I've tried using source control for a couple projects but still don't really understand it. For these projects, we've used TortoiseSVN and have only had one line of revisions. (No trunk, branch, or any of that.) If there is a recommended way to set up source control systems, what are they? What are the reasons and benifits for setting it up that way? What is the underlying differences between the workings of a centralized and distributed source control system?
Think of source control as a giant "Undo" button for your source code. Every time you check in, you're adding a point to which you can roll back. Even if you don't use branching/merging, this feature alone can be very valuable.
Additionally, by having one 'authoritative' version of the source control, it becomes much easier to back up.
Centralized vs. distributed... the difference is really that in distributed, there isn't necessarily one 'authoritative' version of the source control, although in practice people usually still do have the master tree.
The big advantage to distributed source control is two-fold:
When you use distributed source control, you have the whole source tree on your local machine. You can commit, create branches, and work pretty much as though you were all alone, and then when you're ready to push up your changes, you can promote them from your machine to the master copy. If you're working "offline" a lot, this can be a huge benefit.
You don't have to ask anybody's permission to become a distributor of the source control. If person A is running the project, but person B and C want to make changes, and share those changes with each other, it becomes much easier with distributed source control.
I recommend checking out the following from Eric Sink:
http://www.ericsink.com/scm/source_control.html
Having some sort of revision control system in place is probably the most important tool a programmer has for reviewing code changes and understanding who did what to whom. Even for single person projects, it is invaluable to be able to diff current code against previous known working version to understand what might have gone wrong due to a change.
Here are two articles that are very helpful for understanding the basics. Beyond being informative, Sink's company sells a great source control product called Vault that is free for single users (I am not affiliated in any way with that company).
http://www.ericsink.com/scm/source_control.html
http://betterexplained.com/articles/a-visual-guide-to-version-control/
Vault info at www.vault.com.
Even if you don't branch, you may find it useful to use tags to mark releases.
Imagine that you rolled out a new version of your software yesterday and have started making major changes for the next version. A user calls you to report a serious bug in yesterday's release. You can't just fix it and copy over the changes from your development trunk because the changes you've just made the whole thing unstable.
If you had tagged the release, you could check out a working copy of it and use it to fix the bug.
Then, you might choose to create a branch at the tag and check the bug fix into it. That way, you can fix more bugs on that release while you continue to upgrade the trunk. You can also merge those fixes into the trunk so that they'll be present in the next release.
The common standard for setting up Subversion is to have three folders under the root of your repository: trunk, branches and tags. The trunk folder holds your current "main" line of development. For many shops and situations, this is all they ever use... just a single working repository of code.
The tags folder takes it one step further and allows you to "checkpoint" your code at certain points in time. For example, when you release a new build or sometimes even when you simply make a new build, you "tag" a copy into this folder. This just allows you to know exactly what your code looked like at that point in time.
The branches folder holds different kinds of branches that you might need in special situations. Sometimes a branch is a place to work on experimental feature or features that might take a long time to get stable (therefore you don't want to introduce them into your main line just yet). Other times, a branch might represent the "production" copy of your code which can be edited and deployed independently from your main line of code which contains changes intended for a future release.
Anyway, this is just one aspect of how to set up your system, but I think giving some thought to this structure is important.
Related
I'm curious to get people's thoughts on how to manage version control for unrelated functions in Matlab.
I keep a reasonably large set of general purpose scripts, each of which is more or less independent of the others. I've been keeping them all in a single directory, containing a single repository in Mercurial. I'm starting to collaborate much more, and I'd like my collaborators to be able modify the files, commit, branch, and merge.
The problem is that the files are independent of one another. Essentially, they're like many separate little projects. But Mercurial treats the repository as a single entity. So if a collaborator modifies file A and B, and I only want to merge in the changes from file A, things get complicated. I know that I could merge from the collaborator, then revert file B, but I'm wondering if there's a simpler way to handle this setup.
I could set up many tiny repositories to manage each file separately, but that also gets complicated.
I'm open to changing version control systems (although I like Mercurial a lot). Any suggestions?
