Merge branch 'master+foreachneighbor'

4 files changed, 124 insertions, 107 deletions

diff --git a/include/users.h b/include/users.h
index ceee4396b..fa8f610bc 100644
--- a/include/users.h
+++ b/include/users.h
@@ -248,6 +248,19 @@ class CoreExport User : public Extensible
 	std::bitset<ModeParser::MODEID_MAX> modes;
 
  public:
+	/** To execute a function for each local neighbor of a user, inherit from this class and
+	 * pass an instance of it to User::ForEachNeighbor().
+	 */
+	class ForEachNeighborHandler
+	{
+	 public:
+		/** Method to execute for each local neighbor of a user.
+		 * Derived classes must implement this.
+		 * @param user Current neighbor
+		 */
+		virtual void Execute(LocalUser* user) = 0;
+	};
+
 	/** List of Memberships for this user
 	 */
 	typedef insp::intrusive_list<Membership> ChanList;
@@ -535,12 +548,15 @@ class CoreExport User : public Extensible
 	 */
 	void WriteCommon(const char* text, ...) CUSTOM_PRINTF(2, 3);
 
-	/** Write a quit message to all common users, as in User::WriteCommonExcept but with a specific
-	 * quit message for opers only.
-	 * @param normal_text Normal user quit message
-	 * @param oper_text Oper only quit message
+	/** Execute a function once for each local neighbor of this user. By default, the neighbors of a user are the users
+	 * who have at least one common channel with the user. Modules are allowed to alter the set of neighbors freely.
+	 * This function is used for example to send something conditionally to neighbors, or to send different messages
+	 * to different users depending on their oper status.
+	 * @param handler Function object to call, inherited from ForEachNeighborHandler.
+	 * @param include_self True to include this user in the set of neighbors, false otherwise.
+	 * Modules may override this. Has no effect if this user is not local.
 	 */
-	void WriteCommonQuit(const std::string &normal_text, const std::string &oper_text);
+	void ForEachNeighbor(ForEachNeighborHandler& handler, bool include_self = true);
 
 	/** Dump text to a user target, splitting it appropriately to fit
 	 * @param linePrefix text to prefix each complete line with
diff --git a/src/modules/m_ircv3.cpp b/src/modules/m_ircv3.cpp
index 4eb54d2a6..b1c04cdf5 100644
--- a/src/modules/m_ircv3.cpp
+++ b/src/modules/m_ircv3.cpp
@@ -20,6 +20,26 @@
 #include "modules/account.h"
 #include "modules/cap.h"
 
+class WriteNeighboursWithExt : public User::ForEachNeighborHandler
+{
+	const LocalIntExt& ext;
+	const std::string& msg;
+
+	void Execute(LocalUser* user) CXX11_OVERRIDE
+	{
+		if (ext.get(user))
+			user->Write(msg);
+	}
+
+ public:
+	WriteNeighboursWithExt(User* user, const std::string& message, const LocalIntExt& extension)
+		: ext(extension)
+		, msg(message)
+	{
+		user->ForEachNeighbor(*this, false);
+	}
+};
+
 class ModuleIRCv3 : public Module
 {
 	GenericCap cap_accountnotify;
@@ -31,44 +51,6 @@ class ModuleIRCv3 : public Module
 
 	CUList last_excepts;
 
