Microsoft Visual SourceSafe

Microsoft Visual SourceSafe (VSS) is a source control software package oriented towards small software development projects. Like most source control systems, SourceSafe creates a virtual library of computer files. While most commonly used for source code, SourceSafe can actually handle any type of file in its database, but prior versions have been shown^{[citation needed]} to be unstable when confronted with large amounts of non-textual data (images, binary executables, etc).

History

SourceSafe was originally created by a company called One Tree Software. The first published version of the product was 3.1, which was a 16-bit application. Microsoft at the time had a less powerful source code control system named Delta. In 1994, Microsoft bought One Tree Software and went on to modify the 16-bit version of SourceSafe 3.1. The result was version 4.0 of Visual SourceSafe (VSS), which was a 32-bit edition of the product. It was released sometime around 1995.

Overview

SourceSafe was initially not a client/server SCM, but rather a local only SCM. Architecturally, this serves as both a strength and weakness of design, depending on the environment in which it is being used. It allows a single user system to be set up with less configuration than that of some other SCM systems. In addition, the process of backing up can be as simple as copying all of the contents of a single directory tree. For multi-user environments, however, it lacks many important features found in other SCM products, including support for atomic commits of multiple files (CVS has the same problem as it is built upon the original RCS). SourceSafe inherits its shared functionality using direct remote file system access to all the files in the repository. This, together with a bug where the code is using old memory after a call to reallocate, are contributing factors to why SS databases sometimes go bad.^{[citation needed]}

Starting with VSS 2005, Microsoft has added a client-server mode. In this mode, clients don't need write access to an SMB share where they can potentially damage the SS database. Instead, files must be accessed through the VSS client tools - the VSS windows client, the VSS command-line tool, or else some application which integrates with or emulates these client tools.^{[citation needed]}

Advantages

Visual SourceSafe's advantages are relative ease of use^{[citation needed]} and some degree of integration with other Microsoft development solutions. For small or medium scale development, where multiple versions are not simultaneously supported, its limitations do not cause major problems^{[citation needed]}. Further strong points include its integration with Microsoft Visual Studio and the fact that it is included as part of most Visual Studio versions.

Criticisms

Due to the nature of its design, the performance of SourceSafe is greatly affected by the type of environment in which it is deployed.^{[citation needed]} The optimal environment is that in which a small team of developers is accessing repository content via a LAN.^{[citation needed]} The criticism concerning instability stems largely from the manner in which Visual SourceSafe uses a direct, file-based access mechanism allowing any client to modify a file in the repository after locking it. If a client machine crashes in the middle of updating a file, it can leave that file in a corrupted state. Many users of Visual SourceSafe mitigate this risk by making use of a utility provided by Visual SourceSafe that checks the database for corruption and, when able, corrects errors that it finds.

Microsoft in-house use

Although "eating their own dog food" is often said to be part of Microsoft's culture, VSS appears to be an exception; it is widely rumored , that very few projects within Microsoft rely on VSS, and that the predominant tool is SourceDepot. According to Matthew Doar

Microsoft itself used an internally developed version of RCS named SLM until 1999, when it began using a version of Perforce named SourceDepot.

The Microsoft Developer Division is now using the new Visual Studio Team System for most of its internal projects, although a VSS transcript implied that other large teams use "a mix of customized in-house tools."

SourceSafe's future

An updated version called Visual SourceSafe 2005 was released in November 2005, promising improved performance and stability, better merging for Unicode and XML files, as well as the ability to check files out over HTTP. It was included with Visual Studio 2005 Team System editions, but is not included with Visual Studio 2008 Team System. It can be purchased separately as a retail product and is part of certain MSDN subscriptions.

However, Microsoft also introduced a source control and project lifecycle management product called Team Foundation Server, which is part of Visual Studio Team System. This product addresses many of Visual SourceSafe's shortcomings, making it suitable for larger teams requiring high levels of stability and control over activities.

According to the "Visual SourceSafe Road Map" and between-the-lines reading of a VSS transcript, Visual Source Safe is targeted towards individual developers or small teams with lightweight SCM needs. Microsoft is encouraging everyone else to migrate to the more sophisticated Visual Studio Team System.

Chats

On August 5, 2004 and December 29, 2004 the Visual SourceSafe product team hosted online chats on MSDN to answer questions about Visual SourceSafe 6.0 and the upcoming Visual SourceSafe 2005. Transcripts of these chats were hosted on MSDN site but are not available for now.

Books on Visual SourceSafe

• Visual SourceSafe 2005 Software Configuration Management in Practice (Packt Publishing, 2007)
• Real World Software Configuration Management (Apress, 2003)
• Essential SourceSafe (Hentzenwerke Publishing, 2001)

See also

• Revision control
• Configuration management
• Software configuration management
• Change management
• List of software engineering topics
• Comparison of revision control software

External links

• Product Overview
• Features Overview
• Microsoft SourceSafe 6.0 General Q & A
• Microsoft SourceSafe 6.0 Technical FAQ
• Product Documentation
• Microsoft VisualSourceSafe Road Map This article gives an overview of Visual SourceSafe and provides a look at where this technology is headed in the future
• SourceSafe Team's WebLog
• Source Safe Best Practices Outlines recommended practices to help prevent data corruption in Microsoft Visual SourceSafe.
• Team Development with Visual Studio .NET and Visual SourceSafe Guidance and recommendations by the Patterns and Practices Team
• Visual Source Safe 2005 Web Cast Source Control and Team Development Using Visual Studio .NET and Visual SourceSafe
• Visual Source Safe 2005 at MSDN
• VSS plugin for Eclipse
• Visual SourceSafe Version Control: Unsafe at any Speed?
• Visual Studio 6.0 SP6 for Latest VSS Service Pack (6.0d)