From 6d875f1ec17f7fd9dcfae0fb28fe0686508248d7 Mon Sep 17 00:00:00 2001
From: Amnon Heiman <amnon@cloudius-systems.com>
Date: Sun, 23 Aug 2015 17:02:10 +0300
Subject: [PATCH] token_metadata: Add const when applicable

This patch adds a const version for get_datacenter_endpoints and
get_topology.

It modified the token iterator to use a const version of token_metadata
and it make first_token, first_token_index, tokens_end and ring_range to
be a const method.

Signed-off-by: Amnon Heiman <amnon@cloudius-systems.com>
---
 locator/token_metadata.cc |  6 +++---
 locator/token_metadata.hh | 24 +++++++++++++++++-------
 2 files changed, 20 insertions(+), 10 deletions(-)

diff --git a/locator/token_metadata.cc b/locator/token_metadata.cc
index 01de4505e4..131287c719 100644
--- a/locator/token_metadata.cc
+++ b/locator/token_metadata.cc
@@ -110,7 +110,7 @@ void token_metadata::update_normal_tokens(std::unordered_map<inet_address, std::
     }
 }
 
-size_t token_metadata::first_token_index(const token& start) {
+size_t token_metadata::first_token_index(const token& start) const {
     assert(_sorted_tokens.size() > 0);
     auto it = std::lower_bound(_sorted_tokens.begin(), _sorted_tokens.end(), start);
     if (it == _sorted_tokens.end()) {
@@ -120,7 +120,7 @@ size_t token_metadata::first_token_index(const token& start) {
     }
 }
 
-const token& token_metadata::first_token(const token& start) {
+const token& token_metadata::first_token(const token& start) const {
     return _sorted_tokens[first_token_index(start)];
 }
 
@@ -212,7 +212,7 @@ void token_metadata::add_bootstrap_token(token t, inet_address endpoint) {
 boost::iterator_range<token_metadata::tokens_iterator>
 token_metadata::ring_range(
     const std::experimental::optional<query::partition_range::bound>& start,
-    bool include_min)
+    bool include_min) const
 {
     auto r = ring_range(start ? start->value().token() : dht::minimum_token(), include_min);
 
diff --git a/locator/token_metadata.hh b/locator/token_metadata.hh
index 3fc5970ce1..19bd8ae851 100644
--- a/locator/token_metadata.hh
+++ b/locator/token_metadata.hh
@@ -68,6 +68,12 @@ public:
         return _dc_endpoints;
     }
 
+    const std::unordered_map<sstring,
+                           std::unordered_set<inet_address>>&
+    get_datacenter_endpoints() const {
+        return _dc_endpoints;
+    }
+
     std::unordered_map<sstring,
                        std::unordered_map<sstring,
                                           std::unordered_set<inet_address>>>&
@@ -126,7 +132,7 @@ private:
         : _cur_it(it), _ring_pos(pos), _insert_min(false) {}
 
     public:
-        tokens_iterator(const token& start, token_metadata* token_metadata, bool include_min = false)
+        tokens_iterator(const token& start, const token_metadata* token_metadata, bool include_min = false)
         : _token_metadata(token_metadata) {
             _cur_it = _token_metadata->sorted_tokens().begin() + _token_metadata->first_token_index(start);
             _insert_min = include_min && *_token_metadata->sorted_tokens().begin() != dht::minimum_token();
@@ -180,7 +186,7 @@ private:
         bool _insert_min;
         bool _min = false;
         const token _min_token = dht::minimum_token();
-        token_metadata* _token_metadata = nullptr;
+        const token_metadata* _token_metadata = nullptr;
 
         friend class token_metadata;
     };
@@ -192,8 +198,8 @@ public:
     void update_normal_token(token token, inet_address endpoint);
     void update_normal_tokens(std::unordered_set<token> tokens, inet_address endpoint);
     void update_normal_tokens(std::unordered_map<inet_address, std::unordered_set<token>>& endpoint_tokens);
-    const token& first_token(const token& start);
-    size_t first_token_index(const token& start);
+    const token& first_token(const token& start) const;
+    size_t first_token_index(const token& start) const;
     std::experimental::optional<inet_address> get_endpoint(const token& token) const;
     std::vector<token> get_tokens(const inet_address& addr) const;
     const std::map<token, inet_address>& get_token_to_endpoint() const {
@@ -211,7 +217,7 @@ public:
         return _bootstrap_tokens;
     }
 
-    tokens_iterator tokens_end() {
+    tokens_iterator tokens_end() const {
         return tokens_iterator(sorted_tokens().end(), sorted_tokens().size());
     }
 
@@ -223,19 +229,23 @@ public:
      *
      * @return The requested range (see the description above)
      */
-    auto ring_range(const token& start, bool include_min = false) {
+    auto ring_range(const token& start, bool include_min = false) const {
         auto begin = tokens_iterator(start, this, include_min);
         auto end = tokens_end();
         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);
+        const std::experimental::optional<query::partition_range::bound>& start, bool include_min = false) const;
 
     topology& get_topology() {
         return _topology;
     }
 
+    const topology& get_topology() const {
+        return _topology;
+    }
+
     void debug_show();
 #if 0
     private static final Logger logger = LoggerFactory.getLogger(TokenMetadata.class);