I dunno man

fxl.codes.kisekae.data/Archives/Algorithms/LZW.cs

@@ -4,24 +4,38 @@ namespace fxl.codes.kisekae.data.Archives.Algorithms;
 
 internal class LZW : IAlgorithm
 {
+    private static readonly Dictionary<uint, string> DecodeDictionary;
+    private static readonly Dictionary<string, uint> EncodeDictionary;
     private readonly int Max;
 
+    static LZW()
+    {
+        DecodeDictionary = new Dictionary<uint, string>();
+        EncodeDictionary = new Dictionary<string, uint>();
+
+        for (uint i = 0; i <= byte.MaxValue; i++)
+        {
+            var value = $"{(char)i}";
+            DecodeDictionary.Add(i, value);
+            EncodeDictionary.Add(value, i);
+        }
+    }
+
     internal LZW(int max = short.MaxValue)
     {
         Max = max;
     }
 
-    public byte[] Decode(ReadOnlySpan<byte> stream)
+    public byte[] Decode(Stream stream, int bitLength = 32)
     {
+        var dictionary = DecodeDictionary.ToDictionary(x => x.Key, x => x.Value);
         uint next = byte.MaxValue + 1;
-        var dictionary = new Dictionary<uint, string>();
-        for (uint i = 0; i <= byte.MaxValue; i++) dictionary.Add(i, $"{(char)i}");
-
         var buffer = "";
         var decoded = new List<string>();
-        for (var i = 0; i < stream.Length; i += 4)
+        var bitStream = new BitStream(stream);
+        while (bitStream.Position < bitStream.Length)
         {
-            var code = BitConverter.ToUInt32(stream[i..(i + 4)]);
+            var code = bitStream.ReadBits(bitLength);
             if (!dictionary.ContainsKey(code)) dictionary[code] = buffer + buffer[0];
 
             decoded.Add(dictionary[code]);
@@ -33,17 +47,18 @@ internal class LZW : IAlgorithm
         return decoded.SelectMany(Encoding.UTF8.GetBytes).ToArray();
     }
 
-    public byte[] Encode(ReadOnlySpan<byte> stream)
+    public byte[] Encode(Stream stream)
     {
-        var next = byte.MaxValue + 1;
-        var dictionary = new Dictionary<string, int>();
-        for (var i = 0; i <= byte.MaxValue; i++) dictionary.Add($"{(char)i}", i);
+        uint next = byte.MaxValue + 1;
+        var dictionary = EncodeDictionary.ToDictionary(x => x.Key, x => x.Value);
 
         var buffer = "";
-        var encoded = new List<int>();
-        foreach (var part in stream)
+        var encoded = new List<uint>();
+        while (true)
         {
-            var charValue = (char)part;
+            if (stream.Position >= stream.Length) break;
+
+            var charValue = (char)stream.ReadByte();
             buffer += charValue;
             if (dictionary.ContainsKey(buffer)) continue;
             if (next <= Max) dictionary.Add(buffer, next++);