2004-12-03 Lluis Sanchez Gual <lluis@novell.com>
[mono.git] / mcs / class / corlib / System.IO / BinaryReader.cs
index 30295dceb9f4fb58789c97dd640662bf44e044e7..7958b70efb0a40521488a6e03209415214e26922 100644 (file)
@@ -3,6 +3,30 @@
 //
 // Author:
 //   Matt Kimball (matt@kimball.net)
+//   Dick Porter (dick@ximian.com)
+//
+
+//
+// Copyright (C) 2004 Novell, Inc (http://www.novell.com)
+//
+// 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;
@@ -16,11 +40,10 @@ namespace System.IO {
                int m_encoding_max_byte;
 
                byte[] m_buffer;
-               int m_buffer_used;
-               int m_buffer_pos;
-
+               
+               private bool m_disposed = false;
 
-               public BinaryReader(Stream input) : this(input, Encoding.UTF8) {
+               public BinaryReader(Stream input) : this(input, Encoding.UTF8Unmarked) {
                }
 
                public BinaryReader(Stream input, Encoding encoding) {
@@ -43,16 +66,18 @@ namespace System.IO {
 
                public virtual void Close() {
                        Dispose (true);
-                       m_stream.Close();
+                       m_disposed = true;
                }
                
-               protected void Dispose (bool disposing)
+               protected virtual void Dispose (bool disposing)
                {
-                       if (disposing)
+                       if (disposing && m_stream != null)
                                m_stream.Close ();
 
+                       m_disposed = true;
                        m_buffer = null;
-                       m_buffer_used = 0;
+                       m_encoding = null;
+                       m_stream = null;
                }
 
                void IDisposable.Dispose() 
@@ -60,163 +85,251 @@ namespace System.IO {
                        Dispose (true);
                }
 
-               protected virtual void FillBuffer(int bytes) {
-                       if (!EnsureBuffered(m_buffer_used - m_buffer_pos + bytes)) {
-                               throw new EndOfStreamException();
+               protected virtual void FillBuffer (int bytes)
+               {
+                       if (m_disposed)
+                               throw new ObjectDisposedException ("BinaryReader", "Cannot read from a closed BinaryReader.");
+                       if (m_stream==null)
+                               throw new IOException("Stream is invalid");
+                       
+                       CheckBuffer(bytes);
+
+                       /* Cope with partial reads */
+                       int pos=0;
+
+                       while(pos<bytes) {
+                               int n=m_stream.Read(m_buffer, pos, bytes-pos);
+                               if(n==0) {
+                                       throw new EndOfStreamException();
+                               }
+
+                               pos+=n;
                        }
                }
 
                public virtual int PeekChar() {
-                       EnsureBuffered(m_encoding_max_byte);
-                       
-                       int i;
-                       for (i = 1; m_encoding.GetCharCount(m_buffer, m_buffer_pos, i) == 0; i++) {
-                               if (m_buffer_pos + i >= m_buffer_used) {
-                                       return -1;
-                               }
+                       if(m_stream==null) {
+                               
+                               if (m_disposed)
+                                       throw new ObjectDisposedException ("BinaryReader", "Cannot read from a closed BinaryReader.");
+
+                               throw new IOException("Stream is invalid");
                        }
 
-                       char[] decode = m_encoding.GetChars(m_buffer, m_buffer_pos, i);
-                       return decode[0];
+                       if ( !m_stream.CanSeek )
+                       {
+                               return -1;
+                       }
+
+                       char[] result = new char[1];
+                       byte[] bytes;
+                       int bcount;
+
+                       int ccount = ReadCharBytes (result, 0, 1, out bytes, out bcount);
+
+                       // Reposition the stream
+                       m_stream.Position -= bcount;
+
+                       // If we read 0 characters then return -1
+                       if (ccount == 0) 
+                       {
+                               return -1;
+                       }
+                       
+                       // Return the single character we read
+                       return result[0];
                }
 
                public virtual int Read() {
                        char[] decode = new char[1];
 
