Add CompressSave, with Chinese instructions in READMEs

CompressSave/SaveUtil.cs

@@ -0,0 +1,99 @@
+using System;
+using System.IO;
+using BepInEx.Logging;
+using CompressSave.LZ4Wrap;
+
+namespace CompressSave;
+
+class SaveUtil
+{
+    public static ManualLogSource logger;
+        
+
+    public static readonly Version VerifiedVersion = new Version
+    {
+        Major = 0,
+        Minor = 9,
+        Release = 26,
+    };
+
+    public static string UnzipToFile(LZ4DecompressionStream lzStream, string fullPath)
+    {
+        lzStream.ResetStream();
+        string dir = Path.GetDirectoryName(fullPath);
+        string filename = "[Recovery]-" + Path.GetFileNameWithoutExtension(fullPath);
+        fullPath = Path.Combine(dir, filename + GameSave.saveExt);
+        int i = 0;
+        while(File.Exists(fullPath))
+        {
+            fullPath = Path.Combine(dir, $"{filename}[{i++}]{GameSave.saveExt}"); 
+        }
+        var buffer = new byte[1024 * 1024];
+        using (var fs = new FileStream(fullPath, FileMode.Create))
+        using (var br = new BinaryWriter(fs))
+        {
+            for (int read = lzStream.Read(buffer, 0, buffer.Length); read > 0; read = lzStream.Read(buffer, 0, buffer.Length))
+            {
+                fs.Write(buffer, 0, read);
+            }
+            fs.Seek(6L, SeekOrigin.Begin);
+            br.Write(fs.Length);
+
+        }
+        return Path.GetFileNameWithoutExtension(fullPath);
+    }
+
+    public static bool DecompressSave(string saveName, out string newSaveName)
+    {
+        newSaveName = string.Empty;
+        string path = GameConfig.gameSaveFolder + saveName + GameSave.saveExt;
+        try
+        {
+            using (FileStream fileStream = new FileStream(path, FileMode.Open, FileAccess.Read))
+            {
+                if (!IsCompressedSave(fileStream)) return false;
+                using (var lzstream = new LZ4DecompressionStream(fileStream))
+                {
+                    newSaveName = UnzipToFile(lzstream, path);
+                }
+            }
+            return true;
+        }
+        catch (Exception e)
+        {
+            logger.LogError(e);
+            return false;
+        }
+    }
+    public static bool IsCompressedSave(FileStream fs)
+    {
+        for (int i = 0; i < 4; i++)
+        {
+            if (0xCC != fs.ReadByte())
+                return false;
+        }
+        return true;
+    }
+
+    internal static bool IsCompressedSave(string saveName)
+    {
+        if (string.IsNullOrEmpty(saveName)) return false;
+        try
+        {
+            using (FileStream fileStream = new FileStream(GetFullSavePath(saveName), FileMode.Open))
+                return IsCompressedSave(fileStream);
+        }
+        catch (Exception e)
+        {
+            logger.LogWarning(e);
+            return false;
+        }
+    }
+
+    public static string GetFullSavePath(string saveName) => GameConfig.gameSaveFolder + saveName + GameSave.saveExt;
+
+    public static bool VerifyVersion(int majorVersion, int minorVersion, int releaseVersion)
+    {
+        return new Version(majorVersion, minorVersion, releaseVersion) == VerifiedVersion;
+    }
+}