NSURLSession: New Features and Best Practices · Beneﬁts NSURLSession Example HTTP/1.1, SPDY, HTTP/2 App Transport Security (ATS)

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System Frameworks #WWDC16

Session 711

NSURLSession: New Features and Best Practices

Jeff Jenkins Software Engineer, Internet Technologies

Agenda

Agenda

Evolving NSURLSession API

Agenda

Evolving NSURLSession APISecurity

Agenda

Evolving NSURLSession APISecurityBest practices and tips

Networking API

NSStream

NSNetServices

NSURLConnection

Foundation

Networking API

NSStream

NSNetServices

NSURLConnection

Foundation

Deprecated2015

Networking API

Foundation NSNetServices

NSStream

NSURLSessionNew2013

NSStream

NSNetServices

NSURLConnection

Foundation

Deprecated2015

Networking API

ReviewNSURLSession

BenefitsNSURLSession Example


HTTP/1.1, SPDY, HTTP/2



App Transport Security (ATS)




HTTP Strict Transport Security (HSTS)





Cache, cookies, proxy, authentication





Cache, cookies, proxy, authentication

Configuration


NSURLSessionConfiguration



Transport Layer Security (TLS) version




Prohibit cellular usage





Network service type






Cookie policy






Cookie policy

Cache policy






Cookie policy

Cache policy

Storage objects






Cookie policy

Cache policy

Storage objects

Request and resource timeouts

ReviewNSURLSession Example


let config = NSURLSessionConfiguration.defaultSessionConfiguration()



let session = NSURLSession(configuration: config)



let url = NSURL(string: "https://www.example.com/")!

let task = session.dataTask(with: url) { (data: NSData?, response: NSURLResponse?, error:

NSError?) in

...

}




NSError?) in

...

}




NSError?) in

...

}



task.resume()



Summary: Three-step process


Summary: Three-step process• Configuration


Summary: Three-step process• Configuration• Session


Summary: Three-step process• Configuration• Session• Tasks



Task 1 Session 1

Task 3 Session 3Task 2 Session 2



Task 1 Session 1


Task 1Task 2

Task 3

Session 1



Task 1 Session 1


Task 1Task 2

Task 3

Session 1

HTTP/2NSURLSession API

HTTP/2NSURLSession API NEW


• Apple• Facebook• Instagram• Wikipedia• Twitter• YouTube• Yahoo

HTTP/2 Protocol



HTTP/2 Protocol • Multiplexing and concurrency



HTTP/2 Protocol • Multiplexing and concurrency• Header compression



HTTP/2 Protocol • Multiplexing and concurrency• Header compression• Stream priorities



HTTP/2 Protocol • Multiplexing and concurrency• Header compression• Stream priorities

