From 2ce53fef3cbc91c90f53b4849a3113511950e791 Mon Sep 17 00:00:00 2001
From: Jason Volk <jason@zemos.net>
Date: Fri, 12 Apr 2019 00:09:32 -0700
Subject: [PATCH] modules/federation/federation: Abstract the m::feds request
 process.

---
 modules/federation/federation.cc | 204 +++++++++++--------------------
 1 file changed, 73 insertions(+), 131 deletions(-)

diff --git a/modules/federation/federation.cc b/modules/federation/federation.cc
index a2ca2e281..db86d7e77 100644
--- a/modules/federation/federation.cc
+++ b/modules/federation/federation.cc
@@ -18,7 +18,16 @@ IRCD_MODULE
 
 namespace ircd::m::feds
 {
-	template<class T> struct request;
+	template<class T>
+	struct request;
+
+	template<class T>
+	static bool
+	handler(const opts &, const closure &, std::list<request<T>> &);
+
+	template<class T>
+	static std::list<request<T>>
+	creator(const opts &, const std::function<T (request<T> &, const string_view &origin)> &);
 }
 
 template<class T>
@@ -38,37 +47,27 @@ ircd::m::feds::request<T>::request(const std::function<T (request &)> &closure)
 :T{closure(*this)}
 {}
 
-bool
-IRCD_MODULE_EXPORT
-ircd::m::feds::version(const opts &opts,
-                       const closure &closure)
+template<class T>
+std::list<m::feds::request<T>>
+ircd::m::feds::creator(const opts &opts,
+                       const std::function<T (request<T> &, const string_view &origin)> &closure)
 {
-	static const auto make_request{[]
-	(auto &request, const auto &origin)
+	assert(opts.room_id);
+	const m::room::origins origins
 	{
-		m::v1::version::opts opts;
-		opts.dynamic = false;
-		opts.remote = string_view
-		{
-			request.origin, strlcpy{request.origin, origin}
-		};
+		opts.room_id
+	};
 
-		return m::v1::version
-		{
-			request.buf, std::move(opts)
-		};
-	}};
-
-	std::list<m::feds::request<m::v1::version>> reqs;
-	m::room::origins{opts.room_id}.for_each([&reqs]
+	std::list<m::feds::request<T>> ret;
+	origins.for_each([&ret, &closure]
 	(const string_view &origin)
 	{
 		if(!server::errmsg(origin)) try
 		{
-			reqs.emplace_back([&origin]
+			ret.emplace_back([&closure, &origin]
 			(auto &request)
 			{
-				return make_request(request, origin);
+				return closure(request, origin);
 			});
 		}
 		catch(const std::exception &)
@@ -77,6 +76,15 @@ ircd::m::feds::version(const opts &opts,
 		}
 	});
 
+	return ret;
+}
+
+template<class T>
+bool
+ircd::m::feds::handler(const opts &opts,
+                       const closure &closure,
+                       std::list<request<T>> &reqs)
+{
 	const auto when
 	{
 		now<steady_point>() + opts.timeout
@@ -100,8 +108,9 @@ ircd::m::feds::version(const opts &opts,
 		auto &req{*it}; try
 		{
 			const auto code{req.get()};
-			const json::object &response{req};
-			if(!closure({req.origin, {}, response}))
+			const json::array &array{req.in.content};
+			const json::object &object{req.in.content};
+			if(!closure({req.origin, {}, object, array}))
 				return false;
 		}
 		catch(const std::exception &)
@@ -117,6 +126,35 @@ ircd::m::feds::version(const opts &opts,
 	return true;
 }
 
+bool
+IRCD_MODULE_EXPORT
+ircd::m::feds::version(const opts &opts,
+                       const closure &closure)
+{
+	static const auto make_request{[]
+	(auto &request, const auto &origin)
+	{
+		m::v1::version::opts opts;
+		opts.dynamic = false;
+		opts.remote = string_view
+		{
+			request.origin, strlcpy{request.origin, origin}
+		};
+
+		return m::v1::version
+		{
+			request.buf, std::move(opts)
+		};
+	}};
+
+	auto requests
+	{
+		creator<m::v1::version>(opts, make_request)
+	};
+
+	return handler(opts, closure, requests);
+}
+
 bool
 IRCD_MODULE_EXPORT
 ircd::m::feds::state(const opts &opts,
@@ -140,62 +178,12 @@ ircd::m::feds::state(const opts &opts,
 		};
 	}};
 
-	std::list<m::feds::request<m::v1::state>> reqs;
-	m::room::origins{opts.room_id}.for_each([&reqs, &make_request]
-	(const string_view &origin)
+	auto requests
 	{
-		if(!server::errmsg(origin)) try
-		{
-			reqs.emplace_back([&origin, &make_request]
-			(auto &request)
-			{
-				return make_request(request, origin);
-			});
-		}
-		catch(const std::exception &)
-		{
-			return;
-		}
-	});
-
-	const auto when
-	{
-		now<steady_point>() + opts.timeout
+		creator<m::v1::state>(opts, make_request)
 	};
 
-	while(!reqs.empty())
-	{
-		auto next
-		{
-			ctx::when_any(begin(reqs), end(reqs))
-		};
-
-		if(!next.wait_until(when, std::nothrow))
-			break;
-
-		const auto it
-		{
-			next.get()
-		};
-
-		auto &req{*it}; try
-		{
-			const auto code{req.get()};
-			const json::object &response{req};
-			if(!closure({req.origin, {}, response}))
-				return false;
-		}
-		catch(const std::exception &)
-		{
-			const ctx::exception_handler eptr;
-			if(!closure({req.origin, eptr}))
-				return false;
-		}
-
-		reqs.erase(it);
-	}
-
-	return true;
+	return handler(opts, closure, requests);
 }
 
 bool
@@ -218,64 +206,18 @@ ircd::m::feds::head(const opts &opts,
 		};
 	}};
 
-	std::list<m::feds::request<m::v1::make_join>> reqs;
-	m::room::origins{opts.room_id}.for_each([&reqs, &make_request]
-	(const string_view &origin)
+	auto requests
 	{
-		if(!server::errmsg(origin)) try
-		{
-			reqs.emplace_back([&origin, &make_request]
-			(auto &request)
-			{
-				return make_request(request, origin);
-			});
-		}
-		catch(const std::exception &)
-		{
-			return;
-		}
-	});
-
-	const auto when
-	{
-		now<steady_point>() + opts.timeout
+		creator<m::v1::make_join>(opts, make_request)
 	};
 
-	while(!reqs.empty())
-	{
-		auto next
-		{
-			ctx::when_any(begin(reqs), end(reqs))
-		};
-
-		if(!next.wait_until(when, std::nothrow))
-			break;
-
-		const auto it
-		{
-			next.get()
-		};
-
-		auto &req{*it}; try
-		{
-			const auto code{req.get()};
-			const json::object &response{req};
-			if(!closure({req.origin, {}, response}))
-				return false;
-		}
-		catch(const std::exception &)
-		{
-			const ctx::exception_handler eptr;
-			if(!closure({req.origin, eptr}))
-				return false;
-		}
-
-		reqs.erase(it);
-	}
-
-	return true;
+	return handler(opts, closure, requests);
 }
 
+//
+// legacy
+//
+
 extern "C" void
 feds__event(const m::event::id &event_id, std::ostream &out)
 {