IsoFilePatcher-Archive/Iso9660/PathEntry.cs

using System;
using System.Collections.Generic;
using System.Diagnostics;
using System.IO;
using System.Text;

namespace IsoFilePatcher.Iso9660
{
    [DebuggerDisplay("\\{ Name={Name} {ChildPathEntries} \\}")]
    internal class PathEntry
    {
        public static PathEntry Parse(Stream stream, VolumeDescriptor volumeDescriptor)
        {
            var obj = new PathEntry();
            obj.VolumeDescriptor = volumeDescriptor;
            obj.Read(stream);
            return obj;
        }

        public VolumeDescriptor VolumeDescriptor { get; set; }

        private void Read(Stream stream)
        {
            var begin = stream.Position; // For DEBUGGING watch

            var len = stream.ReadByte(); //this byte included in size
            if (len == 0)
            {
                InvalidData = true;
                return;
            }

            int nameByteLen;
            using (var br = new BinaryReader(stream, Encoding.ASCII, true))
            {
                ExtendedAttributeRecordlength = br.ReadByte();
                ExtentLba = br.ReadUInt32LsbMsb();
                DataLength = br.ReadUInt32LsbMsb();
                Date = br.ReadFileRecordDate();
                FileFlags = br.ReadByte();
                FileUnitSize = br.ReadByte();
                InterleaveGapSize = br.ReadByte();
                VolumeSequenceNumber = br.ReadUInt16LsbMsb();
                nameByteLen = br.ReadByte();
                Name = br.ReadString(nameByteLen, VolumeDescriptor.Encoding);
                if (Name.EndsWith(";1"))
                    Name = Name.Substring(0, Name.Length - 2);

                if (nameByteLen % 2 == 0)
                {
                    PaddingByte = br.ReadByte();
                    if (PaddingByte != 0)
                    {
                        throw new InvalidDataException("Invalid padding byte, data error?");
                    }
                }

                var remain = len - (stream.Position - begin);
                if (remain > 0)
                    RemainBytes = br.ReadBytes((int)remain);
            }
        }

        public byte? PaddingByte { get; set; }

        public byte[] RemainBytes { get; set; }

        public bool InvalidData { get; set; }

        public string Name { get; set; }

        public ushort VolumeSequenceNumber { get; set; }

        public byte InterleaveGapSize { get; set; }

        public byte FileUnitSize { get; set; }

        public byte FileFlags { get; set; }

        public DateTime Date { get; set; }

        public uint DataLength { get; set; }

        public uint ExtentLba { get; set; }

        public byte ExtendedAttributeRecordlength { get; set; }

        public bool IsHidden => (FileFlags & 1) != 0;
        public bool IsDirectory => (FileFlags & (1 << 1)) != 0;
        public bool IsAssociatedFile => (FileFlags & (1 << 2)) != 0;

        public PathEntry[] ChildPathEntries { get; set; }

        public void ScanChilds(Stream stream)
        {
            stream.Seek(ExtentLba * VolumeDescriptor.LogicalBlockSize, SeekOrigin.Begin);

            var list = new List<PathEntry>();

            var endofData = stream.Position + DataLength;
            while (stream.Position < endofData)
            {
                var item = Parse(stream, VolumeDescriptor);
                if (VolumeDescriptor.Type == 1)
                    if (item.Name == "\0" || item.Name == "\u0001") continue;
                if(VolumeDescriptor.Type==2)
                    if (item.Name == "�" || item.Name == "\u0001") continue;
                if (item.InvalidData) break;
                list.Add(item);
            }
            ChildPathEntries = list.ToArray();

            list.ForEach(p =>
            {
                if (p.IsDirectory)
                    p.ScanChilds(stream);
            });
        }
    }
}