/r.elementsPerLong] >> ((i % r.elementsPerLong) * int32(r.bpe))) & r.mask)
+	if r.palette == nil { // direct
+		s = v
+		return
+	}
+	s = r.palette[v] // should allways be true cause data checking
+	return
+}
+
+func (r *RealStorage) set(i int32, v int32) {
+	shift := (i % r.elementsPerLong) * int32(r.bpe)
+	r.data[i/r.elementsPerLong] = (r.data[i/r.elementsPerLong] & ^(r.mask << shift)) | (uint64(v) << shift)
+}
+
+func (r *RealStorage) Set(i int32, v int32) (err error) {
+	if i < 0 || i >= r.format.Len {
+		err = OutOfBoundsErr
+		return
+	}
+	if r.palette != nil {
+		iv := slices.Index(r.palette, v)
+		if iv == -1 {
+			iv, err = r.appendPalette(v)
+		}
+	}
+	return
+}
+
+func (r *RealStorage) appendPalette(v int32) (i int, err error) {
+	i = len(r.palette) + 1
+	if i <= int(r.maxAtCurrentBpe) {
+		r.palette = append(r.palette, v)
+		return
+	}
+	if r.format.AvailableBpes == nil {
+		err = NoAvailableBpeErr
+		return
+	}
+
+	bpei := slices.Index(r.format.AvailableBpes, r.bpe)
+	if bpei == len(r.format.AvailableBpes)-1 {
+		err = CannotGrowPalletErr
+		return
+	}
+	newBpe := r.format.AvailableBpes[bpei+1]
+	r.resize(newBpe)
+	return
+}

level/storage2.go

@@ -0,0 +1,13 @@
+package level
+
+// This is the func to generate a block storage or whatever like block storagw would be
+// Len=4096
+// DynamicResolver=dynamicblockresolver1.21.11
+// PossibleBpes=0, 4, 5, 6,7, 8, 9, 15
+// T=*BlockState
+func NewStorageFormat() {
+
+}
+
+// StorageFormat.ImportLongArrays(bpe, r) -> *Storage
+// StorageFormat.ImportReaderReader(bpe, r) -> *Storage

level/storage_test.go

@@ -82,7 +82,7 @@ func TestResizePreservesData(t *testing.T) {
 	for i, want := range []int32{10, 20, 30, 40} {
 		got := s.Get(i)
 		if got != want {
-			t.Errorf("Get(%d) = %d, want %d (Resize repacks with old BPE)", i, got, want)
+			t.Errorf("Get(%d) = %d, want %d (resize repacks with old BPE)", i, got, want)
 		}
 	}
 }
@@ -132,7 +132,7 @@ func TestResizeElementsPerLong(t *testing.T) {
 	s.Set(4, 50)
 
 	if s.ElementsPerLong != 16 {
-		t.Errorf("ElementsPerLong = %d, want 16 (Resize stores old ElementsPerLong)", s.ElementsPerLong)
+		t.Errorf("ElementsPerLong = %d, want 16 (resize stores old ElementsPerLong)", s.ElementsPerLong)
 	}
 }