presentations/git-gerrit-workshop/commits-are-snapshots.txt

Commits are Complete Snapshots
------------------------------

[graphviz]
----
digraph {
    node [shape=box, style=filled, fillcolor="#ABFFBB", fontname=arial, fontsize=18]
    edge [arrowhead=none]

    L [label="", shape=box, width=0, height=0]
    R [label="", shape=box, width=0, height=0]
    {rank=source; L; R}
    commit1 [fillcolor="#FFAAA1", label="Commit 1"]
    commit1 -> A -> B -> C

    commit2 [fillcolor="#FFAAA1", label="Commit 2"]
    link1B [label="B", style=dashed]
    commit2 -> A1 -> link1B -> C1

    commit3 [fillcolor="#FFAAA1", label="Commit 3"]
    link2B [label="B", style=dashed]
    link1A1 [label="A1", style=dashed]
    commit3 -> link1A1 -> link2B -> C2

    commit1 -> commit2 -> commit3 [style=invis]
    {rank=same; commit1; commit2; commit3 }
    L -> commit1 [style=invis]
    R -> commit3 [style=invis]
    L -> R [label=time, arrowhead=normal, fontsize=20, fontname=arial]
}
----

[role="incremental"]
* imagine our project contains 3 files: `A`, `B` and `C`
* every time we commit changes a new commit is created: `Commit 1`, `Commit 2`
  and `Commit 3`
* every commit is a 'full snapshot' of the whole project
* Git optimizes storage, will not create copies of non-modified files