Kevin Parsons
33a480106a
A recent OS change altered how sparse files are represented in backup streams. This caused backuptar to no longer work with certain files. The specific behavior that changed is as follows: - Empty sparse files (size = 0), previously did not have any data or sparse block streams in the backup stream. Now, they will have a data stream with size = 0, and no sparse block streams. - Sparse files with a single allocated range (e.g. a normal file that has the sparse attribute set) previously would not show as sparse in the backup stream. Now, they will show as sparse. The old backuptar behavior assumed that if the sparse flag was set on the data stream, then there would always be a set of sparse blocks following. These changes break this assumption, and so require special handling. It is unsupported to have a data stream, marked sparse, that contains file content AND a series of sparse block streams following. As far as I can tell this is not a valid case for backup streams. This change also cleans up some code and error messages, and expands on the test coverage for backuptar. For more information on backup stream format see: https://docs.microsoft.com/en-us/openspecs/windows_protocols/ms-bkup/f67950c8-d583-469a-83dd-c4ff4cedf533 Signed-off-by: Kevin Parsons <kevpar@microsoft.com>
go-winio 
This repository contains utilities for efficiently performing Win32 IO operations in Go. Currently, this is focused on accessing named pipes and other file handles, and for using named pipes as a net transport.
This code relies on IO completion ports to avoid blocking IO on system threads, allowing Go to reuse the thread to schedule another goroutine. This limits support to Windows Vista and newer operating systems. This is similar to the implementation of network sockets in Go's net package.
Please see the LICENSE file for licensing information.
Contributing
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Code of Conduct
This project has adopted the Microsoft Open Source Code of Conduct. For more information see the Code of Conduct FAQ or contact opencode@microsoft.com with any additional questions or comments.
Special Thanks
Thanks to natefinch for the inspiration for this library. See https://github.com/natefinch/npipe for another named pipe implementation.