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> the Perforce model I've used both Git and SVN enough to understand how a VCS might change how an organization creates code, but I've never used Perforce. Wh

by nix0n 5y ago

> the Perforce model I've used both Git and SVN enough to understand how a VCS might change how an organization creates code, but I've never used Perforce. What is "the Perforce model"?

jeffbee 5y ago
In Perforce the concepts are different. You have a client, with a view that includes a subset of the repo, and you have changelists which incorporates your related edits. When done with a changelist, you submit it to trunk, usually, because while you can branch a Perforce repo, you mostly don't need to. Basically all the stuff in the first half of the talk where he whines about stepping on toes, conflicting with other people, politics, special write access groups, are all non-issues that do not sound familiar to Perforce users. If two people are using Perforce they can both work on changes to the same files taken from the main branch (trunk) and submit them separately without conflict or even awareness of the other person. As a bonus this is all dramatically faster in Perforce than in git for large repos. In this talk Linus demonstrates that he believes git is a state-of-the-art SCM system, without being familiar with the actual state of the art.
- kubanczyk 5y ago
  Let's say we collaborate on the code below. I'll change line 1, you'll change line 5, we'll merge both changes and then we'll see how Perforce makes the code run successfully "without conflict or even awareness of other person". 1 x := 0 2 x++ 3 x++ 4 x++ 5 if x > 7 { 6 fail_horribly_at_runtime() 7 }
  - jeffbee 5y ago
    Explain how you think git is different in this regard.
    - detaro 5y ago
      You're the one that claimed Perforce was better than git and could do this "without conflict or even awareness of the other person", so why don't you explain how git is worse? (I've never used Perforce and am genuinely curious what clever kinds of things it can do around merges, but more detail than "it's state-of-the-art and git is not" would be useful)
      - jeffbee 5y ago
        No, it is Linus who makes a bunch of claims about how Perforce is worse, in the video. If two people edit the same line of code based on the same original version, that's a conflict and there's nothing any SCM can do about it. Human must merge. But there's no reason that several developers can't work on different functions or other disjoint areas of the same file, unlike what Linus is claiming in the video. The video is essentially a long straw-man argument where Linus takes shitty part of CVS and SVN, which were terrible, and applies them to Perforce, which it's clear he has never used.
  - LenP 5y ago
    To answer your question, neither Git nor Perforce will cause a merge conflict. You’d need a SCM that isn’t line-based for that. With large teams, you need code review (which this bug can elide), great test coverage (the tests will likely have a merge conflict) and very importantly, a commit-by-commit build health indicator after merging. You can also do this in batches and bisect to find poisonous commits should a batch be broken - flakes notwithstanding.
- tick_tock_tick 5y ago
  > In this talk Linus demonstrates that he believes git is a state-of-the-art SCM system, without being familiar with the actual state of the art. I don't think that's very fair Perforce is mostly just a shitty subset of git's features that some people pretend is sufficient. You can use git almost the same as Perforce and have almost as bad of an experience as using Perforce directly.

by nix0n 5y ago

> the Perforce model I've used both Git and SVN enough to understand how a VCS might change how an organization creates code, but I've never used Perforce. What is "the Perforce model"?

jeffbee 5y ago

In Perforce the concepts are different. You have a client, with a view that includes a subset of the repo, and you have changelists which incorporates your related edits. When done with a changelist, you submit it to trunk, usually, because while you can branch a Perforce repo, you mostly don't need to. Basically all the stuff in the first half of the talk where he whines about stepping on toes, conflicting with other people, politics, special write access groups, are all non-issues that do not sound familiar to Perforce users. If two people are using Perforce they can both work on changes to the same files taken from the main branch (trunk) and submit them separately without conflict or even awareness of the other person. As a bonus this is all dramatically faster in Perforce than in git for large repos. In this talk Linus demonstrates that he believes git is a state-of-the-art SCM system, without being familiar with the actual state of the art.

kubanczyk 5y ago
Let's say we collaborate on the code below. I'll change line 1, you'll change line 5, we'll merge both changes and then we'll see how Perforce makes the code run successfully "without conflict or even awareness of other person". 1 x := 0 2 x++ 3 x++ 4 x++ 5 if x > 7 { 6 fail_horribly_at_runtime() 7 }
- jeffbee 5y ago
  Explain how you think git is different in this regard.
  - detaro 5y ago
    You're the one that claimed Perforce was better than git and could do this "without conflict or even awareness of the other person", so why don't you explain how git is worse? (I've never used Perforce and am genuinely curious what clever kinds of things it can do around merges, but more detail than "it's state-of-the-art and git is not" would be useful)
    - jeffbee 5y ago
      No, it is Linus who makes a bunch of claims about how Perforce is worse, in the video. If two people edit the same line of code based on the same original version, that's a conflict and there's nothing any SCM can do about it. Human must merge. But there's no reason that several developers can't work on different functions or other disjoint areas of the same file, unlike what Linus is claiming in the video. The video is essentially a long straw-man argument where Linus takes shitty part of CVS and SVN, which were terrible, and applies them to Perforce, which it's clear he has never used.
- LenP 5y ago
  To answer your question, neither Git nor Perforce will cause a merge conflict. You’d need a SCM that isn’t line-based for that. With large teams, you need code review (which this bug can elide), great test coverage (the tests will likely have a merge conflict) and very importantly, a commit-by-commit build health indicator after merging. You can also do this in batches and bisect to find poisonous commits should a batch be broken - flakes notwithstanding.
tick_tock_tick 5y ago
> In this talk Linus demonstrates that he believes git is a state-of-the-art SCM system, without being familiar with the actual state of the art. I don't think that's very fair Perforce is mostly just a shitty subset of git's features that some people pretend is sufficient. You can use git almost the same as Perforce and have almost as bad of an experience as using Perforce directly.