It is considered a best practice to check in code after each bug fix/feature addition/or what not. Given your files are really independent "projects" it seems unlikely a bug or feature would span multiple files. Probably the best you can do is encourage your colleagues in best practices to commit changes only for a single file at once. Explain that better discipline about checking in leads to more manageable source control later. Hopefully you can get most to follow the practice and the few obstinate ones just stop taking their commits for.
It really depends on your typical reasons for merging one change but not the other. If you're using it to create a software configuration, i.e. sometimes you want to use version 1 of file A and version 2 of file B and sometimes it's the other way around, then you probably want to use subrepos to hold each file. If it's because you never want to accept part of a collaborator's change, then they need to be instructed how to make their changes more cohesive and submit them separately. That can sometimes be a difficult concept for people who either haven't used source control before, or who are accustomed to source control like svn that has little or no intrinsic concept of a changeset.
It depends whether you want to maintain a single 'master' version of the files, merging in changes that you like and ignoring others. If collaborators want to develop other branches, then they should perhaps clone the repository, and you can then accept the changesets that you want in the master.
If you want to veto changes by other collaborators, then the changes either need to be kept separate (via a cloned repository or branch) or you need a review process before changes are pushed back to the trunk.
I always use incoming repositories for collaborators. They match what the other person has made, but it avoids messing with my own repository. When you do this, you can then cherrypick their new changesets into your own repository with the transplant extension.
We have 2 kinds of people at my shop:
The ones that starts to check-in the code since the first successful compilation.
The others that only checks-in the code when the project is almost done.
I am part of group 1, and trying to convince people of group 2 to act like me. Their arguments are like the following:
I'm the solo developer of this project.
It's just a prototype, maybe I'll have to rewrite from scratch again.
I don't want to pollute the Source Control with incomplete versions.
If I am right, please help me to raise arguments to convince them. If you agree with them tell me why.
When someone asked for good excuses not to use version control, they got 75 answers and 45 upvotes.
And when they asked Why should my team adopt source control, they got 26 answers.
Maybe you'll find something helpful there.
You don't need "arguments to convince them." Discourse is not a game, and you should not use your work as a debating platform. That's what your spouse is for :) Seriously, though, you need to explain why you care how other devs work on solo projects in which other people are not involved. What are you missing because they don't use source control? Do you need to see their early ideas to understand their later code? If you can sucessfully do that, you may be able to convince them.
I personally use version control at all times, but only because I don't walk a tightrope without a net. Other people have more courage, less time to spend on infrastructure, etc. Note that in 2009, in my opinion, hard disks rarely fail and rewritten code is often better than the code that it replaces.
While I'm answering a question with a question, let me ask another one: does your code need to compile/work/not-break-the-build to be checked in? I like my branches to get good and broken, then fixed, working, debugged, etc. At the same time, I like other devs to use source control however they want. Branches were invented for just that reason: so that people who can't get along do not have to cohabitate.
Here's my view to your points.
1) Even solo developers need somewhere to keep their code when their PC fails. What happens if they accidentally delete a file without source control?
2/3) Prototypes belong in source control so other team members can look at the code. We put our prototype code in a seperate location to the mainline branch. We call it Spike. Here's a great article on why you should keep Spike code- http://odetocode.com/Blogs/scott/archive/2008/11/17/12344.aspx
If I'm the sole developer on a project (in other words, the repository, or part of it, is under my complete control), then I start committing source code as soon as it's written, and I tend to check in after every incremental change, whether or not it works or represents any kind of milestone.
If I'm working in a repository on a project with others, then I tend to try and make my commits such that they don't break the mainline development, pass any tests, etc.
Whether or not it's a prototype, it deserves to go into source control; prototypes represent a lot of work, and lessons learned from them are valuable. Plus, prototypes have an awful habit of becoming production code, which you'll want in source control.
I try to only write code that compiles (everything else is commented out with a TODO/FIXME tag)... and also add everything to source control.
Argument 1: Even as a single dev it's nice to roll back to a running version, to track your progress, etc.
