ACE学习手记----ACE_INET_Addr类
ACE_INET_Addr类，在这个ACE_网络框架中，应该是比较重要的辅助类，该类主要封装了C SOCKET 的地址对象，通过外观封装的模式，把struct sockaddr_in封装在内。方便用户的操作。
因此个人认为掌握此类的常用构造方法和常用的成员函数，并深刻的理解，对于后续的学习ACE或者开发ACE网络应用程序应该会起到很大的帮助。工欲用其器、必先利其器。就先让我们把ACE_INET_Addr对象深刻的牢记在心中吧。
- /* -*- C++ -*- */
- //=============================================================================
- /**
- * @file INET_Addr.h
- *
- * $Id: INET_Addr.h 78617 2007-06-27 20:40:19Z mesnier_p $
- *
- * @author Douglas C. Schmidt
- */
- //=============================================================================
- #ifndef ACE_INET_ADDR_H
- #define ACE_INET_ADDR_H
- #include /**/ "ace/pre.h"
- #include "ace/Sock_Connect.h"
- #if !defined (ACE_LACKS_PRAGMA_ONCE)
- # pragma once
- #endif /* ACE_LACKS_PRAGMA_ONCE */
- #include "ace/Addr.h"
- #if defined(ACE_VXWORKS)
- // Needed to get INET_ADDR_LEN
- # include /**/ "inetLib.h"
- #endif /* ACE_VXWORKS */
- ACE_BEGIN_VERSIONED_NAMESPACE_DECL
- /**
- * @class ACE_INET_Addr
- *
- * @brief Defines a C++ wrapper facade for the Internet domain address
- * family format.
- */
- class ACE_Export ACE_INET_Addr : public ACE_Addr
- {
- public:
- // = Initialization methods.
- /// Default constructor.
- /// 默认构造函数
- ACE_INET_Addr (void);
- /// Copy constructor.
- /// 拷贝构造函数
- ACE_INET_Addr (const ACE_INET_Addr &);
- /// Creates an ACE_INET_Addr from a sockaddr_in structure.
- /// 使用参数@addr 地址初始化ACE_INET_Addr对象。
- /// 参数@len 为 @addr结构地址对象的长度，使用 sizeof(strcut sockaddr_in)
- ACE_INET_Addr (const sockaddr_in *addr, int len);
- /// Creates an ACE_INET_Addr from a
and the remote - ///
. The port number is assumed to be in host byte order. - /// To set a port already in network byte order, please @see set().
- /// Use address_family to select IPv6 (PF_INET6) vs. IPv4 (PF_INET).
- /// 使用参数 @port_number 和 host_name 构造一个ACE_INET_Addr对象。
- /// @port_number应该为主机字节序，构造函数需要把它转换了网络字节序。
- /// 如果port_number为网络字节序，请使用 set成员函数或者set_port_number成员函数。
- /// @address_family 用于指定ACE_INET_Addr的地址类型PF_INET(IPv4)或者PF_INET6(IPv6)
- ACE_INET_Addr (u_short port_number,
- const char host_name[],
- int address_family = AF_UNSPEC);
- /**
- * Initializes an ACE_INET_Addr from the , which can be
- * "ip-number:port-number" (e.g., "tango.cs.wustl.edu:1234" or
- * "128.252.166.57:1234"). If there is no ':' in the it
- * is assumed to be a port number, with the IP address being
- * INADDR_ANY.
- * 使用参数@address初始化一个ACE_INET_Addr对象。
- * address的格式为 ip-number:port-number 或者 port-number.
- * ip-number 可以为点分号的IP地址，也可是是域名地址。
- * 如果参数@address没有提供 ip-number，只提供port-number时，地址被初始化为INADDR_ANY
- * port-number 为主机字节序。
- */
- explicit ACE_INET_Addr (const char address[],
- int address_family = AF_UNSPEC);
- /**
- * Creates an ACE_INET_Addr from a
and an Internet - *
. This method assumes that and - * are in host byte order. If you have addressing information in
- * network byte order, @see set().
