Add support for the IRCv3 batch specification.

Co-authored-by: Attila Molnar <attilamolnar@hush.com>

4 files changed, 430 insertions, 1 deletions

diff --git a/docs/conf/modules.conf.example b/docs/conf/modules.conf.example
index 5995580f9..9e023e9ed 100644
--- a/docs/conf/modules.conf.example
+++ b/docs/conf/modules.conf.example
@@ -1037,11 +1037,22 @@
 #<ircv3 accountnotify="on" awaynotify="on" extendedjoin="on">
 
 #-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#
+# IRCv3 cap-notify module: Provides the cap-notify IRCv3.2 extension.
+# Required for IRCv3.2 conformance.
+#<module name="ircv3_capnotify">
+
+#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#
 # IRCv3 account-tag module. Adds the 'account' tag which contains the
 # services account name of the message sender.
 #<module name="ircv3_accounttag">
 
 #-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#
+# IRCv3 batch module: Provides the batch IRCv3 extension which allows
+# the server to inform a client that a group of messages are related to
+# each other.
+#<module name="ircv3_batch">
+
+#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#
 # IRCv3 cap-notify module: Provides the cap-notify IRCv3.2 extension.
 # Required for IRCv3.2 conformance.
 #<module name="ircv3_capnotify">
diff --git a/include/modules/ircv3_batch.h b/include/modules/ircv3_batch.h
new file mode 100644
index 000000000..841554bdb
--- /dev/null
+++ b/include/modules/ircv3_batch.h
@@ -0,0 +1,185 @@
+/*
+ * InspIRCd -- Internet Relay Chat Daemon
+ *
+ *   Copyright (C) 2016 Attila Molnar <attilamolnar@hush.com>
+ *
+ * This file is part of InspIRCd.  InspIRCd is free software: you can
+ * redistribute it and/or modify it under the terms of the GNU General Public
+ * License as published by the Free Software Foundation, version 2.
+ *
+ * This program is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
+ * FOR A PARTICULAR PURPOSE.  See the GNU General Public License for more
+ * details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+
+#pragma once
+
+// For CapReference
+#include "modules/cap.h"
+
+namespace IRCv3
+{
+	namespace Batch
+	{
+		typedef uint64_t RefTag;
+		class Manager;
+		class ManagerImpl;
+		class Batch;
+		struct BatchInfo;
+		class API;
+		class CapReference;
+
+		static const unsigned int MAX_BATCHES = (sizeof(intptr_t) * 8) - 1;
+	}
+}
+
+/** Batch Manager.
+ * Implements batch starting and stopping. When it becomes unavailable (due to e.g. module unload)
+ * all running batches are stopped.
+ */
+class IRCv3::Batch::Manager : public DataProvider, public ClientProtocol::MessageTagProvider
+{
+ public:
+	/** Constructor.
+	 * @param mod Module that owns the Manager.
+	 */
+	Manager(Module* mod)
+		: DataProvider(mod, "batchapi")
+		, ClientProtocol::MessageTagProvider(mod)
+	{
+	}
+
+	/** Start a batch.
+	 * Check Batch::IsRunning() to learn if the batch has been started.
+	 * @param batch Batch to start.
+	 */
+	virtual void Start(Batch& batch) = 0;
+
+	/** End a batch.
+	 * @param batch Batch to end.
+	 */
+	virtual void End(Batch& batch) = 0;
+};
+
+/** Represents a batch.
+ * Batches are used to group together physically separate client protocol messages that logically belong
+ * together for one reason or another. The type of a batch, if provided, indicates what kind of grouping
+ * it does.
+ *
+ * Batch objects have two states: running and stopped. If a batch is running, messages can be added to it.
+ * If a message has been added to a batch and that message is sent to a client that negotiated the batch
+ * capability then the client will receive a message tag attached to the message indicating the batch that
