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iOS 之 socket

2015-08-29 18:59 483 查看
公司项目有用到socket,所以这几天学习了下,发现确实socket通信优势还是蛮大的,以前做的网络这块都是用的HTTP,也就是请求--响应这种应答式的方式。这种的话如果是比较小的项目还是蛮合适的,能够节省资源。但是比较大的项目的话就比较劣势了,而用socket就比较好,因为项目中网络请求比较多,时不时的需要发请求,socket的响应速度比HTTP要快,用户体验会要好很多。

socket其实就是tcp连接,当客户端与服务端三次握手之后就一直连着,所以他的响应速度会比HTTP的应答式快。

研究了一下C语言的socket,直接上代码,下面演示一个一对一的socket服务端对客户端的demo:

服务端:

首先是sockaddr_in 这个结构体是用来保存socket地址的,具体参数基本看得懂

接下来是创建socket,使用的是socket()这个API创建的,具体参数以后在讲

然后是socket绑定地址也就是刚刚创建的sockaddr_in这个结构体,用bind()这个API绑定

接下来是监听这个socket了,用listen()这个API,注意监听的socket是只用来监听的,不能用来读写数据

监听之后就是新建一个socket用来读写数据了,用accept()这个API

最后就是读写数据嘛,分别用send(),recv()者两个API

代码如下:

/*
C语言  socket
*/
struct sockaddr_in server_addr;
server_addr.sin_len = sizeof(struct sockaddr_in);
server_addr.sin_family = AF_INET;//Address families AF_INET互联网地址簇
server_addr.sin_port = htons(11332);
server_addr.sin_addr.s_addr = inet_addr("127.0.0.1");
bzero(&(server_addr.sin_zero),8);

//创建socket
int server_socket = socket(AF_INET, SOCK_STREAM, 0);//SOCK_STREAM 有连接
if (server_socket == -1) {
perror("socket error");
return 1;
}

//绑定socket:将创建的socket绑定到本地的IP地址和端口,此socket是半相关的,只是负责侦听客户端的连接请求,并不能用于和客户端通信
int bind_result = bind(server_socket, (struct sockaddr *)&server_addr, sizeof(server_addr));
if (bind_result == -1) {
perror("bind error");
return 1;
}

//listen侦听 第一个参数是套接字,第二个参数为等待接受的连接的队列的大小,在connect请求过来的时候,完成三次握手后先将连接放到这个队列中,直到被accept处理。如果这个队列满了,且有新的连接的时候,对方可能会收到出错信息。
if (listen(server_socket, 5) == -1) {
perror("listen error");
return 1;
}

struct sockaddr_in client_address;
socklen_t address_len;
int client_socket = accept(server_socket, (struct sockaddr *)&client_address, &address_len);
//返回的client_socket为一个全相关的socket,其中包含client的地址和端口信息,通过client_socket可以和客户端进行通信。
if (client_socket == -1) {
perror("accept error");
return -1;
}

char recv_msg[1024];
char reply_msg[1024];

while (1) {
bzero(recv_msg, 1024);
bzero(reply_msg, 1024);

printf("reply:");
scanf("%s",reply_msg);
send(client_socket, reply_msg, 1024, 0);

long byte_num = recv(client_socket,recv_msg,1024,0);
recv_msg[byte_num] = '\0';
printf("client said:%s\n",recv_msg);

}
客户端:

基本步骤和服务端一样,

首先保存创建socket地址,不同的是客户端需要写服务端的IP地址

然后是创建socket,绑定地址

接下来和服务端不同,需要连接服务端,所以用到connect()这个API来连接服务端

连接之后就是读写数据了

代码如下:

/*
C语言 socket
*/
struct sockaddr_in server_addr;
server_addr.sin_len = sizeof(struct sockaddr_in);
server_addr.sin_family = AF_INET;
server_addr.sin_port = htons(11332);
server_addr.sin_addr.s_addr = inet_addr("127.0.0.1");
bzero(&(server_addr.sin_zero),8);

int server_socket = socket(AF_INET, SOCK_STREAM, 0);
if (server_socket == -1) {
perror("socket error");
return 1;
}
char recv_msg[1024];
char reply_msg[1024];

if (connect(server_socket, (struct sockaddr *)&server_addr, sizeof(struct sockaddr_in))==0)     {
//connect 成功之后,其实系统将你创建的socket绑定到一个系统分配的端口上,且其为全相关,包含服务器端的信息,可以用来和服务器端进行通信。
while (1) {
bzero(recv_msg, 1024);
bzero(reply_msg, 1024);
long byte_num = recv(server_socket,recv_msg,1024,0);
recv_msg[byte_num] = '\0';
printf("server said:%s\n",recv_msg);

printf("reply:");
scanf("%s",reply_msg);
if (send(server_socket, reply_msg, 1024, 0) == -1) {
perror("send error");
}
}

