Template NoteLog Singleton function

Author: zfields

src/NoteLog.hpp

@@ -6,12 +6,6 @@
 class NoteLog
 {
 public:
-    /**************************************************************************/
-    /*!
-        @brief  Type used to abstract specific hardware implementation types.
-    */
-    /**************************************************************************/
-    typedef void * param_t;
 
     virtual ~NoteLog(void) {}
 
@@ -36,8 +30,7 @@ class NoteLog
                the platform specific log output implementation.
 */
 /******************************************************************************/
-NoteLog * make_note_log (
-    NoteLog::param_t log_parameters
-);
+template <typename T> NoteLog * make_note_log (T & log_parameters);
+NoteLog * make_note_log (nullptr_t);
 
 #endif // NOTE_LOG_HPP

src/NoteLog_Arduino.cpp

@@ -1,19 +1,35 @@
 #include "NoteLog_Arduino.hpp"
 
+// Singleton instance of the NoteLog_Arduino class
+namespace instance {
+    inline NoteLog* & note_log (void) {
+        static NoteLog* note_log = nullptr;
+        return note_log;
+    }
+};
+
 NoteLog *
 make_note_log (
-    NoteLog::param_t log_parameters_
-)
-{
-    static NoteLog * note_log = nullptr;
-    if (!log_parameters_) {
-        if (note_log) {
-            delete note_log;
-            note_log = nullptr;
-        }
-    } else if (!note_log) {
-        note_log = new NoteLog_Arduino(reinterpret_cast<Stream *>(log_parameters_));
+    nullptr_t
+) {
+    NoteLog* & note_log = instance::note_log();
+    if (note_log) {
+        delete note_log;
+        note_log = nullptr;
+    }
+    return note_log;
+}
+
+template <typename T>
+NoteLog *
+make_note_log (
+    T & log_parameters_
+) {
+    NoteLog* & note_log = instance::note_log();
+    if (!note_log) {
+        note_log = new NoteLog_Arduino(reinterpret_cast<T *>(&log_parameters_));
     }
+
     return note_log;
 }
 
@@ -35,3 +51,6 @@ NoteLog_Arduino::print (
 
     return result;
 }
+
+// Explicitly instantiate the template function for the supported types
+template NoteLog * make_note_log<Stream>(Stream &);

src/Notecard.h

@@ -67,7 +67,7 @@ class Notecard
         begin(make_note_serial(&arduino_parameters));
     }
     inline void setDebugOutputStream(Stream &dbgserial) {
-        setDebugOutputStream(make_note_log(&dbgserial));
+        setDebugOutputStream(make_note_log(dbgserial));
     }
     inline void setTransactionPins(uint8_t ctx_pin, uint8_t rtx_pin) {
         uint8_t txn_pins[2] = {ctx_pin, rtx_pin};

test/NoteLog_Arduino.test.cpp

@@ -16,7 +16,7 @@ int test_make_note_log_instantiates_notelog_object()
     NoteLog * notelog = nullptr;
 
     // Action
-    notelog = make_note_log(reinterpret_cast<NoteLog::param_t>(&Serial));
+    notelog = make_note_log(*reinterpret_cast<Stream *>(&Serial));
 
     // Assert
     if (nullptr != notelog)
@@ -42,10 +42,10 @@ int test_make_note_log_enforces_singleton_by_returning_same_notelog_object_for_a
     int result;
 
     // Arrange
-    NoteLog * const notelog_1 = make_note_log(reinterpret_cast<NoteLog::param_t>(&Serial));
+    NoteLog * const notelog_1 = make_note_log(*reinterpret_cast<Stream *>(&Serial));
 
     // Action
-    NoteLog * const notelog_2 = make_note_log(reinterpret_cast<NoteLog::param_t>(&Serial));
+    NoteLog * const notelog_2 = make_note_log(*reinterpret_cast<Stream *>(&Serial));
 
     // Assert
     if (notelog_1 == notelog_2)
@@ -72,7 +72,7 @@ int test_make_note_log_deletes_singleton_when_nullptr_is_passed_as_parameter()
     int result;
 
     // Arrange
-    NoteLog * notelog = make_note_log(reinterpret_cast<NoteLog::param_t>(&Serial));
+    NoteLog * notelog = make_note_log(*reinterpret_cast<Stream *>(&Serial));
     assert(notelog);
 
     // Action

test/mock/NoteLog_Mock.cpp

@@ -1,11 +1,26 @@
 #include "mock/NoteLog_Mock.hpp"
 
-MakeNoteLog_Parameters make_note_log_Parameters;
+MakeNoteLog_Parameters<HardwareSerial> make_note_log_Parameters;
 NoteLogPrint_Parameters noteLogPrint_Parameters;
 
 NoteLog *
 make_note_log (
-    NoteLog::param_t log_parameters_
+    nullptr_t
+) {
+    // Record invocation(s)
+    ++make_note_log_Parameters.invoked;
+
+    // Stash parameter(s)
+    make_note_log_Parameters.log_parameters = nullptr;
+
+    // Return user-supplied result
+    return make_note_log_Parameters.result;
+}
+
+template <typename T>
+NoteLog *
+make_note_log (
+    T & log_parameters_
 )
 {
     // Record invocation(s)

test/mock/NoteLog_Mock.hpp

@@ -5,13 +5,15 @@
 #include <stdint.h>
 
 #include "NoteLog.hpp"
+#include "mock-arduino.hpp"
 
 class NoteLog_Mock final : public NoteLog
 {
 public:
     size_t print(const char * message) override;
 };
 
+template <typename T>
 struct MakeNoteLog_Parameters {
     MakeNoteLog_Parameters(
         void
@@ -28,7 +30,7 @@ struct MakeNoteLog_Parameters {
         result = nullptr;
     }
     size_t invoked;
-    NoteLog::param_t log_parameters;
+    T * log_parameters;
     NoteLog * result;
 };
 
@@ -52,7 +54,7 @@ struct NoteLogPrint_Parameters {
     size_t result;
 };
 
-extern MakeNoteLog_Parameters make_note_log_Parameters;
+extern MakeNoteLog_Parameters<HardwareSerial> make_note_log_Parameters;
 extern NoteLogPrint_Parameters noteLogPrint_Parameters;
 
 #endif // MOCK_NOTE_LOG_HPP