dossier-dot-net 1.4.0

Dossier.NET

A transactional file management library for the .NET Framework.

How it Works

All actions are added to a queue which can be rolled back should one or more of them fail. The bytes of any files copied, moved or deleted are held in memory until the transaction object is disposed.

using (var fsContext = new Dossier.FileSystemContext())
{
    using (var trx = fsContext.BeginTransaction())
    {    
        try
        {
            var myFile = fsContext.WriteFile(".\\hello-world.txt", "Hello World!");
            fsContext.CopyFile(".\\hello-world.txt", ".\\my-file.txt");

            fsContext.CreateDirectory(".\\MyDirectory"");
            fsContext.MoveFile(".\\my-file.txt", ".\\MyDirectory\\my-file.txt");

            fsContext.MoveDirectory(".\\MyDirectory", ".\\MySecondDirectory");
            fsContext.DeleteFile(".\\MySecondDirectory\\my-file.txt");     
        
            var newFile = fsContext.WriteFile(".\\newfile.txt", "Another file!");
            fsContext.MoveFile(".\\new-file.txt", ".\\moved-file.txt");        
                
            trx.Commit();
        }
        catch
        {
            // if any of the operations in the
            // transaction queue throw an exception,
            // roll it back

            trx.Rollback();
        }
    }
}

You can also specify a temp directory to use instead of storing rollback data in memory. This is especially useful if you are working with a large amount of data. To use a temp directory, simply specify a path to the desired temporary storage location when creating a FileSystemContext.

using (var fsContext = new Dossier.FileSystemContext("\\data\\temp\\"))
{
    // do stuff
}

Each transaction will create a temporary folder named with the unique identifier for the transaction. Every operation will then store it's rollback data in a file in the transaction folder with a unique identifier for the operation. The transaction folder is deleted when the transaction committed, rolled back, or disposed.

When using a temp directory for rollbacks, a transaction.txt file is updated in the folder for each transaction whenever an operation is executed. Upon creation of a new FileSystemContext, the temp directory is checked for any existing transactions, which will be visible through the Transactions collection of the FileSystemContext.

This enables recovering partially completed transactions in the event of power loss or an unexpected application crash.

using Dossier;

using(var fsContext = new FileSystemContext("\\my-temp-directory"))
{
    if (fsContext.Transactions.Any())
    {
        // clean up partially completed transactions
        foreach (var trx in fsContext.Transactions)
        {
            trx.Rollback();
        }
    }
}

You may also call the UseTransaction() method to resume using a previously existing transaction.

using Dossier;

using (var fsContext = new FileSystem.Context("\\my-temp-directory"))
{
    ITransaction trx;

    if (fsContext.Transactions.Any())
    {
        trx = fsContext.Transactions.First();
        fsContext.UseTransaction(trx);
    }
    else
    {
        trx = fsContext.BeginTransaction();
    }

    fsContext.MoveFile("\\file1.txt", "\\file2.txt");

    try
    {
        trx.Commit();
    }
    catch (Exception)
    {
        trx.Rollback();
    }
}