major improvements for big apps

Source/Components/Interfaces/DebugService/DebugServiceBase.h

@@ -125,6 +125,22 @@ public:
 
     static const uint32 GET_VALUE_MAX_ELEMENTS = 256u;
 
+    /**
+     * @brief Pre-build DISCOVER and TREE response caches.
+     *
+     * Called automatically by SetFullConfig() once the application is fully
+     * initialised.  After this point, DISCOVER and TREE are served from the
+     * pre-built string with no mutex contention and no JSON generation cost.
+     * Both caches are invalidated whenever a new signal is registered (which
+     * normally only happens during broker init, before SetFullConfig).
+     */
+    void BuildDiscoverCache();
+    void BuildTreeCache();
+
+    // Number of signals per DISCOVER_PART TCP chunk.  Responses larger than
+    // this are split so the Go client can start parsing immediately.
+    static const uint32 DISCOVER_CHUNK_SIGNALS = 256u;
+
 protected:
     // =========================================================================
     // Virtual hooks for transport subclasses
@@ -183,6 +199,13 @@ protected:
 
     ConfigurationDatabase fullConfig;
     bool manualConfigSet;
+
+    // Pre-built response caches.  Guarded by mutex (brief lock for swap,
+    // none needed for reads once cacheValid is true and construction is done).
+    StreamString  discoverCache;   // full chunked DISCOVER_PART+DISCOVER payload
+    StreamString  treeCache;       // full TREE payload including sentinel
+    volatile bool discoverCacheValid;
+    volatile bool treeCacheValid;
 };
 
 } // namespace MARTe