Use const char * for throttler name to prevent dangling references

serxa · claude · serxa · commit 960b132779d3 · 2026-03-20T18:49:20.000Z
Change `throttler_name` from `std::string_view` to `const char *`
to prevent misuse with temporary `std::string` values. Unlike
`std::string_view`, `const char *` has no implicit conversion from
`std::string`, so passing a temporary is a compile error.

Co-Authored-By: Claude Opus 4.6 (1M context) &lt;noreply@anthropic.com&gt;
diff --git a/src/Common/Throttler.cpp b/src/Common/Throttler.cpp
@@ -27,7 +27,7 @@ namespace ErrorCodes
 /// Just 10^9.
 static constexpr auto NS = 1000000000UL;
 
-Throttler::Throttler(std::string_view throttler_name_, size_t max_speed_, const ThrottlerPtr & parent_,
+Throttler::Throttler(const char * throttler_name_, size_t max_speed_, const ThrottlerPtr & parent_,
         ProfileEvents::Event event_amount_,
         ProfileEvents::Event event_sleep_us_)
     : throttler_name(throttler_name_)
@@ -40,13 +40,13 @@ Throttler::Throttler(std::string_view throttler_name_, size_t max_speed_, const
     , event_sleep_us(event_sleep_us_)
 {}
 
-Throttler::Throttler(std::string_view throttler_name_, size_t max_speed_,
+Throttler::Throttler(const char * throttler_name_, size_t max_speed_,
         ProfileEvents::Event event_amount_,
         ProfileEvents::Event event_sleep_us_)
     : Throttler(throttler_name_, max_speed_, nullptr, event_amount_, event_sleep_us_)
 {}
 
-Throttler::Throttler(std::string_view throttler_name_, size_t max_speed_, size_t limit_, const char * limit_exceeded_exception_message_, const ThrottlerPtr & parent_)
+Throttler::Throttler(const char * throttler_name_, size_t max_speed_, size_t limit_, const char * limit_exceeded_exception_message_, const ThrottlerPtr & parent_)
     : throttler_name(throttler_name_)
     , max_speed(max_speed_)
     , max_burst(max_speed_ * default_burst_seconds)
diff --git a/src/Common/Throttler.h b/src/Common/Throttler.h
@@ -4,7 +4,6 @@
 #include <Common/Logger.h>
 #include <Common/ProfileEvents.h>
 #include <mutex>
-#include <string_view>
 #include <base/sleep.h>
 #include <base/types.h>
 #include <atomic>
@@ -21,33 +20,33 @@ class Throttler : public IThrottler
 public:
     static const size_t default_burst_seconds = 1;
 
-    Throttler(std::string_view throttler_name_, size_t max_speed_, size_t max_burst_, const ThrottlerPtr & parent_ = nullptr,
+    Throttler(const char * throttler_name_, size_t max_speed_, size_t max_burst_, const ThrottlerPtr & parent_ = nullptr,
             ProfileEvents::Event event_amount_ = ProfileEvents::end(),
             ProfileEvents::Event event_sleep_us_ = ProfileEvents::end())
         : throttler_name(throttler_name_), max_speed(max_speed_), max_burst(max_burst_), limit_exceeded_exception_message(""), tokens(static_cast<double>(max_burst)), parent(parent_)
         , event_amount(event_amount_), event_sleep_us(event_sleep_us_)
     {}
 
-    Throttler(std::string_view throttler_name_, size_t max_speed_, size_t max_burst_,
+    Throttler(const char * throttler_name_, size_t max_speed_, size_t max_burst_,
             ProfileEvents::Event event_amount_ = ProfileEvents::end(),
             ProfileEvents::Event event_sleep_us_ = ProfileEvents::end())
         : throttler_name(throttler_name_), max_speed(max_speed_), max_burst(max_burst_), limit_exceeded_exception_message(""), tokens(static_cast<double>(max_burst))
         , event_amount(event_amount_), event_sleep_us(event_sleep_us_)
     {}
 
-    explicit Throttler(std::string_view throttler_name_, size_t max_speed_, const ThrottlerPtr & parent_ = nullptr,
+    explicit Throttler(const char * throttler_name_, size_t max_speed_, const ThrottlerPtr & parent_ = nullptr,
         ProfileEvents::Event event_amount_ = ProfileEvents::end(),
         ProfileEvents::Event event_sleep_us_ = ProfileEvents::end());
 
-    Throttler(std::string_view throttler_name_, size_t max_speed_,
+    Throttler(const char * throttler_name_, size_t max_speed_,
         ProfileEvents::Event event_amount_,
         ProfileEvents::Event event_sleep_us_);
 
-    Throttler(std::string_view throttler_name_, size_t max_speed_, size_t max_burst_, size_t limit_, const char * limit_exceeded_exception_message_,
+    Throttler(const char * throttler_name_, size_t max_speed_, size_t max_burst_, size_t limit_, const char * limit_exceeded_exception_message_,
               const ThrottlerPtr & parent_ = nullptr)
         : throttler_name(throttler_name_), max_speed(max_speed_), max_burst(max_burst_), limit(limit_), limit_exceeded_exception_message(limit_exceeded_exception_message_), tokens(static_cast<double>(max_burst)), parent(parent_) {}
 
-    Throttler(std::string_view throttler_name_, size_t max_speed_, size_t limit_, const char * limit_exceeded_exception_message_,
+    Throttler(const char * throttler_name_, size_t max_speed_, size_t limit_, const char * limit_exceeded_exception_message_,
               const ThrottlerPtr & parent_ = nullptr);
 
     /// Use `amount` tokens, sleeps if required or throws exception on limit overflow.
@@ -77,7 +76,7 @@ class Throttler : public IThrottler
     void throttleImpl(size_t amount, size_t & count_value, double & tokens_value, size_t & max_speed_value);
 
     /// Human-readable name for logging (e.g. "backups_query", "remote_read_server")
-    std::string_view throttler_name;
+    const char * throttler_name;
     LoggerPtr log = getLogger("Throttler");
 
     size_t count{0};
