CSC/ECE 517 Fall 2014/OSS M1450 vda
Implement Window.sessionStorage
This wiki page contains details on the work done for the initial step of the task Implement Window.sessionStorage for the Mozilla research project Servo.
Introduction
Rust
Rust is a modern systems programming language focusing on safety and speed to build reliable and efficient systems <ref> http://doc.rust-lang.org/nightly/intro.html </ref>. It accomplishes the goals of memory safe without using garbage collection and it supports concurrency and parallelism in building platforms.
Rust’s lightweight task mechanism also promises to allow fine-grained isolation between browser components, such as tabs and extensions, without the need for expensive runtime protection schemes, like operating system process isolation. <ref> https://www.mozilla.org/en-US/research/projects/ </ref>
Servo
Mozilla Research team is currently working on an experimental project to develop a new Web browser engine "Servo", that is capable of supporting a variety of current and next generation of hardware like mobile devices, multi-core processors and high-performance GPUs. Servo builds on top of Rust to provide a secure and reliable foundation. It is currently developed on 64 bit devices.<ref> https://www.mozilla.org/en-US/research/projects/ </ref>
The main objectives of this experimentation project is improving the layout to graphics rendering - to optimize for power efficiency and maximize parallelism. <ref> https://www.mozilla.org/en-US/research/projects/ </ref>
Window.sessionStorage
Developer Environment Setup
Installing Required Packages for Servo
On Debian-based Linuxes:
sudo apt-get install curl freeglut3-dev \
libfreetype6-dev libgl1-mesa-dri libglib2.0-dev xorg-dev \ msttcorefonts gperf g++ cmake python-virtualenv \ libssl-dev libglfw-dev
On Fedora:
sudo yum install curl freeglut-devel libtool gcc-c++ libXi-devel \
freetype-devel mesa-libGL-devel glib2-devel libX11-devel libXrandr-devel gperf \ fontconfig-devel cabextract ttmkfdir python python-virtualenv expat-devel \ rpm-build openssl-devel glfw-devel cmake
pushd . cd /tmp wget http://corefonts.sourceforge.net/msttcorefonts-2.5-1.spec rpmbuild -bb msttcorefonts-2.5-1.spec sudo yum install $HOME/rpmbuild/RPMS/noarch/msttcorefonts-2.5-1.noarch.rpm popd
On Arch Linux:
sudo pacman -S base-devel git python2 python2-virtualenv mesa glfw ttf-font cmake
Building Servo
Clone the Servo repository hosted at https://github.com/servo/servo.
git clone https://github.com/servo/servo
Switch to the servo directory and invoke mach to build Servo.
cd servo ./mach build
Note: Building the servo browser engine will take a considerable amount of time.
Once the build is successful, launch the browser using below command.
./mach run tests/html/about-mozilla.html
SNAPSHOT OF SERVO BROWSER ENGINE
Implementation
Work Done as part of OSS Project
Now, we have the servo browser engine in our machine. In order to implement Window.sessionStorage we need to add two files - an interface WEB IDL file and the implementation file
- Create a new file called Storage.webidl file under the specified folder components/script/dom/webidls. This file contains the basic information about the methods that will be used in the storage.rs file.
- Next, create another file called storage.rs file under the specified folder components/script/dom. This file contains the actual implementation of the sessionStorage. It has the basic methods for the creation of a storage object.
- Now we have to add our module to lib.rs file so that the build file knows that there is a new file that has been added.
- Build the servo once again and test to see if the servo browser is running perfectly.
FEW SNAPSHOTS
Future Work <ref> https://github.com/servo/servo/wiki/Storage-student-project </ref>
- Create the WindowSessionStorage interface making it return a Storage instance.
- Create a Storage task which will be used to contain all stored data.
- Define a message-passing interface for reading and writing stored data for a particular browser tab.
- Use the Storage task in the implementation of Storage.
- When the value of a stored data is changed, notify its respective browser tab.
- Pass as many tests as possible.
- Implement the WindowLocalStorage interface which behaves slightly different from the WindowSessionStorage interface.
Further Readings
Servo Design: https://github.com/servo/servo/wiki/Design/ Rust by Example: http://rustbyexample.com/ Javascript as Servo's Garbage Collector: https://blog.mozilla.org/research/2014/08/26/javascript-servos-only-garbage-collector/
References
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