Argument 2: Who cares if it's just a prototype? You might stumble upon a similar problem in six months or so, and then just start looking for this other code...
Argument 3: Why not use more than one repo? I like to file misc stuff to my personal repo.
Start using source control about 20 minutes before you write your first line of your first artifact. There is never a good time to start after you're begun writing things.
some people can only learn from experience.
like a hard drive failure. or coding yourself into a dead-end after deleting code that actually worked
now, i'm not saying that you should erase their hard drive and then taunt them with "if only you had used source control"...but if something like were to happen, hopefully there would be a backup done first ;-)
Early and Often. As the Pragmatic Programmers say, source control is like a time machine, and you never know when you'll want to go back.
I would say to them...
I'm the solo developer of this project.
And when you leave or hand it off we'll have 0 developers. All the more reason to use source control.
The code belongs to the company not you and the company would like some accountability. Checking in code doesn't require too much effort:
svn ci <files> -m " implement ajax support for grid control
Next time someone new wants to make some changes on the grid control or do something related, they will have a great starting point. All projects start off with one or two people. Source control is easier now than it ever was--have they arranged a 30 minute demo of Tortoise SVN with them?
It's just a prototype, maybe I'll have to rewrite from scratch again.
Are they concerned about storage? Storage is cheap. Are they concerned about time wasted on versioning? It takes less time then the cursory email checks. If they are re-writing bits then source control is even more important to be able to reference old bits.
I don't want to pollute the Source Control with incomplete versions.
That's actually a good concern. I used to think the same thing at one point and avoided checking in code until it was nice and clean which is not a bad thing in and of itself but many times I just wanted to goof around. At this point learning about branching helps. Though I wish wish SVN had full support for purging folders like Perforce.
Let see their arguments:
I'm the solo developer of this project.
It's just a prototype, maybe I'll have to rewrite from scratch again.
I don't want to pollute the Source Control with incomplete versions.
First, the 3rd one. I can see the reasoning, but it is based on a bad assumption.
At work, we use Perforce, a centralized VCS, and indeed we only check in source that compile successfully and doesn't break anything (in theory, of course!), after peer review.
So when I start a non trivial change, I feel the need to intermediary commits. For example, recently I started to make some changes (somehow, in solo for this particular task, so I address point 1) on a Java code using JDom (XML parsing). Then I was stuck and wanted to use Java 1.6's built in XML parsing. It was obviously time to keep a trace of the current work, in case my attempt was failed and wanted to go back. Note this case somehow addresses the point 2.
The solution I chose is simple: I use an alternative SCM! Although some centralized VCS like SVN are usable in local (on the developer's computer), I was seduced by distributed VCS and after briefly testing Mercurial (which is good), I found Bazaar better suited to my needs and taste.
DVCS are well suited for this task because they are lightweight, flexible, allow alternative branches, doesn't "pollute" the source directory (all data is in one directory at the root of the project), etc.
By making a parallel source management, you don't pollute the source of other developers, while keeping the possibility to go back or quickly try alternative solutions.
At the end, by committing the final version to the official SCM, the result is the same, but with added security at the level of the developer.
I'd like to add two things. With version control you can:
Revert to last version that worked, or at least check how it looked like. For that you would need SCM which supports changesets / uses whole-tree commits.
Use it to find bugs, by using so called 'diff debugging' by finding commit in history that introduced the bug. You would want SCM which support it in automated or semi-automated fashion.
Personally, I often start version control after the first sucessful compile.
I just wonder why nobody mentioned distributed version control systems in this context: If you could manage to switch over to a distributed system (git, bazaar, mercury), most arguments of your second group would become pointless since they can just start their repository locally and push it to the server when they want (and they can also just remove it, if they want to restart from scratch).
For me, it's about having a consistent process. If you are writing code, it should follow the same source control process that your production code does. That helps build and enforce good development practices across the development team.
Categorizing the code as a prototype or other non-production type of project should just be used to determine where in the source control tree you put it.
We use both CVS (for non .NET projects) and TFS (for .NET projects) where I work, and the TFS repository has a Developer Sandbox folder where developers can check in personal experimental projects (prototypes).
