Initial checkin

Bwg.Scsi/FileReader.cs

@@ -0,0 +1,142 @@
+//
+// BwgBurn - CD-R/CD-RW/DVD-R/DVD-RW burning program for Windows XP
+// 
+// Copyright (C) 2006 by Jack W. Griffin (butchg@comcast.net)
+//
+// This program is free software; you can redistribute it and/or modify 
+// it under the terms of the GNU General Public License as published by 
+// the Free Software Foundation; either version 2 of the License, or 
+// (at your option) any later version.
+//
+// This program 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 General Public License 
+// for more details.
+//
+// You should have received a copy of the GNU General Public License along 
+// with this program; if not, write to the 
+//
+// Free Software Foundation, Inc., 
+// 59 Temple Place, Suite 330, 
+// Boston, MA 02111-1307 USA
+//
+
+using System;
+using System.Collections.Generic;
+using System.Text;
+using System.Runtime.InteropServices;
+//using Bwg.Utils;
+
+namespace Bwg.Scsi
+{
+    /// <summary>
+    /// This class reads data from a file and sends this data to the buffered
+    /// write stream.
+    /// </summary>
+    public unsafe class FileReader
+    {
+        #region private member variables
+        /// <summary>
+        /// The OS file for reading data from a file into a memory buffer (IntPtr)
+        /// </summary>
+        private OsFileReader m_reader;
+
+        /// <summary>
+        /// The buffer pool to receive the data
+        /// </summary>
+        private WriteBufferPool m_buffer_stream;
+        #endregion
+
+
+        /// <summary>
+        /// Create a new file reader that sends the data read to a buffer stream
+        /// object
+        /// </summary>
+        /// <param name="buffer">the buffer to receive the data</param>
+        public FileReader(WriteBufferPool buffer)
+        {
+            m_buffer_stream = buffer;
+            m_reader = new OsFileReader();
+        }
+
+        /// <summary>
+        /// Open a file to read data from
+        /// </summary>
+        /// <param name="filename">the name of the file</param>
+        /// <returns>true if the file is opened, false otherwise</returns>
+        public bool Open(string filename)
+        {
+            return m_reader.Open(filename);
+        }
+
+        /// <summary>
+        /// This method closes an open file.
+        /// </summary>
+        /// <returns>true if the file is closed sucessfully, false otherwise</returns>
+        public bool Close()
+        {
+            return m_reader.Close();
+        }
+
+        /// <summary>
+        /// This function reads data from the file and sends it to the
+        /// buffer stream to be sent to the burner.  This function does not
+        /// return until all of the data from the file is read.
+        /// </summary>
+        /// <returns></returns>
+        public bool ReadData(int sector_size, long lba)
+        {
+            bool shortbuf = false;
+            int NumberRead ;
+            int num_sectors ;
+            bool first = true;
+            
+            // This is the number of whole sectors that will fit into the buffer.
+            num_sectors = m_buffer_stream.PageSize / sector_size;
+
+            while (true)
+            {
+                WriteBuffer buf ;
+                
+                buf = m_buffer_stream.GetFreeBuffer();
+                if (!m_reader.ReadData(buf.BufferPtr, num_sectors * sector_size, out NumberRead))
+                    return false ;
+
+                // If the read succeeded, but read zero bytes, we have reached the
+                // end of the file.
+                if (NumberRead == 0)
+                    return true;
+
+                if (shortbuf)
+                    throw new Exception("read two short packets");
+
+                // Mark the buffer with the amount of data that has
+                // been read from the file
+                int sectors = NumberRead / sector_size ;
+                if ((NumberRead % sector_size) != 0)
+                {
+                    shortbuf = true;
+                    sectors++;
+                }
+
+                if (first)
+                {
+                    buf.SourceString = "First block from FileReader";
+                    buf.LogicalBlockAddress = lba;
+                    first = false;
+                }
+                else
+                {
+                    buf.SourceString = "Not first block from FileReader";
+                    buf.LogicalBlockAddress = long.MaxValue;
+                }
+
+                buf.SectorSize = sector_size;
+                buf.DataSize = sectors;
+
+                // Send the buffer to the device
+                m_buffer_stream.SendBufferToDevice(buf);
+            }
+        }
+    }
+}