---

author: Boris Feld <boris.feld@octobus.net>

title: Changeset evolution

date: June 23, 2017

---

# Why Evolve is the future? (TO CHANGE)

Use hexagon or drop all of themes

Use old names

Replace hg amend by commit --amend

Flow

Basic - Feature - Tool / instability - command semantic

Basic (local amend + local rebase)

Stabilization -> Evolution

Feature

# Local amend

## Amending commits

We all makes mistake:

~~~graphviz

    digraph G {

        rankdir="BT";

        graph[splines=polyline];

        node[fixedsize=true, width=1, height=1, style="filled", fillcolor="#7F7FFF"];

        // Revisions

        node[group=main];

        Parent -> "Fx bug[case";

    }

~~~

## Some times pass

## Urgent Amend needed

But it's easy to fix the fix:

~~~ {.sh}

hg commit --amend -m "Fix bug"

~~~

~~~graphviz

    digraph G {

        rankdir="BT";

        graph[splines=polyline];

        node[fixedsize=true, width=1, height=1, style="filled", fillcolor="#7F7FFF"];

        // Revisions

        node[group=main];

        Parent -> "Fix bug";

    }

~~~

## So easy to do something wrong

But wait you had local changes! And they get incorporated into the amend.

## Too bad

It's too late, they are gone!

<img src="https://media1.giphy.com/media/vMiCDfoKdJP0c/giphy.gif">

## HARD

UNbundle, get the rev, strip

## Never without Evolve!

<img src="https://media3.giphy.com/media/EVbEdEW3kuu0o/giphy.gif">

## Let's try again!

~~~graphviz

    digraph G {

        rankdir="BT";

        graph[splines=polyline];

        node[fixedsize=true, width=1, height=1, style="filled", fillcolor="#7F7FFF"];

        // Revisions

        node[group=main];

        Parent -> "Fx bug";

    }

~~~

## Evolve powa

With evolve this time:

~~~ {.sh}

hg commit --amend -m "Fix bug"

~~~

~~~graphviz

    digraph G {

        rankdir="BT";

        graph[splines=polyline];

        node[fixedsize=true, width=1, height=1, style="filled", fillcolor="#7F7FFF"];

        // Revisions

        node[group=main];

        Parent -> "Fix bug";

    }

~~~

## Ok what the difference?

<pre class="shell_output">

$> hg log -G

@  <span style="color:olive;">changeset:   3:467de638a224</span>

|  tag:         tip

|  parent:      0:852811e0e2a8

|  user:        Boris Feld <boris.feld@octobus.net>

|  date:        Wed Jun 21 14:15:55 2017 +0200

|  summary:     Fix bug

|

o  <span style="color:olive;">changeset:   0:852811e0e2a8</span>

   user:        Boris Feld <boris.feld@octobus.net>

   date:        Wed Jun 21 14:15:55 2017 +0200

   summary:     Root

</pre>

## The difference

<pre class="shell_output">

$> hg log -G --hidden

@  <span style="color:olive;">changeset:   3:467de638a224</span>

|  tag:         tip

|  parent:      0:852811e0e2a8

|  user:        Boris Feld <boris.feld@octobus.net>

|  date:        Wed Jun 21 14:15:55 2017 +0200

|  summary:     Fix bug

|

| x  <span style="color:olive;">changeset:   2:614cb09cc83d</span>

| |  user:        Boris Feld <boris.feld@octobus.net>

| |  date:        Wed Jun 21 14:15:55 2017 +0200

| |  summary:     temporary amend commit for e46245132d3d

| |

| x  <span style="color:olive;">changeset:   1:e46245132d3d</span>

|/   user:        Boris Feld <boris.feld@octobus.net>

|    date:        Wed Jun 21 14:15:55 2017 +0200

|    summary:     Fx bug

|

o  <span style="color:olive;">changeset:   0:852811e0e2a8</span>

   user:        Boris Feld <boris.feld@octobus.net>

   date:        Wed Jun 21 14:15:55 2017 +0200

   summary:     Root

</pre>

## Perf impact

No strip == no cache bust, == faster

# Local rebase

## You are working on your branch

~~~graphviz

    digraph G {

        rankdir="LR";

        graph[splines=polyline];

        node[fixedsize=true, width=1, height=1, style="filled", fillcolor="#7F7FFF"];

        // Revisions

        node[group=feature];

        Parent -> "Feature";

    }

~~~

## More work

~~~graphviz

    digraph G {

        rankdir="LR";

        graph[splines=polyline];

        node[fixedsize=true, width=1, height=1, style="filled", fillcolor="#7F7FFF"];

        // Revisions

        node[group=feature];

        Parent -> "Feature" -> "Feature 2";

    }

