MITgcm/mitgcm.org/cvspolicy.html

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<h1>
MITgcm CVS policy</h1></center>

<h2>
Introduction</h2>
This note describes policies that apply to the MITGCM CVS repository.
<h2>
Why have a policy?</h2>
CVS itself is a liberal free-for-all product that can be used in a variety
of ways. It is designed to provide a system for storing arbitrary files
in a way that allows the change history of the individual files to be tracked.
If CVS is used without any other policy the result can be a collection
of files each of which has complex, multiply branched set of inter-related
versions. This sort of CVS repository can be come like a library where
books are simply stored in a huge heap. Although nothing is actually lost,
the task of finding a coherent collection of material soon becomes impossible.
<p>The policies we employ address tree areas
<ol>
<li>
Maintaining an orderly and easily identifiable, coherent set of evolving
"products".</li>

<li>
Allowing concurrent, on-going development of product components.</li>

<li>
Making the integration&nbsp; of achieved developments easy, rapid, organized
and clear.</li>
</ol>

<h2>
Development trees and checkpoint trees</h2>
A directory within the MITGCM repository resides under either the development
branch or the checkpoint branch. Files within each branch follow different
policies.
<h2>
Development tree policies</h2>
Development trees are intended to be flexible areas where arbitrary files
can be stored with multiple versions, many branches supporting multiple
ongoing streams of development. Development trees have no policies in place
to control complexity. Development trees might be associated with a particular
person, a certain project or a particular special piece of work. These
trees are intended to be useful areas for storing current work and for
archiving partially finished work so that it doesn't get mislaid and so
that some record of the development history can be easily maintained. The
only policy that applies to development trees is that this style of tree
is not intended to be used for providing a "checkpoint" distribution. Tagged
configurations of tools built from this style of tree can be distributed,
but because these trees do not have any policies regarding testing of functionality,
platform coverage or documentation these trees are not allowed to form
the basis of "checkpoint" distributions or formal "releases". Other policies
can be defined by individuals users of these trees but there are no further
global policies. The MITGCM repository development_tree/ sub-directory
is reserved for holding development trees. Development trees also serve
as experimental areas for exploring new code management policies.
<h2>
Checkpoint tree policies</h2>
Checkpoint trees are intended to provide structured storage areas for holding
code that is intended for open distribution and is to be readily downloaded.
There are policies governing the operation of these trees which are designed
to ensure that distributed codes are early identified and meet certain
levels of quality.
<ol>
<li>
Check-out</li>

<br>Just do it! Two mechanisms are available. cvsanon for read only access
and regular cvs co .... for read/write access.
<li>
Check-in</li>

<br>The code check in procedure for a "checkpoint" tree is as follows
<ol>
<li>
Check out the latest main branch revision.</li>

<li>
Merge your changes into that revision.</li>

<li>
Build and validate new code.</li>

<li>
Check that there have been no further changes to the repository. Repeat
from 2.1 if repository has changed.</li>

<li>
Get clearance from other developers to check in your changes.</li>

<li>
Check in your changed main branch.</li>

<li>
Build and validate the new changes.</li>

<li>
Tag code as "checkpointNN". Add records to docs/tag-index.</li>

<li>
Build and validate test cases (see testing).</li>

<li>
Create and install checkpointNN.tar.gz</li>
</ol>

<li>
Testing</li>

<br>Things in a checkpoint tree require a test case that can be used to
validate the component.
<li>
Checkpoint tagging</li>

<br>No code should be left in limbo (un-tagged) for extended periods. On
the other hand it's unnecessary to create a checkpoint tag for every little
change. Checkpoint tags should be made after a particularly significant
code modification or otherwise on a regular basis, say bi-weekly. Very
often we set a list of goals to be reached by the next checkpoint which
sometimes takes more than two weeks to achieve. Obviously, in this case
a bi-weekly checkpoint would not be useful.
<li>
Release tagging</li>

<br>Releases are only based on checkpoint tree code. Maintenance fixes
to releases are also maintained within the checkpoint tree. Files within
a release must have accompanying documentation. The form of this documentation
depends on the file type.
<li>
Branches</li>

<br>Branches are a useful tool for making changes prior to checkpoints
without breaking other working versions but it must be understood that
branches are short-lived and that releases and checkpoints not be made
from a branch. Branches are especially useful for adding totally
<br>new features. bug-fixes to checkpoints are introduced by moving checkpoint
levels forward. The only historical code maintenance that s employed is
for fixes and patches to formal releases - not checkpoints.</ol>

