Make save reading/writing more efficient

api/savedata-helper.go

@@ -1,7 +1,6 @@
 package api
 
 import (
-	"bytes"
 	"encoding/gob"
 	"encoding/hex"
 	"fmt"
@@ -15,24 +14,17 @@ import (
 func readSystemSaveData(uuid []byte) (defs.SystemSaveData, error) {
 	var system defs.SystemSaveData
 
-	save, err := os.ReadFile("userdata/" + hex.EncodeToString(uuid) + "/system.pzs")
+	file, err := os.Open("userdata/" + hex.EncodeToString(uuid) + "/system.pzs")
 	if err != nil {
-		return system, fmt.Errorf("failed to read save file: %s", err)
+		return system, fmt.Errorf("failed to open save file: %s", err)
 	}
 
-	zstdReader, err := zstd.NewReader(nil)
+	zstdDecoder, err := zstd.NewReader(file)
 	if err != nil {
-		return system, fmt.Errorf("failed to create zstd reader: %s", err)
+		return system, fmt.Errorf("failed to create zstd decoder: %s", err)
 	}
 
-	decompressed, err := zstdReader.DecodeAll(save, nil)
-	if err != nil {
-		return system, fmt.Errorf("failed to decompress save file: %s", err)
-	}
-
-	gobDecoderBuf := bytes.NewBuffer(decompressed)
-
-	err = gob.NewDecoder(gobDecoderBuf).Decode(&system)
+	err = gob.NewDecoder(zstdDecoder).Decode(&system)
 	if err != nil {
 		return system, fmt.Errorf("failed to deserialize save: %s", err)
 	}
@@ -48,24 +40,17 @@ func readSessionSaveData(uuid []byte, slotID int) (defs.SessionSaveData, error)
 		fileName += strconv.Itoa(slotID)
 	}
 
-	save, err := os.ReadFile(fmt.Sprintf("userdata/%s/%s.pzs", hex.EncodeToString(uuid), fileName))
+	file, err := os.Open(fmt.Sprintf("userdata/%s/%s.pzs", hex.EncodeToString(uuid), fileName))
 	if err != nil {
-		return session, fmt.Errorf("failed to read save file: %s", err)
+		return session, fmt.Errorf("failed to open save file: %s", err)
 	}
 
-	zstdReader, err := zstd.NewReader(nil)
+	zstdDecoder, err := zstd.NewReader(file)
 	if err != nil {
-		return session, fmt.Errorf("failed to create zstd reader: %s", err)
+		return session, fmt.Errorf("failed to create zstd decoder: %s", err)
 	}
 
-	decompressed, err := zstdReader.DecodeAll(save, nil)
-	if err != nil {
-		return session, fmt.Errorf("failed to decompress save file: %s", err)
-	}
-
-	gobDecoderBuf := bytes.NewBuffer(decompressed)
-
-	err = gob.NewDecoder(gobDecoderBuf).Decode(&session)
+	err = gob.NewDecoder(zstdDecoder).Decode(&session)
 	if err != nil {
 		return session, fmt.Errorf("failed to deserialize save: %s", err)
 	}

api/savedata.go

@@ -1,7 +1,6 @@
 package api
 
 import (
-	"bytes"
 	"encoding/gob"
 	"encoding/hex"
 	"fmt"
@@ -72,27 +71,24 @@ func handleSavedataUpdate(uuid []byte, slot int, save any) error {
 			return fmt.Errorf("failed to update account stats: %s", err)
 		}
 
-		var gobBuffer bytes.Buffer
-		err = gob.NewEncoder(&gobBuffer).Encode(save)
-		if err != nil {
-			return fmt.Errorf("failed to serialize save: %s", err)
-		}
-
-		zstdWriter, err := zstd.NewWriter(nil)
-		if err != nil {
-			return fmt.Errorf("failed to create zstd writer, %s", err)
-		}
-
-		compressed := zstdWriter.EncodeAll(gobBuffer.Bytes(), nil)
-
 		err = os.MkdirAll("userdata/"+hexUUID, 0755)
 		if err != nil && !os.IsExist(err) {
 			return fmt.Errorf("failed to create userdata folder: %s", err)
 		}
 
-		err = os.WriteFile("userdata/"+hexUUID+"/system.pzs", compressed, 0644)
+		file, err := os.OpenFile("userdata/"+hexUUID+"/system.pzs", os.O_WRONLY | os.O_TRUNC, 0644)
 		if err != nil {
-			return fmt.Errorf("failed to write save file: %s", err)
+			return fmt.Errorf("failed to open save file for writing: %s", err)
+		}
+
+		zstdEncoder, err := zstd.NewWriter(file)
+		if err != nil {
+			return fmt.Errorf("failed to create zstd encoder: %s", err)
+		}
+
+		err = gob.NewEncoder(zstdEncoder).Encode(save)
+		if err != nil {
+			return fmt.Errorf("failed to serialize save: %s", err)
 		}
 	case defs.SessionSaveData: // Session
 		if slot < 0 || slot >= sessionSlotCount {
@@ -104,27 +100,24 @@ func handleSavedataUpdate(uuid []byte, slot int, save any) error {
 			fileName += strconv.Itoa(slot)
 		}
 
-		var gobBuffer bytes.Buffer
-		err = gob.NewEncoder(&gobBuffer).Encode(save)
-		if err != nil {
-			return fmt.Errorf("failed to serialize save: %s", err)
-		}
-
-		zstdWriter, err := zstd.NewWriter(nil)
-		if err != nil {
-			return fmt.Errorf("failed to create zstd writer, %s", err)
-		}
-
-		compressed := zstdWriter.EncodeAll(gobBuffer.Bytes(), nil)
-
 		err = os.MkdirAll("userdata/"+hexUUID, 0755)
 		if err != nil && !os.IsExist(err) {
 			return fmt.Errorf(fmt.Sprintf("failed to create userdata folder: %s", err))
 		}
 
-		err = os.WriteFile(fmt.Sprintf("userdata/%s/%s.pzs", hexUUID, fileName), compressed, 0644)
+		file, err := os.OpenFile(fmt.Sprintf("userdata/%s/%s.pzs", hexUUID, fileName), os.O_WRONLY | os.O_TRUNC, 0644)
 		if err != nil {
-			return fmt.Errorf("failed to write save file: %s", err)
+			return fmt.Errorf("failed to open save file for writing: %s", err)
+		}
+		
+		zstdEncoder, err := zstd.NewWriter(file)
+		if err != nil {
+			return fmt.Errorf("failed to create zstd encoder: %s", err)
+		}
+
+		err = gob.NewEncoder(zstdEncoder).Encode(save)
+		if err != nil {
+			return fmt.Errorf("failed to serialize save: %s", err)
 		}
 
 		db.DeleteClaimedAccountCompensations(uuid)