Network and Multitasking

Networking & Multitasking

孔祥波

12年12月23⽇日星期⽇日

network,tcp/ip,socket,CFNetWork

http, restful api

thread: posix thread, NSThread,NSOperation,push notification

Block and GCD


tcp/ip

20世纪六十年代美国国防部

加州伯克利大学 BSD Unix

OSI 七层/TCP/IP四层模型

应用层http, pop3,smtp,ftp&


Socket

tcp/udp

tcp 三次握手

server/client 模型

server: open/bind/listen/connected/(send,recv)/close

client: open/bind/connect/(send,recv)/close


CFNetworkCFStream

RUNLoop base

CFReadStream create stream, set call back and runloop， call back read bytes

CFWriteStream


http

http protocol

Web service,SOAP,XML-RPC

Get RSS and ATOM feeds

download file


web service restful api


one more thing


debug network package

tcpdump -A -s0 -i en1 host hostnameand port 80

Wireshark network protocol dump


Multitasking


Why Concurrency?

With a single thread,long-running operations may interfere with user interaction

Multiple threads allow you to load resources or perform computations without locking up your entire application


Threads on the iOS

Based on the POSIX threading API

/usr/include/pthread.h

Higher-level wrappers in the Foundation framework(NSSThread)


NSThread Basics

Run loop automatically instantiated for each thread

Each NSThread needs to create its own autorelease pool

Convenience methods for messaging between threads


Sample - (void)someAction:(id)sender

{

// Fire up a new thread

[NSThread detachNewThreadSelector:@selector(doWork:)

withTarget:self object:someData];

}

- (void)doWork:(id)someData

{

NSAutoreleasePool *pool = [[NSAutoreleasePool alloc] init];

[someData doLotsOfWork];

// Message back to the main thread

[self performSelectorOnMainThread:@selector(allDone:)

withObject:[someData result] waitUntilDone:NO]; ／／同步主线程

[pool release];

}


UIKit and Threads

Unless otherwise noted, UIKit classes are not threadsafe

Objects must be created and messaged from the main thread


debug




build thread- (void)threadDownload:(id)data{ NSAutoreleasePool *pool=[[NSAutoreleasePool alloc] init]; NSString *urlStr=@"http://www.apple.com/home/images/t_hero.png"; NSData *imageData=[NSData dataWithContentsOfURL:[NSURL URLWithString:urlStr]]; UIImage *image=[UIImage imageWithData:imageData]; [self performSelectorOnMainThread:@selector(freshUIWith:) withObject:image waitUntilDone:YES]; [pool drain];}- (void)freshUIWith:(UIImage*)image{ self.imageView.image = image;}


NSOperation


basic

Abstract superclass

Manages thread creation and lifecycle

Encapsulate a unit of work in an object

•Specify priorities and dependencies


NSOperationQueue

Operations are typically scheduled by adding to a queue

Choose a maximum number of concurrent operations

Queue runs operations based on priority and dependencies


KVC/KVO


Key-Value Coding (KVC) •Access object values ■ NSString *name = person.name; ■ NSString *name = [person name]; ■ NSString *name = [person valueForKey:@“name”];

•Set object values: ■ [person setName:@“Pee-Wee Herman”]; ■ person.name = @“Pee-Wee Herman”; ■[person setValue:@“Pee-Wee Herman” forKey:@“name”];


Key-Value Coding (KVC)

•Get/set a value on an object by key (a string)

•First attempts to access via KVC-Compliant getters/setters

•If that fails, attempts to get to value directly

Key Paths

•Traverse objects using dot-separated keys

•Ex: @”person.address.street”

•Must use “keyPath” methods, instead of “key” methods to automatically parse the string

- (id)valueForKeyPath:(NSString *)keyPath;

- (void)setValue:(id)value forKeyPath:(NSString *)keyPath;


Accessing Undefined Keys •What if you try to access a key that is undefined? ■NSUndefinedKeyException •But you can override! -(id)valueForUndefinedKey:(NSString *)key; -(void)setValue:(id)value forUndefinedKey:(NSString *)key;


Key-Value Observing (KVO)

•Listen for changes to an object’s KVC-compliant values

•NSObject automatically broadcasts changes to observers

•No changes required to object being listened to


Key-Value Observing (KVO)

•To listen for changes:

