SimpleChatServer Class Reference

A simple chat server. More...

#include <SimpleChatServer.h>

Classes
class	Client
struct	ClientInfo

Public Types
typedef std::set< Wt::WString >	UserSet
	Typedef for a collection of user names. More...

Public Member Functions
	SimpleChatServer (Wt::WServer &server)
	Create a new chat server. More...
	SimpleChatServer (const SimpleChatServer &)=delete
SimpleChatServer &	operator= (const SimpleChatServer &)=delete
bool	connect (Client *client, const ChatEventCallback &handleEvent)
	Connects to the chat server. More...
bool	disconnect (Client *client)
	Disconnect from the chat server. More...
bool	login (const Wt::WString &user)
	Try to login with given user name. More...
void	logout (const Wt::WString &user)
	Logout from the server. More...
bool	changeName (const Wt::WString &user, const Wt::WString &newUser)
	Changes the name. More...
Wt::WString	suggestGuest ()
	Get a suggestion for a guest user name. More...
void	sendMessage (const Wt::WString &user, const Wt::WString &message)
	Send a message on behalve of a user. More...
UserSet	users ()
	Get the users currently logged in. More...

Private Types
typedef std::map< Client *, ClientInfo >	ClientMap

Private Member Functions
void	postChatEvent (const ChatEvent &event)

Private Attributes
Wt::WServer &	server_
std::recursive_mutex	mutex_
ClientMap	clients_
UserSet	users_

Detailed Description

A simple chat server.

Definition at line 84 of file SimpleChatServer.h.

Member Typedef Documentation

ClientMap

typedef std::map<Client *, ClientInfo> SimpleChatServer::ClientMap

private

Definition at line 154 of file SimpleChatServer.h.

UserSet

typedef std::set<Wt::WString> SimpleChatServer::UserSet

Typedef for a collection of user names.

Definition at line 142 of file SimpleChatServer.h.

Constructor & Destructor Documentation

SimpleChatServer() [1/2]

SimpleChatServer::SimpleChatServer

(

Wt::WServer &

server

)

Create a new chat server.

Definition at line 55 of file SimpleChatServer.C.

  : server_(server)
{ }

SimpleChatServer() [2/2]

SimpleChatServer::SimpleChatServer ( const SimpleChatServer &  )

delete

Member Function Documentation

changeName()

bool SimpleChatServer::changeName	(	const Wt::WString &	user,
		const Wt::WString &	newUser
	)

Changes the name.

Definition at line 111 of file SimpleChatServer.C.

{
  if (user == newUser)
    return true;
 
  std::unique_lock<std::recursive_mutex> lock(mutex_);
 
  UserSet::iterator i = users_.find(user);
 
  if (i != users_.end()) {
    if (users_.count(newUser) == 0) {
      users_.erase(i);
      users_.insert(newUser);
 
      postChatEvent(ChatEvent(ChatEvent::Rename, user, newUser));
 
      return true;
    } else
      return false;
  } else
    return false;
}

connect()

bool SimpleChatServer::connect	(	Client *	client,
		const ChatEventCallback &	handleEvent
	)

Connects to the chat server.

The passed callback method is posted to when a new chat event is received.

Returns whether the client has been connected (or false if the client was already connected).

Definition at line 59 of file SimpleChatServer.C.

{
  std::unique_lock<std::recursive_mutex> lock(mutex_);
 
  if (clients_.count(client) == 0) {
    ClientInfo clientInfo;
 
    clientInfo.sessionId = Wt::WApplication::instance()->sessionId();
    clientInfo.eventCallback = handleEvent;
 
    clients_[client] = clientInfo;
 
    return true;
  } else
    return false;
}

disconnect()

bool SimpleChatServer::disconnect

(

Client *

client

)

Disconnect from the chat server.

Returns whether the client has been disconnected (or false if the client was not connected).

Definition at line 77 of file SimpleChatServer.C.

{
  std::unique_lock<std::recursive_mutex> lock(mutex_);
 
  return clients_.erase(client) == 1;
}

login()

bool SimpleChatServer::login

(

const Wt::WString &

user

)

Try to login with given user name.

Returns false if the login was not successful.

Definition at line 84 of file SimpleChatServer.C.

{
  std::unique_lock<std::recursive_mutex> lock(mutex_);
 
  if (users_.find(user) == users_.end()) {
    users_.insert(user);
 
    postChatEvent(ChatEvent(ChatEvent::Login, user));
 
    return true;
  } else
    return false;
}

logout()

void SimpleChatServer::logout

(

const Wt::WString &

user

)

Logout from the server.

Definition at line 98 of file SimpleChatServer.C.

{
  std::unique_lock<std::recursive_mutex> lock(mutex_);
 
  UserSet::iterator i = users_.find(user);
 
  if (i != users_.end()) {
    users_.erase(i);
 
    postChatEvent(ChatEvent(ChatEvent::Logout, user));
  }
}

operator=()

SimpleChatServer& SimpleChatServer::operator= ( const SimpleChatServer &  )

delete

postChatEvent()

void SimpleChatServer::postChatEvent ( const ChatEvent &  event )

private

Definition at line 152 of file SimpleChatServer.C.

{
  std::unique_lock<std::recursive_mutex> lock(mutex_);
 
  Wt::WApplication *app = Wt::WApplication::instance();
 
  for (ClientMap::const_iterator i = clients_.begin(); i != clients_.end();
       ++i) {
    /*
     * If the user corresponds to the current application, we directly
     * call the call back method. This avoids an unnecessary delay for
     * the update to the user causing the event.
     *
     * For other uses, we post it to their session. By posting the
     * event, we avoid dead-lock scenarios, race conditions, and
     * delivering the event to a session that is just about to be
     * terminated.
     */
    if (app && app->sessionId() == i->second.sessionId)
      i->second.eventCallback(event);
    else
      server_.post(i->second.sessionId,
                   std::bind(i->second.eventCallback, event));
  }
}

sendMessage()

void SimpleChatServer::sendMessage	(	const Wt::WString &	user,
		const Wt::WString &	message
	)

Send a message on behalve of a user.

Definition at line 147 of file SimpleChatServer.C.

{
  postChatEvent(ChatEvent(user, message));
}

suggestGuest()

Wt::WString SimpleChatServer::suggestGuest

(

)

Get a suggestion for a guest user name.

Definition at line 134 of file SimpleChatServer.C.

{
  std::unique_lock<std::recursive_mutex> lock(mutex_);
 
  for (int i = 1;; ++i) {
    std::string s = "guest " + std::to_string(i);
    Wt::WString ss = s;
 
    if (users_.find(ss) == users_.end())
      return ss;
  }
}

users()

SimpleChatServer::UserSet SimpleChatServer::users

(

)

Get the users currently logged in.

Definition at line 178 of file SimpleChatServer.C.

{
  std::unique_lock<std::recursive_mutex> lock(mutex_);
 
  UserSet result = users_;
 
  return result;
}

Member Data Documentation

clients_

ClientMap SimpleChatServer::clients_

private

Definition at line 158 of file SimpleChatServer.h.

mutex_

std::recursive_mutex SimpleChatServer::mutex_

private

Definition at line 157 of file SimpleChatServer.h.

server_

Wt::WServer& SimpleChatServer::server_

private

Definition at line 156 of file SimpleChatServer.h.

users_

UserSet SimpleChatServer::users_

private

Definition at line 159 of file SimpleChatServer.h.

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The documentation for this class was generated from the following files:

• simplechat/SimpleChatServer.h
• simplechat/SimpleChatServer.C