From 8ec7c988a3e56ebb596449d3e857fe7acb9990bd Mon Sep 17 00:00:00 2001
From: Jason Volk <jason@zemos.net>
Date: Fri, 29 Dec 2017 21:20:16 -0700
Subject: [PATCH] ircd::net: Add mass-resolution function.

---
 include/ircd/net/remote.h |  4 +++-
 ircd/net.cc               | 26 ++++++++++++++++++++++++++
 2 files changed, 29 insertions(+), 1 deletion(-)

diff --git a/include/ircd/net/remote.h b/include/ircd/net/remote.h
index d9edd249c..996e58d71 100644
--- a/include/ircd/net/remote.h
+++ b/include/ircd/net/remote.h
@@ -98,8 +98,9 @@ struct ircd::net::hostport
 	friend std::ostream &operator<<(std::ostream &, const hostport &);
 };
 
-/// DNS resolution section
+/// DNS resolution suite.
 ///
+/// There are plenty of ways to resolve plenty of things. Still more to come.
 struct ircd::net::resolve
 {
 	using callback_one = std::function<void (std::exception_ptr, const ipport &)>;
@@ -109,6 +110,7 @@ struct ircd::net::resolve
 	resolve(const hostport &, callback_many);
 	resolve(const hostport &, ctx::future<ipport> &);
 	resolve(const hostport &, ctx::future<std::vector<ipport>> &);
+	resolve(const vector_view<hostport> &in, const vector_view<ipport> &out);
 };
 
 /// This lightweight structure holds an IP address and port in native byte
diff --git a/ircd/net.cc b/ircd/net.cc
index 0065bcf6c..12a15eadc 100644
--- a/ircd/net.cc
+++ b/ircd/net.cc
@@ -1686,6 +1686,32 @@ ircd::net::resolve::resolve(const hostport &hostport,
 	});
 }
 
+ircd::net::resolve::resolve(const vector_view<hostport> &in,
+                            const vector_view<ipport> &out)
+{
+	assert(in.size() == out.size());
+	const size_t count
+	{
+		std::min(in.size(), out.size())
+	};
+
+	size_t a{0}, b{0};
+	ctx::ctx &c{ctx::cur()};
+	for(; a < count; ++a) resolve
+	{
+		in[a], [&b, &c, &count, &ret(out[a])]
+		(std::exception_ptr eptr, const ipport &ip) noexcept
+		{
+			ret = ip;
+			if(++b >= count)
+				notify(c);
+		}
+	};
+
+	while(b < count)
+		ctx::wait();
+}
+
 ircd::net::resolve::resolve(const hostport &hostport,
                             callback_many callback)
 {