📄 datatransfers.cs
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using System;
using System.Data;
using System.Runtime.Serialization;
using System.Runtime.Serialization.Formatters.Binary;
using System.IO;
using System.IO.Compression;
using System.Collections.Generic;
using System.Linq;
using System.ServiceModel;
using System.Text;
///日期:2008-04-16
///作者:旋风
///来自:http://cnblogs.com/xuanfeng
namespace WCFDataTransfers
{
public class DataTransfers :IDataTransfers
{
/// <summary>
/// 无参数构造函数
/// </summary>
public DataTransfers()
{
InitBuffers(InitTestDataSet());
}
private byte[] buffer_all = null;
private byte[] buffer_currect = null;
private int get_buffer_length = 1000;
private long remain_length;
private MemoryStream stream;
/// <summary>
/// 生成一个测试的数据集
/// </summary>
/// <returns></returns>
private DataSet InitTestDataSet()
{
DataSet ds = new DataSet("test");
DataTable table = new DataTable("test");
DataColumn column = new DataColumn("test");
column.DataType = Type.GetType("System.String");
table.Columns.Add(column);
DataRow row;
for (int i = 0; i < 100000;i++ )
{
row = table.NewRow();
row["test"] = "测试数据 !";
table.Rows.Add(row);
}
ds.Tables.Add(table);
return ds;
}
/// <summary>
/// 初始化压缩字节流
/// </summary>
/// <param name="ds"></param>
private void InitBuffers(DataSet ds)
{
IFormatter formatter = new BinaryFormatter();
MemoryStream stream_ = new MemoryStream();
formatter.Serialize(stream_, ds);
buffer_all = stream_.ToArray();
stream_.Close();
byte[] bytes_c = Compression(buffer_all, CompressionMode.Compress);
stream = new MemoryStream(bytes_c);
stream.Position = 0;
remain_length = stream.Length;
}
/// <summary>
/// 提供内部使用压缩字流的方法
/// </summary>
/// <param name="data"></param>
/// <param name="mode"></param>
/// <returns></returns>
private byte[] Compression(byte[] data, CompressionMode mode)
{
DeflateStream zip = null;
try
{
if (mode == CompressionMode.Compress)
{
MemoryStream ms = new MemoryStream();
zip = new DeflateStream(ms, mode, true);
zip.Write(data, 0, data.Length);
zip.Close();
return ms.ToArray();
}
else
{
MemoryStream ms = new MemoryStream();
ms.Write(data, 0, data.Length);
ms.Flush();
ms.Position = 0;
zip = new DeflateStream(ms, mode, true);
MemoryStream os = new MemoryStream();
int SIZE = 1024;
byte[] buf = new byte[SIZE];
int l = 0;
do
{
l = zip.Read(buf, 0, SIZE);
if (l == 0) l = zip.Read(buf, 0, SIZE);
os.Write(buf, 0, l);
} while (l != 0);
zip.Close();
return os.ToArray();
}
}
catch
{
if (zip != null) zip.Close();
return null;
}
finally
{
if (zip != null) zip.Close();
}
}
#region IDataTransfers 成员
/// <summary>
/// 获取所有字节流
/// </summary>
/// <returns></returns>
public byte[] GetAllBuffer()
{
if (buffer_all != null)
return buffer_all;
else return null;
}
/// <summary>
/// 设置压缩后字节流分块,每一块的大小
/// </summary>
/// <param name="length"></param>
public void SetBufferLength(int length)
{
this.get_buffer_length=length;
}
/// <summary>
/// 读取压缩后字节流一块,并提升字节流的位置
/// </summary>
/// <returns></returns>
public bool ReadNextBuffer()
{
bool bo;
if (remain_length > 0)
{
if (remain_length> get_buffer_length)
{
buffer_currect = new byte[get_buffer_length];
stream.Read(buffer_currect, 0, get_buffer_length);
remain_length -= get_buffer_length;
}
else
{
buffer_currect = new byte[remain_length];
stream.Read(buffer_currect, 0, (int)remain_length);
remain_length = 0;
}
bo = true;
}
else
bo = false;
return bo;
}
/// <summary>
/// 获取当前块的字节流
/// </summary>
/// <returns></returns>
public byte[] GetCurrentBuffer()
{
if (buffer_currect != null)
return buffer_currect;
else
return null;
}
#endregion
}
}
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