- * 使用主机字节序的@port_number 和 @ip_addr初始化一个ACE_INET_Addr对象。
- * 如port_number或者 ip_addr为网络字节序时，请使用 set成员函数。
- */
- explicit ACE_INET_Addr (u_short port_number,
- ACE_UINT32 ip_addr = INADDR_ANY);
- /// Uses
to create an ACE_INET_Addr from a - ///
, the remote , and the . - /// 通过 getservbyname API获得port_name的端口，eg port_name="ftp"时，得到的端口是21.
- ACE_INET_Addr (const char port_name[],
- const char host_name[],
- const char protocol[] = "tcp");
- /**
- * Uses
to create an ACE_INET_Addr from a - *
, an Internet , and the . This - * method assumes that
is in host byte order. - */
- ACE_INET_Addr (const char port_name[],
- ACE_UINT32 ip_addr,
- const char protocol[] = "tcp");
- #if defined (ACE_HAS_WCHAR)
- ACE_INET_Addr (u_short port_number,
- const wchar_t host_name[],
- int address_family = AF_UNSPEC);
- explicit ACE_INET_Addr (const wchar_t address[],
- int address_family = AF_UNSPEC);
- ACE_INET_Addr (const wchar_t port_name[],
- const wchar_t host_name[],
- const wchar_t protocol[] = ACE_TEXT_WIDE ("tcp"));
- ACE_INET_Addr (const wchar_t port_name[],
- ACE_UINT32 ip_addr,
- const wchar_t protocol[] = ACE_TEXT_WIDE ("tcp"));
- #endif /* ACE_HAS_WCHAR */
- /// Default dtor.
- ~ACE_INET_Addr (void);
- // = Direct initialization methods.
- // = 直接初始化方法。当使用默认构造函数创建一个ACE_INET_Addr对象时，可以使用
- // 下面的来设置一个ACE_INET_Addr对象的地址和端口。
- // These methods are useful after the object has been constructed.
- /// Initializes from another ACE_INET_Addr.
- /// 使用一个已经存在的ACE_INET_Addr对象来初始化本对象。
- int set (const ACE_INET_Addr &);
- /**
- * Initializes an ACE_INET_Addr from a
and the - * remote
. - * 使用参数@port_number 和@host_name初始化 ACE_INET_Addr 对象。
- * If
is non-zero then is - * converted into network byte order, otherwise it is assumed to be
- * in network byte order already and are passed straight through.
- * 如果参数@encode 为TRUE(非零),表示需要set函数内部进行网络字节序的转换,
- * 也就是此时 port_number属于主机字节序的值。否则port_number就是已经是网络
- * 字节序了，无需进行转换，直接赋值即可。
- * address_family can be used to select IPv4/IPv6 if the OS has
- * IPv6 capability (ACE_HAS_IPV6 is defined). To specify IPv6, use
- * the value AF_INET6. To specify IPv4, use AF_INET.
- * 参数@address_family 用于选定IPv4/IPv6的地址格式。使用AF_INET指定IPv4地址,
- * AF_INET6指定IPv4地址格式。
- */
- int set (u_short port_number,
- const char host_name[],
- int encode = 1,
- int address_family = AF_UNSPEC);
- /**
- * Initializes an ACE_INET_Addr from a @a port_number and an Internet
- * @a ip_addr.
- * 使用参数@port_number 和参数 @ip_addr初始化 ACE_INET_Addr对象。
- * If @a encode is non-zero then the port number and IP address
- * are converted into network byte order, otherwise they are assumed to be
- * in network byte order already and are passed straight through.
- * 如果参数@encode 为TRUE(非零)时，表面 @port_number、@ip_addr 为主机字节序，
- * set 函数内部需要把它们转换为网络字节序。否则它们为网络字节序，无需而外的转换
- * 直接赋值。
- * If
- * then this address will be set to the IPv4-mapped IPv6 address of it.