+ * the message is a part of. If a message M is part of a batch B and M is sent to a client that hasn't yet
+ * received any message from batch B it will get a batch start message for B before M. When a batch B is
+ * stopped, every client that received at least one message which was in batch B will receive an end of
+ * batch message for B.
+ * A message may only be part of a single batch at any given time.
+ */
+class IRCv3::Batch::Batch
+{
+	Manager* manager;
+	const std::string type;
+	RefTag reftag;
+	std::string reftagstr;
+	unsigned int bit;
+	BatchInfo* batchinfo;
+	ClientProtocol::Message* batchstartmsg;
+
+	void Setup(unsigned int b)
+	{
+		bit = b;
+		reftag = (1 << bit);
+		reftagstr = ConvToStr(reftag);
+	}
+
+	unsigned int GetId() const { return bit; }
+	intptr_t GetBit() const { return reftag; }
+
+ public:
+	/** Constructor.
+	 * The batch is initially stopped. To start it, pass it to Manager::Start().
+	 * @param Type Batch type string, used to indicate what kind of grouping the batch does. May be empty.
+	 */
+	Batch(const std::string& Type)
+		: manager(NULL)
+		, type(Type)
+		, batchinfo(NULL)
+		, batchstartmsg(NULL)
+	{
+	}
+
+	/** Destructor.
+	 * If the batch is running, it is ended.
+	 */
+	~Batch()
+	{
+		if (manager)
+			manager->End(*this);
+	}
+
+	/** Add a message to the batch.
+	 * If the batch isn't running then this method does nothing.
+	 * @param msg Message to add to the batch. If it is already part of any batch, this method is a no-op.
+	 */
+	void AddToBatch(ClientProtocol::Message& msg)
+	{
+		if (manager)
+			msg.AddTag("batch", manager, reftagstr, this);
+	}
+
+	/** Get batch reference tag which is an opaque id for the batch and is used in the client protocol.
+	 * Only running batches have a reference tag assigned.
+	 * @return Reference tag as a string, only valid if the batch is running.
+	 */
+	const std::string& GetRefTagStr() const { return reftagstr; }
+
+	/** Get batch type.
+	 * @return Batch type string.
+	 */
+	const std::string& GetType() const { return type; }
+
+	/** Check whether the batch is running.
+	 * Batches can be started with Manager::Start() and stopped with Manager::End().
+	 * @return True if the batch is running, false otherwise.
+	 */
+	bool IsRunning() const { return (manager != NULL); }
+
+	/** Get the batch start client protocol message.
+	 * The returned message object can be manipulated to add extra parameters or labels to the message. The first
+	 * parameter of the message is the batch reference tag generated by the module providing batch support.
+	 * If the batch type string was specified, it will be the second parameter of the message.
+	 * May only be called if IsRunning() == true.
+	 * @return Mutable batch start client protocol message.
+	 */
+	ClientProtocol::Message& GetBatchStartMessage() { return *batchstartmsg; }
+
+	friend class ManagerImpl;
+};
+
+/** Batch API. Use this to access the Manager.
+ */
+class IRCv3::Batch::API : public dynamic_reference_nocheck<Manager>
+{
+ public:
+	API(Module* mod)
+		: dynamic_reference_nocheck<Manager>(mod, "batchapi")
+	{
+	}
+};
+
+/** Reference to the batch cap.
+ * Can be used to check whether a user has the batch client cap enabled.
+ */
+class IRCv3::Batch::CapReference : public Cap::Reference
+{
+ public:
+	CapReference(Module* mod)
+		: Cap::Reference(mod, "batch")
+	{
+	}
+};
diff --git a/src/modules/m_chanhistory.cpp b/src/modules/m_chanhistory.cpp
index 57db002a8..fe4bd9477 100644
--- a/src/modules/m_chanhistory.cpp
+++ b/src/modules/m_chanhistory.cpp
@@ -19,6 +19,7 @@
 
