muduo源码学习(19)-socket封装

在net/Endian.h中，提供了字节序转换的全局函数:

inline uint64_t hostToNetwork64(uint64_t host64)
{
return htobe64(host64);
}

inline uint32_t hostToNetwork32(uint32_t host32)
{
return htobe32(host32);
}

inline uint16_t hostToNetwork16(uint16_t host16)
{
return htobe16(host16);
}

inline uint64_t networkToHost64(uint64_t net64)
{
return be64toh(net64);
}

inline uint32_t networkToHost32(uint32_t net32)
{
return be32toh(net32);
}

inline uint16_t networkToHost16(uint16_t net16)
{
return be16toh(net16);
}


net/SocketsOps.h中提供了一些基本的读写操作
int createNonblockingOrDie();

int connect(int sockfd, const struct sockaddr_in& addr);

void bindOrDie(int sockfd, const struct sockaddr_in& addr);

void listenOrDie(int sockfd);

int accept(int sockfd, struct sockaddr_in* addr);
ssize_t read(int sockfd, void *buf, size_t count);
ssize_t readv(int sockfd, const struct iovec *iov, int iovcnt);
ssize_t write(int sockfd, const void *buf, size_t count);

void close(int sockfd);

void shutdownWrite(int sockfd);

void toIpPort(char* buf, size_t size,
const struct sockaddr_in& addr);
void toIp(char* buf, size_t size,
const struct sockaddr_in& addr);
void fromIpPort(const char* ip, uint16_t port,
struct sockaddr_in* addr);

int getSocketError(int sockfd);

struct sockaddr_in getLocalAddr(int sockfd);
struct sockaddr_in getPeerAddr(int sockfd);
bool isSelfConnect(int sockfd);


函数的实现比较简单，在muduo中，socket描述符都是非阻塞的，acept后也会设置为非阻塞。
muduo采用了RAII技法封装了socket描述符，在net/Socket.h中:

class Socket : boost::noncopyable
{
public:
explicit Socket(int sockfd)
: sockfd_(sockfd)
{ }

// Socket(Socket&&) // move constructor in C++11
~Socket();
int fd() const { return sockfd_; }

/// abort if address in use
void bindAddress(const InetAddress& localaddr);

/// abort if address in use
void listen();

/// On success, returns a non-negative integer that is
/// a descriptor for the accepted socket, which has been
/// set to non-blocking and close-on-exec. *peeraddr is assigned.
/// On error, -1 is returned, and *peeraddr is untouched.

//peeraddr
int accept(InetAddress* peeraddr);

void shutdownWrite();

///
/// Enable/disable TCP_NODELAY (disable/enable Nagle's algorithm).
///
void setTcpNoDelay(bool on);

///
/// Enable/disable SO_REUSEADDR
///
void setReuseAddr(bool on);

///
/// Enable/disable SO_KEEPALIVE
///
void setKeepAlive(bool on);

private:
//
const int sockfd_;
};
无非就是对socket描述符的操作，还有socket选项的设置。在析构函数中，关闭了描述符:
Socket::~Socket()
{
sockets::close(sockfd_);
}InetAdddress是对地质的封装,在net/InetAddress.h中:
class InetAddress : public muduo::copyable
{
public:
/// Constructs an endpoint with given port number.
/// Mostly used in TcpServer listening.
explicit InetAddress(uint16_t port);

/// Constructs an endpoint with given ip and port.
/// @c ip should be "1.2.3.4"
InetAddress(const StringPiece& ip, uint16_t port);

/// Constructs an endpoint with given struct @c sockaddr_in
/// Mostly used when accepting new connections
InetAddress(const struct sockaddr_in& addr)
: addr_(addr)
{ }

string toIp() const;
string toIpPort() const;
string toHostPort() const __attribute__ ((deprecated))
{ return toIpPort(); }

// default copy/assignment are Okay

const struct sockaddr_in& getSockAddrInet() const { return addr_; }
void setSockAddrInet(const struct sockaddr_in& addr) { addr_ = addr; }

uint32_t ipNetEndian() const { return addr_.sin_addr.s_addr; }
uint16_t portNetEndian() const { return addr_.sin_port; }

private:
struct sockaddr_in addr_;
};
就是一个sockaddr_in 类型变量，还有地址转换函数，比较简单。