If and when a project starts to get used in production, the code is moved out of the Developer Sandbox folder into it's own folder in the main tree.
I would say you should start adding the source and checking in before you even build the first time. It is then much easier to avoid checking in generated artifacts. I always use some source control, even for my small hobby hacks, just because it automatically filters the relevant from the noise.
So when I start prototyping I might create a project and then before building it I do "git init, git add ., git commit -a -m ..." just so that when I want to move the interesting parts I just clone over using git and then I can add it to the subversion repository or whatever is used where I am working at the moment.
It's called branching people try to get with the program :p Prototyping? Work in a branch. Experimenting? Work in a branch. New feature? Work in a branch.
Merge your branches into the main trunk when it makes sense.
I guess people tend to be laid back when it comes to setting up source control initially if the code may never be used. I have projects I coded belonging to both groups and the ones outside source control are not less important. It is one of those things that gets postponed everyday when it really should not.
On the other hand I sometimes commit too seldom complicating a revert once I screw up some CSS code and not knowing what I changed e.g. to make the footer of the site end up behind the header.
I check-in the project in source control before I start coding.
The first thing I do is create and organize the projects and support files (such as .sln files in .NET development) with the necessary support libraries and tools (usually in a lib folder) I know I will use in my project.
If I already have some code written, then I add it too, even if it is an incomplete application. Then I check-in everything. From there, everything is as usual, write some code, compile it, test it, check-in it...
You probably won't need to branch from this point or revert your changes, but I think it is a good practice to have everything under source control since the beginning, even if you don't have anything to compile.
I create a directory in source control before I start writing code for a project. I do the first commit after creating the project skeleton.
i'm drunk and and i do first git -init and then vim foo.cpp.
Any decent modern source control platform (of which VSS is not one) should not in any way be polluted by putting source code files into it. I am of the opinion that anything that has a life expectancy of more than about 1/2 an hour should be in source control as early as possible. Solo develpment is no longer a valid excuse for not using source control. It is not about security it is about bugs and long term history.
My co-workers and I are having an argument over the value and usage of Tags in release/SCM systems. We're looking to the StackOverflow community to put in their thoughts to help us resolve the issue.
One side claims that Tags are a valuable addition to release management. An example of their use: we do a Maven release, which makes a new Tag (call it 1.0) which is code snapshot used for this release. This Tag should be a READONLY branch. When a bug needs to be fixed we can make a copy of the Tag into a new Branch (call it 1.1). Bug fixes go there. These fixes may be merged back into Trunk so that the main dev branch gets the bug fixes. Finally, 1.1 is released and a Tag 1.1 is automatically created. This cycle continues. The main benefit here of the Tag is that if you ever need to re-release version 1.0 for any reason, you can just release the Tag 1.0 with the confidence that it's never been altered by anyone. Also, saying "Release Tag 1.0" is cleaner than saying "Release revision 1 of branch 1.0 which is the original 1.0 without the fixes".
The other side claims that Tags aren't providing any valuable benefit, especially in a system like Subversion with global revisions, which act like a Tag in CVS. Plus, Subversion only gives a warning when committing to a Tag; it doesn't actually stop it. Their method is developing in Trunk and upon release you'd make a Branch called 1.0. You'd continue bug fixes in Trunk and if you needed to re-release those bug fixes to production, you'd merge them into 1.0 Branch and re-release 1.0. At some point, perhaps after major fixes or features in Trunk, you'd release and make Branch 1.1. Cycle continues. If you ever need to release the original 1.0 version, you'd have to check out Branch 1.0 revision 1.
Clearly both methods work. I'd like to hear the community's thoughts on which method is preferred and why.
Edit: I'm a little worried that the "best" way depends on the underlying SCM system. Either settle on Subversion for answers or if possible keep it SCM agnostic.
From an SCM agnostic point of view, a tag is very different from a revision.
