The simple working principle of 1 Virtual memory system
Microsoft's VSS6.0 solves the long-standing problem of version management faced by software development teams. It can effectively help the person in charge of the project development team to manage the project program and store all the project source files (including various file types) in the database in a unique way. Members of the development team cannot directly modify the files in the database, but the version manager will copy the source program of the project or subproject to its own working directory for debugging and modification, and then submit the modified project file to VSS for comprehensive update. VSS also supports fast and efficient file sharing among multiple projects. When a member adds a file to VSS, the file will be backed up in the database so that it can be used by all members. In addition, the changes made by each member to all project files will be recorded in the database, so you can recover and undo the changes anytime and anywhere. Team members can get the latest version of the project, modify it and save a new version.
The project organization management of VSS makes the coordination of development teams simple, easy and intuitive. When a file or a group of files is distributed to another member, group, website or any other address, VSS ensures the real enjoyment between them and the security of different versions of the selected file group. Now, more and more developers can access the functions of VSS through their development environment. Moreover, VSS can be easily integrated with Microsoft Access, Vi sual Basic, Visual C++, Visual FoxPro and other development tools. Once VSS is integrated into the development environment, it can be used as a control, which can well reflect the usability and powerful functions of VSS.
2.2. Several important concepts in VSS.
In order to better understand VSS, it is necessary to explain the following concepts.
First, the concept of the project. A project is a set of files (of any type) stored in VSS, which can be added, deleted, edited and enjoyed within or between projects. A project has many similarities with folders in the operating system, but it better supports file merging, history and version control. All files are stored in the project of VSS database. Development team members can't operate the master backup file in VSS (except for special circumstances such as checking and version comparison), but VSS will provide each member with a copy in their respective working directories for their work. Although you can view files without a working directory, if you really want to work under VSS management, you must create a working directory.
VSS can maintain multiple versions of a file, including change records of different versions. Version control includes the following aspects:
Intra-group coordination-Under normal circumstances, only one member can modify a specific file at any time, which can prevent the file from being accidentally updated by the modification of other members. Of course, VSS administrators can change this default setting to allow a single file to be checked out multiple times at the same time, and still prohibit overwriting other people's modifications.
Version Tracking-Archive and track old versions of source code and other files, which can be retrieved for error tracking or other purposes.
Cross-platform development-supports version control of the same code across multiple development platforms.
Reuse or object-oriented code-keep track of which programs use which reusable code.
The meaning of version control will be further discussed in later chapters.
As we all know, VSS provides version control and history services to ensure that every version of a file is recoverable. VSS uses date/timestamp to record the check-out or modification time of files. There are three main ways to track the versions of files and projects:
Version number: This is an internal number 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 is increasing.
Tags: These are strings assigned by users to a certain version of a project or file, which can be strings in any format and the length is no more than 3 1 character.
Date/Time Stamp: It gives information about the time when the file was last modified or checked in. VSS supports 12 hours and 24 hours.
The working directory is where users actually debug and modify project files. When a user checks out or extracts a file, VSS copies the item to the user's working directory. When a user modifies a file and checks it in or submits it, VSS copies it from the user's working directory back to the VSS database. When the user checks out, VSS will automatically manage his working directory, such as creating necessary subdirectories. And you can create or modify the working directory at any time.
3. Some new features and functions of 3.VSS 6.0
Archiving and Recovery-In VSS6.0, these two operations were performed in the user-friendly VSS Administrator Wizard, whereas in previous versions, they could only be realized through the command line.
Move files-When users move files, VSS6.0 will automatically share the files in the new project and delete the files in the original project. In the new project, the properties of this file are shared by * * * *.
Compare differences between multiple projects-This feature allows users to compare differences between different projects.
Expansion of a single file-in previous versions, VSS can only expand one directory (folder), and in VSS6.0, one file can be expanded at the same time.
Fast extraction-due to the performance improvement of VSS6.0, the file extraction speed is about twice as fast as that of the previous VSS version.
Historical information filtering -VSS6.0 supports viewing the history of unmarked files and projects.
Clear temporary folder option-This new feature makes it easy for users to clear temporary folders.
Check external hyperlinks-In earlier versions of VSS, only hyperlinks and jumps inside the project were checked, while VSS6.0 allowed users to check hyperlinks and jumps outside the project.
Create shortcut keys to open VSS databases-Users can use this new feature in VSS Explorer to create desktop shortcut keys to open specific VSS databases.
Help in HTML format-previous version of -VSS uses WinHelp format.