Version Control Systems and CC

Transcript

1. Version Control Systems Version Control Systems Rahul Gopinath A moment from the history of linux kernel
2. Version Control Systems are the lifeblood of Software Engineering. History Reproducibility Synchronization Concurrency Why?
3. Concepts (C) Timeline (H) Choice Calculus (V) Representation (R) Structure of the talk 1
4. C1 Versions Merges Tags Common Concepts
5. Versions A box A large box A large blue box A small blue box C2 Revisions
6. Versions A cup of water B A C A cup of milk A cup of cows milk A cup of coffee A cup of sea water C3 A cup of salty sea water A cup of hot coffee A cup of hot tea A cup of cold coffee Branches
7. Merging water A small cup of water A cup of cold water A cup of water A small bottle of water A cup of cold sea water A small bottle of cold sea water C4 A small cup of water A cup of water A small bottle of water A small bottle of water C4 Revisions Branches
8. Conflicts C5 water A small cup of water A cup of cold water A cup of water A small bottle of hot water A cup of cold sea water A small bottle of (hotcold) sea water
9. Tags Alpha Beta Stable Demo C6 Next: Time line
10. Early History Patchy Clear/Caster Source Code Control System Revision Control System Mainframe Dumb terminals H1
11. Delta Storage Interleaved Composable (Forward| Reverse) H2
12. Operation Based State Based A B C D E A B D E C History Models H3
13. Client Server Generations Local Open Syntax Aware Architecture H4 R e p l i c a t e d
14. Client Server Concurrent Versioning System Subversion Server Clients H5
15. Replicated Clear Case Code Co-Op Past Watch Peers H6
16. Open TeamWare Bitkeeper Git Mercurial Darcs Peers H7
17. Syntax Aware Monticello MolhadoRef H8 Next: CC
18. Choice Calculus : Syntax V1 Formal system to describe variations Dimension Choice Dim Platform<Win,Mac> in Platform<ie, safari> is a web browser. Platform<Office, iWork> is an office suite. Tag Plain Text : Comon parts
19. V2 Choice Calculus : Semantics dim Platform<Win,Linux> in dim UI<Gnome,KDE> in Platform<ie, Firefox> is a web browser. Platform<Office, UI<OpenOffice,KOffice>> is an office suite. Tag Selection {Platform.Linux,UI.KDE} → Firefoxi is a web browser. KOffice is an office suite Semantics {Platform.Win, UI.Gnome} => ie is a web browser. Office is an office suite {Platform.Win, UI.KDE} => ie is a web browser. Office is an office suite {Platform.Linux, UI.Gnome} => Firefox is a web browser. OpenOffice is an office suite {Platform.Linux, UI.KDE} => Firefox is a web browser. KOffice is an office suite
20. V3 Choice Calculus : Alternate representations for choices dim Platform<Win,Linux> in dim UI<Gnome,KDE> in Platform<ie, Firefox> is a web browser. Platform<Office, UI<OpenOffice,KOffice>> is an office suite. Semantics {Platform.Win, UI.Gnome} => ie is a web browser. MSOffice is an office suite {Platform.Win, UI.KDE} => ie is a web browser. MSOffice is an office suite {Platform.Linux, UI.Gnome} => Firefox is a web browser. OpenOffice is an office suite {Platform.Linux, UI.KDE} => Firefox is a web browser. KOffice is an office suite dim Platform<Win,Linux> in dim UI<Gnome,KDE> in Platform<ie, Firefox> is a web browser. UI<Platform<MSOffice, OpenOffice>,Platform<MSOffice, KOffice>> is an office suite. Equivalent to
