There seems to be some consternation about two file types that, in my case, TFS checks in when a new solution or project are created: .vssscc and .vspscc files.
I found a page that describes that these files are for, and yet another that recommends checking them in. I'm perfectly fine with this, but I have heard some grumblings in the internet that these files can cause issues with collaboration between projects, such as merge conflicts and project load errors.
I do recall having some issues in my own organization where the .vspscc file caused some issues, where a developer had caused some edits to it and didn't check it in with the rest of his changes. We were able to repair easily, however.
My question is: what issues should I be aware of, and in the case that issues exist, what precautions can I recommend to my organization to avoid any trouble?
The only issue I've ever come across is a minor annoyance- the .vssscc is included as a change with many checkins even though the .vssscc contents have not changed. I'm guessing the last modified date is being updated.
Apparently Microsoft was looking into fixing this in 2010.
It seems unlikely that these files contain anything of importance to the source code. As far as I can tell it's just cached data about the current code.
I opened an issue at https://github.com/dotnet/project-system/issues/1801, so go there and let them know how this affects you.
Related
I've been working with a lot of my files on the go recently, and in the process often times accumulated several copies of files in different stages of completion/revision. I'm working on any number of projects at a given time, so it's not always easy to remember or figure out quickly which version I should continue working on.
What type of options would you recommend that allow me to track changes locally and if possible with files I work on while at a remote location? I've never worked with file versioning or tracking systems, so not sure what direction I should be looking in. I work mostly with HTML, CSS, and PHP.
Any help is awesomely appreciated! Thanks.
PS. Don't know if I should have this in a separate question but what options are available for the same type of thing, change tracking/logging for files on server? Preferably something that not only vaguely notes a file has been changed, but that tracks specific changes that have occurred in files.
It's seems to me that github is prefect choice for your requirement. You can create repository for maintain the history, it's easy to use and it is free
https://github.com/
In the early stages of a project when lots of files are being added and the project is being worked on by more than one person concurrently, Xcode project files tend to come into conflict often under source control. Merging those is a pain and often results in lost file references if you're not careful.
Has anyone worked out a tried and true system for collaborating using a common Xcode project file? Does anyone keep a separate project file for each collaborator and worry about file dependencies when the problems arise? This seems like a pretty common problem, so I'm sure plenty of people have worked out a system for this type of thing.
I do have my own system for this involving separate project files for each collaborator, but that's kind of a bummer in the early stages...
The best answer I have found is simply "Commit early and commit often." Don't wait until you've amassed a ton of changes to commit your work — when you add a new file to your project, check it in. When you move or rename a class, check it in. You get the idea…
The project format actually is fairly robust for automated merges. It's just that automated merges fall down pretty quickly when there are lots of small changes distributed all over the file.
The obvious caveats are:
There are going to be periods of time where there is a bunch of half-baked clutter in TOT. You will want to start using branches and/or tags to keep track of "when things were good."
For this to work, everyone on the team has to be on board with this. If you have any holdouts, their pain will be increased by the frequency of everyone else's check-ins.
My team works this way, and it works well enough for us. It's certainly no more painful than managing classic Makefiles, IMHO.
I'm learning mercurial as my solo scm software. With other management software, you can put change comments into the file header through tags. With hg you comment the change set, and that doesn't get into the source. I'm more used to central control like VSS.
Why should I put the file history into the header of the source file? Should I let mercurial manage the history with my changeset comments?
Let the source control system handle it.
If you put change details in the header it will soon become unwieldy and overwhelm the actual code.
Additionally if the scm has the concept of changelists (where many files are grouped into a single change) then you'll be able to write the comment so that it applies to the whole change and not just the edits in the one file (if that makes sense), giving you a clearer picture of why the edit was required.
Yes; let the source control system handle your changeset comments. The rationale for this is that it makes considerably more sense when you're viewing the change log later, trying to work out what's going on between two versions of a file - the source control system can present the change comment to try and enlighten the situation.
There's no reason to manually maintain a file history when SCM software is much better suited to solve this problem. All too often I see partially-completed file histories in the source, which actually hurts, because people incorrectly assume it is accurate.
The difference is not whether it's a centralized or distributed VCS, it's more about what's being changed.
When I moved to .Net, the number of files updated for any individual change seemed to skyrocket. If I had to log the change in each file, I'd never get any real work done. By commenting on the set of changes, it doesn't matter how many files I had to update.
If I ever needed to identify all of the changes for a particular change, I can diff between the two versions of the project.
