Version Control with Subversion

This is the Title of the Book, eMatter Edition

Copyright © 2007 O’Reilly & Associates, Inc. All rights reserved.

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Chapter 2: Basic Concepts

The output from the svn update command indicates that Subversion updated the

contents of button.c. Note that Sally didn’t need to specify which files to update;

Subversion uses the information in the .svn directory, and further information in the

repository, to decide which files need to be brought up to date.

Revisions

An svn commit operation can publish changes to any number of files and directories

as a single atomic transaction. In your working copy, you can change files’ contents;

create, delete, rename and copy files and directories; and then commit the complete

set of changes as a unit.

In the repository, each commit is treated as an atomic transaction: either all the com-

mit’s changes take place, or none of them take place. Subversion tries to retain this

atomicity in the face of program crashes, system crashes, network problems, and

other users’ actions.

Each time the repository accepts a commit, this creates a new state of the filesystem

tree, called a revision. Each revision is assigned a unique natural number, one greater

than the number of the previous revision. The initial revision of a freshly created

repository is numbered 0, and consists of nothing but an empty root directory.

Figure 2-7 illustrates a nice way to visualize the repository. ...