•To stop listening for changes: -(void)addObserver:(NSObject *)anObserver forKeyPath:(NSString *)keyPath options:(NSKeyValueObservingOptions)options context:(void *)context;

-(void)removeObserver:(NSObject *)anObserver forKeyPath:(NSString *)keyPath;


Key-Value Observing (KVO) •Observing a value change: -(void)observeValueForKeyPath:(NSString *)keyPath ofObject:(id)object change:(NSDictionary *)change context:(void *)context { if (context == myContext) { // Do something } else { // Don’t forget to call super } }


Demo


NSInvocationOperation

Concrete subclass of NSOperation

For lightweight tasks where creating a subclass is overkill- (void)someAction:(id)sender

{

NSInvocationOperation *operation =

[[NSInvocationOperation alloc] initWithTarget:self selector:@selector(doWork:)

object:someObject];

[queue addObject:operation];

[operation release];

}


Apple Push Notification Service





工作流



Block and GCD


Block定义

int (^oneFrom)(int); ! ! oneFrom = ^(int anInt) { ! ! return anInt - 1; ! }; ! ! NSLog(@"%d",oneFrom(10));




Writing to Local Variables


Writing to Local Variables


typedef void (^ScheduleFetcherResultBlock)(NSArray *classes, ! ! ! ! ! ! ! ! ! ! NSError *error);

- (void)fetchClassesWithBlock:(ScheduleFetcherResultBlock)theBlock;


- (void)fetchClassesWithBlock:(ScheduleFetcherResultBlock)theBlock { ! // Copy the block to ensure that it is not kept on the stack: ! resultBlock = [theBlock copy]; ! ! NSURL *xmlURL = [NSURL URLWithString: ! ! ! ! ! @"http://bignerdranch.com/xml/schedule"]; ! NSURLRequest *req = [NSURLRequest requestWithURL:xmlURL ! ! ! ! ! ! ! ! ! ! cachePolicy:NSURLRequestReturnCacheDataElseLoad ! ! ! ! ! ! ! ! ! timeoutInterval:30]; ! connection = [[NSURLConnection alloc] initWithRequest:req ! ! ! ! ! ! ! ! ! ! ! ! delegate:self]; ! if (connection) ! { ! ! responseData = [[NSMutableData alloc] init]; ! }resultBlock(nil, error);

}





UIViewAnimation style Animation

- (void)setSelectedVeg:(id)sender{ [selectedVegetableIcon setAlpha:0.0];! [UIView beginAnimations:@"setSelectedVeg" context:nil];! float angle = [self spinnerAngleForVegetable:sender];! [vegetableSpinner setTransform:CGAffineTransformMakeRotation(angle)];! [UIView setAnimationDuration:0.4];! [UIView setAnimationDelegate:self];! [UIView setAnimationDidStopSelector:@selector(done)];! [UIView commitAnimations];!}-(void)done{! [selectedVegetableIcon setAlpha:1.0];}


- (void)setSelectedVeg:(id)sender{ [selectedVegetableIcon setAlpha:0.0]; [UIView animateWithDuration:0.4 animations: ^{ float angle = [self spinnerAngleForVegetable:sender]; [vegetableSpinner setTransform:CGAffineTransformMakeRotation(angle)]; } completion:^(BOOL finished) { [selectedVegetableIcon setAlpha:1.0]; }];

}以上代码来⾃自WWDC2010 iPlant PlantCareViem.m


NSNotification ! void (^block)(NSNotification *); ! block=^(NSNotification *noti){ ! ! NSLog(@"%@",[noti object]); ! }; ! queue =[[NSOperationQueue alloc] init]; ! [[NSNotificationCenter defaultCenter] addObserverForName:@"Blocktest" ! ! ! ! ! ! ! ! ! ! ! ! ! object:self ! ! ! ! ! ! ! ! ! ! ! ! ! queue:queue ! ! ! ! ! ! ! ! ! ! ! ! usingBlock:block];

[[NSNotificationCenter defaultCenter] postNotificationName:@"Blocktest" object:self];


NSOperation

! void (^oneFrom)(void); ! ! oneFrom = ^(void) { ! ! NSLog(@"from opt"); ! }; ! NSOperation *opt=[[NSOperation alloc] init]; ! [opt setCompletionBlock:oneFrom]; ! [queue addOperation:opt];


