feat: Adding methods for inspecting contents of a ZIP file

ICD.Common.Utils/ICD.Common.Utils_SimplSharp.csproj

@@ -98,6 +98,7 @@
     <Compile Include="Extensions\UriExtensions.cs" />
     <Compile Include="Extensions\UshortExtensions.cs" />
     <Compile Include="IcdUriBuilder.cs" />
+    <Compile Include="IO\Compression\IcdZipEntry.cs" />
     <Compile Include="IO\IcdBinaryReader.cs" />
     <Compile Include="IO\eSeekOrigin.cs" />
     <Compile Include="ProcessorUtils.SimplSharp.cs" />
@@ -124,7 +125,7 @@
     <Compile Include="IcdEnvironment.cs" />
     <Compile Include="IcdEnvironment.SimplSharp.cs" />
     <Compile Include="IcdEnvironment.Standard.cs" />
-    <Compile Include="IcdZip.cs" />
+    <Compile Include="IO\Compression\IcdZip.cs" />
     <Compile Include="IO\IcdDirectory.cs" />
     <Compile Include="EnumUtils.cs" />
     <Compile Include="Extensions\AssemblyExtensions.cs" />

ICD.Common.Utils/IO/Compression/IcdZip.cs

@@ -0,0 +1,163 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using Crestron.SimplSharp;
+#if SIMPLSHARP
+
+#else
+using System.IO.Compression;
+#endif
+
+namespace ICD.Common.Utils.IO.Compression
+{
+	/// <summary>
+	/// Utils for managing archives.
+	/// </summary>
+	public static class IcdZip
+	{
+		private const int DIRECTORY_SIGNATURE = 0x06054B50;
+		private const int ENTRY_SIGNATURE = 0x02014B50;
+
+		/// <summary>
+		/// Unzips the archive at the given path.
+		/// </summary>
+		/// <param name="path"></param>
+		/// <param name="outputPath"></param>
+		/// <param name="message"></param>
+		public static bool Unzip(string path, string outputPath, out string message)
+		{
+			try
+			{
+#if SIMPLSHARP
+				CrestronZIP.ResultCode result = CrestronZIP.Unzip(path, outputPath);
+				message = result.ToString();
+				return result == CrestronZIP.ResultCode.ZR_OK;
+#else
+                using (ZipArchive archive = ZipFile.Open(path, ZipArchiveMode.Read))
+                    archive.ExtractToDirectory(outputPath);
+				message = "Success";
+				return true;
+#endif
+			}
+			catch (Exception e)
+			{
+				message = e.Message;
+				return false;
+			}
+		}
+
+		/// <summary>
+		/// Gets the sequence of files names in the archive at the given path.
+		/// </summary>
+		public static IEnumerable<string> GetFileNames(string path)
+		{
+			return GetEntries(path).Select(e => e.Name)
+			                       .Where(f => !f.EndsWith("/"))
+			                       .OrderBy(f => f);
+		}
+
+		/// <summary>
+		/// Gets sequence of zip file entries in the archive at the given path.
+		/// </summary>
+		public static IEnumerable<IcdZipEntry> GetEntries(string path)
+		{
+			using (IcdStream stream = IcdFile.OpenRead(path))
+			{
+				using (IcdBinaryReader reader = new IcdBinaryReader(stream))
+				{
+					if (stream.Length < 22)
+						yield break;
+
+					stream.Seek(-22, eSeekOrigin.End.ToSeekOrigin());
+
+					// find directory signature
+					while (reader.ReadInt32() != DIRECTORY_SIGNATURE)
+					{
+						if (stream.Position <= 5)
+							yield break;
+
+						// move 1 byte back
+						stream.Seek(-5, eSeekOrigin.Current.ToSeekOrigin());
+					}
+
+					// read directory properties
+					stream.Seek(6, eSeekOrigin.Current.ToSeekOrigin());
+					ushort entries = reader.ReadUInt16();
+					int difSize = reader.ReadInt32();
+					uint dirOffset = reader.ReadUInt32();
+					stream.Seek(dirOffset, eSeekOrigin.Begin.ToSeekOrigin());
+
+					// read directory entries
+					for (int i = 0; i < entries; i++)
+					{
+						if (reader.ReadInt32() != ENTRY_SIGNATURE)
+							continue;
+
+						// read file properties
+						reader.ReadInt32();
+						bool utf8 = (reader.ReadInt16() & 0x0800) != 0;
+						short method = reader.ReadInt16();
+						int timestamp = reader.ReadInt32();
+						uint crc32 = reader.ReadUInt32();
+						int compressedSize = reader.ReadInt32();
+						int fileSize = reader.ReadInt32();
+						short fileNameSize = reader.ReadInt16();
+						short extraSize = reader.ReadInt16();
+						short commentSize = reader.ReadInt16();
+						int headerOffset = reader.ReadInt32();
+						reader.ReadInt32();
+						int fileHeaderOffset = reader.ReadInt32();
+						byte[] fileNameBytes = reader.ReadBytes(fileNameSize);
+						stream.Seek(extraSize, eSeekOrigin.Current.ToSeekOrigin());
+						byte[] fileCommentBytes = reader.ReadBytes(commentSize);
+						int fileDataOffset = CalculateFileDataOffset(stream, reader, fileHeaderOffset);
+
+						// decode zip file entry
+						Encoding encoder = utf8 ? Encoding.UTF8 : Encoding.Default;
+
+						yield return new IcdZipEntry
+						{
+							Name = encoder.GetString(fileNameBytes, 0, fileNameBytes.Length),
+							Comment = encoder.GetString(fileCommentBytes, 0, fileCommentBytes.Length),
+							Crc32 = crc32,
+							CompressedSize = compressedSize,
+							OriginalSize = fileSize,
+							HeaderOffset = fileHeaderOffset,
+							DataOffset = fileDataOffset,
+							Deflated = method == 8,
+							Timestamp = ConvertToDateTime(timestamp)
+						};
+					}
+				}
+			}
+		}
+
+		private static int CalculateFileDataOffset(IcdStream stream, IcdBinaryReader reader, int fileHeaderOffset)
+		{
+			long position = stream.Position;
+			stream.Seek(fileHeaderOffset + 26, eSeekOrigin.Begin.ToSeekOrigin());
+			short fileNameSize = reader.ReadInt16();
+			short extraSize = reader.ReadInt16();
+
+			int fileOffset = (int)stream.Position + fileNameSize + extraSize;
+			stream.Seek(position, eSeekOrigin.Begin.ToSeekOrigin());
+			return fileOffset;
+		}
+
+		/// <summary>
+		/// Converts DOS timestamp to a <see cref="DateTime"/> instance.
+		/// </summary>
+		/// <param name="dosTimestamp">The DOS timestamp.</param>
+		/// <returns>The <see cref="DateTime"/> instance.</returns>
+		private static DateTime ConvertToDateTime(int dosTimestamp)
+		{
+			return new DateTime((dosTimestamp >> 25) + 1980,
+			                    (dosTimestamp >> 21) & 15,
+			                    (dosTimestamp >> 16) & 31,
+			                    (dosTimestamp >> 11) & 31,
+			                    (dosTimestamp >> 5) & 63,
+			                    (dosTimestamp & 31) * 2);
+		}
+	}
+}

