From 6882e6ca508d0655172f7dcd3ef728a42cbe49d5 Mon Sep 17 00:00:00 2001
From: Tomasz Grabiec <tgrabiec@cloudius-systems.com>
Date: Wed, 22 Jul 2015 10:12:58 +0200
Subject: [PATCH] storage_proxy: Fix range splitting when split point is
 exlcluded by lower bound

If we had a range (x; ...] then x is excluded, but token iterator was
initialized with x. The splitting loop would exit prematurely because
it would detect that the token is outside the range.

The fix is to teach ring_range() to recognize this and always give
tokens which are not smaller than the range's lower bound.
---
 locator/token_metadata.cc | 21 +++++++++++++++++++++
 locator/token_metadata.hh |  4 ++++
 service/storage_proxy.cc  |  2 +-
 3 files changed, 26 insertions(+), 1 deletion(-)

diff --git a/locator/token_metadata.cc b/locator/token_metadata.cc
index d78b78cf61..6ed022d60c 100644
--- a/locator/token_metadata.cc
+++ b/locator/token_metadata.cc
@@ -198,6 +198,27 @@ void token_metadata::add_bootstrap_token(token t, inet_address endpoint) {
     add_bootstrap_tokens(tokens, endpoint);
 }
 
+boost::iterator_range<token_metadata::tokens_iterator>
+token_metadata::ring_range(
+    const std::experimental::optional<query::partition_range::bound>& start,
+    bool include_min)
+{
+    auto r = ring_range(start ? start->value().token() : dht::minimum_token(), include_min);
+
+    if (!r.empty()) {
+        // We should skip the first token if it's excluded by the range.
+        if (start
+            && !start->is_inclusive()
+            && !start->value().has_key()
+            && start->value().token() == *r.begin())
+        {
+            r.pop_front();
+        }
+    }
+
+    return r;
+}
+
 void token_metadata::add_bootstrap_tokens(std::unordered_set<token> tokens, inet_address endpoint) {
     for (auto t : tokens) {
         auto old_endpoint = _bootstrap_tokens.find(t);
diff --git a/locator/token_metadata.hh b/locator/token_metadata.hh
index 2a6269e5e6..714847f342 100644
--- a/locator/token_metadata.hh
+++ b/locator/token_metadata.hh
@@ -29,6 +29,7 @@
 #include "utils/UUID.hh"
 #include <experimental/optional>
 #include <boost/range/iterator_range.hpp>
+#include "query-request.hh"
 
 // forward declaration since database.hh includes this file
 class keyspace;
@@ -228,6 +229,9 @@ public:
         return boost::make_iterator_range(begin, end);
     }
 
+    boost::iterator_range<tokens_iterator> ring_range(
+        const std::experimental::optional<query::partition_range::bound>& start, bool include_min = false);
+
     topology& get_topology() {
         return _topology;
     }
diff --git a/service/storage_proxy.cc b/service/storage_proxy.cc
index 33b275e99d..81f234b9f0 100644
--- a/service/storage_proxy.cc
+++ b/service/storage_proxy.cc
@@ -2457,7 +2457,7 @@ storage_proxy::get_restricted_ranges(keyspace& ks, const schema& s, query::parti
     std::vector<query::partition_range> ranges;
 
     // divide the queryRange into pieces delimited by the ring and minimum tokens
-    auto ring_iter = tm.ring_range(start_token(range), true);
+    auto ring_iter = tm.ring_range(range.start(), true);
     query::partition_range remainder = std::move(range);
     for (const dht::token& upper_bound_token : ring_iter)
     {