public Stream Open(string filename, FileMode fileMode, FileAccess fileAccess)
{
Stream result;
IPseudoFile pseudoFile;
bool fileExists = pseudoFiles.TryGetValue(filename, out pseudoFile);
bool wantsWritable = (fileAccess & FileAccess.Write) != 0;
switch (fileMode)
{
case FileMode.Append:
if (fileExists)
{
if (wantsWritable && !pseudoFile.CanWrite)
{
throw new Exception("'File' is read-only");
}
result = pseudoFile.Open(SeekOrigin.End);
}
else
{
throw new Exception("'File' doesn't exist");
}
break;
case FileMode.Create:
if (fileExists)
{
if (wantsWritable && !pseudoFile.CanWrite)
{
throw new Exception("'File' is read-only");
}
result = pseudoFile.Open(SeekOrigin.Begin);
}
else
{
pseudoFile = new PseudoFile(filename);
pseudoFiles.Add(filename, pseudoFile);
result = pseudoFile.Open(SeekOrigin.Begin);
}
break;
case FileMode.CreateNew:
if (fileExists)
{
throw new Exception("'File' exists");
}
else
{
pseudoFile = new PseudoFile(filename);
pseudoFiles.Add(filename, pseudoFile);
result = pseudoFile.Open(SeekOrigin.Begin);
}
break;
case FileMode.Open:
if (fileExists)
{
if (wantsWritable && !pseudoFile.CanWrite)
{
throw new Exception("'File' is read-only");
}
result = pseudoFile.Open(SeekOrigin.Begin);
}
else
{
throw new Exception("'File' doesn't exist");
}
break;
case FileMode.OpenOrCreate:
if (fileExists)
{
if (wantsWritable && !pseudoFile.CanWrite)
{
throw new Exception("'File' is read-only");
}
result = pseudoFile.Open(SeekOrigin.Begin);
}
else
{
pseudoFile = new PseudoFile(filename);
pseudoFiles.Add(filename, pseudoFile);
result = pseudoFile.Open(SeekOrigin.Begin);
}
break;
case FileMode.Truncate:
if (fileExists)
{
pseudoFile.Delete();
pseudoFile = new PseudoFile(filename);
pseudoFiles[filename] = pseudoFile;
result = pseudoFile.Open(SeekOrigin.Begin);
}
else
{
throw new Exception("'File' doesn't exist");
}
break;
default:
throw new Exception("Unexpected FileMode");
}
return(result);
}
/// <summary>
/// Adds a readonly pseudo file.
/// </summary>
public void AddPseudoFile(string filename, byte[] bytes)
{
IPseudoFile pseudoFile = new PseudoFile(filename, bytes);
pseudoFiles.Add(filename, pseudoFile);
}