The biggest difference (and advantage) I saw when switching away from SourceSafe was the switch from file based to project based commits. As soon as I got used to that, I stopped adding change-log type comments to all of my files.
(As a side effect, I've found that my process description comments have gotten better)
I'm not a big proponent of littering the code with change comments. In the event they are needed they can be looked up in the SCM (at least for the SCM variants I have used). If you do want them in the file, consider putting them at the end instead of the beginning. That way you won't have to scroll down past the (uninteresting, to me at least) comments before you get to the actual code.
Another vote for letting the SCM system handle the checkin comments, but I do have one thing to add.
Some systems allow you to use RCS tags in your source code where the SCM can insert the change history directly into the source file being committed automatically. Sounds like a nice balance because the history is then in the SCM system and then automatically put into the source code itself.
The problem is that this process changes the source file. I think that's a bad idea because the file cannot be changed on disk until after you comment is inserted. If you were a good engineer, you should have built and tested changes before the commit. If your source changes after the commit, then you've essentially got a build that could be broken - but most engineers won't build after a commit - why should they?
But it's just a comment you say! True, but I did have a case where there was code in my source file that strangely enough had reason to look like an RCS header tag and that section of the code got replaced on checkin, thereby munging my code. Easy enough to fix, but bad that a build got broken for 20+ users
Much easier to forget to maintain history in the source, as one always (imo) should comment commits to source control system that problem dissappers. Also if changing lots of files before commit, changing history in every file will be annoying work. This is really one of the points with having scm.
I have experience with this. I've had the file history in the comments, it was awful. Nothing but garbage, sometimes you would have to scroll down almost 1k lines of code changes before you finally got to what you wanted. Not to mention, you're slowing down other aspects of your build process by adding more kb to your source code tree.
I've never really worked with a lot of people where we had to check out code and have repositories of old code, etc. I'm not sure I even know what these terms mean. If I want to to start a new project that involves more than myself that tracks all the code changes, does "check out" (again, don't know what that means), how do I get started? Is that what SVN is for? Something else? Do I download a program that keeps up with the code?
What do I do?
It will all be in house. No Internet for storing code.
I don't even know if what I am asking for is called source control. I see things about checking out, SVN, source control, and so on. I don't know if it is all talking about the same thing or not. I was hoping to use something open source.
So, a long time ago, in the bad old days of yore, source control used a library metaphor. If you wanted to edit a file, the only way to avoid conflicts was to make sure that you were the ONLY one editing the file. What you'd do is ask the source control system to "check out" that file, indicating that you were editing it and nobody else was allowed to edit it until you made your changes and the file was "checked in". If you needed to make a change to a checked out file, you had to go find that freakin' developer who'd had everythingImportant.conf checked out since last Tuesday..freakin' Bill...
Anyway, source control doesn't really work like that anymore, but the language stuck with us. Nowadays, "checking out" code means downloading a copy of the code from the code repository. The files will appear in a local directory, allowing you to use them, compile the code, and even make changes to the source that you could perhaps upload back to the repository later, should you need to. Even better, with just a single command, you can get all the changes that have been made by other developers since the last time you downloaded the code. Good stuff.
There are several major source control libraries, of which SVN (also called Subversion) is one (CVS, Git, HG, Perforce, ClearCase, etc are others). I recommend starting with SVN, Git, or HG, since they're all free and all have excellent documentation.
You might want to start using source control even if you're the only developer. There's nothing worse than realizing that last night the thousand lines of code you deleted as useless were actually critically important and are now lost forever. Source control allows you to zoom forwards and backwards in the history of your files, letting you easily recover stuff that you should not have removed, and giving you a lot more confidence about deleting useless stuff. Plus, fiddling around with it on your own is good practice.
Being comfortable with source/revision control software is a critical job skill of any serious software engineer. Mastering it will effectively level you up as a professional developer. Coming onto a project and finding that the team keeps all their source in a folder somewhere is an awful experience. Good luck! You're already on the right path just by being interested!
Check out Eric Sink's excellent series of articles:
Source Control HOWTO
I recommend Git and Subversion (SVN) both as free, open-source version control systems that work very well. Git has some nice features given that it can be easier to work decentralized.
Checkout means retrieving a file from a source control system. A source control system is a database (some, like CVS, use just specially marked up text files, but a file system is also a database) that holds all versions of your code (that are checked in after you make modifications).
Microsoft Visual SourceSafe uses a very proprietary database which is prone to corruption if it is not regularly maintained and uses reserved checkouts exclusively. Don't use it, for all those reasons.