~~~

## Pull

~~~graphviz

    digraph G {

        rankdir="LR";

        graph[splines=polyline];

        node[fixedsize=true, width=1, height=1, style="filled", fillcolor="#7F7FFF"];

        // Revisions

        node[group=main];

        Parent -> "Trunk" -> "Trunk 2";

        node[group=feature];

        Parent -> "Feature" -> "Feature 2";

    }

~~~

## Time to rebase

~~~graphviz

    digraph G {

        rankdir="LR";

        graph[splines=polyline];

        node[fixedsize=true, width=1, height=1, style="filled", fillcolor="#7F7FFF"];

        // Revisions

        node[group=main];

        Parent -> "Trunk" -> "Trunk 2";

        node[group=feature];

        "Trunk 2" -> "Feature" -> "Feature 2";

    }

~~~

## Without evolve

<pre class="shell_output">

@  <span style="color:olive;">changeset:   6:105f743d81c8</span>

|  tag:         tip

|  user:        Boris Feld <boris.feld@octobus.net>

|  date:        Wed Jun 21 14:47:48 2017 +0200

|  summary:     Feature2

|

o  <span style="color:olive;">changeset:   5:3966a515e569</span>

|  user:        Boris Feld <boris.feld@octobus.net>

|  date:        Wed Jun 21 14:47:48 2017 +0200

|  summary:     Feature

|

o  <span style="color:olive;">changeset:   4:bd3d94325819</span>

|  user:        Boris Feld <boris.feld@octobus.net>

|  date:        Wed Jun 21 14:47:49 2017 +0200

|  summary:     Trunk2

|

o  <span style="color:olive;">changeset:   3:120d3e4ce8b7</span>

|  user:        Boris Feld <boris.feld@octobus.net>

|  date:        Wed Jun 21 14:47:49 2017 +0200

|  summary:     Trunk

|

o  <span style="color:olive;">changeset:   2:36db121866a2</span>

|  user:        Boris Feld <boris.feld@octobus.net>

~  date:        Wed Jun 21 14:47:48 2017 +0200

   summary:     Parent

</pre>

## With evolve

<pre style="font-size: 0.25em !important;">

@  <span style="color:olive;">changeset:   10:2c1a992b87c3</span>

|  tag:         tip

|  user:        Boris Feld <boris.feld@octobus.net>

|  date:        Wed Jun 21 14:50:39 2017 +0200

|  summary:     Feature2

|

o  <span style="color:olive;">changeset:   9:751113c206d0</span>

|  user:        Boris Feld <boris.feld@octobus.net>

|  date:        Wed Jun 21 14:50:39 2017 +0200

|  summary:     Feature

|

o  <span style="color:olive;">changeset:   8:9f9f3db01630</span>

|  user:        Boris Feld <boris.feld@octobus.net>

|  date:        Wed Jun 21 14:50:39 2017 +0200

|  summary:     Trunk2

|

o  <span style="color:olive;">changeset:   7:a5e9a3060e20</span>

|  parent:      4:32253567b531

|  user:        Boris Feld <boris.feld@octobus.net>

|  date:        Wed Jun 21 14:50:39 2017 +0200

|  summary:     Trunk

|

| x  <span style="color:olive;">changeset:   6:a57f1852d740</span>

| |  branch:      feature

| |  user:        Boris Feld <boris.feld@octobus.net>

| |  date:        Wed Jun 21 14:50:39 2017 +0200

| |  summary:     Feature2

| |

| x  <span style="color:olive;">changeset:   5:896dc0771e5e</span>

|/   branch:      feature

|    user:        Boris Feld <boris.feld@octobus.net>

|    date:        Wed Jun 21 14:50:39 2017 +0200

|    summary:     Feature

|

o  <span style="color:olive;">changeset:   4:32253567b531</span>

|  user:        Boris Feld <boris.feld@octobus.net>

~  date:        Wed Jun 21 14:50:39 2017 +0200

   summary:     Parent

</pre>

# How does it works?

## It's smart

<img src="https://media2.giphy.com/media/ZThQqlxY5BXMc/giphy.gif">

## Does Evolve only stores more changesets? (CHANGE)

## Not only

Remember our amend?