-                       Read(decode, 0, 1);
+                       int count=Read(decode, 0, 1);
+                       if(count==0) {
+                               /* No chars available */
+                               return(-1);
+                       }
+                       
                        return decode[0];
                }
 
                public virtual int Read(byte[] buffer, int index, int count) {
+                       if(m_stream==null) {
+
+                               if (m_disposed)
+                                       throw new ObjectDisposedException ("BinaryReader", "Cannot read from a closed BinaryReader.");
+
+                               throw new IOException("Stream is invalid");
+                       }
+                       
                        if (buffer == null) {
-                               throw new ArgumentNullException();
+                               throw new ArgumentNullException("buffer is null");
                        }
-                       if (buffer.Length - index < count) {
-                               throw new ArgumentException();
+                       if (index < 0) {
+                               throw new ArgumentOutOfRangeException("index is less than 0");
                        }
-                       if (index < 0 || count < 0) {
-                               throw new ArgumentOutOfRangeException();
+                       if (count < 0) {
+                               throw new ArgumentOutOfRangeException("count is less than 0");
                        }
-
-                       EnsureBuffered(count);
-                       
-                       if (m_buffer_used - m_buffer_pos < count) {
-                               count = m_buffer_used - m_buffer_pos;
+                       if (buffer.Length - index < count) {
+                               throw new ArgumentException("buffer is too small");
                        }
 
-                       Array.Copy(m_buffer, m_buffer_pos, buffer, index, count);
+                       int bytes_read=m_stream.Read(buffer, index, count);
 
-                       ConsumeBuffered(count);
-                       return count;
+                       return(bytes_read);
                }
 
                public virtual int Read(char[] buffer, int index, int count) {
+
+                       if(m_stream==null) {
+
+                               if (m_disposed)
+                                       throw new ObjectDisposedException ("BinaryReader", "Cannot read from a closed BinaryReader.");
+
+                               throw new IOException("Stream is invalid");
+                       }
+                       
                        if (buffer == null) {
-                               throw new ArgumentNullException();
+                               throw new ArgumentNullException("buffer is null");
                        }
-                       if (buffer.Length - index < count) {
-                               throw new ArgumentException();
+                       if (index < 0) {
+                               throw new ArgumentOutOfRangeException("index is less than 0");
+                       }
+                       if (count < 0) {
+                               throw new ArgumentOutOfRangeException("count is less than 0");
                        }
-                       if (index < 0 || count < 0) {
-                               throw new ArgumentOutOfRangeException();
+                       if (buffer.Length - index < count) {
+                               throw new ArgumentException("buffer is too small");
                        }
 
-                       EnsureBuffered(m_encoding_max_byte * count);
+                       int bytes_read;
+                       byte[] bytes;
+                       return ReadCharBytes (buffer, index, count, out bytes, out bytes_read);
+               }
 
-                       int i;          
-                       for (i = 1; m_encoding.GetCharCount(m_buffer, m_buffer_pos, i) < count; i++) {
-                               if (m_buffer_pos + i >= m_buffer_used) {
-                                       break;
-                               }
-                       }
+               private int ReadCharBytes(char[] buffer, int index, int count, out byte[] bytes, out int bytes_read) \r
+               {
+                       int chars_read=0;
+                       bytes_read=0;
                        
-                       count = m_encoding.GetCharCount(m_buffer, m_buffer_pos, i);
+                       while(chars_read < count) 
+                       {
+                               CheckBuffer(bytes_read + 1);
+
+                               int read_byte = m_stream.ReadByte();
+
+                               if(read_byte==-1) 
+                               {
+                                       /* EOF */
+                                       bytes = m_buffer;
+                                       return(chars_read);
+                               }
+
+                               m_buffer[bytes_read]=(byte)read_byte;
+                               bytes_read++;
 
-                       char[] dec = m_encoding.GetChars(m_buffer, m_buffer_pos, i);
-                       Array.Copy(dec, 0, buffer, index, count);
+                               chars_read=m_encoding.GetChars(m_buffer, 0,
+                                                                                bytes_read,
+                                                                                buffer, index);
+                               
+                       }
 
-                       ConsumeBuffered(i);
-                       return count;
+                       bytes = m_buffer;
+                       return(chars_read);
                }
 
                protected int Read7BitEncodedInt() {
                        int ret = 0;
                        int shift = 0;
-                       int count = 0;
                        byte b;
 
                        do {
-                               if (!EnsureBuffered(++count)) {
-                                       throw new EndOfStreamException();
-                               }
-                               b = m_buffer[m_buffer_pos + count - 1];
+                               b = ReadByte();
                                
                                ret = ret | ((b & 0x7f) << shift);
                                shift += 7;
                        } while ((b & 0x80) == 0x80);
 
