/// <summary>
/// Run a write action to a file.
/// This will always rewrite the file (no appending).
/// </summary>
/// <param name="path">File path to write</param>
/// <param name="action">Action to write into file stream. You do not need to close the stream yourself.</param>
public static void Write(string path, Action <Stream> action)
{
lock (_lock)
{
// if the old copy file exists, this means that we have
// a previous corrupt write, so we will not overrite it, but
// rather overwrite the current file and keep it as our backup.
if (File.Exists(path + ".old_copy") == false)
{
File.Move(path, path + ".old_copy");
}
using (
var stream = new FileStream(path,
FileMode.Create,
FileAccess.Write,
FileShare.None,
0x10000,
FileOptions.WriteThrough | FileOptions.SequentialScan)
)
{
SetPermissions.TryAllowReadWriteForAll(path);
action(stream);
stream.Flush();
}
WaitDelete(path + ".old_copy");
}
}
/// <summary>
/// Run a read action over a file by name.
/// Access is optimised for sequential scanning.
/// No file share is permitted.
/// </summary>
/// <param name="path">File path to read</param>
/// <param name="action">Action to consume file stream. You do not need to close the stream yourself.</param>
public static void Read(string path, Action <Stream> action)
{
lock (_lock)
{
if (File.Exists(path + ".old_copy"))
{
if (WaitDelete(path))
{
File.Move(path + ".old_copy", path);
}
}
using (
var stream = new FileStream(path,
FileMode.OpenOrCreate,
FileAccess.Read,
FileShare.None,
0x10000,
FileOptions.SequentialScan)
)
{
SetPermissions.TryAllowReadWriteForAll(path);
action(stream);
}
}
}
private FileStream CreateWriter()
{
var dataFilePath = GetDataPath(CurrentFileNumber);
var stream = new FileStream(
dataFilePath,
FileMode.OpenOrCreate,
FileAccess.Write,
FileShare.ReadWrite,
0x10000,
FileOptions.Asynchronous | FileOptions.SequentialScan | FileOptions.WriteThrough);
SetPermissions.TryAllowReadWriteForAll(dataFilePath);
return(stream);
}
void CreateDirectory(string s)
{
Directory.CreateDirectory(s);
SetPermissions.TryAllowReadWriteForAll(s);
}