21. V4 Choice Calculus : Eliminate Redundancy dim Platform<Win,Linux> in dim UI<Gnome,KDE> in Platform<ie, Firefox> is a web browser. Platform<Office, UI<OpenOffice,KOffice>> is an office suite. Semantics {Platform.Win, UI.Gnome} => ie is a web browser. MSOffice is an office suite {Platform.Win, UI.KDE} => ie is a web browser. MSOffice is an office suite {Platform.Linux, UI.Gnome} => Firefox is a web browser. OpenOffice is an office suite {Platform.Linux, UI.KDE} => Firefox is a web browser. KOffice is an office suite dim Platform<Win,Linux> in dim UI<Gnome,KDE> in Platform<ie is a web browser, Firefox is a web browser> . Platform<Office, UI<OpenOffice,KOffice>> is an office suite. . Equivalent to
22. V5 Choice Calculus : Embedded Dimension dim Platform<Win,Linux> in Platform<ie, Firefox> is a web browser. Platform<MSOffice,dim UI<Gnome,KDE> in UI<OpenOffice,KOffice>> is an office suite. Tag Selection {Platform.Win} → ie is a web browser. MSOffice is an office suite Semantics {Platform.Win} => ie is a web browser. Office is an office suite {Platform.Linux, UI.Gnome} => Firefox is a web browser. OpenOffice is an office suite {Platform.Linux, UI.KDE} => Firefox is a web browser. KOffice is an office suite Next: Rep
23. Modeling a Repository with Choice Calculus Modeling a Repository with Choice Calculus Temporal Ordering Dependencies C1 C2 C3 C1 C2 Branching Stable Release Dev Merges and Conflicts R1
24. Choices Choices Change Set based | Snapshot based Revisions as: Tags | Dimensions Dim Rev<v.1,v.2,v.3> in Rev<f.1, f.2, f.3> Dim V.1<v-,v+> in Dim V.2<v-,v+> in V.2<V.1<f.0, f.1>,f.2> Branches as: Top level Dims | Dependent Dims Dim Var<dev,stable,maint> in Dim V.1<v-,v+> in V.1<f.0,Var<f.d,f.s,f.m>> Dim V.1<v-,v+> in V.1<f.0, Dim Var<dv,st,t> in Var<f.d, f.s,f.m>> R2
25. Dim Var<dev,stable> in Dim V1<v-,v+> in Dim V2<v-,v+> in Dim V2’<v-,v+> in Dim V3<v-,v+> in Dim V3’<v-,v+> in Var<V3<V2<V1<f.0,f.1>,f.2>,f.3>,V3’<V2’<V1<f.0,f.1>,f.2’>,f.3’>> v.1 v.2 v.2’ v.3 v.3’ v.4 v.4’ Dim Var<dev,stable> in Dim V1<v-,v+> in Dim V2<v-,v+> in Dim V2’<v-,v+> in Dim V3<v-,v+> in Dim V3’<v-,v+> in Dim V4<v-,v+>in Var<V4<V3’<V2’<V1<V3<V2<V1<f.0,f.1>,f.2>,f.3>,f.1>,f.2’>,f.3’>,f.4>,V.3’<V2’<V1<f.0,f.1>,f.2’>,f.3’>> Dim Var<dev,stable> in Dim V1<v-,v+> in Dim V2<v-,v+> in Dim V2’<v-,v+> in Dim V3<v-,v+> in Dim V3’<v-,v+> in Dim V4<v-,v+> in Dim V4'<v-,v+> in Var<V4<V3’<V2’<V1<V3<V2<V1<f.0,f.1>,f.2>,f.3>,f.1>,f.2’>,f.3’>,f.4>,V.4’<V3’<V2’<V1<f.0,f.1>,f.2’>,f.3’>,f.4’>> R3 Before v4 After v4 After v4' Merges Merges
26. Structure Structure V ::= D<t1,t2…> { V } | V; V | q=> V | 1 q ::= D.t Dim A<a1,a2> in A<1,2> :: A<a1,a2> Dim A<a1,a2> Dim B<b1,b2>in A<1,2> :: A<a1,a2>;B<b1,b2> Dim A<a1,a2> in A< Dim B<b1,b2> in 1,2> :: A<a1,a2>;A.a1 => B<b1,b2> R4 Dim Var<dev,stable> in Dim V1<v-,v+> in Dim V2<v-,v+> in Dim V2’<v-,v+> in Dim V3<v-,v+> in Dim V3’<v-,v+> in Dim V4<v-,v+> in Dim V4'<v-,v+> in Var<V4<V3’<V2’<V1<V3<V2<V1<f.0,f.1>,f.2>,f.3>,f.1>,f.2’>,f.3’>,f.4>,V4’<V3’<V2’<V1<f.0,f.1>,f.2’>,f.3’>,f.4’>> :: Var<dev,stable>,V1<v-,v+>V2<v-,v+>V2'<v-,v+>V3<v-,v+>V3'<v-,v+>V4<v-,v+>V4'<v-,v+>
27. Related Fields Concurrency: Software Transactional Memory Distributed and Versioned Data Bases Software Configuration Management
28. Questions?