diff --git a/src/wpiutil/Serialization/Struct/DynamicStruct.cs b/src/wpiutil/Serialization/Struct/DynamicStruct.cs index 01bf0eec..a843bbad 100644 --- a/src/wpiutil/Serialization/Struct/DynamicStruct.cs +++ b/src/wpiutil/Serialization/Struct/DynamicStruct.cs @@ -1,4 +1,5 @@ using System; +using System.Buffers; using System.Buffers.Binary; using System.Text; using CommunityToolkit.Diagnostics; @@ -138,52 +139,17 @@ public string GetStringField(StructFieldDescriptor field) break; } } - // If string is all zeroes, its empty and return an empty string. - if (stringLength == 0) - { - return ""; - } - // Check if the end of the string is in the middle of a continuation byte or not. - if ((bytes[stringLength - 1] & 0x80) != 0) - { - // This is a UTF8 continuation byte. Make sure its valid. - // Walk back until initial byte is found - int utf8StartByte = stringLength; - for (; utf8StartByte > 0; utf8StartByte--) - { - if ((bytes[utf8StartByte - 1] & 0x40) != 0) - { - // Having 2nd bit set means start byte - break; - } - } - if (utf8StartByte == 0) - { - // This case means string only contains continuation bytes - return ""; - } - utf8StartByte--; - // Check if its a 2, 3, or 4 byte - byte checkByte = bytes[utf8StartByte]; - if ((checkByte & 0xE0) == 0xC0 && utf8StartByte != stringLength - 2) - { - // 2 byte, need 1 more byte - stringLength = utf8StartByte; - } - else if ((checkByte & 0xF0) == 0xE0 && utf8StartByte != stringLength - 3) - { - // 3 byte, need 2 more bytes - stringLength = utf8StartByte; - } - else if ((checkByte & 0xF8) == 0xF0 && utf8StartByte != stringLength - 4) - { - // 4 byte, need 3 more bytes - stringLength = utf8StartByte; - } - // If we get here, the string is either completely garbage or fine. - } - return Encoding.UTF8.GetString(bytes[..stringLength]); + OperationStatus result = Rune.DecodeLastFromUtf8(bytes[..stringLength], out var lastChar, out var consumed); +#pragma warning disable CS8509 // The switch expression does not handle all possible values of its input type (it is not exhaustive). + ReadOnlySpan buffer = result switch { + OperationStatus.Done => bytes[..stringLength], // Correct character + OperationStatus.NeedMoreData => new(), // Standalone Surrogate or empty + OperationStatus.InvalidData => bytes[..(stringLength - consumed)] + }; +#pragma warning restore CS8509 // The switch expression does not handle all possible values of its input type (it is not exhaustive). + + return Encoding.UTF8.GetString(buffer); } public bool SetStringField(StructFieldDescriptor field, string value)