Concrete Architecture of Firefox 2

Concrete Architecture of Firefox 2

Team OneJuly 6, 2007

Team OneJuly 6, 2007

AgendaAgenda• Introduction• Concrete Architecture• Comparison with Conceptual• Modules• JavaScript Interpreter• XML Parser• Display Backend

• Conclusion

• Introduction• Concrete Architecture• Comparison with Conceptual• Modules• JavaScript Interpreter• XML Parser• Display Backend

• Conclusion

IntroductionIntroduction

• Analyzing Concrete Architecture• Previously researched

Conceptual Architecture• Extracted Architecture from

code

• Analyzing Concrete Architecture• Previously researched

Conceptual Architecture• Extracted Architecture from

code

Comparison with Conceptual

Comparison with Conceptual

• High cohesion (XPCOM)• Additional layers• Extensions• Common

• Additional dependencies

• High cohesion (XPCOM)• Additional layers• Extensions• Common

• Additional dependencies

Conceptual ArchitectureConceptual Architecture

Concrete BoxesConcrete Boxes

Concrete ArrowsConcrete Arrows

Modules: JS InterpreterModules: JS Interpreter

• Called SpiderMonkey• Written in C• Many classes and packages, but

6 seem to be most important

• Called SpiderMonkey• Written in C• Many classes and packages, but

6 seem to be most important

LiveConnectLiveConnect

• Package in SpiderMonkey• Bridge between JavaScript and

Java• Depends on a few internal

classes and XPCOM

• Package in SpiderMonkey• Bridge between JavaScript and

Java• Depends on a few internal

classes and XPCOM

LiveConnect DependenciesLiveConnect

Dependencies

XPConnectXPConnect

• Package in SpiderMonkey• Allows JavaScript objects access

to XPCOM objects and vice-versa

• Depends on some internal classes and XPCOM

• Package in SpiderMonkey• Allows JavaScript objects access

to XPCOM objects and vice-versa

• Depends on some internal classes and XPCOM

XPConnect Dependencies

XPConnect Dependencies

JSInterpJSInterp

• Class in SpiderMonkey• JavaScript Interpreter Class• All classes that depend on

JSInterp are internal• All classes JSInterp depends on

are internal

• Class in SpiderMonkey• JavaScript Interpreter Class• All classes that depend on

JSInterp are internal• All classes JSInterp depends on

are internal

API ClassesAPI Classes

• JSAPI, JSXDRAPI, JSDbgAPI• Used by external classes• Depend on and are depended

on by many internal classes• Façade Pattern

• JSAPI, JSXDRAPI, JSDbgAPI• Used by external classes• Depend on and are depended

on by many internal classes• Façade Pattern

API ClassesAPI Classes

• JSAPI is the main API for SpiderMonkey

• JSXDRAPI is the external data representation API

• JSDbgAPI is SpiderMonkey’s debug API

• JSAPI is the main API for SpiderMonkey

• JSXDRAPI is the external data representation API

• JSDbgAPI is SpiderMonkey’s debug API

Modules: XML ParserModules: XML Parser

XML ParsersXML Parsers• expat module performs DOM parsing• xml module performs SAX parsing• Both work independently of each other• expat module is self-contained and

has no dependencies; however, xml module relies on stream input and string operations support from xpcom

• expat module performs DOM parsing• xml module performs SAX parsing• Both work independently of each other• expat module is self-contained and

has no dependencies; however, xml module relies on stream input and string operations support from xpcom

htmlparser Modulehtmlparser Module• Abstracts away string and unichar

issues• Delegates parsing requests to expat

and xml modules, and receives the result back.

• Implements something close to a façade, however, xml talks to xpcom

• Abstracts away string and unichar issues

• Delegates parsing requests to expat and xml modules, and receives the result back.

• Implements something close to a façade, however, xml talks to xpcom

Deviation from Conceptual

Deviation from Conceptual

• Nothing is invoking/depending on parser module for XML parsing requests

• Could be a dynamic dependency rather than static, which bfx and lsedit cannot capture

• Nothing is invoking/depending on parser module for XML parsing requests

• Could be a dynamic dependency rather than static, which bfx and lsedit cannot capture

Modules: Display Backend

Modules: Display Backend

• Set of platform-independent drawing primitives

• Adapter to the native graphics interface (GTK, GDI, etc)

• PostScript handling• Shared sub-components

• Set of platform-independent drawing primitives

• Adapter to the native graphics interface (GTK, GDI, etc)

• PostScript handling• Shared sub-components

Modules: Display Backend

Modules: Display Backend

Deviation from Conceptual

Deviation from Conceptual

• UI talks directly to Display Backend

• Interaction with Common• intl• xpcom• nsprpub

• UI talks directly to Display Backend

• Interaction with Common• intl• xpcom• nsprpub

ConclusionConclusion

• Conceptual Architecture Useful• Additional Layers• Additional Dependencies

• Conceptual Architecture Useful• Additional Layers• Additional Dependencies

Thank youThank you

Questions?Questions?