I. Necessity of version management If the software crisis in the 1970s has led to the birth and theoretical system of software engineering ideas, the rapid development of software industry in the 1980s and 1990s has led to another new idea. And implementation, this is the version management of the software.
As long as you participate in the software development, it is clear that the current software project is completely unimaginable and impossible, usually there is a R & D team to analyze, design, encode, and maintain, and have special tests The panel fully tests the software that has completed the encoded debugging. In this huge and complicated process in software development, people involving all aspects, information exchange feedback is more than just between members of the R & D team and each R & D team, but also between customers and R & D. All of these AC feedback information may result in modifications to software, small may be just a change in definition of a variable in a source file, which may even have a change in demand analysis. In this project, due to the intrinsic features inherent, many software versions may be formed, and we cannot guarantee that there is no error, but such a difficult situation is very realistic in the project development manager. In front of him / how can she effectively solve these problems, specifically, the following issues:
1. How to manage the R & D project;
2. How to coordinate between members of the project development team in an effective mechanism;
3. How to manage the unified management of sub-projects that are responsible for team members;
4. How to make a unified summary summary of the revisions made by the members of the R & D team;
5. How to retain the modified trajectory to revoke the wrong change;
6. How to identify, management, and differential identification of various versions of the software formed in the R & D process.
A very direct reaction, we must introduce a management mechanism, a version management mechanism, and is a broad version of management, which not only requires the source version of the source, but also to manage the entire project. The conventional type is known as a good programming style, such as the reasons for the revision, modifying people and dates, modifying people, and dates, if multiple members have made modifications, then need to perform timely artificial Difference comparisons and synthesize to form a unified new version. This approach has become more and more space in the development of large software, it can be said to be a small workshop in the form of a small workshop, and it is impossible to do it.
In fact, the idea of version management has long been in the minds of software developers, but the past awareness is not as urgent in the past. UNIX's program development system provides a tool that can be managed in the development group, and now Linux is a powerful cross-platform version manager, and foreign companies' Windows-based version managers have also been With more mature products, domestic research units, such as Peking University Computer, Case Lab, is also committed to this work. In numerous mature products and test products, this will only be used in a wide range of users, and more user prospects, which can be used to obtain a detailed introduction of the Visual SourceSafe 6.0 of Microsoft, which is a detailed introduction. Solution, and concrete implementation.
Second, Visual SourceSafe 6.0 (VSS 6.0) Introduction
VSS 6.0 is now a member of the developed product family as Microsoft Visual Studio 6.0, such as Visual C 6.0 and Visual J 6.0.
1. Simple working principle of VSS
Microsoft's VSS 6.0 solves the long-term version management problem facing the software development team. It can effectively help the responsible persons of the project development group to manage the project procedures, and all item source files (including various file types) are unique. The way is deposited in the database. The member of the development group cannot be directly modified to files in the database, but by copying the source program of the item or sub-project origin to each member's own work directory for debugging and modification, The modified project file is then submitted to the VSS, which is integrated by it. VSS also supports fast and efficient sharing of files between multiple projects. When a member adds a file to the VSS, the file will be backed up to the database so that all members can share the file. And each member of each member will be recorded in the database, making the recovery and revocation of modified events possible at any time. The team members may get the latest version of the project, modify it, and save a new version. The VSS project organization management makes the development team's coordination easier and intuitive. When a group, a group of files are issued to another member, a group, a web site, or any other address, VSS ensures true sharing between them and Safety of different versions of the selected set of files. Now, more and more developers can access the VSS functionality through their development environment. And VSS can easily integrate Microsoft Access, Visual Basic, Visual C , Visual FoxPro, and other development tools. Once VSS is integrated into the development environment, you can use the control of the control, it can reflect VSS. Easy to use and power.
2. Several important concepts in VSS
In order to better understand the VSS, it is necessary to give a description of some concepts.
The first is the concept of the project, the so-called project is a set of files in the VSS (any type), which can be added, deleted, edited, and shared between items or items. A project has a lot of similarities with the folder of the operating system, but it better supports file merge, history and version control. All files exist in a VSS database project, the development group member cannot work on the primary backup file in the VSS (except for special cases such as check and version comparison) but VSS provides one for each member in their respective working directories. Copy for work. Although a file can also be viewed without a working directory, if you want to work under VSS management, you must create a work directory. VSS can maintain multiple versions of a file, including a record from different versions. Version control includes the following aspects:
Coordination in the group - In general, make sure there is only one member to modify a particular file at any time, which prevents files from being modified by other members. Of course, VSS administrators can change this default settings to allow multiple Checkout for single files, and still prohibit the coverage of others.
