1 files changed, 119 insertions, 0 deletions
diff --git a/SevenZip/sdk/Common/InBuffer.cs b/SevenZip/sdk/Common/InBuffer.cs
new file mode 100644
index 00000000..26f3ae41
--- /dev/null
+++ b/SevenZip/sdk/Common/InBuffer.cs
@@ -0,0 +1,119 @@
+/*  This file is part of SevenZipSharp.
+
+    SevenZipSharp is free software: you can redistribute it and/or modify
+    it under the terms of the GNU Lesser General Public License as published by
+    the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    SevenZipSharp is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU Lesser General Public License for more details.
+
+    You should have received a copy of the GNU Lesser General Public License
+    along with SevenZipSharp.  If not, see <http://www.gnu.org/licenses/>.
+*/
+
+using System.IO;
+
+namespace SevenZip.Sdk.Buffer
+{
+    /// <summary>
+    /// Implements the input buffer work
+    /// </summary>
+    internal class InBuffer
+    {
+        private readonly byte[] m_Buffer;
+        private readonly uint m_BufferSize;
+        private uint m_Limit;
+        private uint m_Pos;
+        private ulong m_ProcessedSize;
+        private Stream m_Stream;
+        private bool m_StreamWasExhausted;
+
+        /// <summary>
+        /// Initializes the input buffer
+        /// </summary>
+        /// <param name="bufferSize"></param>
+        private InBuffer(uint bufferSize)
+        {
+            m_Buffer = new byte[bufferSize];
+            m_BufferSize = bufferSize;
+        }
+
+        /// <summary>
+        /// Initializes the class
+        /// </summary>
+        /// <param name="stream"></param>
+        private void Init(Stream stream)
+        {
+            m_Stream = stream;
+            m_ProcessedSize = 0;
+            m_Limit = 0;
+            m_Pos = 0;
+            m_StreamWasExhausted = false;
+        }
+
+        /// <summary>
+        /// Reads the whole block
+        /// </summary>
+        /// <returns></returns>
+        private 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);
+        }
+
+        /// <summary>
+        /// Releases the stream
+        /// </summary>
+        private void ReleaseStream()
+        {
+            // m_Stream.Close(); 
+            m_Stream = null;
+        }
+
+        /// <summary>
+        /// Reads the byte to check it
+        /// </summary>
+        /// <param name="b"></param>
+        /// <returns></returns>
+        private bool ReadByte(out byte b)
+        {
+            b = 0;
+            if (m_Pos >= m_Limit)
+                if (!ReadBlock())
+                    return false;
+            b = m_Buffer[m_Pos++];
+            return true;
+        }
+
+        /// <summary>
+        /// Reads the next byte
+        /// </summary>
+        /// <returns></returns>
+        private byte ReadByte()
+        {
+            // return (byte)m_Stream.ReadByte();
+            if (m_Pos >= m_Limit)
+                if (!ReadBlock())
+                    return 0xFF;
+            return m_Buffer[m_Pos++];
+        }
+
+        /// <summary>
+        /// Gets processed size
+        /// </summary>
+        /// <returns></returns>
+        private ulong GetProcessedSize()
+        {
+            return m_ProcessedSize + m_Pos;
+        }
+    }
+}
+\ No newline at end of file