Summer of Code/2009/Print Support

About you

1)What is your name?

Vamsi Krishna Davuluri

2)What is your email address?

vamsi<dot>davuluri<at>gmail<dot>com

3)What is your Sugar Labs wiki username?

IwikiwI

4)What is your IRC nickname?

IwikiwI

5)What is your primary language? (We have mentors who speak multiple languages and can match you with one of them if you'd prefer.)

English, Hindi, Telugu. I prefer English!

6)Where are you located, and what hours do you tend to work? (We also try to match mentors by general time zone if possible.)

I am located in india (5:30+ GMT), I usually work in the night, from my 7 pm to 2:30 am So any mentor should be ideal.

7)Have you participated in an open-source project before? If so, please send us URLs to your profile pages for those projects, or some other demonstration of the work that you have done in open-source. If not, why do you want to work on an open-source project this summer?

I have not been part of an open source development team. Nor do I have a very profound understanding of the OS development paradigm yet. But seeing how I could never afford software which was sold at high price even though that software was the bare essential software for a me to get my computer working. And as my experiences are true for almost two thirds of other students, I would like to see them not to have to put up with the buy-what-you-want software, in-fact I would love for them to grow up using free software that I make and hope that they will produce free software themselves, a few of them at least.

Although not really a group developmental project, I have coded two networks projects and a prototype game for windows. (the source is in downloads)

1)Simulation of mobile units and their movement over a network

http://code.google.com/p/iwikiwi/

2)A client/server model for file transfer, md5 check sum, IP translations, and file size requests

http://code.google.com/p/iwikiwi-clientserver/

3)A prototype Bounce game in OpenGL for windows

http://code.google.com/p/iwikiwi-bounce/

About your project

1) What is the name of your project?

Print Support for the XO laptops

2)Describe your project in 10-20 sentences.

As the self explanatory name suggests, the project is to add print support to the laptops.For the time being, the print requests will be sent to the school server which would be connected to a printer/or to a machine with a printer. Later on as we are going with a CUPS architecture, we can include USB printing on demand!

A step by step absraction:

1) During boot of the xos, the shell will compile itself in compliance to supported file types, and have the print button enabled only when they are.

2) The print button on click saves the file to journal.This will have the same implementation as of a save file.

3) There will be a file-transfer-wizard (an activity) which allows the user to send server recognized formats to the school server. This will be provided as a notification in the activity the user is using when he clicks the print button and asks whether the user would like to go to the file-transfer-wizard.

4) The file-transfer-wizard will be a simple interface. It will send the current /stacked up/ files to the school server by the users intervention, this can even be configured to send automatically as well.

5) The school server converts the requests into PDF and will store them in a web folder. And through moodle the teacher will have a page displaying the contents of the folder(a type of queue), and he/she will be able to download them to his remote system, and check them and approve them for printing if he/she wishes. After his approval, a background process on the school server prints to a network printer. Otherwise the job will be left to remain, or be discarded.

In-Depth analysis.

The easiest way to implement step-1 would be to check which mime types exist on the server side in the etc/cups/mime.types file with a simple python method (getAllowableMIMETypes) and make it available on the server's web folder, and access it with a c program during the xo's boot and append the list to our client side mime.types. So anything non-existent here will have its corresponding activities print button disabled

As an Alternative, CUPS print function returns a python -1/ C 0 when a non-supported MIME type is used, so we can take advantage of that display a non supported format error.

The xo already comes with a nice save feature which saves files to the journal and categorizes them under the activity name. I will use a similar implementation for the print button in activities (which is activated from step-1) and have it save files under a 'To Print' category/tag in the journal.

for step-3, we use CUPS. The API has a nice array of functions, one of which is to get the printers name (we will be having the network printer, and especially the cups-pdf printer installed on the server). Since we know the name is CUPS-PDF, we can check it, and print our file as a PDF on the server. For the sake of our python convenience we will be using a python wrapper to cups, pycups.

for step-4, we will be using our Sugar api to create a nice simple interface, and for communicating with the journal through the D-BUS IPC, this will just be a click of a button. And when a print is finally done(see step -5 expansion), an acknowledgement notification pops back. The server background program sends a string packet back.This will be done with minimal client/server code. (the sending back of a notification)

for step-5, We will be saving the printed pdf files into a web folder, and we will add a page which lists the contents dynamically to moodle.And provide access rights only to the teacher's log in. The teacher can download the file to his/her terminal from the page, view it and approve it for printing. Here comes to light a background program written in C which listens to requests every sleep(30) secs, and this will every time it wakes up access the moodle's datastore( mysql table) and checks if the approve has been hit for a specific id(id is generated with respect to job arrival, and every time a job in between is printed or removed, the ids sort themselves back). Consequently a remove buttom will also be provided, which does just what it says.

