From 562836ac5e554c3abe0da00ce4f61669e1a1865f Mon Sep 17 00:00:00 2001
From: Tnze <cjd001113@outlook.com>
Date: Sun, 22 May 2022 09:58:41 +0800
Subject: [PATCH] dim manager test 1

---
 save/chunk.go                   | 17 ++++++++
 server/dimension/loadmanager.go | 53 +++++++++++++++++++++++
 server/dimension/pool.go        | 74 +++++++++++++++++++++++++++++++++
 3 files changed, 144 insertions(+)
 create mode 100644 server/dimension/loadmanager.go
 create mode 100644 server/dimension/pool.go

diff --git a/save/chunk.go b/save/chunk.go
index 83a72ca..9975f2e 100644
--- a/save/chunk.go
+++ b/save/chunk.go
@@ -74,3 +74,20 @@ func (c *Chunk) Load(data []byte) (err error) {
 	_, err = nbt.NewDecoder(r).Decode(c)
 	return
 }
+
+func (c *Chunk) Data(compressingType byte) ([]byte, error) {
+	var buff bytes.Buffer
+
+	buff.WriteByte(compressingType)
+	var w io.Writer
+	switch compressingType {
+	default:
+		return nil, errors.New("unknown compression")
+	case 1:
+		w = gzip.NewWriter(&buff)
+	case 2:
+		w = zlib.NewWriter(&buff)
+	}
+	err := nbt.NewEncoder(w).Encode(c, "")
+	return buff.Bytes(), err
+}
diff --git a/server/dimension/loadmanager.go b/server/dimension/loadmanager.go
new file mode 100644
index 0000000..37c3640
--- /dev/null
+++ b/server/dimension/loadmanager.go
@@ -0,0 +1,53 @@
+package dimension
+
+import (
+	"container/list"
+
+	"github.com/Tnze/go-mc/level"
+)
+
+type manager struct {
+	storage
+	elements     map[level.ChunkPos]*list.Element
+	activeChunks *list.List
+
+	chunkLoadQueue   []level.ChunkPos
+	chunkUnloadQueue []level.ChunkPos
+}
+
+type chunkHandler struct {
+	level.ChunkPos
+	*level.Chunk
+}
+
+func (m *manager) refresh(players [][2]int) {
+	m.chunkLoadQueue = m.chunkLoadQueue[:0]
+	m.chunkUnloadQueue = m.chunkUnloadQueue[:0]
+
+	newActives := list.New()
+	const N = 16
+	for _, p := range players {
+		for i := 1 - N; i < N; i++ {
+			for j := 1 - N; j < N; j++ {
+				pos := level.ChunkPos{
+					X: p[0] + i,
+					Z: p[1] + j,
+				}
+				if e := m.elements[pos]; e != nil {
+					// chunk exist, move into newActives
+					v := m.activeChunks.Remove(e)
+					m.elements[pos] = newActives.PushBack(v)
+				} else {
+					// not exist, load from storage
+					m.chunkLoadQueue = append(m.chunkLoadQueue, pos)
+				}
+			}
+		}
+	}
+	for e := m.activeChunks.Front(); e != nil; e = e.Next() {
+		pos := e.Value.(chunkHandler).ChunkPos
+		m.chunkUnloadQueue = append(m.chunkUnloadQueue, pos)
+		m.elements[pos] = newActives.PushBack(e.Value)
+	}
+	m.activeChunks = newActives
+}
diff --git a/server/dimension/pool.go b/server/dimension/pool.go
new file mode 100644
index 0000000..b435fc8
--- /dev/null
+++ b/server/dimension/pool.go
@@ -0,0 +1,74 @@
+package dimension
+
+import (
+	"fmt"
+	"path/filepath"
+
+	"github.com/Tnze/go-mc/level"
+	"github.com/Tnze/go-mc/save"
+	"github.com/Tnze/go-mc/save/region"
+)
+
+// TODO: Cache regions and chunks
+type storage struct {
+	regionDir string
+}
+
+func (s *storage) GetChunk(pos level.ChunkPos) (lc *level.Chunk, err error) {
+	filename := fmt.Sprintf("r.%d.%d.mca", pos.X>>5, pos.Z>>5)
+
+	var r *region.Region
+	r, err = region.Open(filepath.Join(s.regionDir, filename))
+	if err != nil {
+		return nil, err
+	}
+	defer func() {
+		err2 := r.Close()
+		if err == nil && err2 != nil {
+			err = err2
+		}
+	}()
+
+	sector, err := r.ReadSector(region.In(pos.X, pos.Z))
+	if err != nil {
+		return nil, err
+	}
+
+	var sc save.Chunk
+	err = sc.Load(sector)
+	if err != nil {
+		return nil, err
+	}
+
+	return level.ChunkFromSave(&sc)
+}
+
+func (s *storage) PutChunk(pos level.ChunkPos, c *level.Chunk) (err error) {
+	var sc save.Chunk
+	err = level.ChunkToSave(c, &sc)
+	if err != nil {
+		return
+	}
+
+	var data []byte
+	data, err = sc.Data(1)
+	if err != nil {
+		return
+	}
+
+	filename := fmt.Sprintf("r.%d.%d.mca", pos.X>>5, pos.Z>>5)
+	var r *region.Region
+	r, err = region.Open(filepath.Join(s.regionDir, filename))
+	if err != nil {
+		return err
+	}
+	defer func() {
+		err2 := r.Close()
+		if err == nil && err2 != nil {
+			err = err2
+		}
+	}()
+	x, z := region.In(pos.X, pos.Z)
+	err = r.WriteSector(x, z, data)
+	return
+}