- */
- int set (u_short port_number,
- ACE_UINT32 ip_addr = INADDR_ANY,
- int encode = 1,
- int map = 0);
- /// Uses
to initialize an ACE_INET_Addr from a - ///
, the remote , and the . - int set (const char port_name[],
- const char host_name[],
- const char protocol[] = "tcp");
- /**
- * Uses
to initialize an ACE_INET_Addr from a - *
, an , and the . This assumes that - *
is already in network byte order. - */
- int set (const char port_name[],
- ACE_UINT32 ip_addr,
- const char protocol[] = "tcp");
- /**
- * Initializes an ACE_INET_Addr from the @a addr, which can be
- * "ip-number:port-number" (e.g., "tango.cs.wustl.edu:1234" or
- * "128.252.166.57:1234"). If there is no ':' in the it
- * is assumed to be a port number, with the IP address being
- * INADDR_ANY.
- * 参数@addr格式为 %s:%d 或者 %d。
- * %s为 IP地址或者域名， %d 为服务端口号。
- * 也就是如果addr 数组中没有 冒号':' 时，此时地址被设置为 INADD_ANY，端口为@addr指定。
- */
- int set (const char addr[], int address_family = AF_UNSPEC);
- /// Creates an ACE_INET_Addr from a sockaddr_in structure.
- /// 使用 sockaddr_in 结构设置ACE_INET_Addr对象。
- int set (const sockaddr_in *,
- int len);
- #if defined (ACE_HAS_WCHAR)
- /**
- * 定义宽字符支持的接口。
- */
- int set (u_short port_number,
- const wchar_t host_name[],
- int encode = 1,
- int address_family = AF_UNSPEC);
- int set (const wchar_t port_name[],
- const wchar_t host_name[],
- const wchar_t protocol[] = ACE_TEXT_WIDE ("tcp"));
- int set (const wchar_t port_name[],
- ACE_UINT32 ip_addr,
- const wchar_t protocol[] = ACE_TEXT_WIDE ("tcp"));
- int set (const wchar_t addr[], int address_family = AF_UNSPEC);
- #endif /* ACE_HAS_WCHAR */
- /// Return a pointer to the underlying network address.
- /// 获得原始的网络地址指针，根据IPv4或者IPv6,可以得到一个 struct sockaddr地址的指针。
- virtual void *get_addr (void) const;
- int get_addr_size(void) const;
- /// Set a pointer to the address.
- virtual void set_addr (void *, int len);
- /// Set a pointer to the address.
- virtual void set_addr (void *, int len, int map);
- /**
- * Transform the current ACE_INET_Addr address into string format.
- * If
is non-0 this produces "ip-number:port-number" - * (e.g., "128.252.166.57:1234"), whereas if
is 0 - * this produces "ip-name:port-number" (e.g.,
- * "tango.cs.wustl.edu:1234"). Returns -1 if the @a size of the
- *
is too small, else 0. - * 把地址转换为字符串， 参数@ipaddr_format指定转换的格式，如果
- * @ipaddr_format为 TRUE(非零)时，转换为点分十进制的IP地址格式。否则
- * 可能转换为域名的地址格式。
- * @return 成功时返回 0，否则返回 -1，此时参数@buffer的长度太短。
- *
- */
- virtual int addr_to_string (ACE_TCHAR buffer[],
- size_t size,
- int ipaddr_format = 1) const;
- /**
- * Initializes an ACE_INET_Addr from the @a address, which can be
- * "ip-addr:port-number" (e.g., "tango.cs.wustl.edu:1234"),
- * "ip-addr:port-name" (e.g., "tango.cs.wustl.edu:telnet"),
- * "ip-number:port-number" (e.g., "128.252.166.57:1234"), or
- * "ip-number:port-name" (e.g., "128.252.166.57:telnet"). If there
- * is no ':' in the it is assumed to be a port number,
- * with the IP address being INADDR_ANY.
