2010

The Subversion Dilemma Check in buggy code and drive everyone else crazy Avoid checking it in until it’s fully debugged or

The Subversion Dilemma Weeks without Version Control

Jens Schumacher – Atlassian What is DVCS and why it will change the way we work 2010

Overview 1. Mercurial vs. Subversion 2. Basic concepts 3. Use cases

Subversion vs Mercurial

Merging

Subversion vs Mercurial Branching

Subversion vs Mercurial Repository Access

Subversion vs Mercurial Performance

Subversion vs Mercurial Sharing

Subversion vs Mercurial Tool Support

Subversion vs Mercurial Authentication

Subversion vs Mercurial Check Out

Subversion vs Mercurial

Overview 1. Mercurial vs. Subversion 2. Basic concepts 3. Use cases

Repository Architecture

Subversion

Mercurial

Subversion Revisions Subversion is always linear

Mercurial Changesets head Each Changeset can have multiple children

Mercurial head

Mercurial Pull Merge

Mercurial "hg commit" adds a new node "hg push" and "hg pull" transfer nodes in the graph between two repositories "hg merge" merge changes in a repository

Branching in Mercurial Forks Named Branches Bookmarks Anonymous Branches

Forks

Complete Isolation Very easy to discard Forking is slower DisadvantagesAdvantages 12

Forks When to use Forks When you don’t have commit access To experiment For a build repository

Named Branches

Branch Metadata Faster than Forking Branch Metadata Closing a Branch (fixed in 1.2) DisadvantagesAdvantages

Named Branches When to use Named Branches Working in a team on a feature

Bookmarks

Lightweight Can be deleted Similar to git Local (fixed in 1.6) Possible loss of context DisadvantagesAdvantages

Bookmarks When to use Bookmarks Working in a team on a feature If you like to way git does branching If you use Mercurial 1.6

Anonymous Branches

Fast No name required No closing required No description Changeset # required (lookup with hg log) DisadvantagesAdvantages

Anonymous Branches When to use Anonymous Branches For quick & small fixes

Overview 1. Mercurial vs. Subversion 2. Basic concepts 3. Use cases

BitBucket Mercurial code hosting Free for 5 users Unlimited public collaborators Unlimited disk space

Getting Started

The Basics hg init create a new repositoryhg commit save your changes in the current repositoryhg log see all changes in your repositoryhg pull pull all changes from another repository into yourshg push push your changes into another repositoryhg merge join different lines of history hg update update the repository's working directoryhg help repositoryrectoryhg help <c

Separate Features Use Case Work on several features in parallel

Separate Features $ hg clone project feature$ cd feature$ (do some changes and commits) Clone

Separate Features $ cd../project$ hg incoming../feature Incoming Use hg incoming --patch to view the diffs

Separate Features $ hg pull../feature Pull The history of feature one is now in your project. However, changes are not yet visible and only stored in the.hg directory

Separate Features $ hg merge Merge $ hg commit(enter commit message) Commit

Separate Features Changesets

Collaborative Feature Development Use Case Using Mercurial to help coordinate the coding

Collaborative Feature Development $ hg branch feature(do some changes)$ hg commit(write commit message) Create a branch $ hg update feature(do some changes)$ hg commit(write commit message)

Collaborative Feature Development $ hg update default$ hg merge feature$ hg commit(write commit message) Merge the named branch Named branches stay in history as permanent records after you finished your work.

Collaborative Feature Development Changesets

Tagging Revisions Use Case Release a plugin

Tagging Revisions $ hg tag -r 8 v0.1 Add a tag $ hg tags See all tags $ hg update v0.1 Update to a tagged revision

Tagging Revisions Tags

Overview 1. Mercurial vs. Subversion 2. Basic concepts 3. Use cases

Try BitBucket bitbucket.org

Links branching-in-mercurial branching-in-mercurial

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