The difference between a reserved checkout and an unreserved checkout is in an unreserved checkout; two people can be modifying the same file at once. The first one to check in gets in no problem, and the second one has to update their code to the latest version and merge the changes into theirs (which usually happens automatically, but if the same area of the file was changed, then there is a conflict, which has to be resolved before it can be checked in).
For some arguments for unreserved checkouts, see here.
Following this, you will be looking at a build process that independently checks out the code and builds the source code, so that everyone's changes are built and distributed together.
Are you creating the project that requires source control? If so, choose a source control system that meets your needs, and read the documentation for how to get it set up. If you are simply using a previously set up source control system for an existing project, ask a coworker who has been using it, or ask the person who set up the source control system.
For choosing a source control system that meets your needs, most source control systems have extensive descriptions of their features online, many provide evaluation or even completely free products, and there are many many many anecdotal descriptions of what working with each individual source control system is like, which can help.
Just don't use Microsoft Visual SourceSafe if you value your sanity and your code.
What is the best solution for maintaining backup and revision control on live websites?
As part of my job I work with several live websites. We need an efficient means of maintaining backups of the live folders over time. Additionally, updating these sites can be a pain, especially if a change happens to break in the live environment for whatever reason.
What would be ideal would be hassle-free source control. I implemented SVN for a while which was great as a semi-solution for backup as well as revision control (easy reversion of temporary or breaking changes) etc.
Unfortunately SVN places .SVN hidden directories everywhere which cause problems, especially when other developers make folder structure changes or copy/move website directories. I've heard the argument that this is a matter of education etc. but the approach taken by SVN is simply not a practical solution for us.
I am thinking that maybe an incremental backup solution may be better.
Other possibilities include:
SVK, which is command-line only which becomes a problem. Besides, I am unsure on how appropriate this would be.
Mercurial, perhaps with some triggers to hide the distributed component which is not required in this case and would be unnecessarily complicated for other developers.
I experimented briefly with Mercurial but couldn't find a nice way to have the repository seperate and kept constantly in-sync with the live folder working copy. Maybe as a source control solution (making repository and live folder the same place) combined with another backup solution this could be the way to go.
One downside of Mercurial is that it doesn't place empty folders under source control which is problematic for websites which often have empty folders as placeholder locations for file uploads etc.
Rsync, which I haven't really investigated.
I'd really appreciate your advice on the best way to maintain backups of live websites, ideally with an easy means of retrieving past versions quickly.
Answer replies:
#Kibbee:
It's not so much about education as no familiarity with anything but VSS and a lack of time/effort to learn anything else.
The xcopy/7-zip approach sounds reasonable I guess but it would quickly take up a lot of room right?
As far as source control, I think I'd like the source control to just say that "this is the state of the folder now, I'll deal with that and if I can't match stuff up that's your fault, I'll just start new histories" rather than fail hard.
#Steve M:
Yeah that's a nicer way of doing it but would require a significant cultural change. Having said that I very much like this approach.
#mk:
Nice, I didn't think about using Rsync to deploy. Does this only upload the differences? Overwriting the entire live directory everytime we make a change would be problematic due to site downtime.
I am still curious to see if there are any more traditional options
You can still use SVN, but instead of doing a checkout on your live environment, do an export, that way no .svn directories will be created. The downside, of course, is that no code changes on your live environment can take place. This is a good thing.
As a general rule, code changes on production systems should never be allowed. The change should be made and tested in a development/test/UAT environment, then once confirmed as OK, you can tag that code in SVN with something like RELEASE-x-x-x. Then, on the live system, export the code with that tag.
We use option 3. Rsync. I wrote a bash script to do this along with some extra checking, but here are the basics of what it does.
Make a tag for pushing to live.
Run svn export on that tag.
rsync to live.
So far it has been working out. We don't have to worry about user conflicts or have a separate user for running svn up on the production machine.
Any source control solution you pick is going to have problems if people are moving, deleting, or adding files and not telling the source control system about it. I'm not aware of any source control item that could solve this problem.
In the case where you just can't educate the people working on the project[1], then you may just have to go with daily snapshots. Something as simple as batch file using xcopy to a network drive, and possibly 7-zip on the command line to compress it so it doesn't take up too much space would probably be the simplest solution.
[1] I would highly disbelieve this, probably just more a case of people being too stubborn and not willing to learn, or do "extra work". Nevermind how much time source control could save them when they have to go back to previous versions, or 2 people have edited the same file.
rsync will only upload the differences. I haven't personally used it, but Mark Pilgrim wrote a long time ago about how it even handles binary diffs brilliantly.
svn+rsync sounds like a fantastic solution. I'll have to try that in the future.