Prepare internal cpio parsing

NyaFs/Filesystem/Cpio/CpioFsReader.cs

@@ -0,0 +1,81 @@
+using Extension.Array;
+using Extension.Packet;
+using NyaFs.Filesystem.Universal;
+using System;
+using System.Collections.Generic;
+using System.Text;
+
+namespace NyaFs.Filesystem.Cpio
+{
+    class CpioFsReader : RawPacket, Universal.IFilesystemReader
+    {
+        private List<Types.CpioNode> Nodes = new List<Types.CpioNode>();
+
+        public CpioFsReader(byte[] Data) : base(Data) { Init(); }
+
+        public CpioFsReader(string Filename) : this(System.IO.File.ReadAllBytes(Filename)) { }
+
+        private void Init()
+        {
+            long Offset = 0;
+            while (Offset < Data.Length)
+            {
+                var FI = new Types.CpioFileInfo(Data, Offset);
+
+                if (FI.IsCorrectMagic)
+                {
+                    var Raw = Data.ReadArray(Offset, FI.FullFileBlockSize);
+                    var F = new Types.CpioNode(Raw);
+
+                    if (!FI.IsTrailer)
+                    {
+                        Nodes.Add(F);
+
+                        Offset += FI.FullFileBlockSize;
+                    }
+                }
+                else
+                    break;
+            }
+        }
+
+        private string UnifyPath(string Path)
+        {
+            if (Path.Length > 0)
+                return (Path[0] == '/') ? Path.Substring(1) : Path;
+            else
+                return Path;
+        }
+
+        byte[] IFilesystemReader.Read(string Path)
+        {
+            foreach (var N in Nodes)
+            {
+                if (UnifyPath(N.Path) == UnifyPath(Path))
+                    return N.Content;
+            }
+
+            return null;
+        }
+
+        FilesystemEntry[] IFilesystemReader.ReadDir(string Path)
+        {
+            var Res = new List<FilesystemEntry>();
+            Path = UnifyPath(Path);
+            foreach (var N in Nodes)
+            {
+                var UPath = UnifyPath(N.Path);
+                int Pos = UPath.IndexOf(Path);
+                if(Pos == 0)
+                {
+                    Pos = Pos + Path.Length + 1;
+                    if(UPath.IndexOf('/', Pos) < 0)
+                    {
+                        Res.Add(new FilesystemEntry(N.FsType, UPath, N.UserId, N.GroupId, N.HexMode, Convert.ToUInt32(N.Content.Length)));
+                    }
+                }
+            }
+            return Res.ToArray();
+        }
+    }
+}

NyaFs/Filesystem/Cpio/Types/CpioFileInfo.cs

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+using Extension.Array;
+using System;
+using System.Collections.Generic;
+using System.Text;
+
+namespace NyaFs.Filesystem.Cpio.Types
+{
+    class CpioFileInfo
+    {
+        private byte[] Raw;
+        private long Offset;
+
+        public CpioFileInfo(byte[] Raw, long Offset)
+        {
+            this.Raw = Raw;
+            this.Offset = Offset;
+        }
+
+        public bool IsCorrectMagic => Magic == "070701";
+
+        private UInt32 GetAsciiValue(long HeaderOffset, int Size)
+        {
+            var Text = Raw.ReadString(Offset + HeaderOffset, Size);
+            return Convert.ToUInt32(Text, 16);
+        }
+
+        /// <summary>
+        /// The string 070701 for new ASCII, the string 070702 for new ASCII with CRC
+        /// </summary>
+        public string Magic => Raw.ReadString(Offset, 6); 
+
+        // https://developer.adobe.com/experience-manager/reference-materials/6-4/javadoc/org/apache/commons/compress/archivers/cpio/CpioArchiveEntry.html
+        public UInt32 INode => GetAsciiValue(6, 8);
+        public UInt32 Mode => GetAsciiValue(14, 8);
+        public UInt32 UserId => GetAsciiValue(22, 8);
+        public UInt32 GroupId => GetAsciiValue(30, 8);
+        public UInt32 NumLink => GetAsciiValue(38, 8);
+        public UInt32 ModificationTime => GetAsciiValue(46, 8);
+
+        /// <summary>
+        /// must be 0 for FIFOs and directories
+        /// </summary>
+        public UInt32 FileSize => GetAsciiValue(54, 8);
+
+
+        public UInt32 Major => GetAsciiValue(62, 8);
+        public UInt32 Minor => GetAsciiValue(70, 8);
+
+        /// <summary>
+        /// only valid for chr and blk special files
+        /// </summary>
+        public UInt32 RMajor => GetAsciiValue(78, 8);
+
+        /// <summary>
+        /// only valid for chr and blk special files
+        /// </summary>
+        public UInt32 RMinor => GetAsciiValue(86, 8);
+
+        /// <summary>
+        /// count includes terminating NUL in pathname
+        /// </summary>
+        public UInt32 NameSize => GetAsciiValue(94, 8); 
+
+        /// <summary>
+        /// 0 for "new" portable format; for CRC format, the sum of all the bytes in the file
+        /// </summary>
+        public UInt32 Check => GetAsciiValue(102, 8);
+
+        public bool IsTrailer => Path == "TRAILER!!!";
+
+        public long PathPadding => (110L + NameSize).MakeSizeAligned(4);
+        public long HeaderWithPathSize => 110 + NameSize + PathPadding;
+
+        public string Path => Raw.ReadString(Offset + 110, NameSize - 1);
+
+        public long FilePadding => (HeaderWithPathSize + FileSize).MakeSizeAligned(4);
+
+        public long FullFileBlockSize => HeaderWithPathSize + FileSize + FilePadding;
+
+    }
+}

NyaFs/Filesystem/Cpio/Types/CpioModeFileType.cs

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+using System;
+using System.Collections.Generic;
+using System.Text;
+
+namespace NyaFs.Filesystem.Cpio.Types
+{
+    public enum CpioModeFileType {
+        C_ISDIR = 0x4000, // Directory
+        C_ISFIFO = 0x1000, // FIFO
+        C_ISREG = 0x8000, // Regular file
+        C_ISBLK = 0x6000, // Block special
+        C_ISCHR = 0x2000, // Character special
+        C_ISCTG = 0x9000, // Reserved
+        C_ISLNK = 0xA000, // Symbolic link.
+        C_ISSOCK = 0xC000, // Socket
+    }
+}

NyaFs/Filesystem/Cpio/Types/CpioModeFlags.cs

@@ -0,0 +1,23 @@
+using System;
+using System.Collections.Generic;
+using System.Text;
+
+namespace NyaFs.Filesystem.Cpio.Types
+{
+    [Flags]
+    public enum CpioModeFlags
+    {
+        C_IRUSR = 0000400, // Read by owner
+        C_IWUSR = 0000200, // Write by owner
+        C_IXUSR = 0000100, // Execute by owner
+        C_IRGRP = 0000040, // Read by group.
+        C_IWGRP = 0000020, // Write by group
+        C_IXGRP = 0000010, // Execute by group
+        C_IROTH = 0000004, // Read by others
+        C_IWOTH = 0000002, // Write by others
+        C_IXOTH = 0000001, // Execute by others
+        C_ISUID = 0004000, // Set user ID
+        C_ISGID = 0002000, // Set group ID
+        C_ISVTX = 0001000 // On directories, restricted deletion flag
+    }
+}