 #include "inspircd.h"
 #include "modules/ircv3_servertime.h"
+#include "modules/ircv3_batch.h"
 
 struct HistoryItem
 {
@@ -123,12 +124,18 @@ class ModuleChanHistory : public Module
 	bool sendnotice;
 	UserModeReference botmode;
 	bool dobots;
+	IRCv3::Batch::CapReference batchcap;
+	IRCv3::Batch::API batchmanager;
+	IRCv3::Batch::Batch batch;
 	IRCv3::ServerTime::API servertimemanager;
 
  public:
 	ModuleChanHistory()
 		: m(this)
 		, botmode(this, "bot")
+		, batchcap(this)
+		, batchmanager(this)
+		, batch("chathistory")
 		, servertimemanager(this)
 	{
 	}
@@ -172,7 +179,7 @@ class ModuleChanHistory : public Module
 		if (list->maxtime)
 			mintime = ServerInstance->Time() - list->maxtime;
 
-		if (sendnotice)
+		if ((sendnotice) && (!batchcap.get(localuser)))
 		{
 			std::string message("Replaying up to " + ConvToStr(list->maxlen) + " lines of pre-join history");
 			if (list->maxtime > 0)
@@ -180,6 +187,12 @@ class ModuleChanHistory : public Module
 			memb->WriteNotice(message);
 		}
 
+		if (batchmanager)
+		{
+			batchmanager->Start(batch);
+			batch.GetBatchStartMessage().PushParamRef(memb->chan->name);
+		}
+
 		for(std::deque<HistoryItem>::iterator i = list->lines.begin(); i != list->lines.end(); ++i)
 		{
 			const HistoryItem& item = *i;
@@ -188,9 +201,13 @@ class ModuleChanHistory : public Module
 				ClientProtocol::Messages::Privmsg msg(ClientProtocol::Messages::Privmsg::nocopy, item.sourcemask, memb->chan, item.text);
 				if (servertimemanager)
 					servertimemanager->Set(msg, item.ts);
+				batch.AddToBatch(msg);
 				localuser->Send(ServerInstance->GetRFCEvents().privmsg, msg);
 			}
 		}
+
+		if (batchmanager)
+			batchmanager->End(batch);
 	}
 
