socketaddress.h

由GOOGLE的JINGLE项目中移植的网络库

/*
 * libjingle
 * Copyright 2004--2005, Google Inc.
 *
 * Redistribution and use in source and binary forms, with or without 
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 *     this list of conditions and the following disclaimer.
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 *     derived from this software without specific prior written permission.
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 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF 
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 */

#ifndef __SOCKETADDRESS_H__
#define __SOCKETADDRESS_H__

#include "basictypes.h"
#include <string>
#undef SetPort

namespace cricket {

// Records an IP address and port, which are 32 and 16 bit integers,
// respectively, both in <b>host byte-order</b>.
class SocketAddress {
public:
  // Creates a missing / unknown address.
  SocketAddress();

  // Creates the address with the given host and port.  If use_dns is true,
  // the hostname will be immediately resolved to an IP (which may block for
  // several seconds if DNS is not available).  Alternately, set use_dns to
  // false, and then call Resolve() to complete resolution later, or use
  // SetResolvedIP to set the IP explictly.
  SocketAddress(const std::string& hostname, int port = 0, bool use_dns = true);

  // Creates the address with the given IP and port.
  SocketAddress(uint32 ip, int port);

  // Creates a copy of the given address.
  SocketAddress(const SocketAddress& addr);

  // Replaces our address with the given one.
  SocketAddress& operator =(const SocketAddress& addr);

  // Changes the IP of this address to the given one, and clears the hostname.
  void SetIP(uint32 ip);

  // Changes the hostname of this address to the given one.
  // Calls Resolve and returns the result.
  bool SetIP(const std::string& hostname, bool use_dns = true);

  // Sets the IP address while retaining the hostname.  Useful for bypassing
  // DNS for a pre-resolved IP.
  void SetResolvedIP(uint32 ip);

  // Changes the port of this address to the given one.
  void SetPort(int port);

  // Returns the IP address.
  uint32 ip() const;

  // Returns the port part of this address.
  uint16 port() const;

  // Returns the IP address in dotted form.
  std::string IPAsString() const;
  
  // Determines whether this represents a missing / any address.
  bool IsAny() const;

  // Synomym for missing / any.
  bool IsNil() const { return IsAny(); }

  // Determines whether the IP address refers to the local host, i.e. within
  // the range 127.0.0.0/8.
  bool IsLocalIP() const;

  // Determines whether the IP address is in one of the private ranges:
  // 127.0.0.0/8 10.0.0.0/8 192.168.0.0/16 172.16.0.0/12.
  bool IsPrivateIP() const;

  // Determines whether the hostname has been resolved to an IP
  bool IsUnresolved() const;

  // Attempt to resolve a hostname to IP address.
  // Returns false if resolution is required but failed.
  // 'force' will cause re-resolution of hostname.
  // 
  bool Resolve(bool force = false, bool use_dns = true);

  // Determines whether this address is identical to the given one.
  bool operator ==(const SocketAddress& addr) const;

  // Compares based on IP and then port.
  bool operator <(const SocketAddress& addr) const;

  // Determines whether this address has the same IP as the one given.
  bool EqualIPs(const SocketAddress& addr) const;

  // Deteremines whether this address has the same port as the one given.
  bool EqualPorts(const SocketAddress& addr) const;

  // Hashes this address into a small number.
  size_t Hash() const;

  // Returns the size of this address when written.
  size_t Size_() const;

  // Writes this address into the given buffer.
  void Write_(char* buf, int len) const;

  // Reads this address from the given buffer.
  void Read_(const char* buf, int len);
  
  // Converts the IP address given in dotted form into compact form.
  // Without 'use_dns', only dotted names (A.B.C.D) are resolved.
  static uint32 StringToIP(const std::string& str, bool use_dns = true);

private:
  std::string hostname_;
  uint32 ip_;
  uint16 port_;

  // Initializes the address to missing / any.
  void Zero();
};

} // namespace cricket

#endif // __SOCKETADDRESS_H__