}


上面讲的是C语言的socket,下面来讲一下OC的socket,其实很多都是C的,不过是对其进行了一层封装

首先服务端:

基本步骤和C语言的一样

创建socket用的是CFSocketCreate();基本参数见代码

然后是创建保存地址

然后是绑定地址,用的是CFSocketSetAddress()这个API

然后就是和C语言不同的地方了,OC由于有runloop,不向C语言一样需要自己写一个死循环,所以需要将socket加入runloop中去,不断的监听

接下来是回调,这个是在创建socket的时候绑定的回调,同样需要重新创建一个socket来管理数据的读写,不过OC可以直接交给CFSocketNativeHandle这个类去处理,同样的数据流也有CFStream这个类去处理,他的子类可以分别管理读写流

代码如下:

-(int)setupSocket
{
CFSocketContext sockContext = {0, // 结构体的版本,必须为0
(__bridge void *)(self),
NULL, // 一个定义在上面指针中的retain的回调, 可以为NULL
NULL,
NULL};

_socket = CFSocketCreate(kCFAllocatorDefault, // 为新对象分配内存,可以为nil
PF_INET, // 协议族,如果为0或者负数,则默认为PF_INET
SOCK_STREAM, // 套接字类型,如果协议族为PF_INET,则它会默认为SOCK_STREAM
IPPROTO_TCP, // 套接字协议,如果协议族是PF_INET且协议是0或者负数,它会默认为IPPROTO_TCP
kCFSocketAcceptCallBack, // 触发回调函数的socket消息类型,具体见Callback Types
SocketConnectionAcceptedCallBack, // 上面情况下触发的回调函数
&sockContext // 一个持有CFSocket结构信息的对象,可以为nil
);
if (NULL == _socket) {
NSLog(@"Cannot create socket!");
return 0;
}

int optval = 1;
setsockopt(CFSocketGetNative(_socket), SOL_SOCKET, SO_REUSEADDR, // 允许重用本地地址和端口
(void *)&optval, sizeof(optval));

struct sockaddr_in addr4;
memset(&addr4, 0, sizeof(addr4));
addr4.sin_len = sizeof(addr4);
addr4.sin_family = AF_INET;
addr4.sin_port = htons(8080);
addr4.sin_addr.s_addr = htonl(INADDR_ANY);
CFDataRef address = CFDataCreate(kCFAllocatorDefault, (UInt8 *)&addr4, sizeof(addr4));

if (kCFSocketSuccess != CFSocketSetAddress(_socket, address))
{
NSLog(@"Bind to address failed!");
if (_socket)
CFRelease(_socket);
_socket = NULL;
return 0;
}

CFRunLoopRef cfRunLoop = CFRunLoopGetCurrent();
CFRunLoopSourceRef source = CFSocketCreateRunLoopSource(kCFAllocatorDefault, _socket, 0);
CFRunLoopAddSource(cfRunLoop, source, kCFRunLoopCommonModes);
CFRunLoopRun();
CFRelease(source);

return 1;
}
//回调
static void SocketConnectionAcceptedCallBack(CFSocketRef socket,
CFSocketCallBackType type,
CFDataRef address,
const void *data, void *info) {

if (kCFSocketAcceptCallBack == type)
{
// 本地套接字句柄
CFSocketNativeHandle nativeSocketHandle = *(CFSocketNativeHandle *)data;
uint8_t name[SOCK_MAXADDRLEN];
socklen_t nameLen = sizeof(name);
if (0 != getpeername(nativeSocketHandle, (struct sockaddr *)name, &nameLen)) {
NSLog(@"error");
exit(1);
}
CFReadStreamRef iStream;
CFWriteStreamRef oStream;
// 创建一个可读写的socket连接
CFStreamCreatePairWithSocket(kCFAllocatorDefault, nativeSocketHandle, &iStream, &oStream);
if (iStream && oStream)
{
CFStreamClientContext streamContext = {0, info, NULL, NULL};
if (!CFReadStreamSetClient(iStream, kCFStreamEventHasBytesAvailable,readStream, &streamContext))
{
exit(1);
}