HTTP/2NSURLSession API

• Server Push

NEW


HTTP/2 Server PushNSURLSession API NEW

HTTP/2 Server PushNSURLSession API

Prevent network round trips

NEW


Prevent network round tripsServer support required

NEW


Prevent network round tripsServer support requiredNow available in NSURLSession

NEW

LoadingHTTP/1.1

App ServerNSURLSessionTi

me

LoadingHTTP/1.1

App ServerNSURLSessionLatencyTi

me

LoadingHTTP/1.1

App ServerNSURLSessionLatencyTi

me

LoadingHTTP/1.1

App Server

GET index.html

NSURLSessionLatencyTi

me

LoadingHTTP/1.1

App Server

GET index.html

NSURLSession

Response

LatencyTi

me

LoadingHTTP/1.1

App Server

GET index.html

index.html

NSURLSession

Response

LatencyTi

me

LoadingHTTP/1.1

App Server

GET index.html

index.html

NSURLSession

GET style.css

Response

LatencyTi

me

LoadingHTTP/1.1

App Server

GET index.html

index.html

NSURLSession

GET style.css

Response

Response

LatencyTi

me

LoadingHTTP/1.1

App Server

GET index.html

index.html

style.css

NSURLSession

GET style.css

Response

Response

LatencyTi

me

LoadingHTTP/1.1

App Server

GET index.html

index.html

style.css

NSURLSession

GET style.css

GET background.jpg

Response

Response

LatencyTi

me

LoadingHTTP/1.1

App Server

GET index.html

index.html

style.css

NSURLSession

GET style.css

GET background.jpg

Response

Response

Response

LatencyTi

me

LoadingHTTP/1.1

App Server

GET index.html

index.html

style.css

background.jpg

NSURLSession

GET style.css

GET background.jpg

Response

Response

Response

LatencyTi

me

LoadingHTTP/1.1

App Server

GET index.html

finish

index.html

style.css

background.jpg

NSURLSession

GET style.css

GET background.jpg

Response

Response

Response

LatencyTi

me

LoadingHTTP/1.1

App Server

GET index.html

finish

index.html

style.css

background.jpg

HTTP/1.1

NSURLSession

GET style.css

GET background.jpg

Response

Response

Response

LatencyTi

me

App ServerNSURLSession

NEWHTTP/2 Server PushLoading

HTTP/1.1

LatencyTi

me

App Server

GET index.html

NSURLSession


HTTP/1.1

LatencyTi

me

App Server

GET index.html

Response

NSURLSession


HTTP/1.1

LatencyTi

me

App Server

index.html

GET index.html

Response

NSURLSession


HTTP/1.1

LatencyTi

me

App Server

index.html

GET index.html

Response

NSURLSession

NEW

PUSH 2, 3, n

HTTP/2 Server PushLoading

HTTP/1.1

LatencyTi

me

App Server

GET style.css

index.html

GET index.html

Response

NSURLSession

NEW

PUSH 2, 3, n


HTTP/1.1

LatencyTi

me

App Server

ResponseGET style.css

index.html

GET index.html

Response

NSURLSession

NEW

PUSH 2, 3, n


HTTP/1.1

LatencyTi

me

App Server


index.html

style.css

GET index.html

Response

NSURLSession

NEW

PUSH 2, 3, n


HTTP/1.1

LatencyTi

me

App Server


index.html

style.css

GET index.html

Response

GET background.jpg

NSURLSession

NEW

PUSH 2, 3, n


HTTP/1.1

LatencyTi

me

App Server


Response

index.html

style.css

GET index.html

Response

GET background.jpg

NSURLSession

NEW

PUSH 2, 3, n


HTTP/1.1

LatencyTi

me

App Server


Response

index.html

style.cssbackground.jpg

GET index.html

Response

GET background.jpg

NSURLSession

NEW

PUSH 2, 3, n


HTTP/1.1

LatencyTi

me

App Server


Response

index.html


finish

GET index.html

Response

GET background.jpg

NSURLSession

NEW

PUSH 2, 3, n


HTTP/1.1

LatencyTi

me

App Server


Response

index.html


finish

HTTP/2 Server Push

GET index.html

Response

GET background.jpg

NSURLSession

NEW

PUSH 2, 3, n


HTTP/1.1

LatencyTi

me

App Server


Response

index.html


finish

HTTP/2 Server Push

GET index.html

Response

GET background.jpg

NSURLSession

NEW

PUSH 2, 3, n


HTTP/1.1

LatencyTi

me

DemoHTTP/2 Server Push

Andreas Garkuscha Software Engineer, Internet Technologies

DemoHTTP/2 Server Push

Andreas Garkuscha Software Engineer, Internet Technologies

SummaryHTTP/2 Server Push


Server Push supported in NSURLSession


Server Push supported in NSURLSessionNo opt in, just works


Server Push supported in NSURLSessionNo opt in, just worksEven better performance

Network statisticsNSURLSession API

Network statisticsNSURLSession API NEW


Did you know?

NEW


Did you know?98% of all statistics are made up!

NEW


Did you know?98% of all statistics are made up!Network statistics: Performance, bugs, understanding

NEW


Did you know?98% of all statistics are made up!Network statistics: Performance, bugs, understandingCurrently supported on iOS, macOS, and tvOS

NEW

Network statistics delegateNSURLSession API NEW

Network statistics delegateNSURLSession API

func urlSession(_ session: NSURLSession, task: NSURLSessionTask,

didFinishCollecting metrics: NSURLSessionTaskMetrics)

NEW

NSURLSessionTaskMetricsNSURLSession API NEW

NSURLSessionTaskMetricsNSURLSession API

NSURLSessionTaskMetrics

NEW


taskInterval: NSDateInterval


NEW



redirectCount: Int


NEW



redirectCount: Int

transactionMetrics: [NSURLSessionTaskTransactionMetrics]


NEW



redirectCount: Int

transactionMetrics: [NSURLSessionTaskTransactionMetrics]


NSURLSessionTaskTransactionMetrics

NEW

Four Categories of Metrics

NSURLSessionTaskTransactionMetricsNSURLSession API NEW

NSURLSessionTaskTransactionMetricsNSURLSession API

1 - Request and Response

NEW



request: NSURLRequest

response: NSURLResponse?