- * 把字符串表示的地址格式转换为 ACE_INET_Addr对象的地址。
- * 地址格式可以为 [{ip-addr|ip-number}:]{port-number|port-name}
- * 如果地址格式没有包括冒号':'时，函数内部认为只是设置 port-number|port-name,
- * 地址被设置为 INADDR_ANY
- */
- virtual int string_to_addr (const char address[],
- int address_family = AF_UNSPEC);
- #if defined (ACE_HAS_WCHAR)
- /*
- virtual int string_to_addr (const char address[]);
- */
- #endif /* ACE_HAS_WCHAR */
- /**
- * Sets the port number without affecting the host name. If
- *
is enabled then is converted into network - * byte order, otherwise it is assumed to be in network byte order
- * already and are passed straight through.
- * 设置ACE_INET_Addr对象的端口部分，不影响地址域。
- * 参数@encode 的意思等同 set函数的@encode参数。
- */
- void set_port_number (u_short,
- int encode = 1);
- /**
- * Sets the address without affecting the port number. If
- *
is enabled then is converted into network - * byte order, otherwise it is assumed to be in network byte order
- * already and are passed straight through. The size of the address
- * is specified in the @a len parameter.
- * If
- *
is an IPv4 address, then this address is set to the IPv4-mapped - * IPv6 address of it.
- * 设置ACE_INET_Addr对象的地址部分，不改变地址对象的端口。
- * 参数@enable与set函数的@encode一致。
- * 参数@len指定 参数@ip_addr的长度。
- * 参数@map 为 TRUE(非零)是，表示支持IPv6地址格式，否则为IPv4的地址。
- */
- int set_address (const char *ip_addr,
- int len,
- int encode = 1,
- int map = 0);
- #if (defined (__linux__) || defined (ACE_WIN32)) && defined (ACE_HAS_IPV6)
- /**
- * Sets the interface that should be used for this address. This only has
- * an effect when the address is link local, otherwise it does nothing.
- */
- int set_interface (const char *intf_name);
- #endif /* (__linux__ || ACE_WIN32) && ACE_HAS_IPV6 */
- /// Return the port number, converting it into host byte-order.
- u_short get_port_number (void) const;
- /**
- * Return the character representation of the name of the host,
- * storing it in the
(which is assumed to be - *
bytes long). This version is reentrant. If - *
is greater than 0 then will be - * NUL-terminated even if -1 is returned.
- */
- int get_host_name (char hostname[],
- size_t hostnamelen) const;
- #if defined (ACE_HAS_WCHAR)
- int get_host_name (wchar_t hostname[],
- size_t hostnamelen) const;
- #endif /* ACE_HAS_WCHAR */
- /**
- * Return the character representation of the hostname. This
- * version is non-reentrant since it returns a pointer to a static
- * data area. You should therefore either (1) do a "deep copy" of
- * the address returned by get_host_name(), e.g., using strdup() or
- * (2) use the "reentrant" version of get_host_name() described
- * above.
- */
- const char *get_host_name (void) const;
- /**
- * Return the "dotted decimal" Internet address representation of
- * the hostname storing it in the @a addr (which is assumed to be
- *
bytes long). This version is reentrant. - */
- const char *get_host_addr (char *addr, int addr_size) const;
- /**
- * Return the "dotted decimal" Internet address representation of
- * the hostname. This version is non-reentrant since it returns a
- * pointer to a static data area. You should therefore either
- * (1) do a "deep copy" of the address returned by get_host_addr(), e.g.,
- * using strdup() or (2) use the "reentrant" version of
- * get_host_addr() described above.
- */
- const char *get_host_addr (void) const;
- /// Return the 4-byte IP address, converting it into host byte
- /// order.
- ACE_UINT32 get_ip_address (void) const;
- /// Return @c true if the IP address is INADDR_ANY or IN6ADDR_ANY.
- bool is_any (void) const;
- /// Return @c true if the IP address is IPv4/IPv6 loopback address.
