feat(PathIO): Support for Windows.Storage.PathIO API

src/Uno.UWP/Storage/PathIO.cs

@@ -0,0 +1,169 @@
+using System;
+using System.Collections.Generic;
+using System.Threading.Tasks;
+using Windows.Foundation;
+using Windows.Storage.Streams;
+using UwpUnicodeEncoding = Windows.Storage.Streams.UnicodeEncoding;
+using UwpBuffer = Windows.Storage.Streams.Buffer;
+
+namespace Windows.Storage
+{
+	public partial class PathIO
+	{
+		public static IAsyncOperation<string> ReadTextAsync(string absolutePath) =>
+			ReadTextTaskAsync(absolutePath).AsAsyncOperation();
+
+		public static IAsyncOperation<string> ReadTextAsync(string absolutePath, UwpUnicodeEncoding encoding) =>
+			ReadTextTaskAsync(absolutePath, encoding).AsAsyncOperation();
+
+		public static IAsyncAction WriteTextAsync(string absolutePath, string contents) =>
+			WriteTextTaskAsync(absolutePath, contents).AsAsyncAction();
+
+		public static IAsyncAction WriteTextAsync(string absolutePath, string contents, UwpUnicodeEncoding encoding) =>
+			WriteTextTaskAsync(absolutePath, contents, encoding).AsAsyncAction();
+
+		public static IAsyncAction AppendTextAsync(string absolutePath, string contents) =>
+			AppendTextTaskAsync(absolutePath, contents).AsAsyncAction();
+
+		public static IAsyncAction AppendTextAsync(string absolutePath, string contents, UwpUnicodeEncoding encoding) =>
+			AppendTextTaskAsync(absolutePath, contents, encoding).AsAsyncAction();
+
+		public static IAsyncOperation<IList<string>> ReadLinesAsync(string absolutePath) =>
+			ReadLinesTaskAsync(absolutePath).AsAsyncOperation();
+
+		public static IAsyncOperation<IList<string>> ReadLinesAsync(string absolutePath, UwpUnicodeEncoding encoding) =>
+			ReadLinesTaskAsync(absolutePath, encoding).AsAsyncOperation();
+
+		public static IAsyncAction WriteLinesAsync(string absolutePath, IEnumerable<string> lines) =>
+			WriteLinesTaskAsync(absolutePath, lines).AsAsyncAction();
+
+		public static IAsyncAction WriteLinesAsync(string absolutePath, IEnumerable<string> lines, UwpUnicodeEncoding encoding) =>
+			WriteLinesTaskAsync(absolutePath, lines, encoding).AsAsyncAction();
+
+		public static IAsyncAction AppendLinesAsync(string absolutePath, IEnumerable<string> lines) =>
+			AppendLinesTaskAsync(absolutePath, lines).AsAsyncAction();
+
+		public static IAsyncAction AppendLinesAsync(string absolutePath, IEnumerable<string> lines, UwpUnicodeEncoding encoding) =>
+			AppendLinesTaskAsync(absolutePath, lines, encoding).AsAsyncAction();
+
+		public static IAsyncOperation<IBuffer> ReadBufferAsync(string absolutePath) =>
+			ReadBufferTaskAsync(absolutePath).AsAsyncOperation();
+
+		public static IAsyncAction WriteBufferAsync(string absolutePath, IBuffer buffer) =>
+			WriteBufferTaskAsync(absolutePath, buffer).AsAsyncAction();
+
+		public static IAsyncAction WriteBytesAsync(string absolutePath, byte[] buffer) =>
+			WriteBytesTaskAsync(absolutePath, buffer).AsAsyncAction();
+
+		private static async Task<string> ReadTextTaskAsync(string path, UwpUnicodeEncoding? encoding = null)
+		{
+			if (path is null)
+			{
+				throw new ArgumentNullException(nameof(path));
+			}
+
+			var file = await StorageFile.GetFileFromPathAsync(path);
+			if (encoding == null)
+			{
+				return await FileIO.ReadTextAsync(file).AsTask();
+			}
+			return await FileIO.ReadTextAsync(file, encoding.Value).AsTask();
+		}
+
+		private static async Task<IList<string>> ReadLinesTaskAsync(string path, UwpUnicodeEncoding? encoding = null)
+		{
+			if (path is null)
+			{
+				throw new ArgumentNullException(nameof(path));
+			}
+
+			var file = await StorageFile.GetFileFromPathAsync(path);
+			if (encoding == null)
+			{
+				return await FileIO.ReadLinesAsync(file).AsTask();
+			}
+			return await FileIO.ReadLinesAsync(file, encoding.Value).AsTask();
+		}
+
+		private static async Task WriteTextTaskAsync(string path, string contents, bool append, UwpUnicodeEncoding? encoding = null)
+		{
+			if (path is null)
+			{
+				throw new ArgumentNullException(nameof(path));
+			}
+
+			var file = await StorageFile.GetFileFromPathAsync(path);
+			if (encoding == null)
+			{
+				return await FileIO.WriteTextAsync(file, contents, append).AsTask();
+			}
+			return await FileIO.WriteTextAsync(file, contents, append, encoding).AsTask();
+		}
+
+		private static async Task WriteBytesTaskAsync(IStorageFile file, byte[] buffer)
+		{
+			if (file is null)
+			{
+				throw new ArgumentNullException(nameof(file));
+			}
+
+			using var fs = File.Create(file.Path);
+			await fs.WriteAsync(buffer, 0, buffer.Length);
+		}
+
+		private static async Task<IBuffer> ReadBufferTaskAsync(IStorageFile file)
+		{
+			using var fs = File.OpenRead(file.Path);
+			var bytes = await fs.ReadBytesAsync();
+			return new UwpBuffer(bytes);
+		}
+
+		private static async Task WriteBufferTaskAsync(IStorageFile file, IBuffer buffer)
+		{
+			if (!(buffer is UwpBuffer inMemoryBuffer))
+			{
+				throw new NotSupportedException("The current implementation can only write a UwpBuffer");
+			}
+
+			await WriteBytesTaskAsync(file, inMemoryBuffer.Data);
+		}
+
+		private static async Task<Encoding> GetEncodingFromFileAsync(IStorageFile file)
+		{
+			if (File.Exists(file.Path))
+			{
+				using Stream fileStream = await file.OpenStreamForReadAsync();
+				var bytes = new byte[2];
+				if (await fileStream.ReadAsync(bytes, 0, bytes.Length) == 2)
+				{
+					if (bytes[0] == 0xff && bytes[1] == 0xfe)
+					{
+						return Encoding.Unicode;
+					}
+					else if (bytes[0] == 0xfe && bytes[1] == 0xff)
+					{
+						return Encoding.BigEndianUnicode;
+					}
+				}
+			}
+			return Encoding.UTF8;
+		}
+
+		private static string ConvertLinesToString(IEnumerable<string> lines) => string.Join(Environment.NewLine, lines);
+
+		private static Encoding UwpEncodingToSystemEncoding(UwpUnicodeEncoding encoding)
+		{
+			switch (encoding)
+			{
+				case UwpUnicodeEncoding.Utf8:
+					return Encoding.UTF8;
+				case UwpUnicodeEncoding.Utf16LE:
+					return Encoding.Unicode;
+				case UwpUnicodeEncoding.Utf16BE:
+					return Encoding.BigEndianUnicode;
+			}
+
+			return Encoding.UTF8;
+		}
+	}
+}