<h2>
Someone checked-in broken code so not my code doesn't work?</h2>
You have several options:
<ol>
<li>
Politely email everyone at support@mitgcm.org asking what&nbsp; has happened
and that it be fixed?</li>

<li>
Figure out why the new code is broken, fix it, check it in and proudly
send a message to support@mitgcm.org to show how constructive you are.</li>

<li>
Complain that the quality of work is too low and then do nothing to fix
the code.<br>
<BR></li>

<br>We advise you to only use the third option if you are confident that
your own contributions to the code are bug-free, well written, documented
and fool proof.&nbsp; :)</ol>

<h2>
These policies are causing me a big problem, what can I do?</h2>
The policies are not enforced by any mechanism other than mutual agreement!
If you think the policies are not appropriate then let us know and we can
discuss changing them. However, if you simply ignore the policies regarding
the checkpoint_release trees then your code may be removed and/or your
access revoked.
<h2>
What about bitkeeper</h2>
We are looking at bitkeeper (www.bitkeeper.com). It looks cool, but policies
are still important. Any experience, suggestions let us know. Watch this
space!
<p>Questions, comments e-mail: code.czars@mitgcm.org
<br>
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<td><font size=-1>Last modified on $Date: 2001/02/17 17:08:40 $</font></td>

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<div align=right><font size=-1>CVS: $Source: /u/gcmpack/mitgcm.org/../cvspolicy.html,v
$Revision: 1.10 $</font></div>
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1	<!doctype html public "-//w3c//dtd html 4.0 transitional//en">
2	<html>
3	<head>
4	<meta http-equiv="Content-Type" content="text/html; charset=iso-8859-1">
5	<meta name="GENERATOR" content="Mozilla/4.76 [en] (X11; U; Linux 2.4.1 i686) [Netscape]">
6	<meta name="Author" content="Chris Hill">
7	<title>MITgcm CVS policy</title>
8	</head>
9	<body text="#000000" bgcolor="#FF99FF" link="#0000EF" vlink="#51188E" alink="#FF0000">
10
11	<center>
12	<h1>
13	MITgcm CVS policy</h1></center>
14
15	<h2>
16	Introduction</h2>
17	This note describes policies that apply to the MITGCM CVS repository.
18	<h2>
19	Why have a policy?</h2>
20	CVS itself is a liberal free-for-all product that can be used in a variety
21	of ways. It is designed to provide a system for storing arbitrary files
22	in a way that allows the change history of the individual files to be tracked.
23	If CVS is used without any other policy the result can be a collection
24	of files each of which has complex, multiply branched set of inter-related
25	versions. This sort of CVS repository can be come like a library where
26	books are simply stored in a huge heap. Although nothing is actually lost,
27	the task of finding a coherent collection of material soon becomes impossible.
28	<p>The policies we employ address tree areas
29	<ol>
30	<li>
31	Maintaining an orderly and easily identifiable, coherent set of evolving
32	"products".</li>
33
34	<li>
35	Allowing concurrent, on-going development of product components.</li>
36
37	<li>
38	Making the integration  of achieved developments easy, rapid, organized
39	and clear.</li>
40	</ol>
41
42	<h2>
43	Development trees and checkpoint trees</h2>
44	A directory within the MITGCM repository resides under either the development
45	branch or the checkpoint branch. Files within each branch follow different
46	policies.
47	<h2>
48	Development tree policies</h2>
49	Development trees are intended to be flexible areas where arbitrary files
50	can be stored with multiple versions, many branches supporting multiple
51	ongoing streams of development. Development trees have no policies in place
52	to control complexity. Development trees might be associated with a particular
53	person, a certain project or a particular special piece of work. These
54	trees are intended to be useful areas for storing current work and for
55	archiving partially finished work so that it doesn't get mislaid and so
56	that some record of the development history can be easily maintained. The
57	only policy that applies to development trees is that this style of tree
58	is not intended to be used for providing a "checkpoint" distribution. Tagged
59	configurations of tools built from this style of tree can be distributed,
60	but because these trees do not have any policies regarding testing of functionality,
61	platform coverage or documentation these trees are not allowed to form
62	the basis of "checkpoint" distributions or formal "releases". Other policies
63	can be defined by individuals users of these trees but there are no further
64	global policies. The MITGCM repository development_tree/ sub-directory
65	is reserved for holding development trees. Development trees also serve