<div class='graph' style='display: flex ;align-items: stretch ;flex-flow: row wrap ; align-items: center;'>

<div class='left' style='order:1; width: 50%'>

~~~graphviz

    digraph G {

        rankdir="BT";

        node[fixedsize=true, width=1, height=1, style="filled", fillcolor="#7F7FFF"];

        // Revisions

        node[group=main];

        Parent -> "Fx bug";

    }

~~~

</div>

<div class='right' style='order:2; width: 50%'>

~~~graphviz

    digraph G {

        rankdir="BT";

        graph[splines=polyline];

        node[fixedsize=true, width=1, height=1, style="filled", fillcolor="#7F7FFF"];

        // Revisions

        node[group=main];

        Parent -> "Fix bug";

    }

~~~

</div>

</div>

## More revisions

<div class='graph' style='display: flex ;align-items: stretch ;flex-flow: row wrap ; align-items: center;'>

<div class='left' style='order:1; width: 50%'>

~~~graphviz

    digraph G {

        rankdir="BT";

        graph[splines=polyline];

        node[fixedsize=true, width=1, height=1, style="filled", fillcolor="#7F7FFF"];

        // Revisions

        node[group=main];

        Parent -> "Fx bug";

    }

~~~

</div>

<div class='right' style='order:2; width: 50%'>

~~~graphviz

    digraph G {

        rankdir="BT";

        graph[splines=polyline];

        node[fixedsize=true, width=1, height=1, style="filled", fillcolor="#7F7FFF"];

        // Revisions

        node[group=main];

        Parent -> "Fix bug";

        node[group=obsolete];

        Parent -> "Fx bug";

    }

~~~

</div>

</div>

## But hidden

<div class='graph' style='display: flex ;align-items: stretch ;flex-flow: row wrap ; align-items: center;'>

<div class='left' style='order:1; width: 50%'>

~~~graphviz

    digraph G {

        rankdir="BT";

        graph[splines=polyline];

        node[fixedsize=true, width=1, height=1, style="filled", fillcolor="#7F7FFF"];

        // Revisions

        node[group=main];

        Parent -> "Fx bug";

    }

~~~

</div>

<div class='right' style='order:2; width: 50%'>

~~~graphviz

    digraph G {

        rankdir="BT";

        graph[splines=polyline];

        node[fixedsize=true, width=1, height=1, style="filled", fillcolor="#7F7FFF"];

        // Revisions

        node[group=main];

        Parent -> "Fix bug";

        node[group=obsolete, style="dotted, filled", fillcolor="#DFDFFF"];

        Parent -> "Fx bug";

    }

~~~

</div>

</div>

## Here is the smartness (change word)!

~~~graphviz

    digraph G {

        rankdir="BT";

        node[fixedsize=true, width=1, height=1, style="filled", fillcolor="#7F7FFF"];

        // Revisions

        node[group=main];

        Parent -> "Fix bug";

        node[group=obsolete, style="dotted, filled", fillcolor="#DFDFFF"];

        Parent -> "Fx bug";

        // Obsolescence links

        edge[dir=back, style=dotted, arrowtail=dot];

        "Fx bug" -> "Fix bug";

    }

~~~

## Obs markers

Obs markers stores the relation between a changeset and its evolutions.

XXX: Speak about META

~~~graphviz

    digraph G {

        rankdir="BT";

        node[fixedsize=true, width=1, height=1, style="filled", fillcolor="#7F7FFF"];

        node[group=obsolete, style="dotted, filled" fillcolor="#DFDFFF"];

        edge[dir=back, style=dotted, arrowtail=dot];

        "Predecessor" -> "Successor";

        "Successor" [style="filled", fillcolor="#7F7FFF"];

    }

~~~

# Phases

## 3 phases

Changesets can be in one of three phases:

* Public

* Draft

* Secrets

## Public

The public phase holds changesets that have been exchanged publicly.

Changesets in the public phase are expected to remain in your repository history and are said to be immutable.

## Drafts

The draft phase holds changesets that are not yet considered a part of the repository's permanent history.

You can safely rewrite them.

New commits are in the draft phase by default.

## Secrets (hide)

The secret phase holds changesets that you do not want to exchange with other repositories.

Secret changesets are hidden from remote peers and will not be included in push operations.

Manual operations or extensions may move a changeset into the secret phase.

## Representation

~~~graphviz

    digraph G {

        rankdir="BT";

        graph[splines=polyline];

        node[fixedsize=true, width=1, height=1, style="filled", fillcolor="#7F7FFF"];

        // Revisions

        node[group=main];

        Public -> Draft -> Secret;

        Draft [shape="pentagon"];

        Secret [shape="square"];

    }

~~~

# Instability (add sub-titles, obsolete -> orphan, etc...)

## Obsolete

~~~graphviz

    digraph G {

        rankdir="BT";

        graph[splines=polyline];

        node[fixedsize=true, style="filled", width=1, height=1, fillcolor="#7F7FFF", shape="pentagon"];

        node[group=main];

        Root -> New;

        node[group=obsolete];

        Root -> Obsolete;

        // Obsolescence links

        edge[dir=back, style=dotted, arrowtail=dot];

        Obsolete -> New;

        Obsolete [fillcolor="#DFDFFF"];

        Root[shape="circle"];