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/4.75 [en] (X11; U; Linux 2.2.14-5.0 i686) [Netscape]"> |
6 |
</head> |
7 |
<body> |
8 |
|
9 |
<h2> |
10 |
Introduction</h2> |
11 |
This note describes policies that apply to the MITGCM CVS repository. |
12 |
<h2> |
13 |
Why have a policy?</h2> |
14 |
CVS itself is a liberal free-for-all product that can be used in a variety |
15 |
of ways. It is designed to provide a system for storing arbitrary files |
16 |
in a way that allows the change history of the individual files to be tracked. |
17 |
If CVS is used without any other policy the result can be a collection |
18 |
of files each of which has complex, multiply branched set of interelated |
19 |
versions. This sort of CVS repository can be come like a library where |
20 |
books are simply stored in a huge heap. Although nothing is actually lost, |
21 |
the task of finding a coherent collection of material soon becomes impossible. |
22 |
<p>The policies we employ address two areas |
23 |
<ol> |
24 |
<li> |
25 |
Maintaining an orderly and easily identifiable, coherent set of evolving |
26 |
"products".</li> |
27 |
|
28 |
<li> |
29 |
Allowing concurrent, on-going development of product components.</li> |
30 |
</ol> |
31 |
|
32 |
<h2> |
33 |
Development trees and checkpoint trees</h2> |
34 |
A directory within the MITGCM repository resides under either the development |
35 |
branch or the checkpoint branch. Files within each branch follow different |
36 |
policies. |
37 |
<h2> |
38 |
Development tree policies</h2> |
39 |
Development trees are intended to be flexible areas where arbitrary files |
40 |
can be stored with multiple versions, many branches supporting multiple |
41 |
ongoing streams of development. Development trees have no policies in place |
42 |
to control complexity. Development trees might be associated with a particular |
43 |
person, a certain project or a particular special piece of work. These |
44 |
trees are intended to be useful areas for storing current work and for |
45 |
archiving partially finished work so that it doesn't get mislaid and so |
46 |
that some record of the development history can be easily maintained. The |
47 |
only policy that applies to development trees is that this style of tree |
48 |
is not intended to be used for providing a "checkpoint" distribution. Tagged |
49 |
configurations of tools built from this style of tree can be distributed, |
50 |
but because these trees do not have any polcies regarding testing of functionality, |
51 |
platform coverage or documentation these trees are not allowed to form |
52 |
the basis of "checkpoint" distrbutions or formal "releases". Other policies |
53 |
can be defined by individuals users of these trees but there are no further |
54 |
global policies. The MITGCM repository development_tree/ subdirectory is |
55 |
reserved for holding development trees. Development trees also serve as |
56 |
experimental areas for exploring new code management policies. |
57 |
<h2> |
58 |
Checkpoint tree policies</h2> |
59 |
Checkpoint trees are intended to provide structured storage areas for holding |
60 |
code that is intended for open distribution and is to be readily downloaded. |
61 |
There are policies governing the operation of these trees which are designed |
62 |
to ensure that distributed codes are early identified and meet certain |
63 |
levels of quality. |
64 |
<ol> |
65 |
<li> |
66 |
Check-out</li> |
67 |
|
68 |
<br>Just do it! Two mechanisms are available. cvsanon for read only access |
69 |
and regular cvs co .... for read/write access. |
70 |
<li> |
71 |
Check-in</li> |
72 |
|
73 |
<br>The code check in procedure for a "checkpoint" tree is as follows |
74 |
<ol> |
75 |
<li> |
76 |
Check out the latest main branch revision.</li> |
77 |
|
78 |
<li> |
79 |
Merge your changes into that revision.</li> |
80 |
|
81 |
<li> |
82 |
Build and validate new code.</li> |
83 |
|
84 |
<li> |
85 |
Check that there have been no further changes to the repository. Repeat |
86 |
from 2.1 if repository has changed.</li> |
87 |
|
88 |
<li> |
89 |
Get clearance from other developers to check in your changes.</li> |
90 |
|
91 |
<li> |
92 |
Check in your changed main branch.</li> |
93 |
|
94 |
<li> |
95 |
Build and validate the new changes.</li> |
96 |
|
97 |
<li> |
98 |
Tag code as "checkpointNN". Add records to docs/tag-index.</li> |
99 |
|
100 |
<li> |
101 |
Build and validate test cases (see testing).</li> |
102 |
|
103 |
<li> |
104 |
Create and install checkpointNN.tar.gz</li> |
105 |
</ol> |
106 |
|
107 |
<li> |
108 |
Testing</li> |
109 |
|
110 |
<br>Things in a checkpoint tree require a test case that can be used to |
111 |
validate the component. |
112 |
<li> |
113 |
Checkpoint tagging</li> |
114 |
|
115 |
<br>No code should be left in limbo. Checking in code and then leaving |
116 |
it in the repository untagged is bad. When you check in code you are creating |
117 |
a new checkpoint. That means you don't check in some code which you "know" |
118 |
works 100% and then go away for two weeks. When you start checking in code |
119 |
you make sure you have time to do the process end-to-end as described in |
120 |
section 2. |
121 |
<li> |
122 |
Release tagging</li> |
123 |
|
124 |
<br>Releases are only based on checkpoint tree code. Maintenance fixes |
125 |
to releases are also maintained within the checkpoint tree. Files within |
126 |
a release must have accompanying documentation. The form of this documentation |
127 |
depends on the file type. |
128 |
<li> |
129 |
Branches</li> |
130 |
|
131 |
<br>Branches are to be used for bug-fixes and code patches to releases |
132 |
only. All other changes e.g. totally new features, bug-fixes to checkpoints |
133 |
are introduced by moving checkpoint levels forward. The only historical |
134 |
code maintenance that is employed is for fixes and patches to formal releases |
135 |
- not checkpoints.</ol> |
136 |
|
137 |
<h2> |
138 |
These policies are causing me a big problem, what can I do?</h2> |
139 |
The policies are not enforced by any mechanism other than mutual agreement! |
140 |
If you think the policies are not appropriate then let us know and we can |
141 |
discuss changing them. However, if you simply ignore the policies regarding |
142 |
the checkpoint_release trees then your code may be removed and/or your |
143 |
access revoked. |
144 |
<h2> |
145 |
What about bitkeeper</h2> |
146 |
We are looking at bitkeeper (www.bitkeeper.com). It looks cool, but policies |
147 |
are still important. Any experience, suggestions let us know. Watch this |
148 |
space! |
149 |
<p>Questions, comments e-mail: code.czars@mitgcm.org |
150 |
<br> |
151 |
<hr WIDTH="100%"> |
152 |
<table CELLSPACING=0 CELLPADDING=0 WIDTH="100%" NOSAVE > |
153 |
<tr NOSAVE> |
154 |
<td><font size=-1>Last modified on $Date: $</font></td> |
155 |
|
156 |
<td> |
157 |
<div align=right><font size=-1>CVS: $Source: $Revision: $</font></div> |
158 |
</td> |
159 |
</tr> |
160 |
</table> |
161 |
|
162 |
</body> |
163 |
</html> |