* Understanding Git

Logical Structure Of Git

• DAG of commit objects

  • Leaf is initial commit

  • Roots are branch tops

• Objects are crypto hashed to get IDs

• Each commit refers to

  • Its "parents" (downward) commit id

  • The objects (files) included in the project at this point

• Files are stored in object store by crypto hash for dedup

Structure Of A Git Repo

• Object store

• Refs

• Index

• Reflog

• Config

Git Operations

• Log

• Commit

• Branch

• Adjust heads

Some Examples

• Why fetch + merge is the new pull

• Revising history; commit --amend and rebase and push -f

• The reflog and recovery (but still make a copy of the repo)