struct column and chunk, and optimization

save/chunk.go

@@ -0,0 +1,71 @@
+package save
+
+import (
+	"bytes"
+	"compress/gzip"
+	"compress/zlib"
+	"errors"
+	"github.com/Tnze/go-mc/nbt"
+	"io"
+)
+
+// Column is 16* chunk
+type Column struct {
+	DataVersion int
+	Level       struct {
+		Heightmaps map[string][]int64
+		Structures struct {
+			References map[string][]int64
+			Starts     map[string]struct {
+				ID string `nbt:"id"`
+			}
+		}
+		// Entities
+		// LiquidTicks
+		// PostProcessing
+		Sections []Chunk
+		// TileEntities
+		// TileTicks
+		InhabitedTime int64
+		IsLightOn     byte `nbt:"isLightOn"`
+		LastUpdate    int64
+		Status        string
+		PosX          int32 `nbt:"xPos"`
+		PosY          int32 `nbt:"yPos"`
+		Biomes        []int32
+	}
+}
+
+type Chunk struct {
+	Palette     []Block
+	Y           byte
+	BlockLight  []byte
+	BlockStates []int64
+	SkyLight    []byte
+}
+
+type Block struct {
+	Name       string
+	Properties map[string]interface{}
+}
+
+// Load read column data from []byte
+func (c *Column) Load(data []byte) (err error) {
+	var r io.Reader = bytes.NewReader(data[1:])
+
+	switch data[0] {
+	default:
+		err = errors.New("unknown compression")
+	case 1:
+		r, err = gzip.NewReader(r)
+	case 2:
+		r, err = zlib.NewReader(r)
+	}
+
+	if err != nil {
+		return err
+	}
+
+	err = nbt.NewDecoder(r).Decode(c)
+	return
+}

save/chunk_test.go

@@ -0,0 +1,53 @@
+package save
+
+import (
+	"github.com/Tnze/go-mc/save/region"
+	"math/rand"
+	"testing"
+)
+
+func TestColumn(t *testing.T) {
+	var c Column
+	r, err := region.Open("testdata/region/r.0.0.mca")
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer r.Close()
+
+	data, err := r.ReadSector(0, 0)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	err = c.Load(data)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	t.Logf("%+v", c)
+}
+
+func BenchmarkColumn_Load(b *testing.B) {
+	// Test how many time we load a chunk
+	var c Column
+	r, err := region.Open("testdata/region/r.-1.-1.mca")
+	if err != nil {
+		b.Fatal(err)
+	}
+	defer r.Close()
+
+	for i := 0; i < b.N; i++ {
+		//x, y := (i%1024)/32, (i%1024)%32
+		x, y := rand.Intn(32), rand.Intn(32)
+
+		data, err := r.ReadSector(x, y)
+		if err != nil {
+			b.Fatal(err)
+		}
+
+		err = c.Load(data)
+		if err != nil {
+			b.Fatal(err)
+		}
+	}
+}

save/region/mca.go

@@ -8,6 +8,7 @@ import (
 	"time"
 )
 
+// Region contain 32*32 chunks in one .mca file
 type Region struct {
 	f          *os.File
 	offsets    [32][32]int32
@@ -26,9 +27,9 @@ func In(cx, cy int) (int, int) {
 	return cx & 31, cy & 31
 }
 
-// OpenRegion open a .mca file and read the head.
+// Open open a .mca file and read the head.
 // Close the Region after used.
-func OpenRegion(name string) (r *Region, err error) {
+func Open(name string) (r *Region, err error) {
 	r = new(Region)
 	r.sectors = make(map[int32]bool)
 
@@ -67,6 +68,7 @@ func OpenRegion(name string) (r *Region, err error) {
 	return r, nil
 }
 
+// Close close the region file
 func (r *Region) Close() error {
 	return r.f.Close()
 }
@@ -75,6 +77,7 @@ func sectorLoc(offset int32) (o, s int32) {
 	return offset >> 8, offset & 0xFF
 }
 
+// ReadSector find and read the Chunk data from region
 func (r *Region) ReadSector(x, y int) (data []byte, err error) {
 	offset, _ := sectorLoc(r.offsets[x][y])
 
@@ -99,6 +102,7 @@ func (r *Region) ReadSector(x, y int) (data []byte, err error) {
 	return
 }
 
+// WriteSector write Chunk data into region file
 func (r *Region) WriteSector(x, y int, data []byte) error {
 	need := int32(len(data)+4)/4096 + 1
 	n, now := sectorLoc(r.offsets[x][y])
@@ -155,6 +159,11 @@ func (r *Region) WriteSector(x, y int, data []byte) error {
 	return nil
 }
 
+// ExistSector return if a sector is exist
+func (r *Region) ExistSector(x, y int) bool {
+	return r.offsets[x][y] != 0
+}
+
 func (r *Region) findSpace(need int32) (n int32) {
 	for i := int32(0); i < need; i++ {
 		if r.sectors[n+i] {

save/region/mca_test.go

@@ -22,7 +22,7 @@ func TestIn(t *testing.T) {
 }
 
 func TestReadRegion(t *testing.T) {
-	r, err := OpenRegion("../testdata/region/r.0.-1.mca")
+	r, err := Open("../testdata/region/r.0.-1.mca")
 	if err != nil {
 		t.Fatal(err)
 	}
@@ -77,3 +77,21 @@ func TestFindSpace(t *testing.T) {
 		}
 	}
 }
+
+func TestCountChunks(t *testing.T) {
+	r, err := Open("../testdata/region/r.-1.-1.mca")
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer r.Close()
+
+	var count int
+	for i := 0; i < 32; i++ {
+		for j := 0; j < 32; j++ {
+			if r.ExistSector(i, j) {
+				count++
+			}
+		}
+	}
+	t.Logf("chunk count: %d", count)
+}