Remove obsolete c_str_safe utility

The old `c_str_safe` utility function allowed Zeek to operator on
`broker::data` and `broker::variant`. The former grants access to actual
`std::string` objects while the latter only provides access to fields
via `std::string_view`. Since the Zeek formatting functions need null
terminated strings, we need to copy the characters into a
null-terminated container first.

After removing support for `broker::data` and `broker::variant` from the
same code paths, we can drop `c_str_safe` and always do the copying
(since we are always dealing with `broker::variant` now).

src/broker/Manager.cc

@@ -42,18 +42,6 @@ broker::vector broker_vector_from(const broker::variant& arg) {
     return std::move(broker::get<broker::vector>(tmp));
 }
 
-// Converts a string_view into a string to make sure that we can safely call `.c_str()` on the result.
-template<class View>
-std::enable_if_t<std::is_same_v<std::decay_t<View>, std::string_view>, std::string> c_str_safe(View&& arg) {
-    return std::string{arg};
-}
-
-// Passes through a string without copying it (already safe to call `.c_str()` on it).
-template<class String>
-std::enable_if_t<std::is_same_v<std::decay_t<String>, std::string>, const std::string&> c_str_safe(String&& arg) {
-    return arg;
-}
-
 void print_escaped(std::string& buf, std::string_view str) {
     buf.push_back('"');
     for ( auto c : str ) {
@@ -712,7 +700,7 @@ bool Manager::PublishLogWrite(EnumVal* stream, EnumVal* writer, const string& pa
         reporter->Error(
             "Failed to remotely log: log_topic func did not return"
             " a value for stream %s at path %s",
-            stream_id, c_str_safe(path).c_str());
+            stream_id, std::string{path}.c_str());
         return false;
     }
 
@@ -1180,7 +1168,7 @@ void Manager::ProcessMessage(std::string_view topic, broker::zeek::Event& ev) {
         // Default to current network time, if the received event did not contain a timestamp.
         ts = run_state::network_time;
 
-    DBG_LOG(DBG_BROKER, "Process event: %s (%.6f) %s", c_str_safe(name).c_str(), ts, RenderMessage(args).c_str());
+    DBG_LOG(DBG_BROKER, "Process event: %s (%.6f) %s", std::string{name}.c_str(), ts, RenderMessage(args).c_str());
     num_events_incoming_metric->Inc();
     auto handler = event_registry->Lookup(name);
 
@@ -1194,7 +1182,7 @@ void Manager::ProcessMessage(std::string_view topic, broker::zeek::Event& ev) {
         if ( strncmp(p.data(), topic.data(), p.size()) != 0 )
             continue;
 
-        DBG_LOG(DBG_BROKER, "Skip processing of forwarded event: %s %s", c_str_safe(name).c_str(),
+        DBG_LOG(DBG_BROKER, "Skip processing of forwarded event: %s %s", std::string{name}.c_str(),
                 RenderMessage(args).c_str());
         return;
     }
@@ -1205,7 +1193,7 @@ void Manager::ProcessMessage(std::string_view topic, broker::zeek::Event& ev) {
         reporter->Warning(
             "got event message '%s' with invalid # of args,"
             " got %zd, expected %zu",
-            c_str_safe(name).c_str(), args.size(), arg_types.size());
+            std::string{name}.c_str(), args.size(), arg_types.size());
         return;
     }
 
@@ -1240,7 +1228,7 @@ void Manager::ProcessMessage(std::string_view topic, broker::zeek::Event& ev) {
                                      expected_type->GetName().c_str());
             }
 
-            reporter->Warning("failed to convert remote event '%s' arg #%zu, %s", c_str_safe(name).c_str(), i,
+            reporter->Warning("failed to convert remote event '%s' arg #%zu, %s", std::string{name}.c_str(), i,
                               msg_addl.c_str());
 
             // If we got a vector and expected a function this is
@@ -1334,7 +1322,7 @@ bool Manager::ProcessMessage(std::string_view, broker::zeek::LogWrite& lw) {
     auto stream_id = detail::data_to_val(wrapped_stream_id, log_id_type);
 
     if ( ! stream_id ) {
-        reporter->Warning("failed to unpack remote log stream id: %s", c_str_safe(stream_id_name).c_str());
+        reporter->Warning("failed to unpack remote log stream id: %s", std::string{stream_id_name}.c_str());
         return false;
     }
 
@@ -1342,7 +1330,7 @@ bool Manager::ProcessMessage(std::string_view, broker::zeek::LogWrite& lw) {
     auto wrapped_writer_id = broker::data{lw.writer_id()};
     auto writer_id = detail::data_to_val(wrapped_writer_id, writer_id_type);
     if ( ! writer_id ) {
-        reporter->Warning("failed to unpack remote log writer id for stream: %s", c_str_safe(stream_id_name).c_str());
+        reporter->Warning("failed to unpack remote log writer id for stream: %s", std::string{stream_id_name}.c_str());
         return false;
     }
 
@@ -1358,7 +1346,7 @@ bool Manager::ProcessMessage(std::string_view, broker::zeek::LogWrite& lw) {
 
     if ( ! success ) {
         reporter->Warning("failed to unserialize remote log num fields for stream: %s",
-                          c_str_safe(stream_id_name).c_str());
+                          std::string{stream_id_name}.c_str());
         return false;
     }
 
@@ -1367,7 +1355,7 @@ bool Manager::ProcessMessage(std::string_view, broker::zeek::LogWrite& lw) {
     for ( int i = 0; i < num_fields; ++i ) {
         if ( ! rec[i].Read(&fmt) ) {
             reporter->Warning("failed to unserialize remote log field %d for stream: %s", i,
-                              c_str_safe(stream_id_name).c_str());
+                              std::string{stream_id_name}.c_str());
 
             return false;
         }
@@ -1387,7 +1375,7 @@ bool Manager::ProcessMessage(std::string_view, broker::zeek::IdentifierUpdate& i
     }
 
     num_ids_incoming_metric->Inc();
-    auto id_name = c_str_safe(iu.id_name());
+    auto id_name = std::string{iu.id_name()};
     auto id_value = iu.id_value().to_data();
     const auto& id = zeek::detail::global_scope()->Find(id_name);