spatial-db/server/simple_server.go
2023-12-13 23:48:53 -08:00

113 lines
2.4 KiB
Go

package server
import (
"encoding/json"
"errors"
"io/fs"
"os"
"path/filepath"
"github.com/NickyBoy89/spatial-db/storage"
"github.com/NickyBoy89/spatial-db/world"
)
const fileCacheSize = 8
type SimpleServer struct {
StorageDir string
storageBackend storage.UnityFile
}
func (s *SimpleServer) SetStorageRoot(path string) {
s.StorageDir = path
var err error
s.storageBackend, err = storage.OpenUnityFile(path, path+".metadata")
if err != nil {
panic(err)
}
}
// Filesystem operations
func (s *SimpleServer) FetchOrCreateChunk(pos world.ChunkPos) (world.ChunkData, error) {
chunkFileName := filepath.Join(s.StorageDir, pos.ToFileName())
var chunkData world.ChunkData
chunkFile, err := os.Open(chunkFileName)
if err != nil {
if errors.Is(err, fs.ErrNotExist) {
// There was no chunk that exists, create a blank one
chunkFile, err = os.Create(chunkFileName)
if err != nil {
return chunkData, err
}
// Initilize the file with some blank data
if err := json.NewEncoder(chunkFile).Encode(chunkData); err != nil {
return chunkData, err
}
if _, err := chunkFile.Seek(0, 0); err != nil {
return chunkData, err
}
} else {
return chunkData, err
}
}
defer chunkFile.Close()
return storage.ReadChunkFromFile(chunkFile)
}
// `FetchChunk' fetches the chunk's data, given the chunk's position
func (s *SimpleServer) FetchChunk(pos world.ChunkPos) (world.ChunkData, error) {
chunkData, err := s.storageBackend.ReadChunk(pos)
if err != nil {
if errors.Is(err, fs.ErrNotExist) {
return chunkData, storage.ChunkNotFoundError
} else {
return chunkData, err
}
}
return chunkData, nil
}
// Voxel server implementation
func (s *SimpleServer) ChangeBlock(
worldPosition world.BlockPos,
targetState world.BlockID,
) error {
chunk, err := s.FetchOrCreateChunk(worldPosition.ToChunkPos())
if err != nil {
return err
}
chunk.SectionFor(worldPosition).UpdateBlock(worldPosition, targetState)
return nil
}
func (s *SimpleServer) ChangeBlockRange(
targetState world.BlockID,
start, end world.BlockPos,
) error {
panic("ChangeBlockRange is unimplemented")
}
func (s *SimpleServer) ReadBlockAt(pos world.BlockPos) (world.BlockID, error) {
chunk, err := s.FetchChunk(pos.ToChunkPos())
if err != nil {
return world.Empty, err
}
return chunk.SectionFor(pos).FetchBlock(pos), nil
}
func (s *SimpleServer) ReadChunkAt(pos world.ChunkPos) (world.ChunkData, error) {
return s.FetchOrCreateChunk(pos)
}