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| 5 | MITGCM CVS policies | 
| 6 | =================== | 
| 7 |  | 
| 8 | o Introduction | 
| 9 |  | 
| 10 | This note describes policies that apply to the MITGCM CVS repository | 
| 11 |  | 
| 12 | o Why have a policy? | 
| 13 |  | 
| 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 | 
| 17 | tracked. If CVS is used without any other policy the result can be a | 
| 18 | collection of files each of which has complex, multiply branched set of | 
| 19 | interelated versions. This sort of CVS repository can be come like a | 
| 20 | library where books are simply stored in a huge heap. Although nothing is | 
| 21 | actually lost, the task of finding a coherent collection of material soon | 
| 22 | becomes impossible. | 
| 23 |  | 
| 24 | The policies we employ address two areas | 
| 25 | 1. Maintaining an orderly and easily identifiable, coherent set of | 
| 26 | evolving "products". | 
| 27 | 2. Allowing concurrent, on-going development of product components. | 
| 28 |  | 
| 29 | o Development trees and checkpoint trees | 
| 30 |  | 
| 31 | A directory within the MITGCM repository resides under either the | 
| 32 | development branch or the checkpoint branch. Files within each branch | 
| 33 | follow different policies. | 
| 34 |  | 
| 35 | o Development tree policies | 
| 36 |  | 
| 37 | Development trees are intended to be flexible areas where arbitrary files | 
| 38 | can be stored with multiple versions, many branches supporting multiple | 
| 39 | ongoing streams of development. Development trees have no policies in | 
| 40 | place to control complexity. Development trees might be associated with | 
| 41 | a particular person, a certain project or a particular special piece of | 
| 42 | work. These trees are intended to be useful areas for storing current | 
| 43 | work and for archiving partially finished work so that it doesn't get | 
| 44 | mislaid and s that some record of the development history can be easily | 
| 45 | maintained. The only policy that applies to development trees is that | 
| 46 | this style of tree is not intended to be used for providing a | 
| 47 | "checkpoint" distribution. Tagged configurations of tools built from this | 
| 48 | style of tree can be distributed, but because these trees do not have any | 
| 49 | polcies regarding testing of functionality, platform coverage or | 
| 50 | documentation these trees are not allowed to form the basis of | 
| 51 | "checkpoint" distrbutions or formal model releases. Other policies can | 
| 52 | be defined by individuals users of these trees but there are no further | 
| 53 | global policies. The MITGCM repository development/ subdirectory is | 
| 54 | reserved for holding development trees. Development trees also serve as | 
| 55 | experimental areas for exploring new code management policies. | 
| 56 |  | 
| 57 | o Checkpoint tree policies | 
| 58 |  | 
| 59 | Checkpoint trees are intended to provide structured storage areas for | 
| 60 | holding code that is intended for open distribution and is to be readily | 
| 61 | downloaded. There are policies governing the operation of these trees | 
| 62 | which are designed to ensure that distributed codes are clearly | 
| 63 | identified and meet certain levels of quality. | 
| 64 |  | 
| 65 | 1. Check-out | 
| 66 |  | 
| 67 | Just do it! Two mechanisms are available. cvsanon for read only access | 
| 68 | and regular cvs co .... for read/write access. | 
| 69 |  | 
| 70 | 2. Check-in. | 
| 71 |  | 
| 72 | The code check in procedure for a "checkpoint" tree is as follows | 
| 73 | 2.1  Check out the latest main branch revision. | 
| 74 | 2.2  Merge your changes into that revision. | 
| 75 | 2.3  Build and validate new code. | 
| 76 | 2.4  Check that there have been no further changes to the | 
| 77 | repository. Repeat from 2.1 if repository has changed. | 
| 78 | 2.5  Get clearance from other developers to check in your changes. | 
| 79 | 2.6  Check in your changed main branch. | 
| 80 | 2.8  Build and validate the new changes. | 
| 81 | 2.9  Tag code as "checkpointNN". Add records to docs/tag-index. | 
| 82 | 2.10 Build and validate test cases (see testing). | 
| 83 | 2.11 Create and install checkpointNN.tar.gz | 
| 84 |  | 
| 85 | 3. Testing | 
| 86 |  | 
| 87 | Things in a checkpoint tree require a test case that | 
| 88 | can be used to validate the component. | 
| 89 |  | 
| 90 | 4. Checkpoint tagging | 
| 91 |  | 
| 92 | No code should be left in limbo. Checking in code and then | 
| 93 | leaving it in the repository untagged is bad. When you check | 
| 94 | in code you are creating a new checkpoint. That means you don't | 
| 95 | check in some code which you "know" works 100% and then go away | 
| 96 | for two weeks. When you start checking in code you make sure | 
| 97 | you have time to do the process end-to-end as described in section | 
| 98 | 2. | 
| 99 |  | 
| 100 | 5. Release tagging | 
| 101 |  | 
| 102 | Releases are only based on checkpoint tree code. Maintenance fixes | 
| 103 | to releases are also maintained within the checkpoint tree. Files | 
| 104 | within a release must have accompanying documentation. The form of this | 
| 105 | documentation depends on the file type. | 
| 106 |  | 
| 107 | 6. Branches | 
| 108 |  | 
| 109 | Branches are to be used for bug-fixes and code patches to releases | 
| 110 | only. All other changes e.g. totally new features, bug-fixes to | 
| 111 | checkpoints are introduced by moving checkpoint levels forward. The | 
| 112 | only historical code maintenance that is employed is for fixes and | 
| 113 | patches to formal releases - not checkpoints. | 
| 114 |  | 
| 115 | o These policies are causing me a big problem, what can I do? | 
| 116 |  | 
| 117 | The policies are not enforced by any mechanism other than mutual | 
| 118 | agreement! If you think the policies are not appropriate then let us know | 
| 119 | and we can discuss changing them. However, if you simply ignore the | 
| 120 | policies regarding the checkpoint_release trees then your code may be | 
| 121 | removed and/or your access revoked. | 
| 122 |  | 
| 123 | o What about bitkeeper | 
| 124 |  | 
| 125 | We are looking at bitkeeper (www.bitkeeper.com). It looks cool, but | 
| 126 | policies are still important. Any experience, suggestions let us know. | 
| 127 | Watch this space! | 
| 128 |  | 
| 129 | Questions, comments e-mail: code.czars@mitgcm.org | 
| 130 | </body> | 
| 131 | </html> |