cryptonote_protocol: retry stale spans early

Connections can be dropped by the net_node layer,
unbeknownst to cryptonote_protocol, which would then
not flush any spans scheduled to that connection,
which would cause it to be only downloaded again
once it becomes the next span (possibly after a small
delay if it had been requested less than 5 seconds
ago).

1 files changed, 16 insertions, 0 deletions

diff --git a/src/cryptonote_protocol/block_queue.cpp b/src/cryptonote_protocol/block_queue.cpp
index 8a78c7562..583c3abf4 100644
--- a/src/cryptonote_protocol/block_queue.cpp
+++ b/src/cryptonote_protocol/block_queue.cpp
@@ -76,6 +76,22 @@ void block_queue::flush_spans(const boost::uuids::uuid &connection_id, bool all)
   }
 }
 
+void block_queue::flush_stale_spans(const std::set<boost::uuids::uuid> &live_connections)
+{
+  boost::unique_lock<boost::recursive_mutex> lock(mutex);
+  block_map::iterator i = blocks.begin();
+  if (i != blocks.end() && is_blockchain_placeholder(*i))
+    ++i;
+  while (i != blocks.end())
+  {
+    block_map::iterator j = i++;
+    if (live_connections.find(j->connection_id) == live_connections.end() && j->blocks.size() == 0)
+    {
+      blocks.erase(j);
+    }
+  }
+}
+
 void block_queue::remove_span(uint64_t start_block_height)
 {
   boost::unique_lock<boost::recursive_mutex> lock(mutex);