66	as experimental areas for exploring new code management policies.
67	<h2>
68	Checkpoint tree policies</h2>
69	Checkpoint trees are intended to provide structured storage areas for holding
70	code that is intended for open distribution and is to be readily downloaded.
71	There are policies governing the operation of these trees which are designed
72	to ensure that distributed codes are early identified and meet certain
73	levels of quality.
74	<ol>
75	<li>
76	Check-out</li>
77
78	<br>Just do it! Two mechanisms are available. cvsanon for read only access
79	and regular cvs co .... for read/write access.
80	<li>
81	Check-in</li>
82
83	<br>The code check in procedure for a "checkpoint" tree is as follows
84	<ol>
85	<li>
86	Check out the latest main branch revision.</li>
87
88	<li>
89	Merge your changes into that revision.</li>
90
91	<li>
92	Build and validate new code.</li>
93
94	<li>
95	Check that there have been no further changes to the repository. Repeat
96	from 2.1 if repository has changed.</li>
97
98	<li>
99	Get clearance from other developers to check in your changes.</li>
100
101	<li>
102	Check in your changed main branch.</li>
103
104	<li>
105	Build and validate the new changes.</li>
106
107	<li>
108	Tag code as "checkpointNN". Add records to docs/tag-index.</li>
109
110	<li>
111	Build and validate test cases (see testing).</li>
112
113	<li>
114	Create and install checkpointNN.tar.gz</li>
115	</ol>
116
117	<li>
118	Testing</li>
119
120	<br>Things in a checkpoint tree require a test case that can be used to
121	validate the component.
122	<li>
123	Checkpoint tagging</li>
124
125	<br>No code should be left in limbo (un-tagged) for extended periods. On
126	the other hand it's unnecessary to create a checkpoint tag for every little
127	change. Checkpoint tags should be made after a particularly significant
128	code modification or otherwise on a regular basis, say bi-weekly. Very
129	often we set a list of goals to be reached by the next checkpoint which
130	sometimes takes more than two weeks to achieve. Obviously, in this case
131	a bi-weekly checkpoint would not be useful.
132	<li>
133	Release tagging</li>
134
135	<br>Releases are only based on checkpoint tree code. Maintenance fixes
136	to releases are also maintained within the checkpoint tree. Files within
137	a release must have accompanying documentation. The form of this documentation
138	depends on the file type.
139	<li>
140	Branches</li>
141
142	<br>Branches are a useful tool for making changes prior to checkpoints
143	without breaking other working versions but it must be understood that
144	branches are short-lived and that releases and checkpoints not be made
145	from a branch. Branches are especially useful for adding totally
146	<br>new features. bug-fixes to checkpoints are introduced by moving checkpoint
147	levels forward. The only historical code maintenance that s employed is
148	for fixes and patches to formal releases - not checkpoints.</ol>
149
150	<h2>
151	Someone checked-in broken code so not my code doesn't work?</h2>
152	You have several options:
153	<ol>
154	<li>
155	Politely email everyone at support@mitgcm.org asking what  has happened
156	and that it be fixed?</li>
157
158	<li>
159	Figure out why the new code is broken, fix it, check it in and proudly
160	send a message to support@mitgcm.org to show how constructive you are.</li>
161
162	<li>
163	Complain that the quality of work is too low and then do nothing to fix
164	the code.<br>
165	<BR></li>
166
167	<br>We advise you to only use the third option if you are confident that
168	your own contributions to the code are bug-free, well written, documented
169	and fool proof.  :)</ol>
170
171	<h2>
172	These policies are causing me a big problem, what can I do?</h2>
173	The policies are not enforced by any mechanism other than mutual agreement!
174	If you think the policies are not appropriate then let us know and we can
175	discuss changing them. However, if you simply ignore the policies regarding
176	the checkpoint_release trees then your code may be removed and/or your
177	access revoked.
178	<h2>
179	What about bitkeeper</h2>
180	We are looking at bitkeeper (www.bitkeeper.com). It looks cool, but policies
181	are still important. Any experience, suggestions let us know. Watch this
182	space!
183	<p>Questions, comments e-mail: code.czars@mitgcm.org
184	<br>
185	<hr WIDTH="100%">
186	<table CELLSPACING=0 CELLPADDING=0 WIDTH="100%" NOSAVE >
187	<tr NOSAVE>
188	<td><font size=-1>Last modified on $Date: 2001/02/17 17:08:40 $</font></td>
189
190	<td>
191	<div align=right><font size=-1>CVS: $Source: /u/gcmpack/mitgcm.org/../cvspolicy.html,v
192	$Revision: 1.10 $</font></div>
193	</td>
194	</tr>
195	</table>
196
197	</body>
198	</html>