-                       ConsumeBuffered(count);
                        return ret;
                }
 
                public virtual bool ReadBoolean() {
-                       if (!EnsureBuffered(1)) {
-                               throw new EndOfStreamException();
-                       }
-
                        // Return value:
                        //  true if the byte is non-zero; otherwise false.
-                       bool ret = (m_buffer[m_buffer_pos] != 0);
-                       ConsumeBuffered(1);
-                       return ret;
+                       return ReadByte() != 0;
                }
 
                public virtual byte ReadByte() {
-                       if (!EnsureBuffered(1)) {
-                               throw new EndOfStreamException();
-                       }
-
-                       byte ret = m_buffer[m_buffer_pos];
-                       ConsumeBuffered(1);
-                       return ret;
+                       int val = m_stream.ReadByte ();
+                       if (val != -1)
+                               return (byte) val;
+                       
+                       throw new EndOfStreamException ();
                }
 
                public virtual byte[] ReadBytes(int count) {
-                       if (count < 0) {
-                               throw new ArgumentOutOfRangeException();
-                       }
+                       if(m_stream==null) {
 
-                       EnsureBuffered(count);
+                               if (m_disposed)
+                                       throw new ObjectDisposedException ("BinaryReader", "Cannot read from a closed BinaryReader.");
 
-                       if (count > m_buffer_used - m_buffer_pos) {
-                               count = m_buffer_used - m_buffer_pos;
+                               throw new IOException("Stream is invalid");
                        }
-
-                       if (count == 0) {
-                               throw new EndOfStreamException();
+                       
+                       if (count < 0) {
+                               throw new ArgumentOutOfRangeException("count is less than 0");
                        }
 
+                       /* Can't use FillBuffer() here, because it's OK to
+                        * return fewer bytes than were requested
+                        */
+
                        byte[] buf = new byte[count];
-                       Read(buf, 0, count);
-                       return buf;
+                       int pos=0;
+                       
+                       while(pos < count) \r
+                       {
+                               int n=m_stream.Read(buf, pos, count-pos);
+                               if(n==0) {
+                                       /* EOF */
+                                       break;
+                               }
+
+                               pos+=n;
+                       }
+                               
+                       if (pos!=count) {
+                               byte[] new_buffer=new byte[pos];
+                               Array.Copy(buf, new_buffer, pos);
+                               return(new_buffer);
+                       }
+                       
+                       return(buf);
                }
 
                public virtual char ReadChar() {
-                       char[] buf = ReadChars(1);
-                       return buf[0];
+                       int ch=Read();
+
+                       if(ch==-1) {
+                               throw new EndOfStreamException();
+                       }
+
+                       return((char)ch);
                }
 
                public virtual char[] ReadChars(int count) {
                        if (count < 0) {
-                               throw new ArgumentOutOfRangeException();
+                               throw new ArgumentOutOfRangeException("count is less than 0");
                        }
 
                        char[] full = new char[count];
-                       count = Read(full, 0, count);
+                       int chars = Read(full, 0, count);
                        
-                       if (count != full.Length) {
-                               char[] ret = new char[count];
-                               Array.Copy(full, 0, ret, 0, count);
+                       if (chars == 0) {
+                               throw new EndOfStreamException();
+                       } else if (chars != full.Length) {
+                               char[] ret = new char[chars];
+                               Array.Copy(full, 0, ret, 0, chars);
                                return ret;
                        } else {
                                return full;
@@ -224,179 +337,144 @@ namespace System.IO {
                }
 
                unsafe public virtual decimal ReadDecimal() {
-                       if (!EnsureBuffered(16)) {
-                               throw new EndOfStreamException();
-                       }
+                       FillBuffer(16);
 
                        decimal ret;
                        byte* ret_ptr = (byte *)&ret;
                        for (int i = 0; i < 16; i++) {
-                               ret_ptr[i] = m_buffer[m_buffer_pos + i];
+                         
+                               /*
+                                * internal representation of decimal is 
+                                * ss32, hi32, lo32, mi32, 
+                                * but in stream it is 
+                                * lo32, mi32, hi32, ss32
+                                * So we have to rerange this int32 values
+                                */                       
+                         
+                               if (i < 4) {
+                                       // lo 8 - 12                      
+                                       ret_ptr [i + 8] = m_buffer [i];
+                               } else if (i < 8) {
+                                       // mid 12 - 16
+                                       ret_ptr [i + 8] = m_buffer [i];
+                               } else if (i < 12) {
+                                       // hi 4 - 8
+                                       ret_ptr [i - 4] = m_buffer [i];
+                               } else if (i < 16) {
+                                       // ss 0 - 4
+                                       ret_ptr [i - 12] = m_buffer [i];
+                               }                               
                        }
 
