From 9dc155a8efdd0beff82ef59a721209d0734011c5 Mon Sep 17 00:00:00 2001
From: Asias He <asias@cloudius-systems.com>
Date: Tue, 4 Aug 2015 10:17:54 +0800
Subject: [PATCH] token_metadata: Make get_endpoint_for_host_id return optional

---
 locator/token_metadata.cc | 9 ++++++---
 locator/token_metadata.hh | 2 +-
 2 files changed, 7 insertions(+), 4 deletions(-)

diff --git a/locator/token_metadata.cc b/locator/token_metadata.cc
index a0131f325c..de220214b0 100644
--- a/locator/token_metadata.cc
+++ b/locator/token_metadata.cc
@@ -182,14 +182,17 @@ utils::UUID token_metadata::get_host_id(inet_address endpoint) {
     return _endpoint_to_host_id_map.at(endpoint);
 }
 
-gms::inet_address token_metadata::get_endpoint_for_host_id(UUID host_id) {
+std::experimental::optional<inet_address> token_metadata::get_endpoint_for_host_id(UUID host_id) {
     auto beg = _endpoint_to_host_id_map.cbegin();
     auto end = _endpoint_to_host_id_map.cend();
     auto it = std::find_if(beg, end, [host_id] (auto x) {
         return x.second == host_id;
     });
-    assert(it != end);
-    return (*it).first;
+    if (it == end) {
+        return {};
+    } else {
+        return (*it).first;
+    }
 }
 
 const std::unordered_map<inet_address, utils::UUID>& token_metadata::get_endpoint_to_host_id_map_for_reading() const{
diff --git a/locator/token_metadata.hh b/locator/token_metadata.hh
index 439c5bf2ea..c80517580e 100644
--- a/locator/token_metadata.hh
+++ b/locator/token_metadata.hh
@@ -420,7 +420,7 @@ public:
     UUID get_host_id(inet_address endpoint);
 
     /** Return the end-point for a unique host ID */
-    inet_address get_endpoint_for_host_id(UUID host_id);
+    std::experimental::optional<inet_address> get_endpoint_for_host_id(UUID host_id);
 
     /** @return a copy of the endpoint-to-id map for read-only operations */
     const std::unordered_map<inet_address, utils::UUID>& get_endpoint_to_host_id_map_for_reading() const;