Changes between Initial Version and Version 1 of VisualizingDjangoChangesetDependencies


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Timestamp:
May 7, 2007, 11:01:21 PM (18 years ago)
Author:
Ramiro Morales < >
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  • VisualizingDjangoChangesetDependencies

    v1 v1  
     1= Visualizing Django source code changeset dependencies =
     2
     3When following the workflow I describe in '''![1]''' to be able to maintain a local copy of Django with selected changes backported from the SVN trunk development evolution to a 0.96 base copy I soon found myself in following situation:
     4
     5Certain changeset ''C'' that I'd want to use wasn't being considered by '''![2]'''{{{darcs}}} as a potential candidate so it didn't offer me to apply it.
     6
     7Later the cause became evident: The ''C'' changeset wasn't being considered by {{{darcs}}} because I had previously answered "no" when it offered me to apply a (chronologically previous) changeset ''B'' on which ''C'' depends (dependency in this context means both ''B'' and ''C'' modify some overlaping section of some file).
     8
     9Given the fact that in {{{darcs}}} patches (changesets, patchsets) are first class citizens, it is easier to track and visualize the dependencies among them by using it together with some related '''![3]'''tools and '''![4]'''{{{GraphViz}}}.
     10
     11If we add a couple of ad-hoc scripts and some tips from the experience gained to the mix we can get something like this:
     12
     13== Scripts ==
     14
     15=== filter1.sh ===
     16{{{
     17#!/bin/sh
     18
     19# This filter changes the labels of the nodes of a Graphviz dot
     20# file as generated by darcs-deps to only consist of the patchset
     21# number.
     22#
     23# It depends on the labels being of the form
     24# "[tailor-project-name @ changeset-number]"
     25#
     26# It needs one command line parameter: The tailor-project-name
     27#
     28
     29if test $# -ne 1; then
     30    echo "Usage:"
     31    echo "$(basename $0) tailor-project-name"
     32    exit 1
     33fi
     34
     35/bin/sed "s/\[$1 @ \\([0-9]\+\\)\]/\1/g"
     36}}}
     37
     38=== filter2.sh ===
     39{{{
     40#!/bin/sh
     41
     42# This filter modifies the properties of the nodes of a Graphviz dot
     43# to add a relative "href" property with the same value as the node label.
     44#
     45# It depends on the labels being the number of the revision/changeset
     46# represented by the node (possibly generated by filtering the darcs-deps
     47# output through filter1.sh).
     48#
     49# It has been created to facilitate the navigation of the Django trunk
     50# changeset dependancy graph, enabling (for the relevant output formats: pdf,
     51# image maps) the user to click on a node and getting a web browser window
     52# opened with the Django Trac page showing the corresponding changeset.
     53#
     54# For this to work, a graph level property href=http://code.djangoproject.com/changeset/
     55# must be also present, it can be added with a -Ghref=... commandline switch
     56# in the dot(1) invocation.
     57
     58if test $# -ne 0; then
     59    echo "Usage:"
     60    echo "$(basename $0)"
     61    exit 1
     62fi
     63
     64/bin/sed "s#label = \"\\([0-9]\+\\)\"#label = \"\1\", href=\"\1\"#g"
     65}}}
     66
     67== Usage ==
     68
     69{{{
     70ramiro@tabaqui:~/src/django/inmutable $ darcs-deps | filter1.sh django096 | filter2.sh | unflatten | dot -Tps2 -Gsize=50,50 -Ghref=http://code.djangoproject.com/changeset/ -o ~/django-deps.ps -Tpng -o ~/django-deps.png
     71Examining patch 249 of 249.
     72
     73ramiro@tabaqui:~/src/django/inmutable $ cd
     74
     75ramiro@tabaqui:~ $ ps2pdf django-deps.ps
     76}}}
     77
     78=== Explanation ===
     79
     80{{{darcs-deps}}} is ran on the {{{inmutable}}} {{{darcs}}} repository (please refer to '''![1]''' to see what that repository is and how to create it), it generates a {{{Graphviz}}} dot language description of the dependancy graph.
     81
     82We filter that otput first through our two custom filtering scripts (see above) to change some graph node attributes, and then through {{{unflatten(1)}}} (part of {{{Graphviz}}}) to enhance the layout of the graphic representation.
     83
     84And finally we feed the result to {{{dot(1)}}} (also part of {{{Graphviz}}}) to get our final output. In the case
     85of some output methods (PDF [via Postscript], server and client side image maps) we'll be able to click on the nodes and get our Web browser to go to the Django Trac page associated with the changeset at hand.
     86
     87== Example output ==
     88
     89Status as of [5165] (May 8 2007 3:43 UTC):
     90
     91
     92== References ==
     93
     94 1. [http://seeonee.homeip.net:81/intdoc/DjangoPost096 Django: My post 0.96 branch]
     95 2. [http://darcs.net darcs]
     96 3. [http://scratchbox.org/~ttimonen/repos/darcs-deps/darcs-deps darcs-deps] (darcs repo: http://scratchbox.org/~ttimonen/repos/darcs-deps)
     97 4. [http://www.graphviz.org/ GraphViz]
     98 5. [http://www.cs.wisc.edu/~ghost/ Ghostscript]
     99
     100== Feedback ==
     101
     102Please direct all feedback to [mailto:cramm0_at_gmail.com Ramiro Morales].
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