-	void WriteNeighboursWithExt(User* user, const std::string& line, const LocalIntExt& ext)
-	{
-		IncludeChanList chans(user->chans.begin(), user->chans.end());
-
-		std::map<User*, bool> exceptions;
-		FOREACH_MOD(OnBuildNeighborList, (user, chans, exceptions));
-
-		// Send it to all local users who were explicitly marked as neighbours by modules and have the required ext
-		for (std::map<User*, bool>::const_iterator i = exceptions.begin(); i != exceptions.end(); ++i)
-		{
-			LocalUser* u = IS_LOCAL(i->first);
-			if ((u) && (i->second) && (ext.get(u)))
-				u->Write(line);
-		}
-
-		// Now consider sending it to all other users who has at least a common channel with the user
-		std::set<User*> already_sent;
-		for (IncludeChanList::const_iterator i = chans.begin(); i != chans.end(); ++i)
-		{
-			const Channel::MemberMap& userlist = (*i)->chan->GetUsers();
-			for (Channel::MemberMap::const_iterator m = userlist.begin(); m != userlist.end(); ++m)
-			{
-				/*
-				 * Send the line if the channel member in question meets all of the following criteria:
-				 * - local
-				 * - not the user who is doing the action (i.e. whose channels we're iterating)
-				 * - has the given extension
-				 * - not on the except list built by modules
-				 * - we haven't sent the line to the member yet
-				 *
-				 */
-				LocalUser* member = IS_LOCAL(m->first);
-				if ((member) && (member != user) && (ext.get(member)) && (exceptions.find(member) == exceptions.end()) && (already_sent.insert(member).second))
-					member->Write(line);
-			}
-		}
-	}
-
  public:
 	ModuleIRCv3() : cap_accountnotify(this, "account-notify"),
 					cap_awaynotify(this, "away-notify"),
diff --git a/src/usermanager.cpp b/src/usermanager.cpp
index 52cb4989f..5d07c4d79 100644
--- a/src/usermanager.cpp
+++ b/src/usermanager.cpp
@@ -24,6 +24,30 @@
 #include "xline.h"
 #include "iohook.h"
 
+namespace
+{
+	class WriteCommonQuit : public User::ForEachNeighborHandler
+	{
+		std::string line;
+		std::string operline;
+
+		void Execute(LocalUser* user) CXX11_OVERRIDE
+		{
+			user->Write(user->IsOper() ? operline : line);
+		}
+
+	 public:
+		WriteCommonQuit(User* user, const std::string& msg, const std::string& opermsg)
+			: line(":" + user->GetFullHost() + " QUIT :")
+			, operline(line)
+		{
+			line += msg;
+			operline += opermsg;
+			user->ForEachNeighbor(*this, false);
+		}
+	};
+}
+
 UserManager::UserManager()
 	: unregistered_count(0)
 {
@@ -180,7 +204,7 @@ void UserManager::QuitUser(User* user, const std::string& quitreason, const std:
 	if (user->registered == REG_ALL)
 	{
 		FOREACH_MOD(OnUserQuit, (user, reason, *operreason));
-		user->WriteCommonQuit(reason, *operreason);
+		WriteCommonQuit(user, reason, *operreason);
 	}
 	else
 		unregistered_count--;
diff --git a/src/users.cpp b/src/users.cpp
index 34986a183..12243c64b 100644
--- a/src/users.cpp
+++ b/src/users.cpp
@@ -845,11 +845,27 @@ void User::WriteFrom(User *user, const char* text, ...)
 	this->WriteFrom(user, textbuffer);
 }
 
-void User::WriteCommon(const char* text, ...)
+namespace
 {
-	if (this->registered != REG_ALL || quitting)
-		return;
+	class WriteCommonRawHandler : public User::ForEachNeighborHandler
+	{
+		const std::string& msg;
 
+		void Execute(LocalUser* user) CXX11_OVERRIDE
+		{
+			user->Write(msg);
+		}
+
+	 public:
+		WriteCommonRawHandler(const std::string& message)
+			: msg(message)
+		{
+		}
+	};
+}
+
+void User::WriteCommon(const char* text, ...)
+{
 	std::string textbuffer;
 	VAFORMAT(textbuffer, text, text);
 	textbuffer = ":" + this->GetFullHost() + " " + textbuffer;
@@ -858,79 +874,58 @@ void User::WriteCommon(const char* text, ...)
 
 void User::WriteCommonRaw(const std::string &line, bool include_self)
 {
-	if (this->registered != REG_ALL || quitting)
-		return;
-
-	LocalUser::already_sent_id++;
-
-	IncludeChanList include_c(chans.begin(), chans.end());
-	std::map<User*,bool> exceptions;
-
-	exceptions[this] = include_self;
-
-	FOREACH_MOD(OnBuildNeighborList, (this, include_c, exceptions));
-
-	for (std::map<User*,bool>::iterator i = exceptions.begin(); i != exceptions.end(); ++i)
-	{
-		LocalUser* u = IS_LOCAL(i->first);
-		if (u && !u->quitting)
-		{
-			u->already_sent = LocalUser::already_sent_id;
-			if (i->second)
-				u->Write(line);
-		}
-	}
-	for (IncludeChanList::const_iterator v = include_c.begin(); v != include_c.end(); ++v)
-	{
-		Channel* c = (*v)->chan;
-		const Channel::MemberMap& ulist = c->GetUsers();
-		for (Channel::MemberMap::const_iterator i = ulist.begin(); i != ulist.end(); ++i)
-		{
-			LocalUser* u = IS_LOCAL(i->first);
-			if (u && u->already_sent != LocalUser::already_sent_id)
-			{
-				u->already_sent = LocalUser::already_sent_id;
-				u->Write(line);
-			}
-		}
-	}
+	WriteCommonRawHandler handler(line);
+	ForEachNeighbor(handler, include_self);
 }
 