if (!CFWriteStreamSetClient(oStream, kCFStreamEventCanAcceptBytes, writeStream, &streamContext))
{
exit(1);
}
CFReadStreamScheduleWithRunLoop(iStream, CFRunLoopGetCurrent(), kCFRunLoopDefaultMode);
CFWriteStreamScheduleWithRunLoop(oStream, CFRunLoopGetCurrent(), kCFRunLoopDefaultMode);
CFReadStreamOpen(iStream);
CFWriteStreamOpen(oStream);
} else
{
close(nativeSocketHandle);
}
}
}

// 读取数据
void readStream(CFReadStreamRef stream, CFStreamEventType eventType, void *clientCallBackInfo)
{
UInt8 buff[1024*4];

NSMutableData *recvData = [NSMutableData data];

while (1) {
CFIndex count = CFReadStreamRead(stream, buff, 1024*4);
if (count==0 || count == -1) {

}else{
[recvData appendBytes:buff length:count];
if (!CFReadStreamHasBytesAvailable(stream)) {
break;
}
}
}
NSString *recvString = [[NSString alloc]initWithData:recvData encoding:NSUTF8StringEncoding];
///根据delegate显示到主界面去
NSString *strMsg = [[NSString alloc]initWithFormat:@"客户端传来消息:%@",recvString];

//	CSocketServer *info = (__bridge CSocketServer*)clientCallBackInfo;
//	[info ShowMsgOnMainPage:strMsg];
NSLog(@"%@",strMsg);

//	char *str = "你好 Client";
NSString *string = @"你好 Client\n";
NSData *data = [string dataUsingEncoding:NSUTF8StringEncoding];

NSMutableData *data1 = [NSMutableData dataWithData:data];
//	uint8_t * uin8b = (uint8_t *)str;
const uint8_t * uin8b = data1.bytes;
if (outputStream != NULL)
{

while (1) {
if (data1.length>0 && CFWriteStreamCanAcceptBytes(outputStream)) {
CFIndex writeLength = CFWriteStreamWrite(outputStream, uin8b, data1.length);

if (writeLength == 0 || writeLength == -1) {

}else{
[data1 replaceBytesInRange:NSMakeRange(0, writeLength) withBytes:NULL length:0];

}
}else{
break;
}

}
}
else {
NSLog(@"Cannot send data!");
}

}
void writeStream (CFWriteStreamRef stream, CFStreamEventType eventType, void *clientCallBackInfo)
{
outputStream = stream;

}


客户端:

步骤和服务端差不多

直接上代码:

-(void)CreateConnect:(NSString*)strAddress
{
CFSocketContext sockContext = {0, // 结构体的版本,必须为0
(__bridge void *)(self),
NULL, // 一个定义在上面指针中的retain的回调, 可以为NULL
NULL,
NULL};
_socket = CFSocketCreate(kCFAllocatorDefault, // 为新对象分配内存,可以为nil
PF_INET, // 协议族,如果为0或者负数,则默认为PF_INET
SOCK_STREAM, // 套接字类型,如果协议族为PF_INET,则它会默认为SOCK_STREAM
IPPROTO_TCP, // 套接字协议,如果协议族是PF_INET且协议是0或者负数,它会默认为IPPROTO_TCP
kCFSocketConnectCallBack, // 触发回调函数的socket消息类型,具体见Callback Types
TCPClientConnectCallBack, // 上面情况下触发的回调函数
&sockContext // 一个持有CFSocket结构信息的对象,可以为nil
);
if(_socket != NULL)
{
struct sockaddr_in addr4;   // IPV4
memset(&addr4, 0, sizeof(addr4));
addr4.sin_len = sizeof(addr4);
addr4.sin_family = AF_INET;
addr4.sin_port = htons(8080);
addr4.sin_addr.s_addr = inet_addr([strAddress UTF8String]);  // 把字符串的地址转换为机器可识别的网络地址