Both may be implemented in the same way, both represents a "time line", but their goal is different:
a tag represent an immutable state where all files are referenced by a unique id. It is a name representing many things but mainly a stable state, ...)
a revision represent a commit transaction (not all SCM have those, especially the old ones with a 'file-by-file approach'). All commits do not represent a "stable" state (as in "compile" or "execute" successfully). They are just a new element of the global history.
The problem with SVN is that revision, tag and branches are all implemented the same.
But I would still prefer the option where a tag is used as a "read-only" branch.
In my opinion tags are useful. There will be times at some point in the life of the project that you come across a bug or a change and you want to know if it was there in a previous release. There will be reasons to compare code from one release to another to measure efficiencies both in performance and actually the development of the code.
Sure, there is a chance you can screw it up, but it can always be undone. There really is no reason not to, and there are several reasons why it might be useful in the future. To me its a no-brainer.
I agree that you should also be using branches and doing your development there, but anytime you actually release something, make a tag out of it.
Yes, you want to use tags.
Think of a tag as just a label or a name for a particular revision. It is very helpful in my experience to tag important milestones in a project, whether it's for production release or even for interim QA releases. You often will want to go back in time and see the source code for a particular release.
If you branch upon release, you can always figure out which revision was released to production, but this is kind of a pain compared to just looking at a tag. If you don't use release branches then it will be easy to lose track of which revision was used to create a particular build.
The problem with svn is that it blurs the distinction between tags and branches. Anyone can always commit to a tag, so it's not guaranteed to be fixed/immutable. In other VCS like PVCS, a "tag" is unchangeable. You can adopt a team convention to prevent commits to tags, or even maybe use commit hooks to prevent commits to tags.
We use tags (labels) when creating new baselines. We do it once a week, but some teams do it even several times a day.
The point (for us) is always making sure the new baseline is stable: so it's not just a build, is a build that passes the entire testsuite, several hours of automated tests plus potentially manual exploratory ones too.
Then the baseline is used as starting point for all tasks during the next iteration: every new task is a new branch starting from the baseline, which is known to be stable so whatever is broken in the task should be easy to trace inside the task itself.
Normally we only put tags (labels) on the main branch (or trunk or master depending on your SCM flavour) which is the integration point for all the other branches.
When we release an official product we create a "release branch for it" so it will only receive fixes while new development stays on "main". Then these "maintenance branches" (hopefully only one or two at a time) can be tagged too.
I like to think about tags as "just a fancy name for a revision". I've always thought about them that way, and IIRC in mercurial they are just that. In subversion however, as you say, they indeed are (cheap) copies of trunk/* to tags/fancy-name/
Honestly, I'd combine the two strategies for optimal results: tag and branch upon release. Your tag is called 1.0.0, branch 1.0-MAINT. Bugfixes go into branches, and bugfix releases are tags again (1.0.1 may by a tag intended to alias 1.0-MAINT at a certain point.)
Do not forget however that tags and branches in subversion are actually the same thing: cheap copies. The only difference between them is the semantics you/your team attributes to them, so it pretty much boils down to getting people to agree on one particualr method and stick to that (might be enforced on the server, eg disallowing commits in tags/ except for release coordinators etc.)
The problem I see though with the second approach is: how are you going to make an easy distinction between software in the field if you re-release 1.0? That means that you may have a 1.0 and another 1.0 actually referring to a different code base... .
Immutable snapshots of a project's source code (and executable) are invaluable for doing testing of any kind, whether structured testing or field usage. For structured testing, you're going to be creating data that might be referenced months or years in the future. Anytime you revisit that data, Murphy's law says you'll need to know what code it comes from and unless you went to the trouble of citing a particular snapshot of the source code, it will be impossible to tell with confidence what source code corresponded to that test data.
I can't tell you how many times someone's come to me and said "This microcontroller code's not working, can you help?" and I ask them, "What version are you using?" and they say "I'm not sure" because they're not doing good release management (at the very least putting a sticker on the device, better to put versioning info in EEPROM that can be queried in realtime). >:(
In SVN, the technical difference between using a tag and tracking a revision is nil. I find myself minimizing tag use based on how SVN's implementation is simply a cheap copy and clutters up your "structure space".
