FIREFOX 6 ARCHITECTURAL ENHANCEMENT (FULLY OPTIMIZED FAVOURITES)By Fully Optimized eXperience (FOX)James Brereton - 06069736Katie Tanner - 06060472Gordon Krull - 06003108Rob Staalduinen - 06009513

PRESENTATION OVERVIEW Introduction Enhancement Implementations Stakeholders & NFRs SAAM Analysis Sequence Diagrams Testing Limitations Lessons Learned & Team Issues Conclusions

INTRODUCTION Everyone uses bookmarks for quicker access

to their favourite pages, but we felt that we could improve upon this

Therefore, our enhancement is a way to give users very fast access to their favourite pages

Will work in conjunction with the current system so that it will not hinder performance when loading other web pages but still allow for faster access

ENHANCEMENT The main goal of our enhancement is to allow

for instant access of a user’s favourite pages by ensuring that pre-rendered, cached versions of the page are continuously updated

Implementation of this enhancement requires the addition of modules and function calls in the UI, Gecko and the Data Persistence

The rationale behind this enhancements is the large amount of unused idle time that tends to exist in a user’s web-browsing session

The UI would see the addition of button next to the “awesome bar” presenting the user with a drop down of their favourite pages

ORIGINAL CONCEPTUAL ARCHITECTURE

IMPLEMENTATION 1 Proposed Design:

Add Favourites Data Component to Data Persistence which holds pre-parsed data, header files, and address of top favourites

Every X amount of time, Favourites Data makes a request to Necko for the header for one of its top favourites and checks for differences

If different, gets full website data and then sends it to Content Model and replaces header file in Favourites Data

After Content Model has manipulated data, the data is sent to Frame Constructor for final rendering before being send back to Favourites Data for storage

IMPLEMENTATION 1 CONCEPTUAL ARCHITECTURE

IMPLEMENTATION 2 Proposed Design:

Would also add Favourites Data component to Data Persistence, but only store parsed data and addresses

An Update Module would be added to Gecko, which would store header files and addresses

Update Module would poll Necko for updates to the favourite sites whenever Necko had idle time

As before, compares header files and retrieves data if they differ

Sends to Content Model for rendering, header files are stored in the module and rendered data gets sent to Favourites Data

IMPLEMENTATION 2 ARCHITECTURE

STAKEHOLDERS & NFRSStakeholders Non-Functional

RequirementsEnd Users •Performance

•Security•Availability•Integration

Developers •Scalability•Modifiability•Security•Availability•Integration

SAAM ANALYSIS: IMPLEMENTATION 1NFR Implementation 1Performance +Loading of favourite page is

faster than other approach-Could reduce overall browsing performance

Availability +Doesn’t affect the overall availability of Firefox

Modifiability +Single module that needs to be updated-Increased architectural complexity

Integration -Must modify functionality of Data Persistence subsystem

SAAM ANALYSIS: IMPLEMENTATION 2NFR Implementation 1Performance +No impact on browser

performance-Updating of favourite websites not consistent

Availability +Doesn’t affect the overall availability of Firefox

Modifiability +Limits dependencies between subsystems-Two modules to update rather than one

Integration +No change in overall functionality of existing Firefox subsystems

CHOSEN DESIGN Based on our SAAM Analysis, we have

decided to choose Implementation 2

Deciding factors: Elimination of impact on browser performance,

as this feature should never affect standard browsing

Fewer dependencies between subsystems eases modifiability and integration

SEQUENCE DIAGRAM: ADDING A NEW FAVOURITE PAGE

SEQUENCE DIAGRAM: LOADING A FAVOURITE PAGE

TESTING Subsytems the enhancement would interact

with that need to be tested include: User Interface Necko Data Persistence

Tests planned for each subsystem User Interface- Measure time required to render the

page, ensure it’s not hindering performance Necko- Ensure resource allocation is being handled

correctly and not interfering with the retrieval of non-favourite sites

Data Persistence- Make sure cached websites don’t inflate data persistence and hinder standard browsing

LIMITATIONS Limitations:

Impossible to determine the full impact on the system without actually having the time to implement the feature

We have no prior experience developing for a large-scale project such as Firefox

LESSONS LEARNED AND TEAM ISSUES Lessons Learned:

Knowledge of concrete architecture made it much easier to determine how our enhancement would affect each component of Firefox as well as how it would affect NFRs

Trade-offs between NFRs are unavoidable Team Issues:

Found it much easier to collaborate on Brain-Storming potential enhancements and implementation details compared to previous deliverable

CONCLUSIONS We chose to implement a ‘Top Favourites”

feature to Firefox which allows users to select approx. 5 pages to be continually updated in cache

Stakeholders: end users and developers Considered 2 alternatives, and based on a

SAAM analysis, chose one consisting of adding a Favourites Data component to Data Persistence and an Update Module to Gecko

Overall layered architecture is preserved; no significant changes to the design other than the addition of components