misc/libphysfs/lzma/CS/7zip/Common/InBuffer.cs
author nemo
Mon, 10 Apr 2017 12:06:43 -0400
changeset 12218 bb5522e88ab2
permissions -rw-r--r--
bulk copy of latest physfs to our misc/libphysfs since this seems to fix an off-by-1 error reliably hit in readln read of 1 byte probably introduced in the addition of the buffered read. Whether this is excessive or whether libphysfs should even be maintained by us is another matter. But at least we shouldn't crash

// InBuffer.cs

namespace SevenZip.Buffer
{
	public class InBuffer
	{
		byte[] m_Buffer;
		uint m_Pos;
		uint m_Limit;
		uint m_BufferSize;
		System.IO.Stream m_Stream;
		bool m_StreamWasExhausted;
		ulong m_ProcessedSize;

		public InBuffer(uint bufferSize)
		{
			m_Buffer = new byte[bufferSize];
			m_BufferSize = bufferSize;
		}

		public void Init(System.IO.Stream stream)
		{
			m_Stream = stream;
			m_ProcessedSize = 0;
			m_Limit = 0;
			m_Pos = 0;
			m_StreamWasExhausted = false;
		}

		public bool ReadBlock()
		{
			if (m_StreamWasExhausted)
				return false;
			m_ProcessedSize += m_Pos;
			int aNumProcessedBytes = m_Stream.Read(m_Buffer, 0, (int)m_BufferSize);
			m_Pos = 0;
			m_Limit = (uint)aNumProcessedBytes;
			m_StreamWasExhausted = (aNumProcessedBytes == 0);
			return (!m_StreamWasExhausted);
		}


		public void ReleaseStream()
		{
			// m_Stream.Close(); 
			m_Stream = null;
		}

		public bool ReadByte(byte b) // check it
		{
			if (m_Pos >= m_Limit)
				if (!ReadBlock())
					return false;
			b = m_Buffer[m_Pos++];
			return true;
		}

		public byte ReadByte()
		{
			// return (byte)m_Stream.ReadByte();
			if (m_Pos >= m_Limit)
				if (!ReadBlock())
					return 0xFF;
			return m_Buffer[m_Pos++];
		}

		public ulong GetProcessedSize()
		{
			return m_ProcessedSize + m_Pos;
		}
	}
}