133 lines
2.1 KiB
C#
133 lines
2.1 KiB
C#
using System;
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namespace Unity.IO.Compression
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{
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internal class OutputBuffer
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{
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internal struct BufferState
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{
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internal int pos;
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internal uint bitBuf;
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internal int bitCount;
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}
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private byte[] byteBuffer;
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private int pos;
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private uint bitBuf;
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private int bitCount;
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internal int BytesWritten
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{
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get
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{
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return pos;
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}
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}
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internal int FreeBytes
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{
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get
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{
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return byteBuffer.Length - pos;
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}
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}
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internal int BitsInBuffer
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{
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get
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{
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return bitCount / 8 + 1;
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}
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}
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internal void UpdateBuffer(byte[] output)
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{
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byteBuffer = output;
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pos = 0;
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}
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internal void WriteUInt16(ushort value)
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{
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byteBuffer[pos++] = (byte)value;
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byteBuffer[pos++] = (byte)(value >> 8);
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}
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internal void WriteBits(int n, uint bits)
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{
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bitBuf |= bits << bitCount;
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bitCount += n;
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if (bitCount >= 16)
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{
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byteBuffer[pos++] = (byte)bitBuf;
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byteBuffer[pos++] = (byte)(bitBuf >> 8);
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bitCount -= 16;
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bitBuf >>= 16;
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}
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}
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internal void FlushBits()
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{
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while (bitCount >= 8)
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{
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byteBuffer[pos++] = (byte)bitBuf;
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bitCount -= 8;
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bitBuf >>= 8;
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}
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if (bitCount > 0)
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{
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byteBuffer[pos++] = (byte)bitBuf;
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bitBuf = 0u;
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bitCount = 0;
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}
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}
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internal void WriteBytes(byte[] byteArray, int offset, int count)
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{
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if (bitCount == 0)
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{
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Array.Copy(byteArray, offset, byteBuffer, pos, count);
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pos += count;
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}
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else
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{
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WriteBytesUnaligned(byteArray, offset, count);
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}
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}
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private void WriteBytesUnaligned(byte[] byteArray, int offset, int count)
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{
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for (int i = 0; i < count; i++)
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{
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byte b = byteArray[offset + i];
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WriteByteUnaligned(b);
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}
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}
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private void WriteByteUnaligned(byte b)
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{
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WriteBits(8, b);
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}
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internal BufferState DumpState()
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{
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BufferState result = default(BufferState);
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result.pos = pos;
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result.bitBuf = bitBuf;
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result.bitCount = bitCount;
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return result;
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}
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internal void RestoreState(BufferState state)
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{
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pos = state.pos;
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bitBuf = state.bitBuf;
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bitCount = state.bitCount;
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}
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}
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}
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