 	Version GetVersion() CXX11_OVERRIDE
diff --git a/src/modules/m_ircv3_batch.cpp b/src/modules/m_ircv3_batch.cpp
new file mode 100644
index 000000000..df2b00f49
--- /dev/null
+++ b/src/modules/m_ircv3_batch.cpp
@@ -0,0 +1,216 @@
+/*
+ * InspIRCd -- Internet Relay Chat Daemon
+ *
+ *   Copyright (C) 2016 Attila Molnar <attilamolnar@hush.com>
+ *
+ * This file is part of InspIRCd.  InspIRCd is free software: you can
+ * redistribute it and/or modify it under the terms of the GNU General Public
+ * License as published by the Free Software Foundation, version 2.
+ *
+ * This program is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
+ * FOR A PARTICULAR PURPOSE.  See the GNU General Public License for more
+ * details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+
+#include "inspircd.h"
+#include "modules/cap.h"
+#include "modules/ircv3_batch.h"
+
+class BatchMessage : public ClientProtocol::Message
+{
+ public:
+	BatchMessage(const IRCv3::Batch::Batch& batch, bool start)
+		: ClientProtocol::Message("BATCH", ServerInstance->Config->ServerName)
+	{
+		char c = (start ? '+' : '-');
+		PushParam(std::string(1, c) + batch.GetRefTagStr());
+		if ((start) && (!batch.GetType().empty()))
+			PushParamRef(batch.GetType());
+	}
+};
+
+/** Extra structure allocated only for running batches, containing objects only relevant for
+ * that specific run of the batch.
+ */
+struct IRCv3::Batch::BatchInfo
+{
+	/** List of users that have received the batch start message
+	 */
+	std::vector<LocalUser*> users;
+	BatchMessage startmsg;
+	ClientProtocol::Event startevent;
+
+	BatchInfo(ClientProtocol::EventProvider& protoevprov, IRCv3::Batch::Batch& b)
+		: startmsg(b, true)
+		, startevent(protoevprov, startmsg)
+	{
+	}
+};
+
+class IRCv3::Batch::ManagerImpl : public Manager
+{
+ 	typedef std::vector<Batch*> BatchList;
+
+	Cap::Capability cap;
+	ClientProtocol::EventProvider protoevprov;
+	LocalIntExt batchbits;
+ 	BatchList active_batches;
+	bool unloading;
+
+	bool ShouldSendTag(LocalUser* user, const ClientProtocol::MessageTagData& tagdata) CXX11_OVERRIDE
+	{
+		if (!cap.get(user))
+			return false;
+
+		Batch& batch = *static_cast<Batch*>(tagdata.provdata);
+		// Check if this is the first message the user is getting that is part of the batch
+		const intptr_t bits = batchbits.get(user);
+		if (!(bits & batch.GetBit()))
+		{
+			// Send the start batch command ("BATCH +reftag TYPE"), remember the user so we can send them a
+			// "BATCH -reftag" message later when the batch ends and set the flag we just checked so this is
+			// only done once per user per batch.
+			batchbits.set(user, (bits | batch.GetBit()));
+			batch.batchinfo->users.push_back(user);
+			user->Send(batch.batchinfo->startevent);
+		}
+
+		return true;
+	}
+
+	unsigned int NextFreeId() const
+	{
+		if (active_batches.empty())
+			return 0;
+		return active_batches.back()->GetId()+1;
+	}
+
+ public:
+	ManagerImpl(Module* mod)
+		: Manager(mod)
+		, cap(mod, "batch")
+		, protoevprov(mod, "BATCH")
+		, batchbits("batchbits", ExtensionItem::EXT_USER, mod)
+		, unloading(false)
+	{
+	}
+
+	void Init()
+	{
+		// Set batchbits to 0 for all users in case we were reloaded and the previous, now meaningless,
+		// batchbits are set on users
+		const UserManager::LocalList& users = ServerInstance->Users.GetLocalUsers();
+		for (UserManager::LocalList::const_iterator i = users.begin(); i != users.end(); ++i)
+		{
+			LocalUser* const user = *i;
+			batchbits.set(user, 0);
+		}
+	}
+
+	void Shutdown()
+	{
+		unloading = true;
+		while (!active_batches.empty())
+			ManagerImpl::End(*active_batches.back());
+	}
+
+	void RemoveFromAll(LocalUser* user)
+	{
+		const intptr_t bits = batchbits.get(user);
+
+		// User is quitting, remove them from all lists
+		for (BatchList::iterator i = active_batches.begin(); i != active_batches.end(); ++i)
+		{
+			Batch& batch = **i;
+			// Check the bit first to avoid list scan in case they're not on the list
+			if ((bits & batch.GetBit()) != 0)
+				stdalgo::vector::swaperase(batch.batchinfo->users, user);
+		}
+	}
+
+	void Start(Batch& batch) CXX11_OVERRIDE
+	{
+		if (unloading)
+			return;
+
+		if (batch.IsRunning())
+			return; // Already started, don't start again
+
+		const size_t id = NextFreeId();
+		if (id >= MAX_BATCHES)
+			return;
+
+		batch.Setup(id);
+		// Set the manager field which Batch::IsRunning() checks and is also used by AddToBatch()
+		// to set the message tag
+		batch.manager = this;
+		batch.batchinfo = new IRCv3::Batch::BatchInfo(protoevprov, batch);
+		batch.batchstartmsg = &batch.batchinfo->startmsg;
+		active_batches.push_back(&batch);
+	}
+
+	void End(Batch& batch) CXX11_OVERRIDE
+	{
+		if (!batch.IsRunning())
+			return;
+
+		// Mark batch as stopped
+		batch.manager = NULL;
+
+		BatchInfo& batchinfo = *batch.batchinfo;
+		// Send end batch message to all users who got the batch start message and unset bit so it can be reused
+		BatchMessage endbatchmsg(batch, false);
+		ClientProtocol::Event endbatchevent(protoevprov, endbatchmsg);
+		for (std::vector<LocalUser*>::const_iterator i = batchinfo.users.begin(); i != batchinfo.users.end(); ++i)
+		{
+			LocalUser* const user = *i;
+			user->Send(endbatchevent);
+			batchbits.set(user, batchbits.get(user) & ~batch.GetBit());
+		}
+
+		// erase() not swaperase because the reftag generation logic depends on the order of the elements
+		stdalgo::erase(active_batches, &batch);
+		delete batch.batchinfo;
+		batch.batchinfo = NULL;
+	}
+};
+
+class ModuleIRCv3Batch : public Module
+{
+	IRCv3::Batch::ManagerImpl manager;
+
+ public:
+	ModuleIRCv3Batch()
+		: manager(this)
+	{
+	}
+
+	void init() CXX11_OVERRIDE
+	{
+		manager.Init();
+	}
+
+	void OnUnloadModule(Module* mod) CXX11_OVERRIDE
+	{
+		if (mod == this)
+			manager.Shutdown();
+	}
+
+	void OnUserDisconnect(LocalUser* user) CXX11_OVERRIDE
+	{
+		// Remove the user from all internal lists
+		manager.RemoveFromAll(user);
+	}
+
+	Version GetVersion() CXX11_OVERRIDE
+	{
+		return Version("Provides the batch IRCv3 extension", VF_VENDOR);
+	}
+};
+
+MODULE_INIT(ModuleIRCv3Batch)