Version Tracking - archives and tracks the old version of the source code and other files, and these versions can be reacted to perform bug tracking or other purposes.
Cross-platform development - supports the same code to control the version of multiple developments.
Reusal or object-oriented code - Track which programs use which code can be reused modules.
The meaning of version control will be further discussed in the later chapter.
We already know that VSS provides version control and historical services to ensure that each version of a file is recoverable. The VSS is used to record the file when the file is CHECKOUT or when it is modified, it mainly has three ways to track files and project versions:
Version number: This is the internal digital data maintained by VSS, and the user has no control over it. Each version of each file and project has a version number, which is always an integer and increment.
Tags: These are a string of a version of a version of a project or file that can be a string of no more than 31 characters in any format. Date / Timestamp: It gives a file that is finally modified, or when a file is checkin. VSS supports 12 hours and 24 hours of time format.
The working directory is where the user really debugs the project file. When the user Checkout is extracted, the VSS copies the item to the user's working directory, when the user modifies the file and uses it when Checkin or submits, VSS Then come back from the user's work directory to the VSS database. When the user make Checkout, VSS will automatically manage his work directory, such as creating the necessary subdirectory. And the working directory can be created or modified at any time.
3. Some new features and features of VSS 6.0
Archiving and Recovery - These two operations in VSS 6.0 are made in a user-friendly VSS admin Wizard, and in previous versions, they can only be implemented by command lines.
Moving files - When the user moves the file, VSS 6.0 automatically shares the file into a new project and deletes it in the original project. In a new project, the properties of the file are shared.
Differences between multiple items comparison - This feature allows users to compare differences between different items.
Unfold from a single file - In the previous version, VSS can only expand a directory (folder), in VSS 6.0, can also expand a file.
Quick extraction - Due to the improvement of VSS 6.0 in performance, the current file extraction speed is twice the faster than the VSS version in the past.
Historical Information Filtering - VSS 6.0 Supports View the history of files and projects that do not have labels.
Clear the temporary folder option - the new feature allows the user to easily clear the temporary folder.
Check the external superconnection - In the earlier version of VSS, only internal super-connected and jump in the project are checked, and VSS 6.0 allows users to check the over-connection and jump outside of the project.
Create shortcuts to open the VSS database - users can create a desktop shortcut to open a particular VSS database using the new feature in VSS Explorer.
HTML format Help - VSS's previous version is used by WinHelp format.
Third, VSS 6.0 solutions have a more comprehensive understanding of the working principle, function and new features of VSS 6.0, we start to enter this section, which is how to use VSS 6.0 to actually solve the version of the software development project. Management and control issues, how to effectively architecture a system solution.
First look at the actual situation of our development team, the most general situation is that the entire project is the microcomputer environment, and each developer uses Microsoft's VC, VB, VJ, etc. to develop projects in their respective Windows microcomputers. Each sub-project or sub-module, usually this team is part of a local area network or a more independent subnet, which may have a dedicated server. Such a development environment is very advantageous for implementation of VSS 6.0, which is very intuitive, because VSS 6.0 also requires this network environment.
Secondly, for the project itself, a project will generally be divided into several sub-projects after analyzing the design, and the actual situation of software development determines that all groups are not completely independent, they Under many cases, we need to coordinate interaction and information feedback. Each step in the development process may lead to amendment to the previous phase, because software development is largely a spiral process, not to say groups. The interior exchanges. In this process of constantly interacting, the number of phases, some versions, and full versions of the project may be imagined, and the conventional version of the usual version of the artificial management is unable to win. And there is also a very important aspect that is not negligible, which is especially obvious to the development of system software, ie software hierarchy. The general approach is to develop corresponding applications for multiple applications above the general system software. It is also generally divided into system development groups and various application development groups, application software development and use. The problem that will be reflected back to countless applications themselves and system software. If you only modify the update system software separately for each application, this inevitably causes the inconsistency of multiple system versions, so that there is a problem that the system exists. It is not your strength. VSS 6.0 is being suitable for this software development architecture, which can create their own projects for each group, and these projects are from a total project, all modifications will be summarized to form a unified version. In response to such a most common software development environment and organization structure, the VSS 6.0 is used to version control management is very effective and the small cost of cost is:
Install the VSS 6.0 server-side software software software installed on a Windows NT server or a more independent Windows 98/95 PC, create a database stored for the entire project, then create each project and sub-project in the database, and Create an account and their respective permissions for each member of the VSS administrator;
Install the VSS client software on the PC of the development team, and create its own work directory, which in the software development process, as long as they log in to the VSS server via this client software, Checkout is currently working. Or files, if there is a modified modification, it is uniformly updated to the VSS server at the end of the work.
The solution is shown below.
