【发布时间】：2014-04-07 11:50:13
【问题描述】：
什么可能导致这个错误？
Invalid wire-type; this usually means you have over-written a file without truncating or setting the length; see http://stackoverflow.com/q/2152978/23354
我按照上面的帮助链接，但设置 FileMode.Truncate 没有帮助...
问题总是发生在一个被反序列化的特定文件的相同位置。我已经多次重新创建该文件。
[ProtoContract]
public class TickRecord
{
[ProtoMember(1, DataFormat = DataFormat.FixedSize)]
public DateTime DT;
[ProtoMember(2)]
public double BidPrice;
[ProtoMember(3)]
public double AskPrice;
[ProtoMember(4, DataFormat = DataFormat.FixedSize)]
public int BidSize;
[ProtoMember(5, DataFormat = DataFormat.FixedSize)]
public int AskSize;
public TickRecord(DateTime DT, double BidPrice, double AskPrice, int BidSize, int AskSize)
{
this.DT = DT;
this.BidPrice = BidPrice;
this.AskPrice = AskPrice;
this.BidSize = BidSize;
this.AskSize = AskSize;
}
public TickRecord()
{
}
}
为乔恩·斯基特编辑
这行得通。但是当我使用我的真实数据（我无法分享）时，我的问题就出现了。我反序列化的大多数文件都可以正常工作，但有一个文件不能......
using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Windows.Forms;
using ProtoBuf;
using System.IO;
using System.Diagnostics;
namespace BinTest3
{
public partial class Form1 : Form
{
public Form1()
{
InitializeComponent();
}
private void Serialize_Click(object sender, EventArgs e)
{
FileStream outBin = null;
string binFileName = @"C:\binfile.dft";
outBin = File.Create(binFileName, 2048, FileOptions.None);
DateTime d = DateTime.Now;
TickRecord tr = new TickRecord(d, 1.02, 1.03,200,300);
for (int i =0; i < 20000000; i++)
{
tr.BidPrice += 1;
Serializer.SerializeWithLengthPrefix(outBin, tr, PrefixStyle.Base128);
}
outBin.Close();
label1.Text = "Done ";
}
private void Deserialize_Click(object sender, EventArgs e)
{
Stopwatch sw = new Stopwatch();
sw.Start();
FileStream fs;
string binFileName = @"C:\binfile.dft";
byte[] data = File.ReadAllBytes(binFileName);
MemoryStream ms = new MemoryStream(data);
long skipRate =10;
int count = 0;
TickRecord tr;
long skip = (38*skipRate);
try
{
while ((tr = Serializer.DeserializeWithLengthPrefix<TickRecord>(ms, PrefixStyle.Base128)) != null) //fs.Length > fs.Position)
{
count++;
ms.Seek(skip, SeekOrigin.Current);
}
}
catch (Exception)
{
}
ms.Close();
sw.Stop();
label1.Text = "Time taken: " + sw.Elapsed + " Count: " + count.ToString("n0");
}
}
[ProtoContract]
public class TickRecord
{
[ProtoMember(1, DataFormat = DataFormat.FixedSize)]
public DateTime DT;
[ProtoMember(2)]
public double BidPrice;
[ProtoMember(3)]
public double AskPrice;
[ProtoMember(4, DataFormat = DataFormat.FixedSize)]
public int BidSize;
[ProtoMember(5, DataFormat = DataFormat.FixedSize)]
public int AskSize;
public TickRecord()
{
}
public TickRecord(DateTime DT, double BidPrice, double AskPrice, int BidSize, int AskSize)
{
this.DT = DT;
this.BidPrice = BidPrice;
this.AskPrice = AskPrice;
this.BidSize = BidSize;
this.AskSize = AskSize;
}
}
}
编辑 2 问题在序列化中 - 它不是我想象的固定大小：
private void Once_Click(object sender, EventArgs e)
{
FileStream outBin = null;
string binFileName = @"C:\binfile.dft";
outBin = File.Create(binFileName, 2048, FileOptions.None);
DateTime d = DateTime.Now;
long lastPosition = 0;
TickRecord tr = new TickRecord(d, 1.02, 1.03, 200, 300);
Serializer.SerializeWithLengthPrefix(outBin, tr, PrefixStyle.Base128);
Console.WriteLine("outBin.Position: " + outBin.Position + " lastPosition: " + lastPosition + " diff: " + (outBin.Position-lastPosition));
lastPosition = outBin.Position;
tr = new TickRecord(d, 1.02, 0.0, 200, 300);
Serializer.SerializeWithLengthPrefix(outBin, tr, PrefixStyle.Base128);
Console.WriteLine("outBin.Position: " + outBin.Position + " lastPosition: " + lastPosition + " diff: " + (outBin.Position - lastPosition));
outBin.Close();
label1.Text = "Done ";
}
[ProtoContract]
public class TickRecord
{
[ProtoMember(1, DataFormat = DataFormat.FixedSize)]
public DateTime DT;
[ProtoMember(2, DataFormat = DataFormat.FixedSize)]
public double BidPrice;
[ProtoMember(3, DataFormat = DataFormat.FixedSize)]
public double AskPrice;
[ProtoMember(4, DataFormat = DataFormat.FixedSize)]
public int BidSize;
[ProtoMember(5, DataFormat = DataFormat.FixedSize)]
public int AskSize;
public TickRecord()
{
}
public TickRecord(DateTime DT, double BidPrice, double AskPrice, int BidSize, int AskSize)
{
this.DT = DT;
this.BidPrice = BidPrice;
this.AskPrice = AskPrice;
this.BidSize = BidSize;
this.AskSize = AskSize;
}
}
这给出了：
outBin.Position: 38 lastPosition: 0 diff: 38
outBin.Position: 67 lastPosition: 38 diff: 29
所以看起来变量的大小在为零时是不同的。
如何使零双精度与非零双精度具有相同的大小？
【问题讨论】：
-
您能否展示一个简短但完整的程序来说明问题？鉴于您之前在流中跳过，我想知道您是否跳到了错误的地方......
-
@JonSkeet 这是一个 SSCCE。它没有显示实际错误，因为我无法上传大数据文件。如果您愿意 - 我可以直接通过电子邮件发送给您...
-
您确定指定
DataFormat = DataFormat.FixedSize是严格要求的吗？我相当有信心反序列化器可以自己找到整数的大小。在我看来，这只会造成麻烦。 -
@aevitas：这是为了确保它是一个固定大小的整数，而不是一个可变长度的整数。这里的背景是 OP 真的想要一个固定的记录长度。
-
您有多确定 38 是正确的数字？你能用少于 2000 万条记录重现这个问题吗？它是否总是以相同的数字失败，如果您以该出价开始它，它会立即失败吗？稍后会尝试您的代码（现在不能这样做），但是您可以将其固定的越多越好。
标签： c# deserialization protobuf-net