The real difference comes when communicating a particular baseline to a large team of developers. Revision tracking brings an extra layer of abstraction that can become a source of errors. And as we're all aware, when you're dealing with 50+ developers, any source of error will become an area of confusion and wasted time. A verbose tag can eliminate that confusion and remove any doubt as to what a baseline's purpose is.
I'd combine both approaches. Whenever you make a release, tag it. Tags should never change, so the presence of a "1.0.0" tag is an indicator that you shouldn't be trying to release anything else as 1.0.0.
At the same time, when it came time to do 1.0.0, I'd put it onto a 1.0 branch. So the flow is: branch trunk to 1.0, tag this new 1.0 as 1.0.0, and deploy. Then bug fixes can be done on the 1.0 branch (to avoid getting mixed up with any 1.1-targetted development that may already be on trunk now) and merged into trunk. Each release of the fixed 1.0 is tagged as 1.0.x from the 1.0 branch. This is basically the approach we use at work with Perforce, and that's very similar indeed to Subversion. (Reading through the replies, I think it's virtually identical to Vincent's recommendation)
As far as the comment about tags being redundant because you have revision numbers--- that's largely true, except that tags also specify a scope: i.e. which files in the repository are covered by the tag. You can reasonably ask someone to look at /svn/proj1/tag/1.0.0 and they are immediately looking at a coherent workspace. If you ask them to look at revision X, they have to first look at revision X to see that it was changing (say) /svn/proj1/trunk/Makefile and hence deduce that /svn/proj1/trunk/#X is what they should be looking at. What happens if revision X touched files in proj1 and proj2? Which is of course evil, but strictly speaking you should be saying /svn/proj1/trunk/#X. And where is the list of revision numbers stored? How do we know that 1.0.0 is revision X? It should IMHO be possible to determine that just from the repository.
In systems like Git, tags and branches are still basically the same thing (just references to the object database), but the convention is that tag refs don't change, and branch refs do (and preferably with a specific constraint on how they change). Perforce also has "labels" which are ways of grouping a set of file revisions together independently of a changelist; which is essentially a tag, but more confusing: historically we've used changelist numbers (equivalent to Subversion revision numbers) qualified with the name of the branch they should be on to identify versions. The two are almost identical any way, so here I guess TMTOWTDI.
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.
Using TFS, when would you label your code and when would you branch?
Is there a concept of mainline/trunk in TFS?
A label in TFS is a way of tagging a collection of files. The label contains a bunch of files and the version of the file. It is a very low cost way of marking which versions of files make up a build etc.
A branch can be thought of as a copy of the files (of a certain version) in a different directory in TFS (with TFS knowing that this is a branch and will remember what files and versions it was a branch of).
As Eric Sink says, a branch is like a puppy. It takes some care and feeding.
Personally, I label often but branch rarely. I create a label for every build, but only branch when I know that I need to work on a historical version or that I need to work in isolation from the main line of code. You can create a branch from any point in time (and also a label) so that works well and means that we don't have branches lying around that are not being used.
Hope that helps,
Martin.
In any VCS, one usually tags when you want a snapshot of the code, to be kept as reference for the future. You branch when you want to develop a new feature, without disturbing the current code.
Andrew claims that labeling is lazier than branching; it's actually more efficient in most cases, not lazy. Labeling can allow users to grab a project at any point in time, keep a history of files changed for a version or build, and branch off of/work with the code at any point and later merge back into the main branch. Instead of what Andrew said, you're advised to only branch when more than one set of binaries is desired- when QC and Dev development are going on simultaneously or when you need to apply a hotfix to an old version, for example.
I always see labels as the lazy man's branch. If you are going to do something so significant that it requires a full-source label then it is probably best to denote this with a branch so that all tasks associated with that effort are in an organized place with only the effected code.
Branching is very powerful however and something worth learning about. TFS is not the best source control but it is not the worst either. TFS does support the concept of a trunk from which all branches sprout as well.
I would recommend this as a good place to read up on best practices - at least as far as TFS is concerned.