ICD.Common.Utils/IO/Compression/IcdZipEntry.cs

@@ -0,0 +1,59 @@
+using System;
+
+namespace ICD.Common.Utils.IO.Compression
+{
+	/// <summary>
+	/// Zip archive entry.
+	/// </summary>
+	public sealed class IcdZipEntry
+	{
+		/// <summary>
+		/// Gets or sets the name of a file or a directory.
+		/// </summary>
+		public string Name { get; set; }
+
+		/// <summary>
+		/// Gets or sets the comment.
+		/// </summary>
+		public string Comment { get; set; }
+
+		/// <summary>
+		/// Gets or sets the CRC32.
+		/// </summary>
+		public uint Crc32 { get; set; }
+
+		/// <summary>
+		/// Gets or sets the compressed size of the file.
+		/// </summary>
+		public int CompressedSize { get; set; }
+
+		/// <summary>
+		/// Gets or sets the original size of the file.
+		/// </summary>
+		public int OriginalSize { get; set; }
+
+		/// <summary>
+		/// Gets or sets a value indicating whether this <see cref="IcdZipEntry" /> is deflated.
+		/// </summary>
+		public bool Deflated { get; set; }
+
+		/// <summary>
+		/// Gets a value indicating whether this <see cref="IcdZipEntry" /> is a directory.
+		/// </summary>
+		public bool IsDirectory { get { return Name.EndsWith("/"); } }
+
+		/// <summary>
+		/// Gets or sets the timestamp.
+		/// </summary>
+		public DateTime Timestamp { get; set; }
+
+		/// <summary>
+		/// Gets a value indicating whether this <see cref="IcdZipEntry" /> is a file.
+		/// </summary>
+		public bool IsFile { get { return !IsDirectory; } }
+
+		public int HeaderOffset { get; set; }
+
+		public int DataOffset { get; set; }
+	}
+}

ICD.Common.Utils/IcdZip.cs

@@ -1,43 +0,0 @@
-using System;
-#if SIMPLSHARP
-using Crestron.SimplSharp;
-#else
-using System.IO.Compression;
-#endif
-
-namespace ICD.Common.Utils
-{
-	/// <summary>
-	/// Utils for managing archives.
-	/// </summary>
-	public static class IcdZip
-	{
-		/// <summary>
-		/// Unzips the archive at the given path.
-		/// </summary>
-		/// <param name="path"></param>
-		/// <param name="outputPath"></param>
-		/// <param name="message"></param>
-		public static bool Unzip(string path, string outputPath, out string message)
-		{
-			try
-			{
-#if SIMPLSHARP
-				CrestronZIP.ResultCode result = CrestronZIP.Unzip(path, outputPath);
-				message = result.ToString();
-				return result == CrestronZIP.ResultCode.ZR_OK;
-#else
-                using (ZipArchive archive = ZipFile.Open(path, ZipArchiveMode.Read))
-                    archive.ExtractToDirectory(outputPath);
-				message = "Success";
-				return true;
-#endif
-			}
-			catch (Exception e)
-			{
-				message = e.Message;
-				return false;
-			}
-		}
-	}
-}