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==Objective==
To write some PERL code that can query Bonsai and use the information available in the place of CVS (as CVS lacks changesets).
==Description==
This code would use a two-step approach: queries would be pulled using Bonsai, code would be checked out using a pure-CVS wrapper (akin to the style Richard used for SVN).
==Why Bonsai?==
Lots of functionality is pre-baked, only needing to be extracted somehow.
==History/What We Tried==
* Downloaded The Bonsai Project source code. See [http://www.mozilla.org/projects/bonsai/ this page] for details on getting the Bonsai source. Unfortunately there wasn't as much documentation as we had hoped for.
* Poked and prodded around, finding the CGIs of interest (and their respective params).
==Exploring Bonsai==
===Useful CGIs===
The particular CGIs in the Bonsai project are of interest to this project.
<table border="1" cellpadding="3">
<tr><td>cvslog.cgi</td><td>A web interface for "cvs log"</td><td>Good for extracting commentary on the what/why a change was made.</td></tr>
<tr><td>cvsquery.cgi</td><td>Displays the results of querying a module with certain critera (who, dates, files, etc.).</td><td>Good for querying high-level results; can see all checkins.</td></tr>
<trbgcolor="#EEEEEE"><td><strike>cvsqueryform.cgi</strike></td><td>Main screen of Bonsai that you use to query with.</td><td>'''Not necessary as the PERL script simulates this action.'''</td></tr>
<tr><td>cvsview2.cgi</td><td>View CVS diffs.</td><td>To extract the changes between two versions of a file.</td></tr>
<tr><td>moduleanalyse.cgi</td><td>Show directories in a module.</td><td>Good to map out the module if not known ahead.</td></tr>
<tr><td>multidiff.cgi</td><td>Show ALL of the diffs.</td><td>Don't have to circumvent pesky pagination with the query results!</td></tr>
<tr><td>rview.cgi</td><td>Lets you browse the contents of a directory.</td><td>Perhaps useful in the discovery of the project contents in question.</td></tr>
<trbgcolor="#EEEEEE"><td>showcheckins.cgi</td><td>Show some set of checkins in a bonsai hook.</td><td>Of questionable benefit at the current time.</td></tr>
</table>
==What =Of Interest to the Delta Debugging Framework===asdf ===How/Particulars===In researching and exploring the options, we discovered that Bonsai can actually output to XML by attaching the param/value pair "xml=1" to the end of a query using the Bonsai CGI scripts. (Thanks go to Reed Loden for pointing this out to us.) This enabled us to probe deeper and investigate interfacing with CVS by way of Bonsai by building a request in PERL, querying Bonsai, and parsing the XML response. Further research was Discoveredput into finding an appropriate parsing means in PERL (no experience in this arena). Turned out that PERL has a DOM-style parsing module named XML::LibXML (among many other XML parsers available). The XML::LibXML module is rather easy to use. For example, to query Bonsai for Checkins in the last 2 hours to the Mozilla trunk, and iterate through them, the below code works: <pre>#!/usr/How it can be donebin/perl use LWP::Simple;use XML::LibXML; #query Bonsaimy $xmloutput = get "http://bonsai.mozilla.org/cvsquery.cgi?treeid=default&module=all&branch=HEAD&branchtype=match&dir=&file=&filetype=match&who=&whotype=match&sortby=Date&date=hours&hours=2&mindate=&maxdate=&cvsroot=%2Fcvsroot&xml=1"; my $parser=XML::LibXML->new;my $domtree=$parser->parse_string($xmloutput); my @checkins=$domtree->getElementsByTagName("ci");foreach my $ci (@checkins) { # who and when, gross dumpage print $ci->getAttribute("who") . " @ " . $ci->getAttribute("date") . "\n";}</particularspre> ==Concerns and Thoughts==Accessing information through Bonsai wouldn't be overly difficult. However, trying to make sense of changesets themselves (the concept of, and what constitutes) might be difficult as CVS doesn't have the notion of a changeset. This means that either the programmer would either define a set of rules on what does/does not make a changeset OR there is something that already exists in Bonsai (which has been overlooked--and that's <i>not hard to do</i>). Additionally, it is apparent that not all CGIs of Bonsai support the xml parameter (and subsequent output). This works on cvsquery.cgi, but is lacking (from what we can see) in the others.
==Roadblocks==
*No previous exposure to Bonsai, CVS or source repository concepts in addition to a total absence of PERL skills.*By the time we discovered how to do it, we ran out of time in the course.
