NetUnicodeInfo/UnicodeInformation/UnicodeData.cs

using System;
using System.Collections.Generic;
using System.Globalization;
using System.IO;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace System.Unicode
{
	public sealed class UnicodeData
	{
		private readonly Version unicodeVersion;
		private readonly UnicodeCharacterData[] characterData;

		public static UnicodeData FromStream(Stream stream)
		{
			using (var reader = new BinaryReader(stream, Encoding.UTF8))
			{
				if (reader.ReadByte() != 'U'
					| reader.ReadByte() != 'C'
					| reader.ReadByte() != 'D')
					throw new InvalidDataException();

				byte formatVersion = reader.ReadByte();

#if !DEBUG
				if (formatVersion != 1) throw new InvalidDataException();
#endif

				var unicodeVersion = new Version(reader.ReadUInt16(), reader.ReadByte());

				var entries = new UnicodeCharacterData[ReadCodePoint(reader)];

				for (int i = 0; i < entries.Length; ++i)
				{
					entries[i] = ReadEntry(reader);
				}

				return new UnicodeData(unicodeVersion, entries);
			}
		}

		private static UnicodeCharacterData ReadEntry(BinaryReader reader)
		{
			var fields = (UcdFields)reader.ReadUInt16();

			var codePointRange = (fields & UcdFields.CodePointRange) != 0 ? new UnicodeCharacterRange(ReadCodePoint(reader), ReadCodePoint(reader)) : new UnicodeCharacterRange(ReadCodePoint(reader));

            string name = (fields & UcdFields.Name) != 0 ? reader.ReadString() : null;
			var category = (fields & UcdFields.Category) != 0 ? (UnicodeCategory)reader.ReadByte() : UnicodeCategory.OtherNotAssigned;
			var canonicalCombiningClass = (fields & UcdFields.CanonicalCombiningClass) != 0 ? (CanonicalCombiningClass)reader.ReadByte() : CanonicalCombiningClass.NotReordered;
			var bidirectionalClass = (fields & UcdFields.BidirectionalClass) != 0 ? (BidirectionalClass)reader.ReadByte() : 0;
			string decompositionType = (fields & UcdFields.DecompositionType) != 0 ? reader.ReadString() : null;
			var numericType = (UnicodeNumericType)((int)(fields & UcdFields.NumericNumeric) >> 6);
			UnicodeRationalNumber numericValue = numericType != UnicodeNumericType.None ?
				new UnicodeRationalNumber(reader.ReadInt64(), reader.ReadByte()) :
				default(UnicodeRationalNumber);
			string oldName = (fields & UcdFields.OldName) != 0 ? reader.ReadString() : null;
			string simpleUpperCaseMapping = (fields & UcdFields.SimpleUpperCaseMapping) != 0 ? reader.ReadString() : null;
			string simpleLowerCaseMapping = (fields & UcdFields.SimpleLowerCaseMapping) != 0 ? reader.ReadString() : null;
			string simpleTitleCaseMapping = (fields & UcdFields.SimpleTitleCaseMapping) != 0 ? reader.ReadString() : null;
			ContributoryProperties contributoryProperties = (fields & UcdFields.ContributoryProperties) != 0 ? (ContributoryProperties)reader.ReadInt32() : 0;

			return new UnicodeCharacterData
			(
				codePointRange,
				name,
				category,
				canonicalCombiningClass,
				bidirectionalClass,
				decompositionType,
				numericType,
				numericValue,
				(fields & UcdFields.BidirectionalMirrored) != 0,
				oldName,
				simpleUpperCaseMapping,
				simpleLowerCaseMapping,
				simpleTitleCaseMapping,
				contributoryProperties,
				null
			);
        }

		//private static int ReadInt24(BinaryReader reader)
		//{
		//	return reader.ReadByte() | ((reader.ReadByte() | (reader.ReadByte() << 8)) << 8);
		//}

		private static int ReadCodePoint(BinaryReader reader)
		{
			byte b = reader.ReadByte();

			if (b < 128) return b;
			else if ((b & 0x40) == 0)
			{
				return 128 + (((b & 0x3F) << 8) | reader.ReadByte());
            }
			else
			{
				return 0x4080 + (((((b & 0x3F) << 8) | reader.ReadByte()) << 8) | reader.ReadByte());
            }
		}

		internal UnicodeData(Version unicodeVersion, UnicodeCharacterData[] characterData)
		{
			this.unicodeVersion = unicodeVersion;
			this.characterData = characterData;
        }

		public Version UnicodeVersion { get { return unicodeVersion; } }

		private UnicodeCharacterData FindCodePoint(int codePoint)
		{
			int minIndex = 0;
			int maxIndex = characterData.Length - 1;

			do
			{
				int index = (minIndex + maxIndex) >> 1;

				int Δ = characterData[index].CodePointRange.CompareCodePoint(codePoint);

				if (Δ == 0) return characterData[index];
				else if (Δ < 0) maxIndex = index - 1;
				else minIndex = index + 1;
			} while (minIndex <= maxIndex);

			return null;
		}

		public UnicodeCharacterData GetUnicodeData(int codePoint)
		{
			return FindCodePoint(codePoint);
		}
	}
}