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/*
* Firebird ADO.NET Data provider for .NET and Mono
*
* The contents of this file are subject to the Initial
* Developer's Public License Version 1.0 (the "License");
* you may not use this file except in compliance with the
* License. You may obtain a copy of the License at
* http://www.firebirdsql.org/index.php?op=doc&id=idpl
*
* Software distributed under the License is distributed on
* an "AS IS" basis, WITHOUT WARRANTY OF ANY KIND, either
* express or implied. See the License for the specific
* language governing rights and limitations under the License.
*
* Copyright (c) 2002, 2005 Carlos Guzman Alvarez
* All Rights Reserved.
*/
using System;
using System.Data;
using System.Text;
using System.IO;
using System.Collections;
namespace FirebirdSql.Data.Common
{
internal abstract class BlobBase
{
#region Fields
private int rblFlags;
private Charset charset;
private int segmentSize;
#endregion
#region Protected Fields
protected long blobId;
protected int blobHandle;
protected int position;
protected ITransaction transaction;
#endregion
#region Properties
public int Handle
{
get { return this.blobHandle; }
}
public long Id
{
get { return this.blobId; }
}
public bool EOF
{
get { return (this.rblFlags & IscCodes.RBL_eof_pending) != 0; }
}
#endregion
#region Protected Properties
protected int SegmentSize
{
get { return this.segmentSize; }
}
#endregion
#region Abstract Properties
public abstract IDatabase DB
{
get;
}
#endregion
#region Constructors
protected BlobBase(IDatabase db)
{
this.segmentSize = db.PacketSize;
this.charset = db.Charset;
}
#endregion
#region Protected Abstract Methods
protected abstract void Create();
protected abstract void Open();
protected abstract byte[] GetSegment();
protected abstract void PutSegment(byte[] buffer);
protected abstract void Seek(int position);
protected abstract void GetBlobInfo();
protected abstract void Close();
protected abstract void Cancel();
#endregion
#region Methods
public string ReadString()
{
byte[] buffer = this.Read();
return this.charset.GetString(buffer, 0, buffer.Length);
}
public byte[] Read()
{
MemoryStream ms = new MemoryStream();
try
{
this.Open();
while (!EOF)
{
byte[] segment = this.GetSegment();
ms.Write(segment, 0, segment.Length);
}
this.Close();
}
catch (Exception)
{
// Cancel the blob and rethrow the exception
this.Cancel();
throw;
}
return ms.ToArray();
}
public void Write(string data)
{
this.Write(this.charset.GetBytes(data));
}
public void Write(byte[] buffer)
{
this.Write(buffer, 0, buffer.Length);
}
public void Write(byte[] buffer, int index, int count)
{
try
{
this.Create();
byte[] tmpBuffer = null;
int length = count;
int offset = index;
int chunk = length >= this.segmentSize ? this.segmentSize : length;
tmpBuffer = new byte[chunk];
while (length > 0)
{
if (chunk > length)
{
chunk = (int)length;
tmpBuffer = new byte[chunk];
}
Array.Copy(buffer, offset, tmpBuffer, 0, chunk);
this.PutSegment(tmpBuffer);
offset += chunk;
length -= chunk;
}
this.Close();
}
catch (Exception)
{
// Cancel the blob and rethrow the exception
this.Cancel();
throw;
}
}
#endregion
#region Protected Methods
protected void RblAddValue(int rblValue)
{
this.rblFlags |= rblValue;
}
protected void RblRemoveValue(int rblValue)
{
this.rblFlags &= ~rblValue;
}
#endregion
}
}
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