CODEWITHSUNDEEP
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Demarsch
Demarsch

Reputation: 1479

Buffer size for File.OpenRead

If you use one of FileStream constructors you can specify buffer size in bytes but if you use File.OpenRead you can't. What is the default value for buffer size which is used in the secondcase?

Upvotes: 2

Views: 1227

Answers (2)

w128
w128

Reputation: 4928

Using Telerik JustDecompile to look at the code, it's 4096 B:

public static FileStream OpenRead(string path)
{
    return new FileStream(path, FileMode.Open, FileAccess.Read, FileShare.Read);
}

public FileStream(string path, FileMode mode, FileAccess access, FileShare share) : this(path, mode, access, share, 4096, FileOptions.None, Path.GetFileName(path), false)
{
}

Upvotes: 5

Mike Perrenoud
Mike Perrenoud

Reputation: 67898

It's 4096 as you can see from this constructor:

[SecuritySafeCritical]
public FileStream(string path, FileMode mode, FileAccess access, FileShare share)
    : this(path, mode, access, share, 4096,
           FileOptions.None, Path.GetFileName(path), false)
{
}

That's the constructor called by OpenRead:

public static FileStream OpenRead(string path)
{
    return new FileStream(path, FileMode.Open, FileAccess.Read, FileShare.Read);
}

Upvotes: 5

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