The FS API, svn_fs_ and svn_repos_, provides access to a repository on the local filesystem. It provides a transactional API to commits: create a txn, populate the txn, commit or delete the txn. The servers svnserve and mod_dav_svn use this API.
The RA API, svn_ra_, provides access to a repository via an URL such as http://, svn://, file:// etc. Usually this repository will be on a remote server running svnserve or mod_dav_svn. It also provides a transactional API to commits but is more restricted: the FS API provides random access to the txn while the RA API requires an ordered pass over the txn. The client svnmucc uses this API. The client API, svn_client_, provides access to a repository via a working copy or via an URL. It provides a higher level API that does not expose transactions, but instead provides functions to make a commit, do an import, etc. The client svn uses this API. If you want network access, or you want to use Subversion's authentication/authorization, then use the RA or client APIs. If you want local access, and more freedom with transaction handling, then use the FS API. "Ren Wang" <renwang...@gmail.com> writes: > Hi Bert, > > > > Thank you very much for the detail explanations. > > > > We have been thinking about the option to develop our own repository layer > vs subversion API file:/// <file:///\\> repository API (libsvn_fs). This is > why we are looking for programming guide and sample code for supporting our > use cases. So far, we only have the test code from subversion, such as > test_fs project which is not enough for us. > > > > I will take a look of the svnmucc code. > > > > Regards, > > > > Ren > > > > From: Bert Huijben [mailto:b...@qqmail.nl] > Sent: Sunday, November 8, 2015 12:28 PM > To: 'Ren Wang' <renwang...@gmail.com>; users@subversion.apache.org > Subject: RE: Subversion C API > > > > Mod_dav mostly uses the repository layer api. In a few specific cases it > goes into the fs layer directly. sometimes because something isn't mapped, > but in other cases because mod_dav was developed very early in the > development process and the repository layer wasn't as complete as it is > today. > > > > But is the client layer really that expensive for you that you can't use it? > Did you measure it? > > > > I can't imagine usecases where the performance is that critical that you > really can't afford the thin layer that the file:/// <file:///\\> > repository api has, but don't want a specialized datastore 100% optimized > for your usecase. > > > > I can think of a few cases where you might want to avoid the overhead of > having a working copy, but even there the costs aren't usually that high > that it makes sense to spend a lot of time to develop something else. > > (And in many cases the still private API behind svnmucc can already help you > there) > > > > Bert > > > > From: Ren Wang [mailto:renwang...@gmail.com] > Sent: vrijdag 6 november 2015 19:44 > To: users@subversion.apache.org <mailto:users@subversion.apache.org> > Subject: Subversion C API > > > > I have posted the same question to the stackoverflow, here it is. Looking > forward to hear from you: > > > > We are considering to use Subversion as the file system layer to store > version enabled documents. Since the security function will be handled by > other code, I am considering to directly use the Subversion FS C API layer. > I wonder if there any good sample code for using Subversion FS APIs? > > > > Someone answered back: > > Subversion's FSFS store is meant to be used by the subversion server. While > it might be useable in other scenarios, whatever sits on top of it will > likely have to act much like a subversion server when interacting with it. > Subversion differentiates between client workspaces and the server storage > space. If you are going to leverage subversion components, your application > needs to realize that these two spaces are not the same within a subversion > architecture, and therefore should not be the same within your solution that > uses their components. > > Why not just embed a subversion client into the place you desire and then go > from there? The user workspace will still be "the subversion user workspace" > and the server side will be the server side. In fact, check out tortise SVN > (or other desktop integrations of subversion). You might not even need to > write anything. > > I asked again with more context for the project: > > SVN Client API will have performance penalty since it will go through other > layers such as user authentications, authorizations, transport etc. which > are not needed for us. Subversion server side API will bypass those calls. I > wonder which API mod_dav_svn used. > > Regards, > > Ren > > > -- Philip Martin WANdisco
