commit 70bcf14c593676a9983ff90693a37173d1430e48
author Patrick Williams <patrick@stwcx.xyz> Wed Jul 26 16:19:48 2023 -0500
committer Patrick Williams <patrick@stwcx.xyz> Thu Aug 17 14:48:31 2023 -0500
tree c040c016c96ba2c5dd00e604d6adb510cd5801b7
parent 757e1ad55c93e1c5a105e795d3bf87538072c238

exception: add string r-value constructor

If we are building a string as part of throwing this exception type,
it is more efficient to move the string rather than getting the
`c_str()` and doing another allocation inside the class.

Signed-off-by: Patrick Williams <patrick@stwcx.xyz>
Change-Id: Ibec1c550f82208d5dde6dfef1626f907b7d2ad50

include/sdbusplus/exception.hpp

diff --git a/include/sdbusplus/exception.hpp b/include/sdbusplus/exception.hpp
index b7d7d50..e7e31ea 100644
--- a/include/sdbusplus/exception.hpp
+++ b/include/sdbusplus/exception.hpp
@@ -52,6 +52,8 @@
     /** Errno must be positive */
     SdBusError(int error, const char* prefix,
                SdBusInterface* intf = &sdbus_impl);
+    SdBusError(int error, std::string&& prefix,
+               SdBusInterface* intf = &sdbus_impl);
     /** Becomes the owner of the error */
     SdBusError(sd_bus_error* error, const char* prefix,
                SdBusInterface* intf = &sdbus_impl);
@@ -75,7 +77,7 @@
 
     /** Populates the full_message from the stored
      *  error and the passed in prefix. */
-    void populateMessage(const char* prefix);
+    void populateMessage(std::string&& prefix);
 
     /** Helper to reduce duplicate move logic */
     void move(SdBusError&& other);

src/exception.cpp

diff --git a/src/exception.cpp b/src/exception.cpp
index a7a3596..1bfd890 100644
--- a/src/exception.cpp
+++ b/src/exception.cpp
@@ -23,6 +23,11 @@
 
 SdBusError::SdBusError(int error_in, const char* prefix,
                        SdBusInterface* intf_in) :
+    SdBusError(error_in, std::string(prefix), intf_in)
+{}
+
+SdBusError::SdBusError(int error_in, std::string&& prefix,
+                       SdBusInterface* intf_in) :
     error(SD_BUS_ERROR_NULL),
     intf(intf_in)
 {
@@ -36,7 +41,7 @@
         throw std::runtime_error("Failed to create SdBusError");
     }
 
-    populateMessage(prefix);
+    populateMessage(std::move(prefix));
 }
 
 SdBusError::SdBusError(sd_bus_error* error_in, const char* prefix,
@@ -47,7 +52,7 @@
     // We own the error so remove the caller's reference
     *error_in = SD_BUS_ERROR_NULL;
 
-    populateMessage(prefix);
+    populateMessage(std::string(prefix));
 }
 
 SdBusError::SdBusError(SdBusError&& other) : error(SD_BUS_ERROR_NULL)
@@ -94,9 +99,9 @@
     return &error;
 }
 
-void SdBusError::populateMessage(const char* prefix)
+void SdBusError::populateMessage(std::string&& prefix)
 {
-    full_message = prefix;
+    full_message = std::move(prefix);
     if (error.name)
     {
         full_message += ": ";