NEW



request: NSURLRequest

response: NSURLResponse?

…URL loading activity…request response

NEW



2 - Protocol and Connection

NEW



networkProtocolName: String?

NEW




http/1.1h2spdy/3, spdy/3.1

NEW




isProxyConnection: Bool


NEW




isProxyConnection: Bool

isReusedConnection: Bool


NEW



3 - Load Info

NEW


3 - Load Info

resourceFetchType: NSURLSessionTaskMetricsResourceFetchType

NEW


3 - Load Info

resourceFetchType: NSURLSessionTaskMetricsResourceFetchType

.networkLoad

.localCache

.serverPush

NEW



4 - Connection Establishment and Transmission

NEW



fetchStartDate: NSDate?

domainLookupStartDate: NSDate?

domainLookupEndDate: NSDate?

connectStartDate: NSDate?

secureConnectionStartDate: NSDate?

secureConnectionEndDate: NSDate?

connectEndDate: NSDate?

NEW



fetchStartDate: NSDate?

domainLookupStartDate: NSDate?

domainLookupEndDate: NSDate?

connectStartDate: NSDate?

secureConnectionStartDate: NSDate?

secureConnectionEndDate: NSDate?

connectEndDate: NSDate?

requestStartDate: NSDate?

requestEndDate: NSDate?

responseStartDate: NSDate?

responseEndDate: NSDate?

