From: Carl Hetherington <cth@carlh.net>
Date: Thu, 12 Apr 2018 23:56:11 +0000 (+0100)
Subject: Update encoding server list when servers disappear (#1176).
X-Git-Tag: v2.13.14~2
X-Git-Url: https://main.carlh.net/gitweb/?p=dcpomatic.git;a=commitdiff_plain;h=6dd6676700f830547e9e7c38781f09de5f2a1a00

Update encoding server list when servers disappear (#1176).
---

diff --git a/ChangeLog b/ChangeLog
index 5201319d6..ded429291 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,5 +1,7 @@
 2018-04-13  Carl Hetherington  <cth@carlh.net>
 
+	* Update encoding server list when one goes away (#1176).
+
 	* Add servers with bad server-link versions in the list (#982).
 
 2018-04-12  Carl Hetherington  <cth@carlh.net>
diff --git a/src/lib/encode_server_description.h b/src/lib/encode_server_description.h
index 864b0fdc1..0b9d72f44 100644
--- a/src/lib/encode_server_description.h
+++ b/src/lib/encode_server_description.h
@@ -21,6 +21,8 @@
 #ifndef DCPOMATIC_ENCODE_SERVER_DESCRIPTION_H
 #define DCPOMATIC_ENCODE_SERVER_DESCRIPTION_H
 
+#include <boost/date_time/posix_time/posix_time.hpp>
+
 /** @class EncodeServerDescription
  *  @brief Class to describe a server to which we can send encoding work.
  */
@@ -31,6 +33,7 @@ public:
 		: _host_name ("")
 		, _threads (1)
 		, _link_version (0)
+		, _last_seen (boost::posix_time::second_clock::local_time())
 	{}
 
 	/** @param h Server host name or IP address in string form.
@@ -41,6 +44,7 @@ public:
 		: _host_name (h)
 		, _threads (t)
 		, _link_version (l)
+		, _last_seen (boost::posix_time::second_clock::local_time())
 	{}
 
 	/* Default copy constructor is fine */
@@ -67,6 +71,14 @@ public:
 		_threads = t;
 	}
 
+	void set_seen () {
+		_last_seen = boost::posix_time::second_clock::local_time();
+	}
+
+	int last_seen_seconds () const {
+		return boost::posix_time::time_duration(boost::posix_time::second_clock::local_time() - _last_seen).total_seconds();
+	}
+
 private:
 	/** server's host name */
 	std::string _host_name;
@@ -74,6 +86,7 @@ private:
 	int _threads;
 	/** server link (i.e. protocol) version number */
 	int _link_version;
+	boost::posix_time::ptime _last_seen;
 };
 
 #endif
diff --git a/src/lib/encode_server_finder.cc b/src/lib/encode_server_finder.cc
index 1234dcd52..06a6a396b 100644
--- a/src/lib/encode_server_finder.cc
+++ b/src/lib/encode_server_finder.cc
@@ -39,6 +39,7 @@ using std::cout;
 using boost::shared_ptr;
 using boost::scoped_array;
 using boost::weak_ptr;
+using boost::optional;
 using dcp::raw_convert;
 
 EncodeServerFinder* EncodeServerFinder::_instance = 0;
@@ -102,6 +103,25 @@ EncodeServerFinder::stop ()
 	_bad_servers.clear ();
 }
 
+static bool
+remove_missing (list<EncodeServerDescription>& servers, int since)
+{
+	bool removed = false;
+	list<EncodeServerDescription>::iterator i = servers.begin();
+	while (i != servers.end()) {
+		if (i->last_seen_seconds() > since) {
+			list<EncodeServerDescription>::iterator j = i;
+			++j;
+			servers.erase (i);
+			i = j;
+			removed = true;
+		} else {
+			++i;
+		}
+	}
+	return removed;
+}
+
 void
 EncodeServerFinder::search_thread ()
 try
@@ -118,6 +138,7 @@ try
         socket.set_option (boost::asio::socket_base::broadcast (true));
 
 	string const data = DCPOMATIC_HELLO;
+	int const interval = 10;
 
 	while (!_stop) {
 		if (Config::instance()->use_any_servers ()) {
@@ -147,8 +168,18 @@ try
 			}
 		}
 
+		/* Discard servers that we haven't seen for a while */
+		{
+			boost::mutex::scoped_lock lm (_servers_mutex);
+			bool g = remove_missing(_good_servers, 2 * interval);
+			bool b = remove_missing(_bad_servers, 2 * interval);
+			if (g || b) {
+				emit (boost::bind (boost::ref (ServersListChanged)));
+			}
+		}
+
 		boost::mutex::scoped_lock lm (_search_condition_mutex);
-		_search_condition.timed_wait (lm, boost::get_system_time() + boost::posix_time::seconds (10));
+		_search_condition.timed_wait (lm, boost::get_system_time() + boost::posix_time::seconds (interval));
 	}
 }
 catch (...)
@@ -207,7 +238,10 @@ EncodeServerFinder::handle_accept (boost::system::error_code ec, shared_ptr<Sock
 	xml->read_string (s);
 
 	string const ip = socket->socket().remote_endpoint().address().to_string ();
-	if (!server_found (ip)) {
+	optional<list<EncodeServerDescription>::iterator> found = server_found (ip);
+	if (found) {
+		(*found)->set_seen ();
+	} else {
 		EncodeServerDescription sd (ip, xml->number_child<int>("Threads"), xml->optional_number_child<int>("Version").get_value_or(0));
 		if (sd.link_version() == SERVER_LINK_VERSION) {
 			boost::mutex::scoped_lock lm (_servers_mutex);
@@ -222,17 +256,17 @@ EncodeServerFinder::handle_accept (boost::system::error_code ec, shared_ptr<Sock
 	start_accept ();
 }
 
-bool
-EncodeServerFinder::server_found (string ip) const
+optional<list<EncodeServerDescription>::iterator>
+EncodeServerFinder::server_found (string ip)
 {
 	boost::mutex::scoped_lock lm (_servers_mutex);
-	list<EncodeServerDescription>::const_iterator i = _good_servers.begin();
+	list<EncodeServerDescription>::iterator i = _good_servers.begin();
 	while (i != _good_servers.end() && i->host_name() != ip) {
 		++i;
 	}
 
 	if (i != _good_servers.end()) {
-		return true;
+		return i;
 	}
 
 	i = _bad_servers.begin();
@@ -240,7 +274,11 @@ EncodeServerFinder::server_found (string ip) const
 		++i;
 	}
 
-	return i != _bad_servers.end ();
+	if (i != _bad_servers.end()) {
+		return i;
+	}
+
+	return optional<list<EncodeServerDescription>::iterator>();
 }
 
 EncodeServerFinder*
diff --git a/src/lib/encode_server_finder.h b/src/lib/encode_server_finder.h
index 90031d27b..58dee7e64 100644
--- a/src/lib/encode_server_finder.h
+++ b/src/lib/encode_server_finder.h
@@ -63,7 +63,7 @@ private:
 	void search_thread ();
 	void listen_thread ();
 
-	bool server_found (std::string) const;
+	boost::optional<std::list<EncodeServerDescription>::iterator> server_found (std::string);
 	void start_accept ();
 	void handle_accept (boost::system::error_code ec, boost::shared_ptr<Socket> socket);