adjust token precision to double to fix rate limit precision (#52)

* adjust token precision to double * Apply suggestions from code review Co-authored-by: Eli Lindsey <[email protected]> Co-authored-by: Shannon Weyrick <[email protected]>
DNS-OARC · Aug 11, 2020 · 77f1072 · 77f1072
1 parent 7add506
commit 77f1072
Show file tree

Hide file tree

Showing 2 changed files with 6 additions and 6 deletions.
diff --git a/flame/main.cpp b/flame/main.cpp
@@ -402,7 +402,7 @@ int main(int argc, char *argv[])
     for (auto i = 0; i < c_count; i++) {
         std::shared_ptr<TokenBucket> rl;
         if (config->rate_limit()) {
-            rl = std::make_shared<TokenBucket>(config->rate_limit() / c_count);
+            rl = std::make_shared<TokenBucket>(config->rate_limit() / static_cast<double>(c_count));
         } else if (args["--qps-flow"]) {
             rl = std::make_shared<TokenBucket>();
             rl_list.push_back(rl);
@@ -494,7 +494,7 @@ int main(int argc, char *argv[])
             std::cout << "query list randomized" << std::endl;
         }
         if (config->rate_limit()) {
-            std::cout << "rate limit @ " << config->rate_limit() << " QPS (" << (config->rate_limit() / c_count) <<
+            std::cout << "rate limit @ " << config->rate_limit() << " QPS (" << config->rate_limit() / static_cast<double>(c_count) <<
             " QPS per concurrent sender)" << std::endl;
         }
     }

diff --git a/flame/tokenbucket.h b/flame/tokenbucket.h
@@ -14,7 +14,7 @@ class TokenBucket
     {
     }
 
-    TokenBucket(const uint64_t rate)
+    TokenBucket(double rate)
         : _rate_qps(rate)
         , _token_wallet(0)
         , _last_fill_ms(0)
@@ -28,7 +28,7 @@ class TokenBucket
                 _last_fill_ms = now_ms;
             } else if (now_ms > _last_fill_ms) {
                 auto elapsed_ms = (now_ms - _last_fill_ms).count();
-                double add = (double)_rate_qps * ((double)elapsed_ms / 1000.0);
+                double add = _rate_qps * elapsed_ms / 1000.0;
                 if (_token_wallet + add >= tokens) {
                     _token_wallet += add;
                     _last_fill_ms = now_ms;
@@ -43,8 +43,8 @@ class TokenBucket
     }
 
 private:
-    uint64_t _rate_qps;
-    uint64_t _token_wallet;
+    double _rate_qps;
+    double _token_wallet;
     // milliseconds, based on uv_now() http://docs.libuv.org/en/v1.x/loop.html#c.uv_now
     uvw::Loop::Time _last_fill_ms;
 };