[regex enumerateMatchesInString:src options:0 range:NSMakeRange(0, [src length]) ! ! usingBlock:^(NSTextCheckingResult *result, NSMatchingFlags flags, BOOL *stop) { ! ! NSString*resultString = [src substringWithRange:[result range]];

NSRange range0= NSMakeRange(0,[resultString length]);NSRange range1= [[regex2 firstMatchInString:resultString options:0 range:range0] range];

! ! NSString*link=[resultString substringWithRange:range1]; ! ! ! ! ! ! ! ! }];

NSRegularExpression* regex2=nil;regex2 =[[NSRegularExpression alloc] initWithPattern:@"(?<=>).*?(?=</a>)" ! ! ! ! ! ! ! ! ! ! options:NSRegularExpressionCaseInsensitive error:nil];

正则匹配


GCD

Grand Central DIspatch












-(IBAction)extractCurAll:(id)sender{ ! [indicator setHidden:NO]; ! [indicator startAnimation:sender]; ! NSLog(@"extractCurAll"); ! ! ! dispatch_queue_t queue; ! queue = dispatch_queue_create("com.example.operation", NULL); ! dispatch_async(queue, ^{ ! ! // Create a CGPDFDocumentRef from the input PDF file. ! ! CGPDFDocumentRef pdfDoc = NULL; ! ! pdfDoc = CGPDFDocumentCreateWithURL((CFURLRef)pdfURL); ! ! [[PDFImageExtrator sharedPDFImageExtrator] setUrl:pdfURL]; ! ! [[PDFImageExtrator sharedPDFImageExtrator] ExtratorWithPDF:pdfDoc]; ! ! dispatch_async(dispatch_get_main_queue(),^{ ! ! ! [indicator stopAnimation:sender]; ! ! ! [indicator setHidden:YES]; ! ! ! [openBtn setEnabled:YES]; ! ! }); ! }); ! dispatch_release(queue);!}


use block and GCD

-(void)blockwork{ dispatch_queue_t queue; ! queue = dispatch_queue_create("com.example.operation", NULL); ! dispatch_async(queue, ^{ ! ! // Create a CGPDFDocumentRef from the input PDF file. NSString *urlStr=@"http://www.apple.com/home/images/t_hero.png"; NSData *imageData=[NSData dataWithContentsOfURL:[NSURL URLWithString:urlStr]]; UIImage *image=[UIImage imageWithData:imageData]; ! ! dispatch_async(dispatch_get_main_queue(),^{ ! ! ! self.imageView.image = image; ! ! }); ! }); ! dispatch_release(queue);!}


use GCD change our NSThread Code!


ResourceSession 102 - What's New in Foundation for iOS 4

Session 110 - Advanced Text Handling for iPhone OS

Session 206 - Introducing Blocks and Grand Central Dispatch on iPhone

Session 211 - Simplifying iPhone App Development with Grand Central Dispatch


Queuesdispatch_queue_t

dispatch_queue_createdispatch_queue_get_labeldispatch_get_main_queuedispatch_get_global_queuedispatch_get_current_queuedispatch_maindispatch_asyncdispatch_async_fdispatch_syncdispatch_sync_fdispatch_afterdispatch_after_fdispatch_applydispatch_apply_f

Timedispatch_time_t

dispatch_timedispatch_walltime

Oncedispatch_once_t

dispatch_oncedispatch_once_f

Sourcesdispatch_source_t

dispatch_source_createdispatch_source_canceldispatch_source_testcanceldispatch_source_merge_datadispatch_source_get_handledispatch_source_get_maskdispatch_source_get_datadispatch_source_set_timerdispatch_source_set_event_handlerdispatch_source_set_event_handler_fdispatch_source_set_cancel_handlerdispatch_source_set_cancel_handler_f

Objectsdispatch_object_t

dispatch_retaindispatch_releasedispatch_suspenddispatch_resumedispatch_debugdispatch_get_contextdispatch_set_contextdispatch_set_finalizer_fdispatch_set_target_queue

Groupsdispatch_group_t

dispatch_group_createdispatch_group_enterdispatch_group_leavedispatch_group_waitdispatch_group_notifydispatch_group_notify_fdispatch_group_asyncdispatch_group_async_f

Semaphoresdispatch_semaphore_t

dispatch_semaphore_createdispatch_semaphore_signaldispatch_semaphore_wait

Not Objects

6012年12月23⽇日星期⽇日

Q&A


Technology

Network and Multitasking