-                       ConsumeBuffered(16);
                        return ret;
                }
 
                public virtual double ReadDouble() {
-                       if (!EnsureBuffered(8)) {
-                               throw new EndOfStreamException();
-                       }
+                       FillBuffer(8);
 
-                       double ret = BitConverter.ToDouble(m_buffer, m_buffer_pos);
-                       ConsumeBuffered(8);
-                       return ret;
+                       return(BitConverter.ToDouble(m_buffer, 0));
                }
 
                public virtual short ReadInt16() {
-                       if (!EnsureBuffered(2)) {
-                               throw new EndOfStreamException();
-                       }
+                       FillBuffer(2);
 
-                       short ret = (short) (m_buffer[m_buffer_pos] | (m_buffer[m_buffer_pos + 1] << 8));
-                       ConsumeBuffered(2);
-                       return ret;
+                       return((short) (m_buffer[0] | (m_buffer[1] << 8)));
                }
 
                public virtual int ReadInt32() {
-                       if (!EnsureBuffered(4)) {
-                               throw new EndOfStreamException();
-                       }
+                       FillBuffer(4);
 
-                       int ret = (m_buffer[m_buffer_pos]             |
-                                  (m_buffer[m_buffer_pos + 1] << 8)  |
-                                  (m_buffer[m_buffer_pos + 2] << 16) |
-                                  (m_buffer[m_buffer_pos + 3] << 24)
-                                 );
-                       ConsumeBuffered(4);
-                       return ret;
+                       return(m_buffer[0] | (m_buffer[1] << 8) |
+                              (m_buffer[2] << 16) | (m_buffer[3] << 24));
                }
 
                public virtual long ReadInt64() {
-                       if (!EnsureBuffered(8)) {
-                               throw new EndOfStreamException();
-                       }
+                       FillBuffer(8);
 
-                       uint ret_low  = (uint) (m_buffer[m_buffer_pos]            |
-                                              (m_buffer[m_buffer_pos + 1] << 8)  |
-                                              (m_buffer[m_buffer_pos + 2] << 16) |
-                                              (m_buffer[m_buffer_pos + 3] << 24)
+                       uint ret_low  = (uint) (m_buffer[0]            |
+                                              (m_buffer[1] << 8)  |
+                                              (m_buffer[2] << 16) |
+                                              (m_buffer[3] << 24)
                                               );
-                       uint ret_high = (uint) (m_buffer[m_buffer_pos + 4]        |
-                                              (m_buffer[m_buffer_pos + 5] << 8)  |
-                                              (m_buffer[m_buffer_pos + 6] << 16) |
-                                              (m_buffer[m_buffer_pos + 7] << 24)
+                       uint ret_high = (uint) (m_buffer[4]        |
+                                              (m_buffer[5] << 8)  |
+                                              (m_buffer[6] << 16) |
+                                              (m_buffer[7] << 24)
                                               );
-                       ConsumeBuffered(8);
                        return (long) ((((ulong) ret_high) << 32) | ret_low);
                }
 
                [CLSCompliant(false)]
-               unsafe public virtual sbyte ReadSByte() {
-                       if (!EnsureBuffered(1)) {
-                               throw new EndOfStreamException();
-                       }
-
-                       sbyte ret;
-                       byte* ret_ptr = (byte *)&ret;
-                       ret_ptr[0] = m_buffer[m_buffer_pos];
-
-                       ConsumeBuffered(1);
-                       return ret;
+               public virtual sbyte ReadSByte() {
+                       return (sbyte) ReadByte ();
                }
 
                public virtual string ReadString() {
+                       /* Inspection of BinaryWriter-written files
+                        * shows that the length is given in bytes,
+                        * not chars
+                        */
                        int len = Read7BitEncodedInt();
 
-                       char[] str = ReadChars(len);
-                       string ret = "";
-                       for (int i = 0; i < str.Length; i++) {
-                               ret = ret + str[i];
-                       }
+                       FillBuffer(len);
+                       
+                       char[] str = m_encoding.GetChars(m_buffer, 0, len);
 