- bool is_loopback (void) const;
- /// Return @c true if the IP address is IPv4/IPv6 multicast address.
- bool is_multicast (void) const;
- #if defined (ACE_HAS_IPV6)
- /// Return @c true if the IP address is IPv6 linklocal address.
- bool is_linklocal (void) const;
- /// Return @c true if the IP address is IPv4-mapped IPv6 address.
- bool is_ipv4_mapped_ipv6 (void) const;
- /// Return @c true if the IP address is IPv4-compatible IPv6 address.
- bool is_ipv4_compat_ipv6 (void) const;
- #endif /* ACE_HAS_IPV6 */
- /**
- * Returns @c true if @c this is less than @a rhs. In this context,
- * "less than" is defined in terms of IP address and TCP port
- * number. This operator makes it possible to use @c ACE_INET_Addrs
- * in STL maps.
- * 定义次函数，有何实际的应用吗？比较2个地址的大小有何实际意义?
- *
- */
- bool operator < (const ACE_INET_Addr &rhs) const;
- /// Compare two addresses for equality. The addresses are considered
- /// equal if they contain the same IP address and port number.
- /// 比较2个地址是否相等，包括地址部分和端口部分。
- bool operator == (const ACE_INET_Addr &SAP) const;
- /// Compare two addresses for inequality.
- /// 比较2个地址是否不相等
- bool operator != (const ACE_INET_Addr &SAP) const;
- /// A variation of the equality operator, this method only compares the
- /// IP address and ignores the port number.
- /// 比较2个地址是否相等，只比较地址部分，忽略端口部分。
- bool is_ip_equal (const ACE_INET_Addr &SAP) const;
- /// Computes and returns hash value.
- virtual u_long hash (void) const;
- /// Dump the state of an object.
- void dump (void) const;
- /// Declare the dynamic allocation hooks.
- ACE_ALLOC_HOOK_DECLARE;
- private:
- /// Insure that @a hostname is properly null-terminated.
- int get_host_name_i (char hostname[], size_t hostnamelen) const;
- // Methods to gain access to the actual address of
- // the underlying internet address structure.
- void *ip_addr_pointer (void) const;
- int ip_addr_size (void) const;
- int determine_type (void) const;
- /// Initialize underlying inet_addr_ to default values
- void reset (void);
- /// Underlying representation.
- /// This union uses the knowledge that the two structures share the
- /// first member, sa_family (as all sockaddr structures do).
- union
- {
- sockaddr_in in4_;
- #if defined (ACE_HAS_IPV6)
- sockaddr_in6 in6_;
- #endif /* ACE_HAS_IPV6 */
- } inet_addr_;
- #if defined (ACE_VXWORKS)
- char buf_[INET_ADDR_LEN];
- #endif
- };
- ACE_END_VERSIONED_NAMESPACE_DECL
- #if defined (__ACE_INLINE__)
- #include "ace/INET_Addr.inl"
- #endif /* __ACE_INLINE__ */
- #include /**/ "ace/post.h"
- #endif /* ACE_INET_ADDR_H */
总结：
1.在set、set_port_number、set_address中都提供了一个参数@encode,此参数在构造函数的参数中并没有提供。因为也意味着，使用任何一个构造函数来创建一个ACE_INET_Addr对象时，其地址和端口必须是主机字节序的。如果地址或者端口为网络字节序时，必须转换为主机字节序才可以使用构造函数。或者使用默认的构造函数，在通过set、set_port_number、set_address等成员函数，指定encode参数为FALSE(0)时，也可以直接把网络字节序的地址和端口设置给ACE_INET_Addr对象。如果地址和端口是2中不同的字节序，需要分别使用set_address和set_port_number进行设置，否则就可以使用set函数一次性设置地址和端口。
2.比较2个ACE_INET_Addr对象的相等性。 根据情况使用不同的成员函数。
地址和端口都要相等时，使用 ==进行比较。
只比较地址时，忽略端口时。使用 is_ip_equal 成员函数。