3)Convince us, in 5-15 sentences, that you will be able to successfully complete your project in the timeline you have described. This is usually where people describe their past experiences, credentials, prior projects, schoolwork, and that sort of thing, but be creative. Link to prior work or other resources as relevant.

I have a fairly good understanding of communication models, and my skill with networks is quite satisfactory. And as most of the implementation is already available in form of python bindings, all that remains is placing them together with a sound design, which I have already discussed with several community members. And I can provide as much time as is required for the work to get done.

My credentials include:

1)The ability to finish projects on his own, with self motivation, as the 3 projects I have attached have been made as a self interest.

2)An internship at Kenexa which had been to develop an assembly which logged database transactions, written in c#, so I have an exposure to infrastructure.

3)winner of a coding event, Mind-Hunters, at a national level technical festival.

I have already added a fix to Write so that it can export to pdf files, and I have provided a temporary fix for a screen bug, for which I will provide a complete fix.

And I have checked the feasibility of my approach by going through the source files, and writing sample programs like

 cups_dest_t *dests, *dest;
 int num_dests = cupsGetDests(&dests);
 int job_id = cupsPrintFile(dests->name,
                            argv[1],
                            "Test",
                             0, NULL);
 if (job_id == 0)
 printf("error printing file, unsupported format");

for printing

You and the community

1) If your project is successfully completed, what will its impact be on the Sugar Labs community? Give 3 answers, each 1-3 paragraphs in length. The first one should be yours. The other two should be answers from members of the Sugar Labs community, at least one of whom should be a Sugar Labs GSoC mentor. Provide email contact information for non-GSoC mentors.

From myself: "The XO users and teachers will greatly benefit from printing, as converting something digital(which may be art, a presentation or a photo) into a physical representation is something very basic, and something very strong. Not only will there be a good deal of happy faces, but it will also kill the effort required to copy content to a portable drive, and go to a terminal and print. "

From Benjamin M schwartz:

"In order for Sugar to be adopted in schools with existing IT infrastructure, it must give users an easy way to print their documents.If that printing could be routed through a teacher-controlled visual print queue, then in this regard Sugar would be the most preferred solution for primary education and schools with limited IT resources."

2) Sugar Labs will be working to set up a small (5-30 unit) Sugar pilot near each student project that is accepted to GSoC so that you can immediately see how your work affects children in a deployment. We will make arrangements to either supply or find all the equipment needed. Do you have any ideas on where you would like your deployment to be, who you would like to be involved, and how we can help you and the community in your area begin it?

I think it would be wonderful to begin with my school, I come from a government funded school, not one of those fancy private schools. The kids there would definitely love the different teaching environment. I will have a talk with the principal, and after that I will further this.

3)What will you do if you get stuck on your project and your mentor isn't around?

I will of course go through the net. And The community has been very helpful without having a mentor as of yet. I will look forward to the community as well.

4)How do you propose you will be keeping the community informed of your progress and any problems or questions you might have over the course of the project?

I intend to provide weekly updates on the wiki itself. And I will also be providing daily updates on the channel.

Miscellaneous

Here [1]

1) What is your t-shirt size? (Yes, we know Google asks for this already; humor us.)

Large! (do I get a sugar tshirt?)

2) Describe a great learning experience you had as a child.

Being alone and not interacting with others is a hard bargain. It might seem appropriate during the experience (as one can brush it off as," who will interact with the lessers"), but its only after you reach an age you realise the tragedy one has brought on himself. I can never change my past, but I am a different person now and will be in the future.

3) Is there anything else we should have asked you or anything else that we should know that might make us like you or your project more?

My motto: There is no such thing as not able to achieve something, the only variable really is effort which differs from achievement to achievement with person to person. what someone else can do, So can I.