-                       return ret;
+                       return(new String(str));
                }
 
                public virtual float ReadSingle() {
-                       if (!EnsureBuffered(4)) {
-                               throw new EndOfStreamException();
-                       }
+                       FillBuffer(4);
 
-                       float ret = BitConverter.ToSingle(m_buffer, m_buffer_pos);
-                       ConsumeBuffered(4);
-                       return ret;
+                       return(BitConverter.ToSingle(m_buffer, 0));
                }
 
                [CLSCompliant(false)]
                public virtual ushort ReadUInt16() {
-                       if (!EnsureBuffered(2)) {
-                               throw new EndOfStreamException();
-                       }
+                       FillBuffer(2);
 
-                       ushort ret = (ushort) (m_buffer[m_buffer_pos] | (m_buffer[m_buffer_pos + 1] << 8));
-                       ConsumeBuffered(2);
-                       return ret;
+                       return((ushort) (m_buffer[0] | (m_buffer[1] << 8)));
                }
 
                [CLSCompliant(false)]
                public virtual uint ReadUInt32() {
-                       if (!EnsureBuffered(4)) {
-                               throw new EndOfStreamException();
-                       }
+                       FillBuffer(4);
+                               
 
-                       uint ret = (uint) (m_buffer[m_buffer_pos]            |
-                                         (m_buffer[m_buffer_pos + 1] << 8)  |
-                                         (m_buffer[m_buffer_pos + 2] << 16) |
-                                         (m_buffer[m_buffer_pos + 3] << 24)
-                                         );
-                       ConsumeBuffered(4);
-                       return ret;
+                       return((uint) (m_buffer[0] |
+                                      (m_buffer[1] << 8) |
+                                      (m_buffer[2] << 16) |
+                                      (m_buffer[3] << 24)));
                }
 
                [CLSCompliant(false)]
                public virtual ulong ReadUInt64() {
-                       if (!EnsureBuffered(8)) {
-                               throw new EndOfStreamException();
-                       }
+                       FillBuffer(8);
 
-                       uint ret_low  = (uint) (m_buffer[m_buffer_pos]            |
-                                              (m_buffer[m_buffer_pos + 1] << 8)  |
-                                              (m_buffer[m_buffer_pos + 2] << 16) |
-                                              (m_buffer[m_buffer_pos + 3] << 24)
+                       uint ret_low  = (uint) (m_buffer[0]            |
+                                              (m_buffer[1] << 8)  |
+                                              (m_buffer[2] << 16) |
+                                              (m_buffer[3] << 24)
                                               );
-                       uint ret_high = (uint) (m_buffer[m_buffer_pos + 4]        |
-                                              (m_buffer[m_buffer_pos + 5] << 8)  |
-                                              (m_buffer[m_buffer_pos + 6] << 16) |
-                                              (m_buffer[m_buffer_pos + 7] << 24)
+                       uint ret_high = (uint) (m_buffer[4]        |
+                                              (m_buffer[5] << 8)  |
+                                              (m_buffer[6] << 16) |
+                                              (m_buffer[7] << 24)
                                               );
-                       ConsumeBuffered(8);
                        return (((ulong) ret_high) << 32) | ret_low;
                }
 
-               
-               bool EnsureBuffered(int bytes) {
-                       int needed = bytes - (m_buffer_used - m_buffer_pos);
-                       if (needed < 0)
-                               return true;
-
-                       if (m_buffer_used + needed > m_buffer.Length) {
-                               byte[] old_buffer = m_buffer;
-                               m_buffer = new byte[m_buffer_used + needed];
-                               Array.Copy(old_buffer, 0, m_buffer, 0, m_buffer_used);
-                               m_buffer_pos = m_buffer_used;
+               /* Ensures that m_buffer is at least length bytes
+                * long, growing it if necessary
+                */
+               private void CheckBuffer(int length)
+               {
+                       if(m_buffer.Length <= length) {
+                               byte[] new_buffer=new byte[length];
+                               Array.Copy(m_buffer, new_buffer,
+                                          m_buffer.Length);
+                               m_buffer=new_buffer;
                        }
-
-                       int n = m_stream.Read(m_buffer, m_buffer_used, needed);
-                       if (n == 0) return false;
-
-                       m_buffer_used += n;
-
-                       return (m_buffer_used >= m_buffer_pos + bytes);
-               }
-
-
-               void ConsumeBuffered(int bytes) {
-                       m_buffer_pos += bytes;
                }
        }
 }