iOS Architecture & File systems

ByRajeev.P.V

CB.EN.P2CSE13014

Smart phones

About iOS

i is the key letter for Apple’s portable line of devices such as:- ipod, ipodTouch,ipodShuffle, iphone, ipad, ipad mini.

iOS is formerly known as iPhone OS.Developed by Apple,Inc.Released on June 29,2007Programmed in c,c++,objective c Available in 34 languages.

iOS mainly developed for iPhone but it can support other devices as:

Unlike Microsoft’s windows phone and Google’s Android Apple does not license iOS for installation on non-Apple hardware

Latest version of iOS i.e. iOS7 was released on September 18, 2013

File SystemImportant.Its where user keeps his stuff.Organization of file system plays an important

role for system and apps to find and access the resources.

Appropriate place.Goal: user should find easily.

File systemThe file system in iOS handle the persistent storage of data files, apps, and the files associated with the operating system .The file system is one of the fundamental resources used by all processes.Based on Unix file system.

iOS Architecture• Similar to basic architecture found in Mac OS X.• Acts as intermediate between applications and

hardware.

iOS apps

Every App is an islandAn iOS app’s interactions with the file system are limited mostly to the directories inside the app’s sandbox.An app is generally prohibited from accessing or creating files in directories outside of its home directory.But it can use public system interfaces to access things such as the user’s contacts or music.

iOS technology layersIn iOS there are 4 abstraction layers: the Core OS layer,the Core Services layer, the Media layer and the Cocoa Touch layer.

Core OS layerThe Core OS layer contains the low-level

features: They are most likely used by frameworks like:Accelerate Framework.External Accessory Framework.Generic Security Services Framework.

Memory management.

Accelerate Framework: The Accelerate framework contains interfaces for performing digital signal processing (DSP),image-processing calculations etc

External Accessory framework: It provides support for communicating with hardware accessories attached to an iOS-based device.

Security Framework: iOS also provides an explicit Security framework that you can use to guarantee the security of the files your app manages.

Core services layerThese are some of the features:Peer-to-Peer Services.iCloud Storage.Data Protection . Mostly c based.

Peer-to-Peer Services:we can use peer-to-peer connectivity to

initiate communication sessions with nearby devices.

iCloud Storage:iCloud storage lets your app write user

documents and data to a central location. Users can then access those items from all of their iOS devices

Data Protection:When your app designates a specific file as

protected, the system stores that file on disk in an encrypted format. While the device is locked, the contents of the file are inaccessible to both your app and to any potential intruders. However, when the device is unlocked by the user, a decryption key is created to allow your app to access the file.

Media layer

The Media layer contains the graphics, audio, and video technologies you use to implement multimedia experiences in your apps.

C and objective C are used.

Coca Touch layerThe key technologies available in the Cocoa Touch

layer are:AirDrop: AirDrop lets users share photos, documents,

URLs, and other kinds of data with nearby devices.Text Kit: Text Kit is a full-featured, high-level

technology for handling text and fine typographyApple Push Notification Service: Apple Push

Notification service provides a way to alert users about new information, even when your app is not actively running.

Gesture recognizers and etc.

References•http://en.wikipedia.org/wiki/Smartphone•http://www.slideshare.net/•www.apple.com

Thank you……….