Question

I was reading a binary file and while waiting for something to happen, I noticed that the program wasn’t doing anything.

It seemed to be stuck at a certain point in execution. I added in some print statements to console, and can see that it gets to a certain point…but then doesn’t seem to want to continue. This is the first couple lines of code:

private BinaryReader inFile;
public void Parser(string path)
{
    byte[] newBytes;
    newBytes =  File.ReadAllBytes(path);

    using (MemoryStream ms = new MemoryStream())
    {
        ms.Write(newBytes, 0, newBytes.Length);
        inFile = new BinaryReader(ms);
        inFile.BaseStream.Seek(0, SeekOrigin.Begin);
    }
}

public void ParseFile()
{
  Console.WriteLine("parsing");
  Console.WriteLine("get size to read"); // prints this out
  int sizeToRead = inFile.ReadInt32();
  Console.WriteLine("Size: {0}", sizeToRead); // doesn't print this out
  Console.WriteLine("Done"); // end file processing
}

When I comment out the read, it works fine. I dumped the contents of inFile into a new file and it was the same as the original file, so it should be a valid stream.

I am not sure how to continue debugging this issue. Anyone ran into similar issues?

EDIT: Sorry, I was posting bits and pieces of different methods. Here’s the whole methods

Answer 1

Once you leave the using block, the MemoryStream is disposed, making your BinaryReader invalid as well. Throwing away the memory stream is pulling the rug out from under your binary reader. Move all of your related reading code into a using block, if you can, and wrap your BinaryReader in one as well.

using (var ms = new MemoryStream(File.ReadAllBytes(path)))
using (var inFile = new BinaryReader(ms))
{
    inFile.ReadInt32();
}

You can read directly from the file as well, unless you have a reason to read it all in and feed it through a MemoryStream.

If the way your code is laid out keeps you from using using, then you can keep track of the MemoryStream and BinaryReader objects and implement IDisposable. Then call Dispose` on them later to clean up.

The garbage collector will clean up eventually if you don’t do this, but calling Dispose on anything that is IDisposable is good habit to get into. If you don’t, you may run into issues with open file handles or GDI objects sitting around in the finalizer queue waiting to be disposed.