Moved PrefixStream class implementation to separate file.

2026-07-08 01:30:18 +08:00 · 2015-02-26 22:07:49 +04:00
parent 74f1f1ef7b
commit 3214e05609
5 changed files with 144 additions and 113 deletions
--- a/ArcFormats/ArcCommon.cs
+++ b/ArcFormats/ArcCommon.cs
@@ -0,0 +1,139 @@
+//! \file       ArcCommon.cs
+//! \date       Tue Aug 19 09:45:38 2014
+//! \brief      Classes and functions common for various resource files.
+//
+// Copyright (C) 2014-2015 by morkt
+//
+// Permission is hereby granted, free of charge, to any person obtaining a copy
+// of this software and associated documentation files (the "Software"), to
+// deal in the Software without restriction, including without limitation the
+// rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
+// sell copies of the Software, and to permit persons to whom the Software is
+// furnished to do so, subject to the following conditions:
+//
+// The above copyright notice and this permission notice shall be included in
+// all copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+// FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
+// IN THE SOFTWARE.
+//
+
+using System;
+using System.IO;
+
+namespace GameRes.Formats
+{
+    public class PrefixStream : Stream
+    {
+        byte[]  m_header;
+        Stream  m_stream;
+        long    m_position = 0;
+
+        public PrefixStream (byte[] header, Stream main)
+        {
+            m_header = header;
+            m_stream = main;
+        }
+
+        public override bool CanRead  { get { return m_stream.CanRead; } }
+        public override bool CanSeek  { get { return m_stream.CanSeek; } }
+        public override bool CanWrite { get { return false; } }
+        public override long Length   { get { return m_stream.Length + m_header.Length; } }
+        public override long Position
+        {
+            get { return m_position; }
+            set
+            {
+                m_position = Math.Max (value, 0);
+                if (m_position > m_header.Length)
+                {
+                    long stream_pos = m_stream.Seek (m_position - m_header.Length, SeekOrigin.Begin);
+                    m_position = m_header.Length + stream_pos;
+                }
+            }
+        }
+
+        public override void Flush()
+        {
+            m_stream.Flush();
+        }
+
+        public override long Seek (long offset, SeekOrigin origin)
+        {
+            if (SeekOrigin.Begin == origin)
+                Position = offset;
+            else if (SeekOrigin.Current == origin)
+                Position = m_position + offset;
+            else
+                Position = Length + offset;
+
+            return m_position;
+        }
+
+        public override int Read (byte[] buffer, int offset, int count)
+        {
+            int read = 0;
+            if (m_position < m_header.Length)
+            {
+                int header_count = Math.Min (count, m_header.Length - (int)m_position);
+                Buffer.BlockCopy (m_header, (int)m_position, buffer, offset, header_count);
+                m_position += header_count;
+                read += header_count;
+                offset += header_count;
+                count -= header_count;
+                if (count > 0)
+                    m_stream.Position = 0;
+            }
+            if (count > 0)
+            {
+                int stream_read = m_stream.Read (buffer, offset, count);
+                m_position += stream_read;
+                read += stream_read;
+            }
+            return read;
+        }
+
+        public override int ReadByte ()
+        {
+            if (m_position < m_header.Length)
+                return m_header[m_position++];
+            if (m_position == m_header.Length)
+                m_stream.Position = 0;
+            int b = m_stream.ReadByte();
+            if (-1 != b)
+                m_position++;
+            return b;
+        }
+
+        public override void SetLength (long length)
+        {
+            throw new NotSupportedException ("PrefixStream.SetLength method is not supported");
+        }
+
+        public override void Write (byte[] buffer, int offset, int count)
+        {
+            throw new NotSupportedException ("PrefixStream.Write method is not supported");
+        }
+
+        public override void WriteByte (byte value)
+        {
+            throw new NotSupportedException ("PrefixStream.WriteByte method is not supported");
+        }
+
+        bool disposed = false;
+        protected override void Dispose (bool disposing)
+        {
+            if (!disposed)
+            {
+                m_stream.Dispose();
+                disposed = true;
+                base.Dispose (disposing);
+            }
+        }
+    }
+}