Data commit

Task/Bitwise-IO/C-sharp/bitwise-io.cs

@@ -0,0 +1,145 @@
+using System;
+using System.IO;
+
+public class BitReader
+{
+    uint readData = 0;
+    int startPosition = 0;
+    int endPosition = 0;
+
+    public int InBuffer
+    {
+        get { return endPosition - startPosition; }
+    }
+
+    private Stream stream;
+
+    public Stream BaseStream
+    {
+        get { return stream; }
+    }
+
+    public BitReader(Stream stream)
+    {
+        this.stream = stream;
+    }
+
+    void EnsureData(int bitCount)
+    {
+        int readBits = bitCount - InBuffer;
+        while (readBits > 0)
+        {
+            int b = BaseStream.ReadByte();
+
+            if (b < 0) throw new InvalidOperationException("Unexpected end of stream");
+
+            readData |= checked((uint)b << endPosition);
+            endPosition += 8;
+            readBits -= 8;
+        }
+    }
+
+    public bool ReadBit()
+    {
+        return Read(1) > 0;
+    }
+
+    public int Read(int bitCount)
+    {
+        EnsureData(bitCount);
+
+        int result = (int)(readData >> startPosition) & ((1 << bitCount) - 1);
+        startPosition += bitCount;
+        if (endPosition == startPosition)
+        {
+            endPosition = startPosition = 0;
+            readData = 0;
+        }
+        else if (startPosition >= 8)
+        {
+            readData >>= startPosition;
+            endPosition -= startPosition;
+            startPosition = 0;
+        }
+
+        return result;
+    }
+
+    public void Align()
+    {
+        endPosition = startPosition = 0;
+        readData = 0;
+    }
+}
+
+public class BitWriter
+{
+    uint data = 0;
+    int dataLength = 0;
+    Stream stream;
+
+    public Stream BaseStream
+    {
+        get { return stream; }
+    }
+
+    public int BitsToAligment
+    {
+        get { return (32 - dataLength) % 8; }
+    }
+
+    public BitWriter(Stream stream)
+    {
+        this.stream = stream;
+    }
+
+    public void WriteBit(bool value)
+    {
+        Write(value ? 1 : 0, 1);
+    }
+
+    public void Write(int value, int length)
+    {
+        uint currentData = data | checked((uint)value << dataLength);
+        int currentLength = dataLength + length;
+        while (currentLength >= 8)
+        {
+            BaseStream.WriteByte((byte)currentData);
+            currentData >>= 8;
+            currentLength -= 8;
+        }
+        data = currentData;
+        dataLength = currentLength;
+    }
+
+    public void Align()
+    {
+        if (dataLength > 0)
+        {
+            BaseStream.WriteByte((byte)data);
+
+            data = 0;
+            dataLength = 0;
+        }
+    }
+}
+
+class Program
+{
+    static void Main(string[] args)
+    {
+        MemoryStream ms = new MemoryStream();
+        BitWriter writer = new BitWriter(ms);
+        writer.WriteBit(true);
+        writer.Write(5, 3);
+        writer.Write(0x0155, 11);
+        writer.Align();
+
+        ms.Position = 0;
+        BitReader reader = new BitReader(ms);
+        Console.WriteLine(reader.ReadBit());
+        Console.WriteLine(reader.Read(3));
+        Console.WriteLine(reader.Read(11).ToString("x4"));
+        reader.Align();
+    }
+}