// 把sockaddr_in结构体中的地址转换为Data
CFDataRef address = CFDataCreate(kCFAllocatorDefault, (UInt8 *)&addr4, sizeof(addr4));
CFSocketConnectToAddress(_socket, // 连接的socket
address, // CFDataRef类型的包含上面socket的远程地址的对象
-1  // 连接超时时间,如果为负,则不尝试连接,而是把连接放在后台进行,如果_socket消息类型为kCFSocketConnectCallBack,将会在连接成功或失败的时候在后台触发回调函数
);
CFRunLoopRef cRunRef = CFRunLoopGetCurrent();    // 获取当前线程的循环
// 创建一个循环,但并没有真正加如到循环中,需要调用CFRunLoopAddSource
CFRunLoopSourceRef sourceRef = CFSocketCreateRunLoopSource(kCFAllocatorDefault, _socket, 0);
CFRunLoopAddSource(cRunRef, // 运行循环
sourceRef,  // 增加的运行循环源, 它会被retain一次
kCFRunLoopCommonModes  // 增加的运行循环源的模式
);
CFRelease(sourceRef);
NSLog(@"connect ok");
}
}

// socket回调函数,同客户端
static void TCPClientConnectCallBack(CFSocketRef socket, CFSocketCallBackType type, CFDataRef address, const void *data, void *info)
{
if (kCFSocketAcceptCallBack == type)
{
// 本地套接字句柄
CFSocketNativeHandle nativeSocketHandle = *(CFSocketNativeHandle *)data;
uint8_t name[SOCK_MAXADDRLEN];
socklen_t nameLen = sizeof(name);
if (0 != getpeername(nativeSocketHandle, (struct sockaddr *)name, &nameLen)) {
NSLog(@"error");
exit(1);
}
CFReadStreamRef iStream;
CFWriteStreamRef oStream;
// 创建一个可读写的socket连接
CFStreamCreatePairWithSocket(kCFAllocatorDefault, nativeSocketHandle, &iStream, &oStream);
if (iStream && oStream)
{
CFStreamClientContext streamContext = {0, info, NULL, NULL};
if (!CFReadStreamSetClient(iStream, kCFStreamEventHasBytesAvailable,readStream, &streamContext))
{
exit(1);
}

if (!CFWriteStreamSetClient(oStream, kCFStreamEventCanAcceptBytes, writeStream, &streamContext))
{
exit(1);
}
CFReadStreamScheduleWithRunLoop(iStream, CFRunLoopGetCurrent(), kCFRunLoopDefaultMode);
CFWriteStreamScheduleWithRunLoop(oStream, CFRunLoopGetCurrent(), kCFRunLoopDefaultMode);
CFReadStreamOpen(iStream);
CFWriteStreamOpen(oStream);
} else
{
close(nativeSocketHandle);
}
}
}

// 读取数据
void readStream(CFReadStreamRef stream, CFStreamEventType eventType, void *clientCallBackInfo)
{
UInt8 buff[1024*4];

NSMutableData *recvData = [NSMutableData data];

while (1) {
CFIndex count = CFReadStreamRead(stream, buff, 1024*4);
if (count==0 || count == -1) {

}else{
[recvData appendBytes:buff length:count];
if (!CFReadStreamHasBytesAvailable(stream)) {
break;
}
}
}
NSString *recvString = [[NSString alloc]initWithData:recvData encoding:NSUTF8StringEncoding];
///根据delegate显示到主界面去
NSString *strMsg = [[NSString alloc]initWithFormat:@"客户端传来消息:%@",recvString];

//	CSocketServer *info = (__bridge CSocketServer*)clientCallBackInfo;
//	[info ShowMsgOnMainPage:strMsg];
NSLog(@"%@",strMsg);

//	char *str = "你好 Client";
NSString *string = @"你好 Client\n";
NSData *data = [string dataUsingEncoding:NSUTF8StringEncoding];

NSMutableData *data1 = [NSMutableData dataWithData:data];
//	uint8_t * uin8b = (uint8_t *)str;
const uint8_t * uin8b = data1.bytes;
if (outputStream != NULL)
{

while (1) {
if (data1.length>0 && CFWriteStreamCanAcceptBytes(outputStream)) {
CFIndex writeLength = CFWriteStreamWrite(outputStream, uin8b, data1.length);

if (writeLength == 0 || writeLength == -1) {

}else{
[data1 replaceBytesInRange:NSMakeRange(0, writeLength) withBytes:NULL length:0];

