change: Finished benchmarking and some more features

storage/file_cache.go

@@ -3,6 +3,7 @@ package storage
 import (
 	"math/rand"
 	"os"
+	"time"
 )
 
 // A `FileCache` stores open file descriptors for all files that have been
@@ -12,6 +13,8 @@ type FileCache struct {
 	fileNames      map[string]int
 	indexesOfFiles map[int]string
 	files          []*os.File
+
+	randSource *rand.Rand
 }
 
 func NewFileCache(cacheSize int) FileCache {
@@ -22,6 +25,8 @@ func NewFileCache(cacheSize int) FileCache {
 	c.indexesOfFiles = make(map[int]string)
 	c.files = make([]*os.File, cacheSize)
 
+	c.randSource = rand.New(rand.NewSource(time.Now().UnixNano()))
+
 	return c
 }
 
@@ -36,8 +41,13 @@ func (fc *FileCache) FetchFile(fileName string) (*os.File, error) {
 
 	// The file was not in the cache, try and insert it
 
+	f, err := os.Open(fileName)
+	if err != nil {
+		return nil, err
+	}
+
 	// Random cache eviction
-	indexToRemove := rand.Intn(fc.cacheSize)
+	indexToRemove := fc.randSource.Intn(fc.cacheSize)
 
 	// Remove the old value
 	oldName, present := fc.indexesOfFiles[indexToRemove]
@@ -48,11 +58,6 @@ func (fc *FileCache) FetchFile(fileName string) (*os.File, error) {
 		delete(fc.indexesOfFiles, indexToRemove)
 	}
 
-	f, err := os.Open(fileName)
-	if err != nil {
-		return nil, err
-	}
-
 	// Insert the new value
 	fc.files[indexToRemove] = f
 	fc.fileNames[fileName] = indexToRemove

storage/hashserver.go

@@ -69,7 +69,7 @@ func (hs *HashServer) ChangeBlockRange(
 }
 
 func (hs *HashServer) ReadBlockAt(pos world.BlockPos) (world.BlockID, error) {
-	panic("Unimplemented")
+	return hs.blocks[pos], nil
 }
 
 func (hs *HashServer) ReadChunkAt(pos world.ChunkPos) (world.ChunkData, error) {

storage/simple_server.go

@@ -18,10 +18,12 @@ var (
 
 type SimpleServer struct {
 	StorageDir string
+	cache      FileCache
 }
 
 func (s *SimpleServer) SetStorageRoot(path string) {
 	s.StorageDir = path
+	s.cache = NewFileCache(256)
 }
 
 // Filesystem operations
@@ -57,12 +59,13 @@ func (s *SimpleServer) FetchOrCreateChunk(pos world.ChunkPos) (world.ChunkData,
 	return ReadChunkFromFile(chunkFile)
 }
 
+// `FetchChunk' fetches the chunk's data, given the chunk's position
 func (s *SimpleServer) FetchChunk(pos world.ChunkPos) (world.ChunkData, error) {
 	chunkFileName := filepath.Join(s.StorageDir, pos.ToFileName())
 
 	var chunkData world.ChunkData
 
-	chunkFile, err := os.Open(chunkFileName)
+	chunkFile, err := s.cache.FetchFile(chunkFileName)
 	if err != nil {
 		if errors.Is(err, fs.ErrNotExist) {
 			return chunkData, ChunkNotFoundError
@@ -70,7 +73,6 @@ func (s *SimpleServer) FetchChunk(pos world.ChunkPos) (world.ChunkData, error) {
 			return chunkData, err
 		}
 	}
-	defer chunkFile.Close()
 
 	return ReadChunkFromFile(chunkFile)
 }
@@ -99,7 +101,7 @@ func (s *SimpleServer) ChangeBlockRange(
 }
 
 func (s *SimpleServer) ReadBlockAt(pos world.BlockPos) (world.BlockID, error) {
-	chunk, err := s.FetchOrCreateChunk(pos.ToChunkPos())
+	chunk, err := s.FetchChunk(pos.ToChunkPos())
 	if err != nil {
 		return world.Empty, err
 	}