-void User::WriteCommonQuit(const std::string &normal_text, const std::string &oper_text)
+void User::ForEachNeighbor(ForEachNeighborHandler& handler, bool include_self)
 {
-	if (this->registered != REG_ALL)
-		return;
+	// The basic logic for visiting the neighbors of a user is to iterate the channel list of the user
+	// and visit all users on those channels. Because two users may share more than one common channel,
+	// we must skip users that we have already visited.
+	// To do this, we make use of a global counter and an integral 'already_sent' field in LocalUser.
+	// The global counter is incremented every time we do something for each neighbor of a user. Then,
+	// before visiting a member we examine user->already_sent. If it's equal to the current counter, we
+	// skip the member. Otherwise, we set it to the current counter and visit the member.
 
-	already_sent_t uniq_id = ++LocalUser::already_sent_id;
-
-	const std::string normalMessage = ":" + this->GetFullHost() + " QUIT :" + normal_text;
-	const std::string operMessage = ":" + this->GetFullHost() + " QUIT :" + oper_text;
-
-	IncludeChanList include_c(chans.begin(), chans.end());
-	std::map<User*,bool> exceptions;
+	// Ask modules to build a list of exceptions.
+	// Mods may also exclude entire channels by erasing them from include_chans.
+	IncludeChanList include_chans(chans.begin(), chans.end());
+	std::map<User*, bool> exceptions;
+	exceptions[this] = include_self;
+	FOREACH_MOD(OnBuildNeighborList, (this, include_chans, exceptions));
 
-	FOREACH_MOD(OnBuildNeighborList, (this, include_c, exceptions));
+	// Get next id, guaranteed to differ from the already_sent field of all users
+	const already_sent_t newid = ++LocalUser::already_sent_id;
 
-	for (std::map<User*,bool>::iterator i = exceptions.begin(); i != exceptions.end(); ++i)
+	// Handle exceptions first
+	for (std::map<User*, bool>::const_iterator i = exceptions.begin(); i != exceptions.end(); ++i)
 	{
-		LocalUser* u = IS_LOCAL(i->first);
-		if (u && !u->quitting)
+		LocalUser* curr = IS_LOCAL(i->first);
+		if (curr)
 		{
-			u->already_sent = uniq_id;
-			if (i->second)
-				u->Write(u->IsOper() ? operMessage : normalMessage);
+			// Mark as visited to ensure we won't visit again if there is a common channel
+			curr->already_sent = newid;
+			// Always treat quitting users as excluded
+			if ((i->second) && (!curr->quitting))
+				handler.Execute(curr);
 		}
 	}
-	for (IncludeChanList::const_iterator v = include_c.begin(); v != include_c.end(); ++v)
+
+	// Now consider the real neighbors
+	for (IncludeChanList::const_iterator i = include_chans.begin(); i != include_chans.end(); ++i)
 	{
-		const Channel::MemberMap& ulist = (*v)->chan->GetUsers();
-		for (Channel::MemberMap::const_iterator i = ulist.begin(); i != ulist.end(); i++)
+		Channel* chan = (*i)->chan;
+		const Channel::MemberMap& userlist = chan->GetUsers();
+		for (Channel::MemberMap::const_iterator j = userlist.begin(); j != userlist.end(); ++j)
 		{
-			LocalUser* u = IS_LOCAL(i->first);
-			if (u && (u->already_sent != uniq_id))
+			LocalUser* curr = IS_LOCAL(j->first);
+			// User not yet visited?
+			if ((curr) && (curr->already_sent != newid))
 			{
-				u->already_sent = uniq_id;
-				u->Write(u->IsOper() ? operMessage : normalMessage);
+				// Mark as visited and execute function
+				curr->already_sent = newid;
+				handler.Execute(curr);
 			}
 		}
 	}