}
}else{
break;
}

}
}
else {
NSLog(@"Cannot send data!");
}

}
void writeStream (CFWriteStreamRef stream, CFStreamEventType eventType, void *clientCallBackInfo)
{
outputStream = stream;

}


Socket基本就是这样了,还有一个牛人封装好的一个socket,用起来确实简单多了,不过坏处是有很多不需要的代码,所以需要自己去优化,也直接上代码吧:

服务端:

-(void)start{
asyncSocket = [[AsyncSocket alloc] initWithDelegate:self];
NSError *err = nil;
if (![asyncSocket acceptOnPort:8080 error:&err]) {
return;
}
NSLog(@"开始监听");
}

- (void)onSocket:(AsyncSocket *)sock didAcceptNewSocket:(AsyncSocket *)newSocket
{
NSLog(@"%s", __func__);

self.clientAsycSocket = newSocket;

}

- (void)onSocket:(AsyncSocket *)sock didConnectToHost:(NSString *)host port:(UInt16)port{
NSLog(@"%s",__func__);

[sock readDataWithTimeout:-1 tag:0];

NSData *aData=[@"Hi there  server" dataUsingEncoding:NSUTF8StringEncoding];
[sock writeData:aData withTimeout:-1 tag:0];
}

//读取数据
-(void)onSocket:(AsyncSocket *)sock didReadData:(NSData *)data withTag:(long)tag
{
NSString *aStr=[[NSString alloc] initWithData:data encoding:NSUTF8StringEncoding];
NSLog(@"aStr==%@",aStr);

}

//是否加密
-(void)onSocketDidSecure:(AsyncSocket *)sock
{
NSLog(@"onSocket:%p did go a secure line:YES",sock);
}

//遇到错误时关闭连接
-(void)onSocket:(AsyncSocket *)sock willDisconnectWithError:(NSError *)err
{
NSLog(@"onSocket:%p will disconnect with error:%@",sock,err);
}

//断开连接
-(void)onSocketDidDisconnect:(AsyncSocket *)sock
{
NSLog(@"onSocketDidDisconnect:%p",sock);

}

- (void )dealloc
{
NSLog(@"%s", __func__);
}


客户端代码:

-(void)start{
asyncSocket = [[AsyncSocket alloc] initWithDelegate:self];
NSError *err = nil;
if(![asyncSocket connectToHost:@"127.0.0.1" onPort:8080 error:&err])
{
NSLog(@"Error: %@", err);
}
//	NSData *aData=[@"Hi there" dataUsingEncoding:NSUTF8StringEncoding];
//	[asyncSocket writeData:aData withTimeout:-1 tag:0];
}

//建立连接
-(void)onSocket:(AsyncSocket *)sock didConnectToHost:(NSString *)host port:(UInt16)port
{
NSLog(@"onScoket:%p did connecte to host:%@ on port:%d",sock,host,port);

//	NSData *aData=[@"Hi there" dataUsingEncoding:NSUTF8StringEncoding];
//	[sock writeData:aData withTimeout:-1 tag:0];

[sock readDataWithTimeout:-1 tag:0];

}

//读取数据
-(void)onSocket:(AsyncSocket *)sock didReadData:(NSData *)data withTag:(long)tag
{
NSString *aStr=[[NSString alloc] initWithData:data encoding:NSUTF8StringEncoding];
NSLog(@"aStr==%@",aStr);

NSData *aData=[@"Hi there" dataUsingEncoding:NSUTF8StringEncoding];
[sock writeData:aData withTimeout:-1 tag:0];

[sock readDataWithTimeout:-1 tag:0];
}

//是否加密
-(void)onSocketDidSecure:(AsyncSocket *)sock
{
NSLog(@"onSocket:%p did go a secure line:YES",sock);
}

//遇到错误时关闭连接
-(void)onSocket:(AsyncSocket *)sock willDisconnectWithError:(NSError *)err
{
NSLog(@"onSocket:%p will disconnect with error:%@",sock,err);
}

//断开连接
-(void)onSocketDidDisconnect:(AsyncSocket *)sock
{
NSLog(@"onSocketDidDisconnect:%p",sock);
}
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