notes and other things concerning combox
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commit 59939370fc87ce1b17caec9c468948c657cafe4b
parent 2bfe06d13dbbc752cc9e546ecad7126bf8c9b727
Author: Siddharth Ravikumar <>
Date:   Tue,  9 Feb 2016 11:00:39 -0500

Drafted sections 4.5, 4.6 and 4.7

report/bib/combox.bib | 14++++++++++++++
report/chapters/4-arch-d.tex | 124+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++--
report/chapters/5-testing.tex | 6+++---
report/combox-report.pdf | 0
4 files changed, 138 insertions(+), 6 deletions(-)

diff --git a/report/bib/combox.bib b/report/bib/combox.bib @@ -27,6 +27,20 @@ title = "PyCrypto - The Python Cryptography Toolkit", url = "", } +@misc{doc:combox-setup-windoze, +title = "setup combox on windows", +url = "" +} + +@misc{py:pip, +title = "pip - PyPA recommended tool for installing Python packages.", +url = "" +} + +@misc{py:package-guide, +title = "Python Packaging User Guide", +url = "" +} % 5 @techreport{dijkstra69, diff --git a/report/chapters/4-arch-d.tex b/report/chapters/4-arch-d.tex @@ -175,6 +175,125 @@ just testing and fixing issues in combox. \section{Operating system compatibility}\label{4-os-compat} -\section{combox as a python package} +combox was developed on a GNU/Linux machine, a conscious effort was +made to write in an operating system independent way. The top criteria +for choosing a library to use in combox was that it had to be +compatible on \emph{all} of the three major computing platforms in +2014-2016\footnote{GNU/Linux, OS X and, Windows}. -\section{With the benefit of hindsight}- \ No newline at end of file +As we were nearing the \verb+0.1.0+ release, combox was tested on OS X +(See chapter \ref{ch:5}) and OS X specific issues that were found +eventually were eventually fixed. The initial \verb+0.1.0+ release was +compatible with GNU/Linux and OS X. + +After the initial release of combox, we wanted to see if combox would +be compatible with Windows. We found that: + +\begin{itemize} +\item Setting up the parapharnalia to run combox was + non-trivial\cite{doc:combox-setup-windoze}. +\item The unit tests for the \verb+combox.file+ module royally failed. +\end{itemize} + +At the time of writing the report, combox is in version \verb+0.2.2+ +and it still not compatible with Windows. Comprehensive documentation +of setting up the development environment for combox on Windows was +written\cite{doc:combox-setup-windoze} to make it less cumbersome for +anyone would want to work on making combox compatible with Windows. + +\section{combox as a python package}\label{4-pypi} + +Before version \verb+0.2.0+, the canonical way to install combox was +to pull the source from the \verb+git+ repository with: + +\begin{verbatim} + git clone git:// +\end{verbatim} + +Then, do: + +\begin{verbatim} + cd combox +\end{verbatim} + +Finally install combox with: + +\begin{verbatim} + python install +\end{verbatim} + +Yes, installing combox on a machine was indeed non-trivial. + +Python has a package registry called CheeseShop\footnote{code name for + Python Package Index, see}; +all packages registered at the CheeseShop can be installed using +\verb+pip+ -- Python's platform independent package managment +system\cite{py:pip} -- with: + +\begin{verbatim} + pip install packagename +\end{verbatim} + +To make it easier for (python) users to install combox on their +machine, an effort was made to make it a python +package\cite{py:package-guide}. From version \verb+0.2.0+, combox has +been registered python package at the CheeseShop. (Python) users can +now easily get a copy of combox on their machine with: + +\begin{verbatim} + pip install combox +\end{verbatim} + +All versions of combox that is available through the CheeseShop are +digitally signed using the following GPG key: + +\begin{verbatim} +pub 4096R/00B252AF 2014-09-08 [expires: 2017-09-07] + Key fingerprint = C174 1162 CEED 5FE8 9954 A4B9 9DF9 7838 00B2 52AF +uid Siddharth Ravikumar (sravik) <> +sub 4096R/09CECEDB 2014-09-08 [expires: 2017-09-07] +\end{verbatim} + +All versions of combox's source are also available as a compressed +\verb+TAR+ ball and as a \verb+ZIP+ archive; they can be downloaded +from \url{}. + +\section{With the benefit of hindsight}\label{4-hindsight} + +combox's node monitor (\ was +written with the assumption that the node monitor will be the only +entity that will be making changes to the node directory that it is +monitoring. When started testing combox with node clients (Dropbox +client and Google Drive client), we observed that the node clients +made changes to the node directory when a file was +created/modified/renamed/deleted; for instance, when a shard, in the +Dropbox node directory, was modified on a remote computer, the Dropbox +client would first pull the newer version of the shard under the +\verb+.dropbox.cache+ directory as a temprorary file, move the older +version of the shard under \verb+.dropbox.cache+ as a backup, and +finally move the latest version of the shard, stored as a temprorary +file under the \verb+.dropbox.cache+ directory, to the respective +location in the Dropbox node directory; when a shard, in the Google +Drive node directory, was remotely modified on a remote computer, the +Google Drive client would delete the older version of the shard from +the Google Drive node directory and then create the newer version of +the shard in the respective location under the Google Drive node +directory. Since combox did not know about the node client's +behaviour, it confused combox and broke it royally; we had to make +major changes to the \verb+combox.eventns.NodeDirMonitor+ class to +make combox aware of the node client's behavior, this eventually +brutally obliterated the simplicity of the +\verb+combox.eventns.NodeDirMonitor+ class which I was proud of. + +I'm not sure how I would have written the \ module +if I had known about the Dropbox and Google Drive client's behaviour +before writing the \ or the +\ classes. Looking back, if there one +thing I would want to re-think/redo, it is the \ +module. + +The most important lesson I'm taking away from the experience of +writing combox is the insight of how easy it is to ruthless crush the +simplicity of a program due to unforeseen use cases. + +\verb+<3+ diff --git a/report/chapters/5-testing.tex b/report/chapters/5-testing.tex @@ -1,9 +1,9 @@ -\chapter{Testing} +\chapter{Testing}\label{ch:5} \epigraph{Testing shows the presence, not the absence of bugs.}{\textit{Dijkstra}\cite{dijkstra69}} -\section{Unit testing} +\section{Unit testing}\label{sec:5-unit-testing} The \verb+nose+\cite{pylib:nose} testing framework was used to write unit tests for the functions and classes part of the @@ -66,7 +66,7 @@ Unit tests failed to reveal bugs \#4, \#5 \#6 \#7 \#5 \#10 \#11\cite{combox-issue-tracker}; these bugs were found when manually testing combox. -\section{Manual testing} +\section{Manual testing}\label{sec:5-manual-testing} The unit tests for the \ module test the correctness of the \verb+ComboxDirMonitor+ and \verb+NodeDirMonitor+ diff --git a/report/combox-report.pdf b/report/combox-report.pdf Binary files differ.