NEW




Task

fetchStart

Task

fetchStart


Task

fetchStart


Task

fetchStart

DNS

domainLookupStart

domainLookupEnd


Task

fetchStart

DNS

domainLookupStart

domainLookupEnd


Task

fetchStart

DNS

domainLookupStart

domainLookupEnd


Connection Establishment

connectEndconnectStart


Task

fetchStart

DNS

domainLookupStart

domainLookupEnd




Task

fetchStart

TCP

DNS

domainLookupStart

domainLookupEnd




connectEnd


Task

fetchStart TCP

connectStart

DNS

domainLookupStart

domainLookupEnd



connectEnd

NEW

Task

fetchStart TCP TLS

secureConnectionEnd

connectStart

secureConnectionStart

DNS

domainLookupStart

domainLookupEnd



connectEnd

NEW

Task

fetchStart TCP

connectStart

TLS

secureConnectionEndsecureConnectionStart

DNS

domainLookupStart

domainLookupEnd



connectEnd

Task

fetchStart TCP TLS

secureConnectionEnd

connectStart


DNS

domainLookupStart

domainLookupEnd



connectEnd

NEW

Task

fetchStart

DNS

domainLookupStart

domainLookupEnd

HTTP

TCP TLS

secureConnectionEndsecureConnectionStart

connectStart



connectEnd

NEW

Task

fetchStart

DNS

domainLookupStart

domainLookupEnd

TCP TLS

secureConnectionEnd

HTTPGET

requestStartrequestEnd


connectStart



connectEnd

NEW

Task

fetchStart

DNS

domainLookupStart

domainLookupEnd

TCP TLS

secureConnectionEnd

HTTP

GET



connectStart



connectEnd

NEW

Task

fetchStart

DNS

domainLookupStart

domainLookupEnd

TCP TLS

secureConnectionEnd

HTTPGET


200 OK

responseStart

responseEnd


connectStart



connectEnd

NEW

Task

fetchStart

DNS

domainLookupStart

domainLookupEnd

TCP TLS

secureConnectionEnd

HTTPGET



connectStart

200 OK

responseStart

responseEnd



connectEnd

NEW

Task

fetchStart

DNS

domainLookupStart

domainLookupEnd

TCP TLS

secureConnectionEnd

HTTPGET


200 OK

responseStart

responseEnd


connectStart


Task

fetchStart

HTTPDNS

domainLookupStart

domainLookupEnd


connectEnd

200 OK

responseStart

responseEnd

NEW

TCP TLS

secureConnectionStart secureConnectionEnd

GET


connectStart


Task

fetchStart

HTTP

Cache

DNS

domainLookupStart

domainLookupEnd


connectEnd

200 OK

responseStart

responseEnd

NEW

TCP TLS

secureConnectionStart secureConnectionEnd

GET


connectStart



class MySessionDelegate: NSObject, NSURLSessionTaskDelegate { @objc(URLSession:task:didFinishCollectingMetrics:) func urlSession(_ session: NSURLSession, task: NSURLSessionTask, didFinishCollecting metrics: NSURLSessionTaskMetrics) {

//metrics.redirectCount //metrics.taskInterval //metrics.transactionMetrics[0].connectStartDate …

}




}

let myDelegate = MySessionDelegate()




}






}



let myDelegateQueue = NSOperationQueue()




}




let session = NSURLSession(configuration: config, delegate: myDelegate, delegateQueue: myDelegateQueue)




}





let url = NSURL(string: "https://www.example.com/")! let task = session.dataTask(with: url) { (data: NSData?, response: NSURLResponse?, error: NSError?) in … }




}





let url = NSURL(string: "https://www.example.com/")! let task = session.dataTask(with: url) { (data: NSData?, response: NSURLResponse?, error: NSError?) in … }

task.resume()

NSURLSession APINetwork statistics

Summary


Summary

Deep view into network loading


Summary


Faster debugging, easier profiling, better performance


Summary


Faster debugging, easier profiling, better performance

Available in NSURLSession


Never an afterthoughtSecurity

SecurityTransport Layer Security


Protects data


Protects dataCipher—algorithm for encrypting/decrypting data



The RC4 cipher is no longer supported

Security

• Tuesday—Security session and labs

How iOS Security Really Works Nob Hill Tuesday 4:00PM

What's New in Security Nob Hill Tuesday 5:00PM

Transport Layer Security


The RC4 cipher is no longer supported

nscurlSecurity

nscurlSecurity

$ nscurl https://insecure.example.com/

nscurlSecurity

$ nscurl https://insecure.example.com/

nscurl[1234:123456] NSURLSession/NSURLConnection HTTP load failed

(kCFStreamErrorDomainSSL, -9824)

nscurlSecurity

$ nscurl —-enable-rc4 https://insecure.example.com/

nscurlSecurity

$ nscurl —-enable-rc4 https://insecure.example.com/

Enabling RC4 cipher suites

<html><body><h1>It works!</h1></body></html>

App Transport Security


NSAllowsArbitraryLoadsInWebContent


NSAllowsArbitraryLoadsInWebContentNSRequiresCertificateTransparency


NSAllowsArbitraryLoadsInWebContentNSRequiresCertificateTransparency

How iOS Security Really Works Nob Hill Tuesday 4:00PM

What's New in Security Nob Hill Tuesday 5:00PM

Summary

Summary

NSURLSession

Summary

• HTTP/2 Server Push

NSURLSession

Summary

• HTTP/2 Server Push Performance!

NSURLSession

Summary


• Network statistics

NSURLSession

Summary


• Network statistics Faster and better analysis of applications

NSURLSession

Summary


• Network statistics• Security

Faster and better analysis of applications

NSURLSession

Summary




Protect user data

NSURLSession

Summary




Protect user data

NSURLSession in your applications!

NSURLSession

More Information

https://developer.apple.com/wwdc16/711

Related Sessions

What’s New in Foundation for Swift Mission Tuesday 4:00PM

What’s New in Security Nob Hill Tuesday 5:00PM

Engineering Privacy for Your Users Pacific Heights Wednesday 4:00PM

Networking for the Modern Internet Pacific Heights Thursday 3:00PM

Related Labs

Networking Lab 1 Frameworks Lab B Thursday 4:00PM

Networking Lab 2 Frameworks Lab D Friday 2:00PM

Documents

NSURLSession: New Features and Best Practices · Beneﬁts NSURLSession Example HTTP/1.1, SPDY, HTTP/2 App Transport Security (ATS)