Version Control with Subversion - Login

Chapter 8. Embedding SubversionSubversion has a modular design: it's implemented as a collection of libraries written in C.Each library has a well-defined purpose and application programming interface (API), andthat interface is available not only for Subversion itself to use, but for any software thatwishes to embed or otherwise programmatically control Subversion. Additionally, Subversion'sAPI is available not only to other C programs, but also to programs written in higherlevellanguages such as Python, Perl, Java, and Ruby.This chapter is for those who wish to interact with Subversion through its public API or itsvarious language bindings. If you wish to write robust wrapper scripts around Subversionfunctionality to simplify your own life, are trying to develop more complex integrationsbetween Subversion and other pieces of software, or just have an interest in Subversion'svarious library modules and what they offer, this chapter is for you. If, however, you don'tforesee yourself participating with Subversion at such a level, feel free to skip this chapterwith the confidence that your experience as a Subversion user will not be affected.Layered Library DesignEach of Subversion's core libraries can be said to exist in one of three main layers—theRepository layer, the Repository Access (RA) layer, or the Client layer (see Figure 1,“Subversion's architecture” in the Preface). We will examine these layers shortly, but first,let's briefly summarize Subversion's various libraries. For the sake of consistency, we willrefer to the libraries by their extensionless Unix library names (libsvn_fs, libsvn_wc,mod_dav_svn, etc.).libsvn_clientPrimary interface for client programslibsvn_deltaTree and byte-stream differencing routineslibsvn_diffContextual differencing and merging routineslibsvn_fsFilesystem commons and module loaderlibsvn_fs_baseThe Berkeley DB filesystem backendlibsvn_fs_fsThe native filesystem (FSFS) backendlibsvn_raRepository Access commons and module loaderlibsvn_ra_localThe local Repository Access modulelibsvn_ra_neonThe WebDAV Repository Access modulelibsvn_ra_serfAnother (experimental) WebDAV Repository Access modulelibsvn_ra_svnThe custom protocol Repository Access module206